Fixed wandering trader spawning

- World injection attaches vanilla event spawners for NORMAL dimension environments
- Covers worlds loaded at server start, Studio worlds and Folia worlds
- Binding test covers overworld and nether environments

.github/release.json

@@ -0,0 +1,8 @@
+{
+  "name": "Iris",
+  "platform": "modded",
+  "versionProperty": "irisVersion",
+  "betaTag": "modded-beta",
+  "targets": "gradle/mod-targets.json",
+  "volmlibRef": "master"
+}

.github/release.py

@@ -0,0 +1,327 @@
+import argparse
+import hashlib
+import json
+import os
+from pathlib import Path
+import re
+import sys
+import tomllib
+import urllib.error
+import urllib.parse
+import urllib.request
+import zipfile
+
+
+def read_config(root: Path) -> dict:
+    return json.loads((root / '.github/release.json').read_text())
+
+
+def targets(root: Path, config: dict) -> list[dict[str, str]]:
+    if config['platform'] == 'bukkit':
+        return [{'id': 'bukkit', 'loader': 'bukkit', 'minecraft': ''}]
+    manifest: Path = root / config['targets']
+    if manifest.is_file():
+        versions: dict = json.loads(manifest.read_text())
+        entries: list[tuple[str, list[str]]] = [(version, ['fabric', 'forge', 'neoforge']) for version in versions]
+    else:
+        entries = []
+        for path in sorted(manifest.glob('*.json')):
+            target: dict = json.loads(path.read_text())
+            if path.stem != target['minecraft']:
+                raise ValueError(f'Minecraft manifest does not match {path.name}')
+            entries.append((target['minecraft'], list(target['loaders'])))
+    matrix: list[dict[str, str]] = []
+    for version, loaders in entries:
+        if not re.fullmatch(r'[0-9]+(?:\.[0-9]+)+', version):
+            raise ValueError(f'Invalid Minecraft version: {version}')
+        if set(loaders) != {'fabric', 'forge', 'neoforge'}:
+            raise ValueError(f'Incomplete loader matrix for {version}')
+        for loader in sorted(loaders):
+            matrix.append({'id': f'{loader}-{version}', 'loader': loader, 'minecraft': version})
+    if not matrix:
+        raise ValueError('Release matrix is empty')
+    return matrix
+
+
+def plan(root: Path, config: dict, event: dict, environment: dict) -> dict:
+    branch: str = event.get('repository', {}).get('default_branch', '')
+    if (environment.get('GITHUB_EVENT_NAME') != 'push' or event.get('deleted')
+            or not branch or event.get('ref') != f'refs/heads/{branch}'):
+        return {'channel': 'none'}
+    commit: dict = event.get('head_commit') or {}
+    message: str = commit.get('message', '')
+    beta: bool = 'B+' in message
+    stable: bool = 'V+' in message
+    if beta and stable:
+        raise ValueError('Use exactly one release marker: B+ or V+')
+    if not beta and not stable:
+        return {'channel': 'none'}
+    sha: str = environment['GITHUB_SHA']
+    if event.get('after') != sha or commit.get('id') != sha or not re.fullmatch(r'[a-f0-9]{40}', sha):
+        raise ValueError('Release commit does not match the pushed HEAD')
+    key: str = config['versionProperty']
+    properties: str = (root / 'gradle.properties').read_text()
+    values: list[str] = re.findall(rf'^{re.escape(key)}\s*=\s*(\S+)\s*$', properties, re.MULTILINE)
+    if len(values) != 1 or not re.fullmatch(r'(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)', values[0]):
+        raise ValueError(f'{key} must declare one stable major.minor.patch version')
+    run: int = int(environment['GITHUB_RUN_NUMBER'])
+    attempt: int = int(environment['GITHUB_RUN_ATTEMPT'])
+    if run < 1 or attempt < 1:
+        raise ValueError('Invalid workflow run identity')
+    version: str = f'{values[0]}-beta.{run}.{attempt}' if beta else values[0]
+    return {
+        'channel': 'beta' if beta else 'stable',
+        'version': version,
+        'version_property': key,
+        'tag': config['betaTag'] if beta else f'v{version}',
+        'sha': sha,
+        'run': run,
+        'attempt': attempt,
+        'matrix': {'include': targets(root, config)},
+        'volmlib_ref': config['volmlibRef'],
+        'wormholes_ref': config.get('wormholesRef', ''),
+    }
+
+
+def collect_artifacts(directory: Path, release: dict) -> dict[str, bytes]:
+    expected: dict[str, dict] = {f"release-{entry['id']}": entry for entry in release['matrix']['include']}
+    if {path.name for path in directory.iterdir()} != set(expected):
+        raise ValueError('Downloaded artifacts do not match the complete release matrix')
+    assets: dict[str, bytes] = {}
+    descriptors: dict[str, str] = {'bukkit': 'plugin.yml', 'fabric': 'fabric.mod.json',
+                                  'forge': 'META-INF/mods.toml', 'neoforge': 'META-INF/neoforge.mods.toml'}
+    for name, target in expected.items():
+        folder: Path = directory / name
+        paths: list[Path] = list(folder.iterdir()) if folder.is_dir() and not folder.is_symlink() else []
+        if len(paths) != 1 or paths[0].suffix != '.jar' or paths[0].is_symlink() or not paths[0].is_file():
+            raise ValueError(f'{name} must contain exactly one runtime jar')
+        path: Path = paths[0]
+        loader: str = target['loader']
+        suffix: str = re.escape(release['version']) + r'-bukkit\.jar'
+        if loader != 'bukkit':
+            display: str = {'fabric': 'Fabric', 'forge': 'Forge', 'neoforge': 'NeoForge'}[loader]
+            suffix = (r'v' + re.escape(release['version']) + r' \[' + display + r'\] '
+                      + re.escape(target['minecraft']) + r'\+[^/\s]+\.jar')
+        if not re.fullmatch(r'[A-Za-z][A-Za-z0-9]*' + ('-' if loader == 'bukkit' else ' ') + suffix, path.name):
+            raise ValueError(f'Artifact does not match the release target: {path.name}')
+        with zipfile.ZipFile(path) as archive:
+            entries: set[str] = set(archive.namelist())
+            descriptor: str = descriptors[target['loader']]
+            if descriptor not in entries:
+                raise ValueError(f'{path.name} is missing {descriptor}')
+            excluded: set[str] = set(descriptors.values()) - {descriptor}
+            if 'velocity-plugin.json' in entries or entries.intersection(excluded):
+                raise ValueError(f'{path.name} contains an excluded platform')
+            contents: str = archive.read(descriptor).decode()
+            if loader == 'bukkit':
+                match: re.Match | None = re.search(r'^version:\s*[\'\"]?([^\s\'\"]+)', contents, re.MULTILINE)
+                version: str | None = match[1] if match else None
+            elif loader == 'fabric':
+                metadata: dict = json.loads(contents)
+                version = metadata.get('version')
+                if metadata.get('depends', {}).get('minecraft') not in (target['minecraft'], '~' + target['minecraft']):
+                    raise ValueError(f'{path.name} declares a different Minecraft target')
+            else:
+                metadata = tomllib.loads(contents)
+                mods: list[dict] = metadata.get('mods', [])
+                version = mods[0].get('version') if len(mods) == 1 else None
+                dependencies: list[dict] = metadata.get('dependencies', {}).get(mods[0].get('modId'), []) if len(mods) == 1 else []
+                minecraft: list[str] = [entry.get('versionRange') for entry in dependencies if entry.get('modId') == 'minecraft']
+                if minecraft != ['[' + target['minecraft'] + ']']:
+                    raise ValueError(f'{path.name} declares a different Minecraft target')
+            if version != release['version']:
+                raise ValueError(f'{path.name} declares a different product version')
+        asset_name: str = re.sub(r'[^A-Za-z0-9._-]+', '-', path.name)
+        if asset_name in assets:
+            raise ValueError(f'Duplicate release asset: {asset_name}')
+        assets[asset_name] = path.read_bytes()
+    checksums: str = ''.join(f'{hashlib.sha256(data).hexdigest()}  {name}\n' for name, data in sorted(assets.items()))
+    assets[f"SHA256SUMS-{release['version']}.txt"] = checksums.encode()
+    return assets
+
+
+class GitHub:
+    def __init__(self, repository: str, token: str):
+        if not re.fullmatch(r'[A-Za-z0-9_.-]+/[A-Za-z0-9_.-]+', repository):
+            raise ValueError('Invalid GitHub repository')
+        self.repository = repository
+        self.token = token
+
+    def request(self, method: str, path: str, payload: dict | bytes | None = None, missing: bool = False) -> dict | list | None:
+        url: str = path if path.startswith('https://uploads.github.com/') else f'https://api.github.com/repos/{self.repository}/{path}'
+        binary: bool = isinstance(payload, bytes)
+        data: bytes | None = payload if binary else json.dumps(payload).encode() if payload is not None else None
+        request: urllib.request.Request = urllib.request.Request(url, data=data, method=method, headers={
+            'Authorization': f'Bearer {self.token}',
+            'Accept': 'application/vnd.github+json',
+            'X-GitHub-Api-Version': '2026-03-10',
+            'Content-Type': 'application/octet-stream' if binary else 'application/json',
+            'User-Agent': 'Volmit-release',
+        })
+        try:
+            with urllib.request.urlopen(request, timeout=120) as response:
+                body: bytes = response.read()
+                return json.loads(body) if body else None
+        except urllib.error.HTTPError as error:
+            if missing and error.code == 404:
+                return None
+            raise RuntimeError(f'GitHub {method} {urllib.parse.urlsplit(url).path}: HTTP {error.code}') from error
+
+    def tag_commit(self, tag: str) -> str | None:
+        reference: dict | None = self.request('GET', f'git/ref/tags/{tag}', missing=True)
+        if reference is None:
+            return None
+        target: dict = reference['object']
+        for _ in range(8):
+            if target['type'] == 'commit':
+                return target['sha']
+            if target['type'] != 'tag':
+                break
+            target = self.request('GET', f"git/tags/{target['sha']}")['object']
+        raise ValueError(f'{tag} does not resolve to a commit')
+
+    def assets(self, release_id: int) -> list[dict]:
+        result: list[dict] = []
+        page: int = 1
+        while True:
+            batch: list[dict] = self.request('GET', f'releases/{release_id}/assets?per_page=100&page={page}')
+            result.extend(batch)
+            if len(batch) < 100:
+                return result
+            page += 1
+
+
+def resolve_dependency(repository: str, reference: str, token: str) -> str:
+    commit: dict = GitHub(repository, token).request('GET', f'commits/{urllib.parse.quote(reference, safe="")}')
+    sha: str = commit['sha']
+    if not re.fullmatch(r'[a-f0-9]{40}', sha):
+        raise ValueError(f'{repository} did not resolve to a commit')
+    return sha
+
+
+def release_metadata(existing: dict) -> dict:
+    match: re.Match | None = re.search(r'<!-- release: (.+) -->', existing.get('body') or '')
+    if match is None:
+        raise ValueError('Existing release has no publication identity; refusing to overwrite it')
+    return json.loads(match[1])
+
+
+def verify_assets(existing: list[dict], assets: dict[str, bytes]) -> bool:
+    return {entry['name']: entry.get('digest') for entry in existing} == {
+        name: 'sha256:' + hashlib.sha256(data).hexdigest() for name, data in assets.items()}
+
+
+def publish(github: GitHub, config: dict, release: dict, assets: dict[str, bytes]) -> str:
+    tag: str = release['tag']
+    beta: bool = release['channel'] == 'beta'
+    existing: dict | None = github.request('GET', f'releases/tags/{tag}', missing=True)
+    commit: str | None = github.tag_commit(tag)
+    if not beta and commit is not None and commit != release['sha']:
+        raise ValueError(f'{tag} already points to another commit')
+    if existing is not None:
+        metadata: dict = release_metadata(existing)
+        if bool(existing['prerelease']) != beta:
+            raise ValueError('Existing release belongs to a different release channel')
+        if beta and (metadata['run'], metadata['attempt']) > (release['run'], release['attempt']):
+            return 'Skipped older beta run'
+        if not beta and metadata['sha'] != release['sha']:
+            raise ValueError('Stable release belongs to another commit')
+        if not existing['draft'] and commit == release['sha'] and metadata['version'] == release['version']:
+            if verify_assets(github.assets(existing['id']), assets):
+                return 'Release already published with identical artifacts'
+            if not beta:
+                raise ValueError('Published release artifacts differ; refusing to overwrite them')
+        if existing.get('immutable'):
+            raise ValueError('Rolling beta requires mutable releases in repository settings')
+        if not beta and not existing['draft']:
+            raise ValueError('Stable release is already published')
+    elif beta and commit is not None:
+        raise ValueError('Beta tag exists without a release; refusing to move it')
+    identity: dict = {key: release[key] for key in ('version', 'sha', 'run', 'attempt', 'volmlib_ref', 'wormholes_ref') if key in release}
+    platform: str = 'Modded' if config['platform'] == 'modded' else 'CraftBukkit'
+    body: str = (f"{platform} jars for {config['name']} {release['version']}.\n\n"
+                 f"Commit: `{release['sha']}`\n\n"
+                 f"<!-- release: {json.dumps(identity, sort_keys=True)} -->")
+    attributes: dict = {
+        'tag_name': tag, 'target_commitish': release['sha'],
+        'name': f"{config['name']} {platform} {'Beta' if beta else release['version']}",
+        'body': body, 'prerelease': beta, 'make_latest': 'false',
+    }
+    if existing is None:
+        existing = github.request('POST', 'releases', {**attributes, 'draft': True})
+    elif beta:
+        existing = github.request('PATCH', f"releases/{existing['id']}", {**attributes, 'draft': True})
+    uploaded: list[dict] = github.assets(existing['id'])
+    by_name: dict[str, dict] = {entry['name']: entry for entry in uploaded}
+    for name, data in assets.items():
+        digest: str = 'sha256:' + hashlib.sha256(data).hexdigest()
+        if name in by_name:
+            if by_name[name].get('state') == 'starter':
+                github.request('DELETE', f"releases/assets/{by_name[name]['id']}")
+            elif by_name[name].get('digest') != digest:
+                raise ValueError(f'Existing asset differs: {name}')
+            else:
+                continue
+        upload_url: str = existing['upload_url'].split('{')[0] + '?' + urllib.parse.urlencode({'name': name})
+        receipt: dict = github.request('POST', upload_url, data)
+        if receipt.get('digest') != digest or receipt['name'] != name:
+            raise ValueError(f'Upload verification failed: {name}')
+    for entry in uploaded:
+        if entry['name'] not in assets:
+            github.request('DELETE', f"releases/assets/{entry['id']}")
+    commit = github.tag_commit(tag)
+    if commit is None:
+        github.request('POST', 'git/refs', {'ref': f'refs/tags/{tag}', 'sha': release['sha']})
+    elif commit != release['sha']:
+        if not beta:
+            raise ValueError('Stable tag changed during publication')
+        github.request('PATCH', f'git/refs/tags/{tag}', {'sha': release['sha'], 'force': True})
+    if not beta and config['platform'] == 'bukkit':
+        latest: dict | None = github.request('GET', 'releases/latest', missing=True)
+        match: re.Match | None = re.match(r'^v?(\d+)\.(\d+)\.(\d+)(?:$|-)', latest['tag_name']) if latest else None
+        if latest is None or (match and tuple(map(int, release['version'].split('.'))) > tuple(map(int, match.groups()))):
+            attributes['make_latest'] = 'true'
+    github.request('PATCH', f"releases/{existing['id']}", {**attributes, 'draft': False})
+    return f"Published {tag} at {release['sha']}"
+
+
+def main() -> None:
+    parser: argparse.ArgumentParser = argparse.ArgumentParser()
+    parser.add_argument('command', choices=['plan', 'publish'])
+    parser.add_argument('--artifacts', type=Path)
+    arguments: argparse.Namespace = parser.parse_args()
+    root: Path = Path(__file__).resolve().parent.parent
+    config: dict = read_config(root)
+    event: dict = json.loads(Path(os.environ['GITHUB_EVENT_PATH']).read_text())
+    environment: dict = dict(os.environ)
+    if arguments.command == 'publish':
+        environment['GITHUB_RUN_ATTEMPT'] = environment['RELEASE_ATTEMPT']
+    release: dict = plan(root, config, event, environment)
+    if arguments.command == 'plan':
+        if release['channel'] != 'none':
+            release['volmlib_ref'] = resolve_dependency('VolmitSoftware/VolmLib', config['volmlibRef'], environment['GH_TOKEN'])
+            if release['wormholes_ref']:
+                release['wormholes_ref'] = resolve_dependency('VolmitSoftware/Wormholes', config['wormholesRef'], environment['GH_TOKEN'])
+        with Path(os.environ['GITHUB_OUTPUT']).open('a') as output:
+            for key, value in release.items():
+                output.write(f'{key}={json.dumps(value, separators=(",", ":")) if isinstance(value, dict) else value}\n')
+        print(f"Release channel: {release['channel']}")
+    elif release['channel'] != 'none':
+        if arguments.artifacts is None:
+            raise ValueError('Publication requires the complete artifact directory')
+        for key in ('volmlib_ref', 'wormholes_ref'):
+            if release[key]:
+                resolved: str = environment[f'RELEASE_{key.upper()}']
+                if not re.fullmatch(r'[a-f0-9]{40}', resolved):
+                    raise ValueError(f'{key} is not a resolved dependency commit')
+                release[key] = resolved
+        github: GitHub = GitHub(os.environ['GITHUB_REPOSITORY'], os.environ['GH_TOKEN'])
+        print(publish(github, config, release, collect_artifacts(arguments.artifacts, release)))
+
+
+if __name__ == '__main__':
+    try:
+        main()
+    except (ValueError, RuntimeError) as error:
+        print(f'::error::{error}', file=sys.stderr)
+        sys.exit(1)

.github/test_release.py

@@ -0,0 +1,718 @@
+import copy
+import hashlib
+import importlib.util
+import io
+import json
+from pathlib import Path
+import tempfile
+import unittest
+from unittest.mock import patch
+import urllib.parse
+import zipfile
+
+
+SPEC = importlib.util.spec_from_file_location('release', Path(__file__).with_name('release.py'))
+release = importlib.util.module_from_spec(SPEC)
+SPEC.loader.exec_module(release)
+
+SHA = 'a' * 40
+OTHER_SHA = 'b' * 40
+
+
+def digest(data: bytes) -> str:
+    return 'sha256:' + hashlib.sha256(data).hexdigest()
+
+
+class FakeGitHub:
+    def __init__(self) -> None:
+        self.tags: dict[str, str] = {}
+        self.releases: dict[int, dict] = {}
+        self.uploads: dict[int, dict[str, dict]] = {}
+        self.writes: list[tuple[str, str]] = []
+        self.latest: dict | None = None
+        self.fail_upload: str | None = None
+        self.fail_delete: int | None = None
+        self.invalid_receipt: bool = False
+        self.next_asset: int = 1
+
+    def seed(self, publication: dict, assets: dict[str, bytes], draft: bool = False,
+             immutable: bool = False) -> dict:
+        identity: dict = {key: publication[key] for key in ('sha', 'version', 'run', 'attempt')}
+        record: dict = {
+            'id': len(self.releases) + 1,
+            'tag_name': publication['tag'],
+            'body': '<!-- release: ' + json.dumps(identity) + ' -->',
+            'draft': draft,
+            'prerelease': publication['channel'] == 'beta',
+            'immutable': immutable,
+        }
+        record['upload_url'] = f"https://uploads.github.com/repos/example/product/releases/{record['id']}/assets{{?name,label}}"
+        self.releases[record['id']] = record
+        self.uploads[record['id']] = {}
+        for name, data in assets.items():
+            self.add_asset(record['id'], name, data)
+        self.tags[publication['tag']] = publication['sha']
+        return record
+
+    def add_asset(self, identifier: int, name: str, data: bytes) -> dict:
+        receipt: dict = {'id': self.next_asset, 'name': name, 'digest': digest(data)}
+        self.next_asset += 1
+        self.uploads[identifier][name] = receipt
+        return copy.deepcopy(receipt)
+
+    def tag_commit(self, tag: str) -> str | None:
+        return self.tags.get(tag)
+
+    def assets(self, identifier: int) -> list[dict]:
+        return copy.deepcopy(list(self.uploads[identifier].values()))
+
+    def request(self, method: str, path: str, payload: dict | bytes | None = None,
+                missing: bool = False) -> dict | list | None:
+        if method != 'GET':
+            self.writes.append((method, path))
+        if method == 'GET' and path.startswith('releases/tags/'):
+            tag: str = path.removeprefix('releases/tags/')
+            return copy.deepcopy(next((record for record in self.releases.values()
+                                       if record['tag_name'] == tag), None))
+        if method == 'GET' and path == 'releases/latest':
+            return copy.deepcopy(self.latest)
+        if method == 'POST' and path == 'releases':
+            identifier: int = len(self.releases) + 1
+            record: dict = copy.deepcopy(payload)
+            record.update({'id': identifier, 'immutable': False,
+                           'upload_url': f'https://uploads.github.com/repos/example/product/releases/{identifier}/assets{{?name,label}}'})
+            self.releases[identifier] = record
+            self.uploads[identifier] = {}
+            return copy.deepcopy(record)
+        if method == 'POST' and path.startswith('https://uploads.github.com/'):
+            address: urllib.parse.SplitResult = urllib.parse.urlsplit(path)
+            name: str = urllib.parse.parse_qs(address.query)['name'][0]
+            if name == self.fail_upload:
+                raise RuntimeError('Upload unavailable')
+            identifier: int = int(address.path.split('/')[-2])
+            receipt: dict = self.add_asset(identifier, name, payload)
+            if self.invalid_receipt:
+                receipt['digest'] = digest(b'corrupted')
+            return receipt
+        if method == 'POST' and path == 'git/refs':
+            tag: str = payload['ref'].removeprefix('refs/tags/')
+            if tag in self.tags:
+                raise RuntimeError('Tag already exists')
+            self.tags[tag] = payload['sha']
+            return {'object': {'type': 'commit', 'sha': payload['sha']}}
+        if method == 'PATCH' and path.startswith('git/refs/tags/'):
+            self.tags[path.removeprefix('git/refs/tags/')] = payload['sha']
+            return None
+        if method == 'DELETE' and path.startswith('releases/assets/'):
+            identifier: int = int(path.rsplit('/', 1)[1])
+            if identifier == self.fail_delete:
+                raise RuntimeError('Delete unavailable')
+            for uploaded in self.uploads.values():
+                for name, entry in list(uploaded.items()):
+                    if entry['id'] == identifier:
+                        del uploaded[name]
+                        return None
+            raise AssertionError(f'Unknown asset: {identifier}')
+        if method == 'PATCH' and path.startswith('releases/'):
+            identifier: int = int(path.rsplit('/', 1)[1])
+            self.releases[identifier].update(copy.deepcopy(payload))
+            if payload.get('make_latest') == 'true':
+                self.latest = copy.deepcopy(self.releases[identifier])
+            return copy.deepcopy(self.releases[identifier])
+        raise AssertionError(f'Unexpected API request: {method} {path}')
+
+
+class ReleaseTestCase(unittest.TestCase):
+    def setUp(self) -> None:
+        temporary: tempfile.TemporaryDirectory = tempfile.TemporaryDirectory()
+        self.addCleanup(temporary.cleanup)
+        self.root: Path = Path(temporary.name)
+        self.config: dict = {'name': 'Example', 'platform': 'bukkit', 'versionProperty': 'exampleVersion',
+                             'betaTag': 'bukkit-beta', 'volmlibRef': 'c' * 40}
+        (self.root / 'gradle.properties').write_text('exampleVersion=1.2.3\n')
+        self.event: dict = {'repository': {'default_branch': 'main'}, 'ref': 'refs/heads/main',
+                            'after': SHA, 'head_commit': {'id': SHA, 'message': 'V+ Publish'}}
+        self.environment: dict = {'GITHUB_EVENT_NAME': 'push', 'GITHUB_SHA': SHA,
+                                  'GITHUB_RUN_NUMBER': '17', 'GITHUB_RUN_ATTEMPT': '2'}
+        network = patch.object(release.urllib.request, 'urlopen', side_effect=AssertionError('Network is forbidden'))
+        network.start()
+        self.addCleanup(network.stop)
+
+    def publication(self, channel: str = 'stable', **changes) -> dict:
+        result: dict = {
+            'channel': channel, 'version': '1.2.3-beta.17.2' if channel == 'beta' else '1.2.3',
+            'tag': 'bukkit-beta' if channel == 'beta' else 'v1.2.3', 'sha': SHA, 'run': 17, 'attempt': 2,
+            'matrix': {'include': [{'id': 'bukkit', 'loader': 'bukkit', 'minecraft': ''}]},
+        }
+        result.update(changes)
+        return result
+
+    def matrix(self, versions: tuple[str, ...] = ('1.20.1', '1.21.1')) -> list[dict]:
+        return [{'id': f'{loader}-{version}', 'loader': loader, 'minecraft': version}
+                for version in versions for loader in ('fabric', 'forge', 'neoforge')]
+
+    def artifact_tree(self, publication: dict, extra: tuple[str, ...] = ()) -> Path:
+        directory: Path = self.root / 'artifacts'
+        directory.mkdir(exist_ok=True)
+        descriptors: dict[str, str] = {'bukkit': 'plugin.yml', 'fabric': 'fabric.mod.json',
+                                      'forge': 'META-INF/mods.toml', 'neoforge': 'META-INF/neoforge.mods.toml'}
+        for target in publication['matrix']['include']:
+            folder: Path = directory / f"release-{target['id']}"
+            folder.mkdir()
+            loader: str = target['loader']
+            if loader == 'bukkit':
+                filename: str = f"Example-{publication['version']}-bukkit.jar"
+                metadata: str = f"name: Example\nversion: {publication['version']}\nmain: example.Plugin\n"
+            else:
+                display: str = {'fabric': 'Fabric', 'forge': 'Forge', 'neoforge': 'NeoForge'}[loader]
+                filename = f"Example v{publication['version']} [{display}] {target['minecraft']}+1.0.0.jar"
+                if loader == 'fabric':
+                    metadata = json.dumps({'schemaVersion': 1, 'id': 'example', 'version': publication['version'],
+                                           'depends': {'minecraft': '~' + target['minecraft']}})
+                else:
+                    metadata = (f"modLoader = 'javafml'\nloaderVersion = '[1,)'\nlicense = 'MIT'\n"
+                                f"[[mods]]\nmodId = 'example'\nversion = '{publication['version']}'\n"
+                                f"[[dependencies.example]]\nmodId = 'minecraft'\n"
+                                f"versionRange = '[{target['minecraft']}]'\n")
+            path: Path = folder / filename
+            with zipfile.ZipFile(path, 'w') as archive:
+                archive.writestr(descriptors[loader], metadata)
+                for name in extra:
+                    archive.writestr(name, '')
+        return directory
+
+
+class PlanTests(ReleaseTestCase):
+    def test_markers_are_case_sensitive(self) -> None:
+        for message, channel in [('B+ Beta', 'beta'), ('V+ Release', 'stable'),
+                                 ('b+ beta', 'none'), ('v+ release', 'none'), ('Fix a bug', 'none')]:
+            with self.subTest(message=message):
+                self.event['head_commit']['message'] = message
+                result: dict = release.plan(self.root, self.config, self.event, self.environment)
+                self.assertEqual(channel, result['channel'])
+                if channel == 'beta':
+                    self.assertEqual('1.2.3-beta.17.2', result['version'])
+                    self.assertEqual('bukkit-beta', result['tag'])
+                elif channel == 'stable':
+                    self.assertEqual('1.2.3', result['version'])
+                    self.assertEqual('v1.2.3', result['tag'])
+
+    def test_both_markers_fail(self) -> None:
+        self.event['head_commit']['message'] = 'B+ first\nV+ second'
+        with self.assertRaises(ValueError):
+            release.plan(self.root, self.config, self.event, self.environment)
+
+    def test_only_pushed_default_branch_head_can_release(self) -> None:
+        cases: list[tuple[dict, dict]] = [
+            ({'ref': 'refs/heads/feature'}, {}), ({'ref': 'refs/tags/V+1.2.3'}, {}),
+            ({'deleted': True}, {}), ({'repository': {}}, {}),
+            ({'head_commit': None}, {}), ({}, {'GITHUB_EVENT_NAME': 'pull_request'}),
+        ]
+        for event_changes, environment_changes in cases:
+            with self.subTest(event=event_changes, environment=environment_changes):
+                self.assertEqual({'channel': 'none'}, release.plan(
+                    self.root, self.config, {**self.event, **event_changes},
+                    {**self.environment, **environment_changes}))
+
+    def test_head_identity_must_match_event_and_environment(self) -> None:
+        for field in ('after', 'commit', 'environment'):
+            with self.subTest(field=field):
+                event: dict = copy.deepcopy(self.event)
+                environment: dict = self.environment.copy()
+                if field == 'commit':
+                    event['head_commit']['id'] = OTHER_SHA
+                elif field == 'environment':
+                    environment['GITHUB_SHA'] = 'not-a-sha'
+                else:
+                    event['after'] = OTHER_SHA
+                with self.assertRaises(ValueError):
+                    release.plan(self.root, self.config, event, environment)
+
+    def test_old_commits_do_not_trigger_release(self) -> None:
+        self.event['commits'] = [{'id': OTHER_SHA, 'message': 'V+ Release'}]
+        self.event['head_commit']['message'] = 'Fix a bug'
+        self.assertEqual({'channel': 'none'}, release.plan(self.root, self.config, self.event, self.environment))
+
+    def test_invalid_or_duplicate_versions_fail(self) -> None:
+        for value in ('', 'exampleVersion=01.2.3\n', 'exampleVersion=1.2\n',
+                      'exampleVersion=1.2.3-beta.1\n', 'exampleVersion=1.2.3\nexampleVersion=2.3.4\n'):
+            with self.subTest(value=value):
+                (self.root / 'gradle.properties').write_text(value)
+                with self.assertRaises(ValueError):
+                    release.plan(self.root, self.config, self.event, self.environment)
+
+    def test_invalid_run_identity_fails(self) -> None:
+        for key in ('GITHUB_RUN_NUMBER', 'GITHUB_RUN_ATTEMPT'):
+            with self.subTest(key=key), self.assertRaises(ValueError):
+                release.plan(self.root, self.config, self.event, {**self.environment, key: '0'})
+
+    def test_minecraft_file_matrix_contains_all_loaders(self) -> None:
+        (self.root / 'targets.json').write_text(json.dumps({'1.20.1': {}, '1.21.1': {}}))
+        config: dict = {**self.config, 'platform': 'modded', 'targets': 'targets.json'}
+        self.assertEqual(self.matrix(), release.targets(self.root, config))
+
+    def test_minecraft_directory_matrix_matches_files(self) -> None:
+        folder: Path = self.root / 'targets'
+        folder.mkdir()
+        (folder / '1.20.1.json').write_text(json.dumps({'minecraft': '1.20.1',
+                                                      'loaders': ['fabric', 'forge', 'neoforge']}))
+        config: dict = {**self.config, 'platform': 'modded', 'targets': 'targets'}
+        self.assertEqual(self.matrix(('1.20.1',)), release.targets(self.root, config))
+        for minecraft, loaders in [('1.20.2', ['fabric', 'forge', 'neoforge']), ('1.20.1', ['fabric'])]:
+            with self.subTest(minecraft=minecraft, loaders=loaders):
+                (folder / '1.20.1.json').write_text(json.dumps({'minecraft': minecraft, 'loaders': loaders}))
+                with self.assertRaises(ValueError):
+                    release.targets(self.root, config)
+
+    def test_empty_or_invalid_minecraft_matrix_fails(self) -> None:
+        for content in ({}, {'invalid': {}}):
+            with self.subTest(content=content):
+                (self.root / 'targets.json').write_text(json.dumps(content))
+                with self.assertRaises(ValueError):
+                    release.targets(self.root, {**self.config, 'platform': 'modded', 'targets': 'targets.json'})
+
+
+class ArtifactTests(ReleaseTestCase):
+    def test_complete_modded_matrix_and_checksums(self) -> None:
+        publication: dict = self.publication(matrix={'include': self.matrix()})
+        assets: dict[str, bytes] = release.collect_artifacts(self.artifact_tree(publication), publication)
+        self.assertEqual(7, len(assets))
+        checksums: bytes = assets.pop('SHA256SUMS-1.2.3.txt')
+        self.assertEqual(''.join(f'{hashlib.sha256(data).hexdigest()}  {name}\n'
+                                 for name, data in sorted(assets.items())).encode(), checksums)
+
+    def test_missing_or_extra_matrix_target_fails(self) -> None:
+        publication: dict = self.publication()
+        directory: Path = self.artifact_tree(publication)
+        (directory / 'release-extra').mkdir()
+        with self.assertRaises(ValueError):
+            release.collect_artifacts(directory, publication)
+        (directory / 'release-extra').rmdir()
+        (directory / 'release-bukkit').rename(directory / 'release-wrong')
+        with self.assertRaises(ValueError):
+            release.collect_artifacts(directory, publication)
+
+    def test_intermediate_artifact_beside_runtime_fails(self) -> None:
+        publication: dict = self.publication()
+        directory: Path = self.artifact_tree(publication)
+        (directory / 'release-bukkit' / 'sources.jar').write_bytes(b'sources')
+        with self.assertRaises(ValueError):
+            release.collect_artifacts(directory, publication)
+
+    def test_symbolic_link_artifacts_fail(self) -> None:
+        publication: dict = self.publication()
+        directory: Path = self.artifact_tree(publication)
+        path: Path = next((directory / 'release-bukkit').iterdir())
+        target: Path = self.root / path.name
+        path.rename(target)
+        path.symlink_to(target)
+        with self.assertRaises(ValueError):
+            release.collect_artifacts(directory, publication)
+
+    def test_bukkit_is_forbidden_in_modded_release(self) -> None:
+        publication: dict = self.publication(matrix={'include': self.matrix(('1.20.1',))})
+        with self.assertRaises(ValueError):
+            release.collect_artifacts(self.artifact_tree(publication, ('plugin.yml',)), publication)
+
+    def test_velocity_is_forbidden_in_bukkit_release(self) -> None:
+        publication: dict = self.publication()
+        with self.assertRaises(ValueError):
+            release.collect_artifacts(self.artifact_tree(publication, ('velocity-plugin.json',)), publication)
+
+    def test_modded_descriptor_is_forbidden_in_bukkit_release(self) -> None:
+        publication: dict = self.publication()
+        with self.assertRaises(ValueError):
+            release.collect_artifacts(self.artifact_tree(publication, ('fabric.mod.json',)), publication)
+
+    def test_required_platform_descriptor_is_checked(self) -> None:
+        publication: dict = self.publication()
+        directory: Path = self.artifact_tree(publication)
+        path: Path = next((directory / 'release-bukkit').iterdir())
+        with zipfile.ZipFile(path, 'w') as archive:
+            archive.writestr('fabric.mod.json', '{}')
+        with self.assertRaises(ValueError):
+            release.collect_artifacts(directory, publication)
+
+    def test_wrong_version_and_embedded_version_suffix_fail(self) -> None:
+        publication: dict = self.publication()
+        directory: Path = self.artifact_tree(publication)
+        path: Path = next((directory / 'release-bukkit').iterdir())
+        for version in ('9.8.7', '11.2.3'):
+            with self.subTest(version=version):
+                changed: Path = path.with_name(f'Example-{version}-bukkit.jar')
+                path.rename(changed)
+                with self.assertRaises(ValueError):
+                    release.collect_artifacts(directory, publication)
+                changed.rename(path)
+
+    def test_descriptor_version_must_match_release(self) -> None:
+        publication: dict = self.publication()
+        directory: Path = self.artifact_tree(publication)
+        path: Path = next((directory / 'release-bukkit').iterdir())
+        with zipfile.ZipFile(path, 'w') as archive:
+            archive.writestr('plugin.yml', 'name: Example\nversion: 1.2.4\nmain: example.Plugin\n')
+        with self.assertRaises(ValueError):
+            release.collect_artifacts(directory, publication)
+
+    def test_modded_descriptor_versions_must_match_release(self) -> None:
+        publication: dict = self.publication(matrix={'include': self.matrix(('1.20.1',))})
+        directory: Path = self.artifact_tree(publication)
+        for folder in directory.iterdir():
+            with self.subTest(target=folder.name):
+                path: Path = next(folder.iterdir())
+                original: bytes = path.read_bytes()
+                with zipfile.ZipFile(path) as archive:
+                    descriptor: str = archive.namelist()[0]
+                    contents: str = archive.read(descriptor).decode().replace('1.2.3', '1.2.4')
+                with zipfile.ZipFile(path, 'w') as archive:
+                    archive.writestr(descriptor, contents)
+                with self.assertRaises(ValueError):
+                    release.collect_artifacts(directory, publication)
+                path.write_bytes(original)
+
+    def test_modded_filename_must_match_minecraft_target(self) -> None:
+        publication: dict = self.publication(matrix={'include': self.matrix(('1.20.1',))})
+        directory: Path = self.artifact_tree(publication)
+        path: Path = next((directory / 'release-fabric-1.20.1').iterdir())
+        path.rename(path.with_name(path.name.replace('1.20.1', '1.21.1')))
+        with self.assertRaises(ValueError):
+            release.collect_artifacts(directory, publication)
+
+    def test_modded_metadata_must_match_minecraft_target(self) -> None:
+        publication: dict = self.publication(matrix={'include': self.matrix(('1.20.1',))})
+        directory: Path = self.artifact_tree(publication)
+        for folder in directory.iterdir():
+            with self.subTest(target=folder.name):
+                path: Path = next(folder.iterdir())
+                original: bytes = path.read_bytes()
+                with zipfile.ZipFile(path) as archive:
+                    descriptor: str = archive.namelist()[0]
+                    contents: str = archive.read(descriptor).decode().replace('1.20.1', '1.21.1')
+                with zipfile.ZipFile(path, 'w') as archive:
+                    archive.writestr(descriptor, contents)
+                with self.assertRaises(ValueError):
+                    release.collect_artifacts(directory, publication)
+                path.write_bytes(original)
+
+
+class PublicationTests(ReleaseTestCase):
+    def setUp(self) -> None:
+        super().setUp()
+        self.github: FakeGitHub = FakeGitHub()
+        self.assets: dict[str, bytes] = {'Example-1.2.3-bukkit.jar': b'jar', 'SHA256SUMS-1.2.3.txt': b'checksums'}
+
+    def test_new_stable_release_is_published_at_head(self) -> None:
+        release.publish(self.github, self.config, self.publication(), self.assets)
+        record: dict = self.github.releases[1]
+        self.assertEqual(SHA, self.github.tags['v1.2.3'])
+        self.assertFalse(record['draft'])
+        self.assertFalse(record['prerelease'])
+        self.assertEqual('true', record['make_latest'])
+        self.assertEqual(set(self.assets), set(self.github.uploads[1]))
+
+    def test_stable_existing_tag_collision_has_no_writes(self) -> None:
+        self.github.tags['v1.2.3'] = OTHER_SHA
+        with self.assertRaises(ValueError):
+            release.publish(self.github, self.config, self.publication(), self.assets)
+        self.assertEqual([], self.github.writes)
+        self.assertEqual(OTHER_SHA, self.github.tags['v1.2.3'])
+
+    def test_stable_same_content_rerun_has_no_writes(self) -> None:
+        self.github.seed(self.publication(), self.assets, immutable=True)
+        result: str = release.publish(self.github, self.config, self.publication(), self.assets)
+        self.assertIn('already published', result)
+        self.assertEqual([], self.github.writes)
+
+    def test_published_stable_artifacts_cannot_be_replaced(self) -> None:
+        self.github.seed(self.publication(), self.assets, immutable=True)
+        with self.assertRaises(ValueError):
+            release.publish(self.github, self.config, self.publication(),
+                            {**self.assets, 'Example-1.2.3-bukkit.jar': b'different'})
+        self.assertEqual([], self.github.writes)
+
+    def test_stable_release_identity_collision_has_no_writes(self) -> None:
+        self.github.seed(self.publication(sha=OTHER_SHA), self.assets)
+        self.github.tags['v1.2.3'] = SHA
+        with self.assertRaises(ValueError):
+            release.publish(self.github, self.config, self.publication(), self.assets)
+        self.assertEqual([], self.github.writes)
+
+    def test_stable_release_cannot_reuse_published_prerelease(self) -> None:
+        record: dict = self.github.seed(self.publication(), self.assets)
+        record['prerelease'] = True
+        with self.assertRaises(ValueError):
+            release.publish(self.github, self.config, self.publication(), self.assets)
+        self.assertEqual([], self.github.writes)
+
+    def test_partially_uploaded_stable_draft_resumes(self) -> None:
+        record: dict = self.github.seed(self.publication(), {'Example-1.2.3-bukkit.jar': b'jar'}, draft=True)
+        original_id: int = self.github.uploads[record['id']]['Example-1.2.3-bukkit.jar']['id']
+        release.publish(self.github, self.config, self.publication(), self.assets)
+        self.assertFalse(self.github.releases[record['id']]['draft'])
+        self.assertEqual(original_id, self.github.uploads[record['id']]['Example-1.2.3-bukkit.jar']['id'])
+        self.assertEqual(set(self.assets), set(self.github.uploads[record['id']]))
+        self.assertEqual(1, len(self.github.releases))
+
+    def test_conflicting_draft_asset_fails_without_replacement(self) -> None:
+        self.github.seed(self.publication(), {'Example-1.2.3-bukkit.jar': b'other'}, draft=True)
+        with self.assertRaises(ValueError):
+            release.publish(self.github, self.config, self.publication(), self.assets)
+        self.assertEqual([], self.github.writes)
+        self.assertTrue(self.github.releases[1]['draft'])
+
+    def test_newer_beta_run_or_attempt_is_preserved(self) -> None:
+        for run, attempt in ((18, 1), (17, 3)):
+            with self.subTest(run=run, attempt=attempt):
+                github: FakeGitHub = FakeGitHub()
+                github.seed(self.publication('beta', run=run, attempt=attempt, sha=OTHER_SHA), self.assets)
+                result: str = release.publish(github, self.config, self.publication('beta'), self.assets)
+                self.assertIn('Skipped', result)
+                self.assertEqual([], github.writes)
+                self.assertEqual(OTHER_SHA, github.tags['bukkit-beta'])
+
+    def test_successful_beta_replaces_assets_and_remains_prerelease(self) -> None:
+        previous: dict = self.publication('beta', run=16, attempt=1, sha=OTHER_SHA, version='1.2.3-beta.16.1')
+        record: dict = self.github.seed(previous, {'old.jar': b'old'})
+        release.publish(self.github, self.config, self.publication('beta'), self.assets)
+        current: dict = self.github.releases[record['id']]
+        self.assertEqual(SHA, self.github.tags['bukkit-beta'])
+        self.assertTrue(current['prerelease'])
+        self.assertFalse(current['draft'])
+        self.assertEqual('false', current['make_latest'])
+        self.assertEqual(set(self.assets), set(self.github.uploads[record['id']]))
+
+    def test_failed_beta_upload_preserves_tag_and_assets_in_recoverable_draft(self) -> None:
+        previous: dict = self.publication('beta', run=16, attempt=1, sha=OTHER_SHA, version='1.2.3-beta.16.1')
+        record: dict = self.github.seed(previous, {'old.jar': b'old'})
+        self.github.fail_upload = 'SHA256SUMS-1.2.3.txt'
+        with self.assertRaises(RuntimeError):
+            release.publish(self.github, self.config, self.publication('beta'), self.assets)
+        self.assertEqual(OTHER_SHA, self.github.tags['bukkit-beta'])
+        self.assertTrue(self.github.releases[record['id']]['draft'])
+        self.assertEqual(17, release.release_metadata(self.github.releases[record['id']])['run'])
+        self.assertIn('old.jar', self.github.uploads[record['id']])
+        self.assertFalse(any(method == 'DELETE' or path.startswith('git/refs')
+                             for method, path in self.github.writes))
+
+    def test_failed_beta_cleanup_resumes_without_reuploading_verified_assets(self) -> None:
+        previous: dict = self.publication('beta', run=16, attempt=1, sha=OTHER_SHA, version='1.2.3-beta.16.1')
+        record: dict = self.github.seed(previous, {'old.jar': b'old'})
+        self.github.fail_delete = self.github.uploads[record['id']]['old.jar']['id']
+        with self.assertRaises(RuntimeError):
+            release.publish(self.github, self.config, self.publication('beta'), self.assets)
+        self.assertTrue(self.github.releases[record['id']]['draft'])
+        self.assertEqual(OTHER_SHA, self.github.tags['bukkit-beta'])
+        uploaded_ids: dict[str, int] = {name: self.github.uploads[record['id']][name]['id'] for name in self.assets}
+        self.github.fail_delete = None
+        release.publish(self.github, self.config, self.publication('beta'), self.assets)
+        self.assertFalse(self.github.releases[record['id']]['draft'])
+        self.assertEqual(SHA, self.github.tags['bukkit-beta'])
+        self.assertEqual(uploaded_ids, {name: entry['id'] for name, entry in self.github.uploads[record['id']].items()})
+
+    def test_incomplete_newer_beta_draft_blocks_older_run(self) -> None:
+        self.github.seed(self.publication('beta', run=18, sha=OTHER_SHA), {}, draft=True)
+        result: str = release.publish(self.github, self.config, self.publication('beta'), self.assets)
+        self.assertIn('Skipped', result)
+        self.assertEqual([], self.github.writes)
+        self.assertTrue(self.github.releases[1]['draft'])
+
+    def test_starter_upload_in_draft_is_replaced_before_publication(self) -> None:
+        self.github.seed(self.publication(), {'Example-1.2.3-bukkit.jar': b''}, draft=True)
+        starter: dict = self.github.uploads[1]['Example-1.2.3-bukkit.jar']
+        identifier: int = starter['id']
+        starter.update({'state': 'starter', 'digest': None})
+        release.publish(self.github, self.config, self.publication(), self.assets)
+        self.assertFalse(self.github.releases[1]['draft'])
+        self.assertNotEqual(identifier, self.github.uploads[1]['Example-1.2.3-bukkit.jar']['id'])
+        self.assertEqual(digest(b'jar'), self.github.uploads[1]['Example-1.2.3-bukkit.jar']['digest'])
+
+    def test_invalid_upload_digest_does_not_create_tag_or_publish(self) -> None:
+        self.github.invalid_receipt = True
+        with self.assertRaises(ValueError):
+            release.publish(self.github, self.config, self.publication(), self.assets)
+        self.assertEqual({}, self.github.tags)
+        self.assertTrue(self.github.releases[1]['draft'])
+
+    def test_beta_will_not_replace_stable_or_immutable_release(self) -> None:
+        for immutable, prerelease in ((True, True), (False, False)):
+            with self.subTest(immutable=immutable, prerelease=prerelease):
+                github: FakeGitHub = FakeGitHub()
+                record: dict = github.seed(self.publication('beta', run=16, sha=OTHER_SHA), self.assets,
+                                           immutable=immutable)
+                record['prerelease'] = prerelease
+                with self.assertRaises(ValueError):
+                    release.publish(github, self.config, self.publication('beta'), self.assets)
+                self.assertEqual([], github.writes)
+
+    def test_unowned_existing_release_is_preserved(self) -> None:
+        record: dict = self.github.seed(self.publication(), self.assets)
+        record['body'] = 'Published manually'
+        with self.assertRaises(ValueError):
+            release.publish(self.github, self.config, self.publication(), self.assets)
+        self.assertEqual([], self.github.writes)
+
+    def test_beta_tag_without_release_is_preserved(self) -> None:
+        self.github.tags['bukkit-beta'] = OTHER_SHA
+        with self.assertRaises(ValueError):
+            release.publish(self.github, self.config, self.publication('beta'), self.assets)
+        self.assertEqual([], self.github.writes)
+
+    def test_modded_stable_release_never_changes_latest(self) -> None:
+        self.github.latest = {'tag_name': 'v1.0.0'}
+        release.publish(self.github, {**self.config, 'platform': 'modded'}, self.publication(), self.assets)
+        self.assertFalse(self.github.releases[1]['prerelease'])
+        self.assertEqual('false', self.github.releases[1]['make_latest'])
+        self.assertEqual('v1.0.0', self.github.latest['tag_name'])
+
+    def test_bukkit_backport_does_not_replace_newer_latest(self) -> None:
+        for latest in ('v1.3.0', 'v2.0.0', 'v1.2.3'):
+            with self.subTest(latest=latest):
+                github: FakeGitHub = FakeGitHub()
+                github.latest = {'tag_name': latest}
+                release.publish(github, self.config, self.publication(), self.assets)
+                self.assertEqual('false', github.releases[1]['make_latest'])
+                self.assertEqual(latest, github.latest['tag_name'])
+
+    def test_newer_bukkit_release_becomes_latest(self) -> None:
+        self.github.latest = {'tag_name': 'v1.2.2'}
+        release.publish(self.github, self.config, self.publication(), self.assets)
+        self.assertEqual('true', self.github.releases[1]['make_latest'])
+        self.assertEqual('v1.2.3', self.github.latest['tag_name'])
+
+
+class GitHubReadTests(ReleaseTestCase):
+    def test_annotated_tag_resolves_to_commit(self) -> None:
+        github: release.GitHub = release.GitHub('example/product', 'test-token')
+        responses: dict[str, dict] = {
+            'git/ref/tags/v1.2.3': {'object': {'type': 'tag', 'sha': OTHER_SHA}},
+            f'git/tags/{OTHER_SHA}': {'object': {'type': 'commit', 'sha': SHA}},
+        }
+        with patch.object(github, 'request', side_effect=lambda method, path, **options: responses[path]):
+            self.assertEqual(SHA, github.tag_commit('v1.2.3'))
+
+    def test_noncommit_tag_cannot_be_published(self) -> None:
+        github: release.GitHub = release.GitHub('example/product', 'test-token')
+        with patch.object(github, 'request', return_value={'object': {'type': 'tree', 'sha': SHA}}):
+            with self.assertRaises(ValueError):
+                github.tag_commit('v1.2.3')
+
+    def test_assets_include_all_pages(self) -> None:
+        github: release.GitHub = release.GitHub('example/product', 'test-token')
+        first: list[dict] = [{'id': number, 'name': f'{number}.jar'} for number in range(100)]
+        last: list[dict] = [{'id': 100, 'name': 'last.jar'}]
+        with patch.object(github, 'request', side_effect=[first, last]):
+            self.assertEqual(first + last, github.assets(1))
+
+    def test_invalid_repository_is_rejected(self) -> None:
+        for repository in ('example', '../example/product', 'example/product/extra'):
+            with self.subTest(repository=repository), self.assertRaises(ValueError):
+                release.GitHub(repository, 'test-token')
+
+
+class DependencyResolutionTests(ReleaseTestCase):
+    def test_branch_resolves_to_full_commit_sha(self) -> None:
+        with patch.object(release.GitHub, 'request', return_value={'sha': SHA}) as request:
+            self.assertEqual(SHA, release.resolve_dependency('example/product', 'master', 'test-token'))
+        request.assert_called_once_with('GET', 'commits/master')
+
+    def test_full_commit_reference_is_verified(self) -> None:
+        with patch.object(release.GitHub, 'request', return_value={'sha': SHA}) as request:
+            self.assertEqual(SHA, release.resolve_dependency('example/product', SHA, 'test-token'))
+        request.assert_called_once_with('GET', f'commits/{SHA}')
+
+    def test_incomplete_or_invalid_resolved_sha_fails(self) -> None:
+        for sha in ('', 'a' * 39, 'a' * 41, 'A' * 40, 'g' * 40, 'master'):
+            with self.subTest(sha=sha), patch.object(release.GitHub, 'request', return_value={'sha': sha}):
+                with self.assertRaises(ValueError):
+                    release.resolve_dependency('example/product', 'master', 'test-token')
+
+    def test_reference_is_encoded_as_single_url_path_component(self) -> None:
+        with patch.object(release.GitHub, 'request', return_value={'sha': SHA}) as request:
+            self.assertEqual(SHA, release.resolve_dependency('example/product', 'feature/next+release #?', 'test-token'))
+        request.assert_called_once_with('GET', 'commits/feature%2Fnext%2Brelease%20%23%3F')
+
+
+class MainTests(ReleaseTestCase):
+    def setUp(self) -> None:
+        super().setUp()
+        self.config.update({'volmlibRef': 'master', 'wormholesRef': 'release/api'})
+        (self.root / '.github').mkdir()
+        (self.root / '.github/release.json').write_text(json.dumps(self.config))
+        self.event['head_commit']['message'] = 'B+ Publish beta'
+        (self.root / 'event.json').write_text(json.dumps(self.event))
+        self.environment.update({
+            'GITHUB_EVENT_PATH': str(self.root / 'event.json'),
+            'GITHUB_OUTPUT': str(self.root / 'output.txt'),
+            'GITHUB_REPOSITORY': 'example/product',
+            'GH_TOKEN': 'test-token',
+        })
+        script = patch.object(release, '__file__', str(self.root / '.github/release.py'))
+        script.start()
+        self.addCleanup(script.stop)
+        output = patch('sys.stdout', new=io.StringIO())
+        output.start()
+        self.addCleanup(output.stop)
+
+    def test_plan_freezes_each_dependency_branch_once(self) -> None:
+        with patch.dict(release.os.environ, self.environment, clear=True), \
+                patch.object(release.sys, 'argv', ['release.py', 'plan']), \
+                patch.object(release.GitHub, 'request', side_effect=[{'sha': SHA}, {'sha': OTHER_SHA}]) as request:
+            release.main()
+        outputs: dict[str, str] = dict(line.split('=', 1) for line in (self.root / 'output.txt').read_text().splitlines())
+        self.assertEqual(SHA, outputs['volmlib_ref'])
+        self.assertEqual(OTHER_SHA, outputs['wormholes_ref'])
+        self.assertEqual('1.2.3-beta.17.2', outputs['version'])
+        self.assertEqual('2', outputs['attempt'])
+        self.assertEqual(2, request.call_count)
+        self.assertEqual(['commits/master', 'commits/release%2Fapi'], [call.args[1] for call in request.call_args_list])
+
+    def test_unmarked_push_never_resolves_dependencies(self) -> None:
+        self.event['head_commit']['message'] = 'Fix a bug'
+        (self.root / 'event.json').write_text(json.dumps(self.event))
+        with patch.dict(release.os.environ, self.environment, clear=True), \
+                patch.object(release.sys, 'argv', ['release.py', 'plan']), \
+                patch.object(release, 'resolve_dependency', side_effect=AssertionError('Unexpected dependency lookup')):
+            release.main()
+        self.assertEqual('channel=none\n', (self.root / 'output.txt').read_text())
+
+    def test_publish_rerun_uses_original_planned_attempt_and_dependency_commits(self) -> None:
+        publication: dict = self.publication('beta')
+        artifacts: Path = self.artifact_tree(publication)
+        github: FakeGitHub = FakeGitHub()
+        self.environment.update({'GITHUB_RUN_ATTEMPT': '3', 'RELEASE_ATTEMPT': '2',
+                                  'RELEASE_VOLMLIB_REF': SHA, 'RELEASE_WORMHOLES_REF': OTHER_SHA})
+        with patch.dict(release.os.environ, self.environment, clear=True), \
+                patch.object(release.sys, 'argv', ['release.py', 'publish', '--artifacts', str(artifacts)]), \
+                patch.object(release, 'GitHub', return_value=github), \
+                patch.object(release, 'resolve_dependency', side_effect=AssertionError('Dependencies must stay frozen')):
+            release.main()
+            metadata: dict = release.release_metadata(github.releases[1])
+            self.assertEqual('1.2.3-beta.17.2', metadata['version'])
+            self.assertEqual(2, metadata['attempt'])
+            self.assertEqual(SHA, metadata['volmlib_ref'])
+            self.assertEqual(OTHER_SHA, metadata['wormholes_ref'])
+            self.assertFalse(github.releases[1]['draft'])
+            self.assertEqual({'Example-1.2.3-beta.17.2-bukkit.jar', 'SHA256SUMS-1.2.3-beta.17.2.txt'},
+                             set(github.uploads[1]))
+            writes: list[tuple[str, str]] = github.writes.copy()
+            release.os.environ['GITHUB_RUN_ATTEMPT'] = '4'
+            release.main()
+            self.assertEqual(writes, github.writes)
+
+    def test_publish_rejects_unresolved_dependency_reference_before_writing(self) -> None:
+        artifacts: Path = self.artifact_tree(self.publication('beta'))
+        github: FakeGitHub = FakeGitHub()
+        self.environment.update({'RELEASE_ATTEMPT': '2', 'RELEASE_VOLMLIB_REF': SHA,
+                                  'RELEASE_WORMHOLES_REF': OTHER_SHA})
+        for key in ('RELEASE_VOLMLIB_REF', 'RELEASE_WORMHOLES_REF'):
+            with self.subTest(key=key), \
+                    patch.dict(release.os.environ, {**self.environment, key: 'master'}, clear=True), \
+                    patch.object(release.sys, 'argv', ['release.py', 'publish', '--artifacts', str(artifacts)]), \
+                    patch.object(release, 'GitHub', return_value=github):
+                with self.assertRaises(ValueError):
+                    release.main()
+                self.assertEqual([], github.writes)
+
+
+if __name__ == '__main__':
+    unittest.main()

.github/workflows/release.yml

@@ -0,0 +1,157 @@
+name: Release
+
+on:
+  push:
+    branches: ['**']
+  pull_request:
+    paths:
+      - '.github/**'
+      - '**/*.gradle'
+      - '**/gradle.properties'
+      - 'gradle/**/*.json'
+
+permissions:
+  contents: read
+
+env:
+  PYTHONDONTWRITEBYTECODE: '1'
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
+        with:
+          persist-credentials: false
+      - name: Test release handling
+        run: python3 -m unittest discover -s .github -p 'test_release.py' -v
+
+  plan:
+    needs: validate
+    if: github.event_name == 'push' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
+    runs-on: ubuntu-latest
+    outputs:
+      channel: ${{ steps.release.outputs.channel }}
+      version: ${{ steps.release.outputs.version }}
+      attempt: ${{ steps.release.outputs.attempt }}
+      version_property: ${{ steps.release.outputs.version_property }}
+      matrix: ${{ steps.release.outputs.matrix }}
+      volmlib_ref: ${{ steps.release.outputs.volmlib_ref }}
+      wormholes_ref: ${{ steps.release.outputs.wormholes_ref }}
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
+        with:
+          persist-credentials: false
+      - name: Select release channel and targets
+        id: release
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: python3 .github/release.py plan
+
+  build:
+    needs: plan
+    if: needs.plan.outputs.channel != 'none'
+    runs-on: ubuntu-latest
+    timeout-minutes: 120
+    strategy:
+      fail-fast: false
+      max-parallel: 3
+      matrix: ${{ fromJSON(needs.plan.outputs.matrix) }}
+    env:
+      ORG_GRADLE_PROJECT_localVolmLibDirectory: ${{ github.workspace }}/VolmLib
+      RELEASE_VERSION: ${{ needs.plan.outputs.version }}
+      VERSION_PROPERTY: ${{ needs.plan.outputs.version_property }}
+      RELEASE_LOADER: ${{ matrix.loader }}
+      MINECRAFT_VERSION: ${{ matrix.minecraft }}
+    steps:
+      - name: Check out release sources
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
+        with:
+          path: project
+          submodules: recursive
+          persist-credentials: false
+      - name: Check out VolmLib
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
+        with:
+          repository: VolmitSoftware/VolmLib
+          ref: ${{ needs.plan.outputs.volmlib_ref }}
+          path: VolmLib
+          persist-credentials: false
+      - name: Check out Wormholes API sources
+        if: needs.plan.outputs.wormholes_ref != ''
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
+        with:
+          repository: VolmitSoftware/Wormholes
+          ref: ${{ needs.plan.outputs.wormholes_ref }}
+          path: WormholesPlugin
+          submodules: recursive
+          persist-credentials: false
+      - name: Set up Java 21 toolchain
+        uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad
+        with:
+          distribution: temurin
+          java-version: '21'
+      - name: Set up Java 25
+        uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad
+        with:
+          distribution: temurin
+          java-version: '25'
+      - uses: gradle/actions/setup-gradle@3f5f9adaf7d9fecd50b5935e54106014257a94e6
+      - name: Build Wormholes API
+        if: needs.plan.outputs.wormholes_ref != ''
+        working-directory: WormholesPlugin
+        run: ./gradlew apiJar --no-daemon --max-workers=2 '-Dorg.gradle.jvmargs=-Xmx2g -Dfile.encoding=UTF-8'
+      - name: Locate Wormholes API
+        if: needs.plan.outputs.wormholes_ref != ''
+        shell: bash
+        run: |
+          api_jars=(WormholesPlugin/build/libs/*-api.jar)
+          test "${#api_jars[@]}" -eq 1
+          test -f "${api_jars[0]}"
+          echo "ORG_GRADLE_PROJECT_wormholesApiJar=$PWD/${api_jars[0]}" >> "$GITHUB_ENV"
+      - name: Build and verify release jar
+        working-directory: project
+        shell: bash
+        run: |
+          arguments=(prepareRelease --no-daemon --max-workers=2
+            '-Dorg.gradle.jvmargs=-Xmx2g -Dfile.encoding=UTF-8'
+            "-P$VERSION_PROPERTY=$RELEASE_VERSION")
+          if [[ "$RELEASE_LOADER" != bukkit ]]; then
+            arguments+=("-PreleaseLoader=$RELEASE_LOADER" "-PminecraftVersion=$MINECRAFT_VERSION"
+              -PmoddedBuildParallelism=1 -PmoddedTestForks=1)
+          fi
+          ./gradlew "${arguments[@]}"
+      - name: Upload verified jar
+        uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9
+        with:
+          name: release-${{ matrix.id }}
+          path: project/build/release/*.jar
+          if-no-files-found: error
+          retention-days: 7
+          compression-level: 0
+
+  publish:
+    needs: [plan, build]
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    concurrency:
+      group: release-publication
+      cancel-in-progress: false
+      queue: max
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
+        with:
+          persist-credentials: false
+      - name: Download complete release matrix
+        uses: actions/download-artifact@9000827ccba6bdab643e8b6fd33ac0654aef8333
+        with:
+          pattern: release-*
+          path: build/release-artifacts
+      - name: Publish verified release
+        env:
+          GH_TOKEN: ${{ github.token }}
+          RELEASE_ATTEMPT: ${{ needs.plan.outputs.attempt }}
+          RELEASE_VOLMLIB_REF: ${{ needs.plan.outputs.volmlib_ref }}
+          RELEASE_WORMHOLES_REF: ${{ needs.plan.outputs.wormholes_ref }}
+        run: python3 .github/release.py publish --artifacts build/release-artifacts

.gitignore

@@ -81,3 +81,5 @@ BUILDS/
 /docs/
 /.perf/
 /.codegraph/
+
+.superpowers/

adapters/bukkit/nms/v26_2_R1/src/test/java/art/arcane/iris/structure/nativegen/NativeStructureVolumeIndexTest.java

@@ -497,7 +497,13 @@ public class NativeStructureVolumeIndexTest {
     private static Map<?, ?> cache(NativeStructureVolumeIndex index, String name) throws Exception {
         Field field = NativeStructureVolumeIndex.class.getDeclaredField(name);
         field.setAccessible(true);
-        return (Map<?, ?>) field.get(index);
+        Object value = field.get(index);
+        if (value instanceof Map<?, ?> map) {
+            return map;
+        }
+        Field entries = value.getClass().getDeclaredField("entries");
+        entries.setAccessible(true);
+        return (Map<?, ?>) entries.get(value);
     }
 
     private static StructureStart swampHut(int chunkX, int chunkZ, int x, int z) {

adapters/bukkit/nms/v26_3_R1/src/offline/java/art/arcane/iris/probe/OfflineRegionGenerator.java

@@ -2,8 +2,9 @@ package art.arcane.iris.probe;
 
 import art.arcane.iris.configuration.IrisSettings;
 import art.arcane.iris.generation.concurrent.MultiBurst;
-import art.arcane.iris.generation.hydrology.HydrologyTileCache;
+import art.arcane.iris.generation.hydrology.engine.HydrologyPregeneration;
-import art.arcane.iris.generation.hydrology.runtime.IrisHydrologyRuntime;
+import art.arcane.iris.generation.hydrology.plan.WindowKey;
+import art.arcane.iris.world.pregen.PregenHydrology;
 import art.arcane.iris.world.pregen.PregenPerformanceProfile;
 
 import net.minecraft.core.registries.Registries;
@@ -31,11 +32,16 @@ import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 import java.nio.file.StandardOpenOption;
 import java.security.MessageDigest;
+import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.HexFormat;
 import java.util.List;
 import java.util.Locale;
+import java.util.Set;
 
 public final class OfflineRegionGenerator {
+    private static final int CHUNKS_PER_HYDROLOGY_REGION = WindowKey.SIZE >> 4;
+
     private OfflineRegionGenerator() {
     }
 
@@ -97,14 +103,13 @@ public final class OfflineRegionGenerator {
             PregenPerformanceProfile.apply(session.engine());
             System.out.println("generationProfile=pregen noiseCacheSize=" + IrisSettings.get().getPerformance().getNoiseCacheSize()
                     + " burstParallelism=" + MultiBurst.burst.parallelism() + " multicore=true");
-            IrisHydrologyRuntime hydrology = session.engine().getComplex().getHydrologyRuntime();
+            try (HydrologyPregeneration pregeneration = PregenHydrology.open(session.engine());
-            try (HydrologyTileCache.PregenerationScope hydrologyScope = hydrology == null ? null
-                    : hydrology.preparePregeneration(configuration.hydrologyArea());
                  HeadlessTerrainContext context = HeadlessTerrainContext.create(new HeadlessTerrainContext.Options(
                     session.engine(), runtime, staged.resolve("templates"), configuration.levelKey(),
                     configuration.noiseSettings(), spigot));
                  RegionGenerationWindow workers = new RegionGenerationWindow(configuration.parallelism(),
                          RegionGenerationWindow.Policy.STANDALONE)) {
+                PregenHydrology.prepareAll(pregeneration, configuration.hydrologyRegions());
                 HeadlessRegionTerrain.Session rolling = new HeadlessRegionTerrain.Session(workers);
                 Path regionDirectory = session.engine().getTarget().getWorld().worldFolder().toPath().resolve("region");
                 Files.createDirectory(regionDirectory);
@@ -239,14 +244,27 @@ public final class OfflineRegionGenerator {
             }
         }
 
-        HydrologyTileCache.PregenerationArea hydrologyArea() {
+        List<long[]> hydrologyRegions() {
             int halo = NativeRegionPlan.terrainHalo();
-            long minimumX = ((long) chunkX - halo) * 16L;
+            Set<Long> seen = new HashSet<>();
-            long minimumZ = ((long) chunkZ - halo) * 16L;
+            List<long[]> regions = new ArrayList<>();
-            long maximumX = ((long) chunkX + (long) width * regionsX + halo) * 16L - 1L;
+            for (int row = 0; row < regionsZ; row++) {
-            long maximumZ = ((long) chunkZ + (long) width * regionsZ + halo) * 16L - 1L;
+                for (int column = 0; column < regionsX; column++) {
-            return new HydrologyTileCache.PregenerationArea(Math.toIntExact((minimumX + maximumX) / 2L),
+                    int regionX = row % 2 == 0 ? column : regionsX - column - 1;
-                    Math.toIntExact((minimumZ + maximumZ) / 2L), minimumX, minimumZ, maximumX, maximumZ);
+                    int minimumX = Math.floorDiv(chunkX + regionX * width - halo, CHUNKS_PER_HYDROLOGY_REGION);
+                    int maximumX = Math.floorDiv(chunkX + (regionX + 1) * width - 1 + halo, CHUNKS_PER_HYDROLOGY_REGION);
+                    int minimumZ = Math.floorDiv(chunkZ + row * width - halo, CHUNKS_PER_HYDROLOGY_REGION);
+                    int maximumZ = Math.floorDiv(chunkZ + (row + 1) * width - 1 + halo, CHUNKS_PER_HYDROLOGY_REGION);
+                    for (int hydrologyZ = minimumZ; hydrologyZ <= maximumZ; hydrologyZ++) {
+                        for (int hydrologyX = minimumX; hydrologyX <= maximumX; hydrologyX++) {
+                            if (seen.add(((long) hydrologyX << 32) | (hydrologyZ & 0xFFFFFFFFL))) {
+                                regions.add(new long[]{hydrologyX, hydrologyZ});
+                            }
+                        }
+                    }
+                }
+            }
+            return regions;
         }
 
         static Configuration parse(String[] arguments) throws IOException {

adapters/bukkit/nms/v26_3_R1/src/test/java/art/arcane/iris/probe/HeadlessChunkGeneratorTest.java

@@ -137,7 +137,7 @@ public class HeadlessChunkGeneratorTest {
         }
         Files.writeString(pack.resolve("dimensions/main.json"), """
                 {"name":"Native columns","focus":"swamp","regions":["owned"],"fluidHeight":40,"logicalHeight":256,
-                 "landChance":1,"carvingEnabled":false,"hydrology":{"rivers":{"enabled":false}}}
+                 "landChance":1,"carvingEnabled":false}
                 """);
         Files.writeString(pack.resolve("regions/owned.json"), "{\"landBiomes\":[\"swamp\"]}");
         Files.writeString(pack.resolve("generators/flat.json"), "{\"composite\":[]}");

adapters/bukkit/nms/v26_3_R1/src/test/java/art/arcane/iris/probe/HeadlessRegionTerrainTest.java

@@ -1,7 +1,6 @@
 package art.arcane.iris.probe;
 
 import art.arcane.iris.structure.nativegen.NativeStructureVolumeIndex;
-import art.arcane.iris.generation.hydrology.HydrologyTileCache;
 import art.arcane.volmlib.nativelib.terrain.structure.NativeStructureVolume;
 import art.arcane.volmlib.util.collection.KList;
 import net.minecraft.nbt.CompoundTag;
@@ -68,11 +67,10 @@ public final class HeadlessRegionTerrainTest {
                 OfflineRegionGenerator.Configuration export = new OfflineRegionGenerator.Configuration(
                         workspace.pack(), "main", 69420L, -3, 2, 1, 2, 3, 4, configuration,
                         "probe", Level.OVERWORLD, NoiseGeneratorSettings.OVERWORLD, root.resolve("export"));
-                HydrologyTileCache.PregenerationArea bounds = export.hydrologyArea();
+                List<long[]> regions = export.hydrologyRegions();
-                assertEquals(-80L, bounds.minimumBlockX());
+                assertEquals(2, regions.size());
-                assertEquals(0L, bounds.minimumBlockZ());
+                assertArrayEquals(new long[]{-1L, 0L}, regions.get(0));
-                assertEquals(15L, bounds.maximumBlockX());
+                assertArrayEquals(new long[]{0L, 0L}, regions.get(1));
-                assertEquals(111L, bounds.maximumBlockZ());
                 assertEquals(1, result.targetChunks());
                 assertEquals(529, result.chunks().size());
                 long terrain = result.chunks().stream().filter(chunk -> chunk.getPersistedStatus() == ChunkStatus.TERRAIN).count();
@@ -189,7 +187,7 @@ public final class HeadlessRegionTerrainTest {
         }
         Files.writeString(pack.resolve("dimensions/main.json"), """
                 {"name":"Native region","focus":"swamp","regions":["owned"],"fluidHeight":40,"logicalHeight":256,
-                 "landChance":1,"carvingEnabled":false,"hydrology":{"rivers":{"enabled":false}}}
+                 "landChance":1,"carvingEnabled":false}
                 """);
         Files.writeString(pack.resolve("regions/owned.json"), "{\"landBiomes\":[\"swamp\"]}");
         Files.writeString(pack.resolve("generators/flat.json"), "{\"composite\":[]}");

adapters/bukkit/nms/v26_3_R1/src/test/java/art/arcane/iris/structure/nativegen/NativeStructureVolumeIndexTest.java

@@ -497,7 +497,13 @@ public class NativeStructureVolumeIndexTest {
     private static Map<?, ?> cache(NativeStructureVolumeIndex index, String name) throws Exception {
         Field field = NativeStructureVolumeIndex.class.getDeclaredField(name);
         field.setAccessible(true);
-        return (Map<?, ?>) field.get(index);
+        Object value = field.get(index);
+        if (value instanceof Map<?, ?> map) {
+            return map;
+        }
+        Field entries = value.getClass().getDeclaredField("entries");
+        entries.setAccessible(true);
+        return (Map<?, ?>) entries.get(value);
     }
 
     private static StructureStart swampHut(int chunkX, int chunkZ, int x, int z) {

adapters/bukkit/plugin/build.gradle

@@ -14,7 +14,7 @@ dependencies {
     // log4j-core Filter interface, so its constructor reference needs the type resolvable.
     compileOnly(libs.log4j.core)
     testImplementation('junit:junit:4.13.2')
-    testImplementation('org.mockito:mockito-core:5.23.0')
+    testImplementation(libs.mockito.core)
     testImplementation(libs.paper.api)
     testImplementation(libs.bstats)
     testImplementation(project(':core'))

adapters/bukkit/plugin/src/main/java/art/arcane/iris/Iris.java

@@ -60,6 +60,7 @@ import art.arcane.iris.integration.MultiverseCoreLink;
 import art.arcane.iris.platform.bukkit.nms.INMS;
 import art.arcane.volmlib.nativelib.terrain.ServerShutdownBoundary;
 import art.arcane.iris.studio.view.BukkitGuiHost;
+import art.arcane.iris.studio.view.GuiHost;
 import art.arcane.iris.studio.view.PregeneratorJob;
 import art.arcane.iris.platform.bukkit.BoardSVC;
 import art.arcane.iris.command.CommandSVC;
@@ -988,6 +989,8 @@ public class Iris extends VolmitPlugin implements Listener, ReloadAware {
     }
 
     public void onDisable() {
+        pendingWorldReplacements.awaitStagingForShutdown();
+        GuiHost.shutdown();
         preservePendingBlockDrops();
         papiLifecycleActive = false;
         if (updateNotifier != null) {
@@ -1004,7 +1007,8 @@ public class Iris extends VolmitPlugin implements Listener, ReloadAware {
         }
         IrisLanguage.shutdown();
         teardownPapi();
-        boolean deferToServerStop = FailedEnableLock.defersTeardownToServerStop(enableFailed, IrisToolbelt.isServerStopping());
+        boolean deferToServerStop = FailedEnableLock.defersTeardownToServerStop(enableFailed, IrisToolbelt.isServerStopping())
+                && INMS.get().deferPluginClassLoaderClose();
         boolean restartingAtStartupBoundary = startupBoundaryRestart.get();
         if (restartingAtStartupBoundary) {
             teardownRuntime("startup-boundary-restart", 30L);
@@ -1036,7 +1040,7 @@ public class Iris extends VolmitPlugin implements Listener, ReloadAware {
         preservePendingBlockDrops();
         papiLifecycleActive = false;
         teardownPapi();
-        if (IrisToolbelt.isServerStopping()) {
+        if (IrisToolbelt.isServerStopping() && INMS.get().deferPluginClassLoaderClose()) {
             quiesceRuntimeForServerShutdown("pre-unload:" + reason);
             startPostStopFinisher();
             Iris.debug("Pre-unload hook deferred generator teardown until Paper closes its chunk schedulers.");
@@ -1128,7 +1132,6 @@ public class Iris extends VolmitPlugin implements Listener, ReloadAware {
 
     private void quiesceRuntimeForServerShutdown(String reason) {
         serverStopTeardownDeferred.set(true);
-        INMS.get().deferPluginClassLoaderClose();
         JigsawStudioService jigsawStudioService = IrisServices.getOrNull(JigsawStudioService.class);
         if (jigsawStudioService != null) {
             try {

adapters/bukkit/plugin/src/main/java/art/arcane/iris/command/CommandFind.java

@@ -31,8 +31,7 @@ import art.arcane.iris.structure.placement.IrisStructureLocator;
 import art.arcane.iris.structure.nativegen.NativeStructureGenerationPolicy;
 import art.arcane.iris.structure.placement.StructureReachability;
 import art.arcane.iris.world.history.GenerationSemanticQueries;
-import art.arcane.iris.generation.hydrology.HydrologyFeatureQuery;
+import art.arcane.iris.generation.hydrology.query.HydrologyFeatureType;
-import art.arcane.iris.generation.hydrology.runtime.IrisHydrologyRuntime;
 import art.arcane.iris.generation.biome.IrisBiome;
 import art.arcane.iris.structure.nativegen.IrisNativeStructureDecision;
 import art.arcane.iris.generation.terrain.IrisRegion;
@@ -196,9 +195,9 @@ public class CommandFind implements DirectorExecutor {
         EngineBukkitOps.gotoPOI(e, type, player(), teleport);
     }
 
-    @Director(description = "Find an accepted hydrology feature", sync = true)
+    @Director(description = "Find a hydrology water feature", sync = true)
     public void river(
-            @Param(description = "Feature type: surface, waterfall, underground, grotto, mouth, or a deep-fluid id", customHandler = HydrologyTypeHandler.class)
+            @Param(description = "Feature type: stream, river, major_river, cascade, waterfall, mouth, pond, lake, dam, sea_inlet or cave_pool", customHandler = HydrologyTypeHandler.class)
             String type,
             @Param(description = "Should you be teleported", defaultValue = "true")
             boolean teleport
@@ -212,42 +211,32 @@ public class CommandFind implements DirectorExecutor {
             }
             return;
         }
-        IrisHydrologyRuntime runtime = activeEngine.getComplex().getHydrologyRuntime();
+        HydrologyFeatureType featureType;
-        HydrologyFeatureQuery query;
         try {
-            query = HydrologyFeatureQuery.parse(type);
+            featureType = HydrologyFeatureType.parse(type);
         } catch (IllegalArgumentException error) {
             commandSender.sendMessage(C.RED + error.getMessage());
             return;
         }
+        String label = featureType.key().replace('_', ' ');
         Location origin = target.getLocation();
         World originWorld = origin.getWorld();
-        int requestedDistance = runtime == null
+        int maximumDistance = GenerationSemanticQueries.RIVER_SEARCH_DISTANCE;
-                ? 8192
+        commandSender.sendMessage(C.GRAY + GenerationSemanticQueries.riverSearchMessage(featureType, maximumDistance));
-                : Math.min(8192, runtime.settings().routing().tileSize() * 15);
-        int maximumDistance = runtime == null
-                ? requestedDistance
-                : runtime.maximumFeatureSearchDistance(
-                        origin.getBlockX(), origin.getBlockZ(), requestedDistance);
-        commandSender.sendMessage(C.GRAY + "Searching accepted hydrology plans for " + type + "...");
         J.a(() -> {
             try {
                 GenerationSemanticQueries.RiverResult feature = GenerationSemanticQueries.nearestRiver(
                         activeEngine,
-                        query,
+                        featureType,
                         origin.getBlockX(),
                         origin.getBlockZ(),
-                        maximumDistance,
+                        maximumDistance
-                        (int visited) -> sendStructureMessage(target, commandSender,
-                                C.GRAY + "Searched " + visited + " hydrology tiles for " + type + "...")
                 ).orElse(null);
                 if (feature == null) {
                     sendStructureMessage(target, commandSender,
-                            C.YELLOW + "No accepted " + type + " hydrology feature found within "
+                            C.YELLOW + GenerationSemanticQueries.riverNotFoundMessage(featureType, maximumDistance));
-                                    + maximumDistance + " blocks.");
                     return;
                 }
-                String label = type + " hydrology feature";
                 if (!teleport) {
                     sendStructureMessage(target, commandSender,
                             C.GREEN + "Found " + label + " at " + feature.x() + ", " + feature.y() + ", " + feature.z() + ".");
@@ -259,8 +248,9 @@ public class CommandFind implements DirectorExecutor {
                         target, originWorld, commandSender, label, destination, true);
             } catch (Throwable error) {
                 sendStructureMessage(target, commandSender,
-                        C.RED + "Could not locate " + type + " hydrology: " + error.getClass().getSimpleName());
+                        C.RED + "Could not search for " + label + ": " + error.getClass().getSimpleName()
-                Iris.reportError("Could not locate accepted hydrology feature '" + type + "'.", error);
+                                + (error.getMessage() == null ? "" : " - " + error.getMessage()));
+                Iris.reportError("Could not locate hydrology feature '" + featureType.key() + "'.", error);
             }
         });
     }

adapters/bukkit/plugin/src/main/java/art/arcane/iris/command/CommandStudio.java

@@ -21,10 +21,9 @@ package art.arcane.iris.command;
 import art.arcane.iris.Iris;
 import art.arcane.iris.platform.bukkit.BukkitPlatform;
 import art.arcane.iris.configuration.IrisSettings;
+import art.arcane.iris.studio.map.MapWindow;
+import art.arcane.iris.studio.map.PaletteExplorerStart;
 import art.arcane.iris.studio.view.GuiHost;
-import art.arcane.iris.studio.view.ImageMapStudioGUI;
-import art.arcane.iris.studio.view.NoiseExplorerGUI;
-import art.arcane.iris.studio.view.VisionGUI;
 import art.arcane.iris.pack.loading.IrisData;
 import art.arcane.iris.studio.workspace.IrisProject;
 import art.arcane.iris.studio.workspace.IrisCodeWorkspace;
@@ -98,7 +97,9 @@ import java.util.Objects;
 import java.util.UUID;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
 
 import art.arcane.iris.localization.IrisLanguage;
 import art.arcane.iris.localization.BukkitCommandMessages;
@@ -255,15 +256,10 @@ public class CommandStudio implements DirectorExecutor {
             long seed
     ) {
         if (noGUI()) return;
-        sender().sendMessage(IrisLanguage.text(BukkitCommandMessagesExtended.COMMAND_STUDIO_OPENING_NOISE_EXPLORER));
+        VolmitSender commandSender = sender();
-
+        UUID openerId = commandSender.isPlayer() ? commandSender.player().getUniqueId() : null;
-        if (generator == null) {
+        MapWindow.NoiseSelection selection = new MapWindow.NoiseSelection(generator == null ? null : generator.getLoadKey(), generator, seed);
-            NoiseExplorerGUI.launch();
+        withPlayerContext(opener -> openNoiseAtPlayer(commandSender, openerId, opener, selection));
-            return;
-        }
-
-        String generatorKey = generator.getLoadKey();
-        NoiseExplorerGUI.launchGeneratorKey(generatorKey, generator, seed);
     }
 
     @Director(description = "Open the image-map studio (External GUI)", descriptionKey = "iris.director.commandstudio.director.open_image_map_studio_external_gui", aliases = {"imap"})
@@ -279,8 +275,7 @@ public class CommandStudio implements DirectorExecutor {
             return;
         }
 
-        Engine activeEngine = IrisToolbelt.access(world).getEngine();
+        requestMapStart(world, MapWindow::openImageMaps);
-        ImageMapStudioGUI.launch(activeEngine);
         sender().sendMessage(IrisLanguage.text(BukkitCommandMessagesExtended.COMMAND_STUDIO_OPENING_IMAGE_MAP_STUDIO));
     }
 
@@ -420,11 +415,61 @@ public class CommandStudio implements DirectorExecutor {
             return;
         }
 
-        UUID openerId = sender().isPlayer() ? player().getUniqueId() : null;
+        requestMapStart(world, MapWindow::openMap);
-        VisionGUI.launch(IrisToolbelt.access(world).getEngine(), openerId);
         sender().sendMessage(IrisLanguage.text(BukkitCommandMessagesExtended.COMMAND_STUDIO_OPENING_MAP));
     }
 
+    // The map opens where the player stands when they are in that world, otherwise at the world origin.
+    private PaletteExplorerStart mapStartIn(World world, Player opener, UUID openerId) {
+        Location center = opener != null && opener.getWorld().equals(world) ? opener.getLocation() : null;
+        return new PaletteExplorerStart(
+                IrisToolbelt.access(world).getEngine(),
+                world.getUID(),
+                openerId,
+                null,
+                center == null ? 0D : center.getX(),
+                center == null ? 0D : center.getZ()
+        );
+    }
+
+    private void requestMapStart(World world, Consumer<PaletteExplorerStart> launch) {
+        UUID openerId = sender().isPlayer() ? player().getUniqueId() : null;
+        withPlayerContext(opener -> launch.accept(mapStartIn(world, opener, openerId)));
+    }
+
+    private void openNoiseAtPlayer(VolmitSender commandSender, UUID openerId, Player opener, MapWindow.NoiseSelection selection) {
+        World world = opener == null ? null : opener.getWorld();
+        PlatformChunkGenerator worldGenerator = world == null ? null : IrisToolbelt.access(world);
+        Engine engine = worldGenerator == null ? GuiHost.get().findActiveEngine() : worldGenerator.getEngine();
+        if (engine == null) {
+            commandSender.sendMessage(IrisLanguage.text(BukkitCommandMessagesExtended.COMMAND_STUDIO_YOU_NEED_BE_SPECIFY_IRIS_GENERATED_WORLD));
+            return;
+        }
+        PaletteExplorerStart start = worldGenerator == null
+                ? new PaletteExplorerStart(engine, null, openerId, null, 0D, 0D)
+                : mapStartIn(world, opener, openerId);
+        MapWindow.openNoise(start, selection);
+        commandSender.sendMessage(IrisLanguage.text(BukkitCommandMessagesExtended.COMMAND_STUDIO_OPENING_NOISE_EXPLORER));
+    }
+
+    private void withPlayerContext(Consumer<Player> action) {
+        Player opener = sender().isPlayer() ? player() : null;
+        if (opener == null) {
+            action.accept(null);
+            return;
+        }
+        AtomicBoolean completed = new AtomicBoolean();
+        Consumer<Player> complete = player -> {
+            if (completed.compareAndSet(false, true)) {
+                action.accept(player);
+            }
+        };
+        Runnable retired = () -> complete.accept(null);
+        if (!J.runEntity(opener, () -> complete.accept(opener.isOnline() ? opener : null), 0, retired)) {
+            retired.run();
+        }
+    }
+
     @Director(description = "Profiles the performance of a dimension", descriptionKey = "iris.director.commandstudio.director.profiles_performance_dimension", origin = DirectorOrigin.PLAYER)
     public void profile(
             @Param(description = "The dimension to profile", descriptionKey = "iris.director.commandstudio.param.dimension_profile", contextual = true, contextualOverride = true, defaultValue = "default", customHandler = DimensionHandler.class)

adapters/bukkit/plugin/src/main/java/art/arcane/iris/platform/bukkit/api/IrisTerrainSVC.java

@@ -17,8 +17,7 @@ import art.arcane.iris.platform.bukkit.terrain.IrisSampleLimits;
 import art.arcane.iris.platform.bukkit.terrain.IrisSurfaceClassifier;
 import art.arcane.iris.platform.bukkit.terrain.IrisWorldInfoFactory;
 import art.arcane.iris.generation.runtime.Engine;
-import art.arcane.iris.generation.hydrology.HydrologyColumnLayer;
+import art.arcane.iris.generation.hydrology.raster.WaterRole;
-import art.arcane.iris.generation.hydrology.HydrologyColumnSample;
 import art.arcane.iris.generation.terrain.InferredType;
 import art.arcane.iris.generation.biome.IrisBiome;
 import art.arcane.iris.generation.terrain.IrisRegion;
@@ -108,15 +107,15 @@ public class IrisTerrainSVC implements IrisService, IrisTerrainService {
 
         try {
             int surface = engine.getHeight(blockX, blockZ);
-            HydrologyColumnSample hydrology = hydrologySample(engine, blockX, blockZ);
+            WaterRole role = engine.getComplex().getWaterRoleStream().get(blockX, blockZ);
             int fluid = (int) Math.round(
-                    engine.getComplex().getRiverWaterSurfaceStream().get(blockX, blockZ));
+                    engine.getComplex().getWaterHeadStream().get(blockX, blockZ));
             InferredType inferredType = null;
             if (IrisSurfaceClassifier.requiresSurfaceBiome(surface, fluid)) {
                 IrisBiome biome = engine.getSurfaceBiome(blockX, blockZ);
                 inferredType = biome == null ? null : biome.getInferredType();
             }
-            return IrisSurfaceClassifier.classify(surface, fluid, inferredType, hydrology);
+            return IrisSurfaceClassifier.classify(surface, fluid, inferredType, role);
         } catch (Throwable error) {
             reportQueryFault("surfaceKind", world, error);
             return IrisSurfaceKind.UNKNOWN;
@@ -266,12 +265,12 @@ public class IrisTerrainSVC implements IrisService, IrisTerrainService {
                     return false;
                 }
 
-                HydrologyColumnSample hydrology = wantRiver
+                WaterRole role = wantRiver
-                        ? hydrologySample(engine, blockX, blockZ)
+                        ? engine.getComplex().getWaterRoleStream().get(blockX, blockZ)
-                        : null;
+                        : WaterRole.NONE;
                 int surface = wantHeight || wantKind ? engine.getHeight(blockX, blockZ) : 0;
                 int fluid = wantRiver
-                        ? (int) Math.round(engine.getComplex().getRiverWaterSurfaceStream().get(blockX, blockZ))
+                        ? (int) Math.round(engine.getComplex().getWaterHeadStream().get(blockX, blockZ))
                         : engine.getDimension().getFluidHeight();
                 boolean needsBiome = wantBiome
                         || (wantKind && IrisSurfaceClassifier.requiresSurfaceBiome(surface, fluid));
@@ -281,29 +280,23 @@ public class IrisTerrainSVC implements IrisService, IrisTerrainService {
                                 surface,
                                 fluid,
                                 biome == null ? null : biome.getInferredType(),
-                                hydrology
+                                role
                         )
                         : IrisSurfaceKind.UNKNOWN;
                 String biomeKey = wantBiome && biome != null ? biome.getLoadKey() : null;
                 int natural = wantNaturalHeight
                         ? (int) Math.round(engine.getComplex().getNaturalHeightStream().get(blockX, blockZ)) + minHeight
                         : IrisColumnSample.UNAVAILABLE_HEIGHT;
-                HydrologyColumnLayer surfaceLayer = hydrology == null
-                        ? null
-                        : hydrology.primarySurfaceLayer().orElse(null);
-                boolean riverPresent = surfaceLayer != null;
                 IrisRiverState riverState = wantRiverState
-                        ? riverState(hydrology)
+                        ? riverState(role)
                         : IrisRiverState.NONE;
-                double riverDistance = wantRiverDistance && riverPresent
+                double riverDistance = wantRiverDistance
-                        ? engine.getComplex().getRiverDistanceStream().get(blockX, blockZ)
+                        ? riverDistance(role)
                         : IrisColumnSample.UNAVAILABLE_RIVER_DISTANCE;
-                int riverFlow = wantRiverFlow && riverPresent
+                int riverFlow = wantRiverFlow
-                        ? (int) Math.round(engine.getComplex().getRiverFlowStream().get(blockX, blockZ))
+                        ? riverFlow(role)
                         : IrisColumnSample.UNAVAILABLE_RIVER_FLOW;
-                int riverWaterSurfaceY = wantRiverWaterSurface
+                int riverWaterSurfaceY = wantRiverWaterSurface && role.wet()
-                        && surfaceLayer != null
-                        && surfaceLayer.connectedFluid()
                         ? fluid + minHeight
                         : IrisColumnSample.UNAVAILABLE_HEIGHT;
                 sink.accept(new IrisColumnSample(
@@ -327,21 +320,25 @@ public class IrisTerrainSVC implements IrisService, IrisTerrainService {
         }
     }
 
-    static IrisRiverState riverState(HydrologyColumnSample hydrology) {
+    static IrisRiverState riverState(WaterRole role) {
-        HydrologyColumnLayer layer = hydrology == null
+        return role.wet() ? IrisRiverState.WET : IrisRiverState.NONE;
-                ? null
-                : hydrology.primarySurfaceLayer().orElse(null);
-        if (layer == null || !layer.channel()) {
-            return IrisRiverState.NONE;
-        }
-        return layer.connectedFluid() ? IrisRiverState.WET : IrisRiverState.DRY;
     }
 
-    private static HydrologyColumnSample hydrologySample(Engine engine, int blockX, int blockZ) {
+    static double riverDistance(WaterRole role) {
-        if (engine.getComplex().getHydrologyRuntime() == null) {
+        return switch (role) {
-            return null;
+            case NONE -> IrisColumnSample.UNAVAILABLE_RIVER_DISTANCE;
+            case CHANNEL, POND, MOUTH, CASCADE, WATERFALL, INLET -> 0D;
+            case SHORE, POND_SHORE -> 1D;
+            case BANK, DAM -> 2D;
+        };
     }
-        return engine.getComplex().getHydrologyRuntime().sample(blockX, blockZ).orElse(null);
+
+    static int riverFlow(WaterRole role) {
+        return switch (role) {
+            case NONE, SHORE, POND_SHORE, BANK, DAM -> IrisColumnSample.UNAVAILABLE_RIVER_FLOW;
+            case CHANNEL, MOUTH, CASCADE, WATERFALL -> 1;
+            case POND, INLET -> 0;
+        };
     }
 
     private static Optional<String> key(IrisBiome biome) {

adapters/bukkit/plugin/src/main/java/art/arcane/iris/platform/bukkit/terrain/IrisSurfaceClassifier.java

@@ -1,8 +1,7 @@
 package art.arcane.iris.platform.bukkit.terrain;
 
 import art.arcane.iris.api.terrain.IrisSurfaceKind;
-import art.arcane.iris.generation.hydrology.HydrologyColumnLayer;
+import art.arcane.iris.generation.hydrology.raster.WaterRole;
-import art.arcane.iris.generation.hydrology.HydrologyColumnSample;
 import art.arcane.iris.generation.terrain.InferredType;
 
 public final class IrisSurfaceClassifier {
@@ -29,25 +28,16 @@ public final class IrisSurfaceClassifier {
             int engineSurfaceHeight,
             int engineFluidHeight,
             InferredType inferredType,
-            HydrologyColumnSample hydrology
+            WaterRole role
     ) {
         if (engineSurfaceHeight <= 0) {
             return IrisSurfaceKind.VOID;
         }
-        HydrologyColumnLayer layer = hydrology == null
+        return switch (role) {
-                ? null
+            case NONE -> classify(engineSurfaceHeight, engineFluidHeight, inferredType);
-                : hydrology.primarySurfaceLayer().orElse(null);
+            case SHORE, POND_SHORE -> IrisSurfaceKind.RIVER_SHORE;
-        if (layer != null) {
+            case BANK, DAM -> IrisSurfaceKind.LAND;
-            if (layer.shore()) {
+            case CHANNEL, POND, MOUTH, CASCADE, WATERFALL, INLET -> IrisSurfaceKind.RIVER;
-                return IrisSurfaceKind.RIVER_SHORE;
+        };
-            }
-            if (layer.channel()) {
-                return layer.connectedFluid() ? IrisSurfaceKind.RIVER : IrisSurfaceKind.DRY_CHANNEL;
-            }
-            if (layer.grading()) {
-                return IrisSurfaceKind.LAND;
-            }
-        }
-        return classify(engineSurfaceHeight, engineFluidHeight, inferredType);
     }
 }

adapters/bukkit/plugin/src/main/java/art/arcane/iris/studio/view/BukkitGuiHost.java

@@ -23,6 +23,8 @@ import art.arcane.iris.world.event.IrisEngineHotloadEvent;
 import art.arcane.iris.world.IrisToolbelt;
 import art.arcane.iris.generation.runtime.Engine;
 import art.arcane.iris.platform.generation.PlatformChunkGenerator;
+import art.arcane.iris.studio.StudioSVC;
+import art.arcane.iris.studio.workspace.IrisProject;
 import org.bukkit.Bukkit;
 import org.bukkit.World;
 import org.bukkit.event.EventHandler;
@@ -40,10 +42,47 @@ public final class BukkitGuiHost implements GuiHost.Provider {
         GuiHost.set(new BukkitGuiHost());
     }
 
+    /**
+     * The engine of the open studio project, which reads the pack folder being edited, or else the first
+     * Iris world. A normal Iris world runs on its own copy of the pack, made when the world was created.
+     */
     @Override
     public Engine findActiveEngine() {
+        Engine studioEngine = findStudioEngine();
+        if (studioEngine != null) {
+            return studioEngine;
+        }
         try {
             for (World world : new ArrayList<>(Bukkit.getWorlds())) {
+                Engine engine = engineOf(world);
+                if (engine != null) {
+                    return engine;
+                }
+            }
+        } catch (Throwable ignored) {
+        }
+        return null;
+    }
+
+    @Override
+    public Engine findEngine(UUID worldId) {
+        World world = worldId == null ? null : Bukkit.getWorld(worldId);
+        return world == null ? null : engineOf(world);
+    }
+
+    private static Engine findStudioEngine() {
+        try {
+            StudioSVC studio = Iris.service(StudioSVC.class);
+            IrisProject project = studio == null || !studio.isProjectOpen() ? null : studio.getActiveProject();
+            PlatformChunkGenerator provider = project == null ? null : project.getActiveProvider();
+            Engine engine = provider == null ? null : provider.getEngine();
+            return engine == null || engine.isClosed() ? null : engine;
+        } catch (Throwable ignored) {
+            return null;
+        }
+    }
+
+    private static Engine engineOf(World world) {
         try {
             PlatformChunkGenerator access = IrisToolbelt.access(world);
             if (access != null && access.getEngine() != null && !access.getEngine().isClosed()) {
@@ -51,9 +90,6 @@ public final class BukkitGuiHost implements GuiHost.Provider {
             }
         } catch (Throwable ignored) {
         }
-            }
-        } catch (Throwable ignored) {
-        }
         return null;
     }
 

adapters/bukkit/plugin/src/main/java/art/arcane/iris/studio/view/BukkitVisionOverlay.java

@@ -18,23 +18,19 @@
 
 package art.arcane.iris.studio.view;
 
-import art.arcane.volmlib.nativelib.view.WorldMarker;
-
-import art.arcane.iris.generation.runtime.IrisComplex;
 import art.arcane.iris.generation.runtime.Engine;
-import art.arcane.iris.studio.render.RenderType;
 import art.arcane.iris.world.IrisWorld;
 import art.arcane.iris.platform.bukkit.BukkitPlatform;
 import art.arcane.iris.platform.bukkit.BukkitWorldBinding;
 import art.arcane.iris.spi.IrisLogging;
 import art.arcane.iris.world.task.J;
 import art.arcane.volmlib.util.format.Form;
+import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.World;
 import org.bukkit.entity.LivingEntity;
 import org.bukkit.entity.Player;
 
-import java.io.File;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -56,7 +52,7 @@ public final class BukkitVisionOverlay implements GuiOverlay {
     private final AtomicBoolean playerRefreshQueued = new AtomicBoolean();
     private final AtomicLong teleportSequence = new AtomicLong();
     private final AtomicReference<VisionTeleportRequest> latestTeleport = new AtomicReference<>();
-    private volatile List<WorldMarker> playerMarkers = List.of();
+    private volatile List<GuiMarker> playerMarkers = List.of();
 
     public BukkitVisionOverlay(Engine engine, UUID openerId) {
         this.engine = engine;
@@ -68,7 +64,7 @@ public final class BukkitVisionOverlay implements GuiOverlay {
      * built by a server thread.
      */
     @Override
-    public List<WorldMarker> players() {
+    public List<GuiMarker> players() {
         queuePlayerRefresh();
         return playerMarkers;
     }
@@ -78,26 +74,48 @@ public final class BukkitVisionOverlay implements GuiOverlay {
             return;
         }
 
-        boolean scheduled = J.runGlobal(() -> {
+        boolean scheduled = J.runGlobal(this::refreshPlayers);
-            try {
-                List<WorldMarker> markers = new ArrayList<>();
-                for (Player player : BukkitWorldBinding.players(engine.getWorld())) {
-                    Location at = player.getLocation();
-                    markers.add(WorldMarker.player(player.getName(), at.getX(), at.getZ()));
-                }
-                playerMarkers = List.copyOf(markers);
-            } finally {
-                playerRefreshQueued.set(false);
-            }
-        });
 
         if (!scheduled) {
             playerRefreshQueued.set(false);
         }
     }
 
+    private void refreshPlayers() {
+        World world = BukkitWorldBinding.world(engine.getWorld());
+        List<Player> players = BukkitWorldBinding.players(engine.getWorld());
+        if (players.isEmpty() || world == null) {
+            playerMarkers = List.of();
+            playerRefreshQueued.set(false);
+            return;
+        }
+        List<GuiMarker> markers = Collections.synchronizedList(new ArrayList<>(players.size()));
+        AtomicInteger pending = new AtomicInteger(players.size());
+        for (Player player : players) {
+            AtomicBoolean completed = new AtomicBoolean();
+            Runnable complete = () -> {
+                if (completed.compareAndSet(false, true) && pending.decrementAndGet() == 0) {
+                    playerMarkers = List.copyOf(markers);
+                    playerRefreshQueued.set(false);
+                }
+            };
+            if (!J.runEntity(player, () -> {
+                try {
+                    if (player.isOnline() && player.getWorld() == world) {
+                        Location at = player.getLocation();
+                        markers.add(GuiMarker.player(player.getName(), at.getX(), at.getZ(), at.getYaw()));
+                    }
+                } finally {
+                    complete.run();
+                }
+            }, 0, complete)) {
+                complete.run();
+            }
+        }
+    }
+
     @Override
-    public void requestEntities(Consumer<List<WorldMarker>> sink) {
+    public void requestEntities(Consumer<List<GuiMarker>> sink) {
         J.runGlobal(() -> {
             IrisWorld target = engine.getWorld();
             World world = BukkitWorldBinding.world(target);
@@ -118,7 +136,7 @@ public final class BukkitVisionOverlay implements GuiOverlay {
                 return;
             }
 
-            List<WorldMarker> collected = Collections.synchronizedList(new ArrayList<>(living.size()));
+            List<GuiMarker> collected = Collections.synchronizedList(new ArrayList<>(living.size()));
             AtomicInteger pending = new AtomicInteger(living.size());
             Runnable complete = () -> {
                 if (pending.decrementAndGet() == 0) {
@@ -144,22 +162,22 @@ public final class BukkitVisionOverlay implements GuiOverlay {
         });
     }
 
-    private WorldMarker marker(LivingEntity entity, Location at) {
+    private GuiMarker marker(LivingEntity entity, Location at) {
         String label = Form.capitalizeWords(entity.getType().name().toLowerCase(Locale.ROOT).replaceAll("\\Q_\\E", " "));
         double maxHealth = 0;
         try {
             maxHealth = entity.getAttribute(MAX_HEALTH).getValue();
         } catch (Throwable ignored) {
         }
-        return WorldMarker.entity(label, at.getX(), at.getY(), at.getZ(), entity.getHealth(), maxHealth);
+        return GuiMarker.entity(label, at.getX(), at.getY(), at.getZ(), entity.getHealth(), maxHealth);
     }
 
     @Override
     public void teleport(double worldX, double worldZ) {
         VisionTeleportRequest request = new VisionTeleportRequest(
                 teleportSequence.incrementAndGet(),
-                VisionGUI.floorWorldCoordinate(worldX),
+                (int) StrictMath.floor(worldX),
-                VisionGUI.floorWorldCoordinate(worldZ));
+                (int) StrictMath.floor(worldZ));
         latestTeleport.set(request);
         startTeleport(request);
     }
@@ -212,6 +230,46 @@ public final class BukkitVisionOverlay implements GuiOverlay {
         }
     }
 
+    @Override
+    public void requestOpenerPosition(Consumer<OpenerPosition> sink) {
+        AtomicBoolean completed = new AtomicBoolean();
+        Consumer<OpenerPosition> complete = position -> {
+            if (completed.compareAndSet(false, true)) {
+                sink.accept(position);
+            }
+        };
+        if (openerId == null) {
+            complete.accept(OpenerPosition.OFFLINE);
+            return;
+        }
+        boolean scheduled = J.runGlobal(() -> {
+            Player player = Bukkit.getPlayer(openerId);
+            if (player == null) {
+                complete.accept(OpenerPosition.OFFLINE);
+                return;
+            }
+            Runnable retired = () -> complete.accept(OpenerPosition.OFFLINE);
+            if (!J.runEntity(player, () -> complete.accept(positionOf(player,
+                    BukkitWorldBinding.world(engine.getWorld()))), 0, retired)) {
+                retired.run();
+            }
+        });
+        if (!scheduled) {
+            complete.accept(OpenerPosition.OFFLINE);
+        }
+    }
+
+    private static OpenerPosition positionOf(Player player, World world) {
+        if (!player.isOnline()) {
+            return OpenerPosition.OFFLINE;
+        }
+        if (world == null || player.getWorld() != world) {
+            return OpenerPosition.IN_OTHER_WORLD;
+        }
+        Location at = player.getLocation();
+        return OpenerPosition.inWorld(at.getX(), at.getY(), at.getZ());
+    }
+
     private Player selectPlayer(List<Player> players) {
         if (openerId == null) {
             return players.isEmpty() ? null : players.get(0);
@@ -316,21 +374,6 @@ public final class BukkitVisionOverlay implements GuiOverlay {
                 + blockX + "," + blockZ + ".", failure);
     }
 
-    @Override
-    public String openInEditor(double worldX, double worldZ, RenderType type) {
-        IrisComplex complex = engine.getComplex();
-        File file = switch (type) {
-            case BIOME, LAYER_LOAD, DECORATOR_LOAD, OBJECT_LOAD, HEIGHT, RIVER ->
-                    complex.getTrueBiomeStream().get(worldX, worldZ).openInVSCode();
-            case BIOME_LAND -> complex.getLandBiomeStream().get(worldX, worldZ).openInVSCode();
-            case BIOME_SEA -> complex.getSeaBiomeStream().get(worldX, worldZ).openInVSCode();
-            case REGION -> complex.getRegionStream().get(worldX, worldZ).openInVSCode();
-            case CAVE_LAND -> complex.getCaveBiomeStream().get(worldX, worldZ).openInVSCode();
-            default -> null;
-        };
-        return file == null ? null : file.getName();
-    }
-
     private static final class VisionTeleportRequest {
         private final long sequence;
         private final int blockX;

adapters/bukkit/plugin/src/main/java/art/arcane/iris/world/PendingWorldReplacementManager.java

@@ -58,6 +58,7 @@ import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
@@ -78,6 +79,9 @@ public final class PendingWorldReplacementManager implements Listener {
     private volatile UUID overworldEntryAwaitingVerification;
     private volatile World overworldEntryWorld;
     private volatile boolean paperEntryListenerRegistered;
+    private final Object stagingMonitor = new Object();
+    private boolean stagingAdmissionOpen = true;
+    private StagingAdmission activeStaging;
 
     public PendingWorldReplacementManager(Iris plugin) {
         this.plugin = Objects.requireNonNull(plugin, "plugin");
@@ -135,7 +139,8 @@ public final class PendingWorldReplacementManager implements Listener {
                 LifecycleOperationCoordinator.Domain.WORLD_MUTATION,
                 LifecycleOperationCoordinator.OperationKind.WORLD_REPLACE,
                 requiredWorldKey.toString()
-        ); WorldReplacementProgress progress = WorldReplacementProgress.start(
+        ); StagingAdmission ignoredAdmission = admitStaging(requiredWorldKey);
+             WorldReplacementProgress progress = WorldReplacementProgress.start(
                 requiredSender, requiredWorldKey.toString())) {
             synchronized (this) {
                 IrisStartupValidation.requireWorldReplacementStagingReady();
@@ -271,6 +276,29 @@ public final class PendingWorldReplacementManager implements Listener {
         }
     }
 
+    public void awaitStagingForShutdown() {
+        StagingAdmission staging;
+        synchronized (stagingMonitor) {
+            stagingAdmissionOpen = false;
+            staging = activeStaging;
+        }
+        if (staging == null) {
+            return;
+        }
+        Iris.warn("Waiting for the replacement of " + staging.worldKey + " to finish staging before Iris shuts down.");
+        boolean interrupted = false;
+        while (staging.finished.getCount() > 0L) {
+            try {
+                staging.finished.await();
+            } catch (InterruptedException e) {
+                interrupted = true;
+            }
+        }
+        if (interrupted) {
+            Thread.currentThread().interrupt();
+        }
+    }
+
     public synchronized void processPendingStartupReplacements() {
         ArrayList<String> failures = new ArrayList<>();
         ArrayList<String> restartBoundaries = new ArrayList<>();
@@ -1048,6 +1076,17 @@ public final class PendingWorldReplacementManager implements Listener {
         return plugin.getDataFolder().toPath().toAbsolutePath().normalize();
     }
 
+    private StagingAdmission admitStaging(NamespacedKey worldKey) throws IOException {
+        synchronized (stagingMonitor) {
+            if (!stagingAdmissionOpen) {
+                throw new IOException("Iris is shutting down. Run the replacement again after the server starts.");
+            }
+            StagingAdmission staging = new StagingAdmission(worldKey);
+            activeStaging = staging;
+            return staging;
+        }
+    }
+
     private synchronized void loadOverworldEntryGuard() throws IOException {
         ExactWorldSlotPathPolicy.Target target = resolveTarget(OVERWORLD_KEY);
         Optional<WorldReplacementEntryGuard.Entry> loaded = WorldReplacementEntryGuard.load(target.worldDirectory());
@@ -1218,6 +1257,25 @@ public final class PendingWorldReplacementManager implements Listener {
     record SavedLocationInspection(boolean safe, Throwable failure) {
     }
 
+    private final class StagingAdmission implements AutoCloseable {
+        private final NamespacedKey worldKey;
+        private final CountDownLatch finished = new CountDownLatch(1);
+
+        private StagingAdmission(NamespacedKey worldKey) {
+            this.worldKey = worldKey;
+        }
+
+        @Override
+        public void close() {
+            synchronized (stagingMonitor) {
+                if (activeStaging == this) {
+                    activeStaging = null;
+                }
+            }
+            finished.countDown();
+        }
+    }
+
     private static final class RestartBoundaryRequired extends IOException {
         private RestartBoundaryRequired(String message) {
             super(message);

adapters/bukkit/plugin/src/test/java/art/arcane/iris/IrisShutdownMaintenanceTest.java

@@ -16,6 +16,7 @@ import art.arcane.iris.world.IrisWorld;
 import art.arcane.iris.world.WorldMaintenance;
 import art.arcane.iris.world.runtime.BukkitEnginePlatformHooks;
 import art.arcane.iris.world.task.J;
+import art.arcane.volmlib.integration.ReloadAware;
 import art.arcane.volmlib.nativelib.terrain.ServerShutdownBoundary;
 import org.bukkit.Bukkit;
 import org.bukkit.NamespacedKey;
@@ -37,9 +38,11 @@ import java.util.concurrent.atomic.AtomicReference;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.CALLS_REAL_METHODS;
+import static org.mockito.Mockito.doCallRealMethod;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.mockStatic;
 import static org.mockito.Mockito.never;
@@ -109,8 +112,6 @@ public class IrisShutdownMaintenanceTest {
                 }
                 verify(fixture.generator).quiesceForServerShutdown();
                 verify(fixture.generator, never()).closeAsync();
-                fixture.nms.verify(INMS::get);
-                verify(fixture.binding).deferPluginClassLoaderClose();
                 verify(fixture.binding, never()).releasePluginClassLoaderClose();
             }
             assertEquals(0, sessions.activeLeases());
@@ -151,6 +152,37 @@ public class IrisShutdownMaintenanceTest {
         }
     }
 
+    @Test
+    public void serverStopPreUnloadDefersTeardownWhileTheClassLoaderIsHeld() throws Exception {
+        try (Fixture fixture = new Fixture()) {
+            when(fixture.binding.deferPluginClassLoaderClose()).thenReturn(true);
+            setField(fixture.plugin, "postStopFinisherStarted", new AtomicBoolean(true));
+            try {
+                fixture.commitReloadDuringServerStop();
+                verify(fixture.generator).quiesceForServerShutdown();
+                verify(fixture.generator, never()).closeAsync();
+                assertTrue(fixture.serverStopTeardownDeferred());
+            } finally {
+                WorldMaintenance.endWorldMaintenance(fixture.identity, "pre-unload:HOT_UNLOAD");
+            }
+        }
+    }
+
+    @Test
+    public void serverStopPreUnloadDrainsInlineWhenTheClassLoaderCannotBeHeld() throws Exception {
+        try (Fixture fixture = new Fixture()) {
+            when(fixture.binding.deferPluginClassLoaderClose()).thenReturn(false);
+            try {
+                fixture.commitReloadDuringServerStop();
+                verify(fixture.generator).closeAsync();
+                verify(fixture.generator, never()).quiesceForServerShutdown();
+                assertFalse(fixture.serverStopTeardownDeferred());
+            } finally {
+                WorldMaintenance.endWorldMaintenance(fixture.identity, "pre-unload:HOT_UNLOAD", true);
+            }
+        }
+    }
+
     private static void setField(Iris plugin, String name, Object value) throws ReflectiveOperationException {
         Field field = Iris.class.getDeclaredField(name);
         field.setAccessible(true);
@@ -206,6 +238,19 @@ public class IrisShutdownMaintenanceTest {
             method.invoke(plugin, "manual_disable", 5L);
         }
 
+        private void commitReloadDuringServerStop() throws ReflectiveOperationException {
+            setField(plugin, "alreadyDrained", new AtomicBoolean());
+            toolbelt.when(IrisToolbelt::isServerStopping).thenReturn(true);
+            doCallRealMethod().when(plugin).commitReload(any());
+            plugin.commitReload(ReloadAware.PreUnloadReason.HOT_UNLOAD);
+        }
+
+        private boolean serverStopTeardownDeferred() throws ReflectiveOperationException {
+            Field field = Iris.class.getDeclaredField("serverStopTeardownDeferred");
+            field.setAccessible(true);
+            return ((AtomicBoolean) field.get(plugin)).get();
+        }
+
         private void startFinisher() throws ReflectiveOperationException {
             Method method = Iris.class.getDeclaredMethod("startPostStopFinisher");
             method.setAccessible(true);

adapters/bukkit/plugin/src/test/java/art/arcane/iris/command/CommandFindHydrologyTest.java

@@ -1,7 +1,7 @@
 package art.arcane.iris.command;
 
 import art.arcane.iris.Iris;
-import art.arcane.iris.generation.hydrology.HydrologyFeatureType;
+import art.arcane.iris.generation.hydrology.query.HydrologyFeatureType;
 import art.arcane.iris.generation.runtime.Engine;
 import art.arcane.iris.generation.runtime.IrisComplex;
 import art.arcane.iris.localization.IrisLanguage;
@@ -22,6 +22,7 @@ import java.util.OptionalLong;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.atomic.AtomicReference;
 
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
@@ -45,7 +46,7 @@ public class CommandFindHydrologyTest {
     @Test
     public void worldChangeDuringSearchDoesNotLoadOrTeleportIntoTheNewWorld() {
         try (Fixture fixture = new Fixture()) {
-            fixture.command.river("surface", true);
+            fixture.command.river("river", true);
             when(fixture.player.getWorld()).thenReturn(mock(World.class));
             fixture.search.get().run();
 
@@ -58,7 +59,7 @@ public class CommandFindHydrologyTest {
     @Test
     public void disconnectDuringSearchDoesNotLoadTheDestination() {
         try (Fixture fixture = new Fixture()) {
-            fixture.command.river("surface", true);
+            fixture.command.river("river", true);
             when(fixture.player.isOnline()).thenReturn(false);
             fixture.search.get().run();
 
@@ -69,7 +70,7 @@ public class CommandFindHydrologyTest {
     @Test
     public void worldChangeWhileLoadingTheDestinationCancelsTeleport() {
         try (Fixture fixture = new Fixture()) {
-            fixture.command.river("surface", true);
+            fixture.command.river("river", true);
             fixture.search.get().run();
             when(fixture.player.getWorld()).thenReturn(mock(World.class));
             fixture.chunk.complete(mock(Chunk.class));
@@ -82,7 +83,7 @@ public class CommandFindHydrologyTest {
     @Test
     public void successIsReportedOnlyAfterTeleportCompletes() {
         try (Fixture fixture = new Fixture()) {
-            fixture.command.river("surface", true);
+            fixture.command.river("river", true);
             fixture.search.get().run();
             fixture.chunk.complete(mock(Chunk.class));
 
@@ -95,7 +96,7 @@ public class CommandFindHydrologyTest {
     @Test
     public void rejectedTeleportReportsFailureWithoutSuccess() {
         try (Fixture fixture = new Fixture()) {
-            fixture.command.river("surface", true);
+            fixture.command.river("river", true);
             fixture.search.get().run();
             fixture.chunk.complete(mock(Chunk.class));
             fixture.teleport.complete(false);
@@ -109,7 +110,7 @@ public class CommandFindHydrologyTest {
     public void failedTeleportReportsTheFullCauseWithoutSuccess() {
         try (Fixture fixture = new Fixture()) {
             IllegalStateException failure = new IllegalStateException("destination unloaded");
-            fixture.command.river("surface", true);
+            fixture.command.river("river", true);
             fixture.search.get().run();
             fixture.chunk.complete(mock(Chunk.class));
             fixture.teleport.completeExceptionally(failure);
@@ -120,6 +121,72 @@ public class CommandFindHydrologyTest {
         }
     }
 
+    @Test
+    public void everyFeatureTypeIsSearchedOffTheCommandThreadAtTheRuntimeRadius() {
+        for (HydrologyFeatureType type : HydrologyFeatureType.values()) {
+            try (Fixture fixture = new Fixture()) {
+                fixture.command.river(type.key(), false);
+                fixture.queries.verify(() -> GenerationSemanticQueries.nearestRiver(any(), any(), anyInt(), anyInt(), anyInt()), never());
+                fixture.search.get().run();
+
+                fixture.queries.verify(() -> GenerationSemanticQueries.nearestRiver(fixture.engine, type, 0, 0,
+                        GenerationSemanticQueries.RIVER_SEARCH_DISTANCE));
+                verify(fixture.sender).sendMessage(contains("Found " + type.key().replace('_', ' ') + " at 32, 63, 32."));
+            }
+        }
+    }
+
+    @Test
+    public void unknownTypeIsRejectedWithTheAcceptedTypesBeforeAnySearch() {
+        try (Fixture fixture = new Fixture()) {
+            fixture.command.river("surface", true);
+
+            verify(fixture.sender).sendMessage(contains("Use one of: stream, river, major_river, cascade, waterfall, mouth, pond, lake, dam, sea_inlet, cave_pool."));
+            assertNull(fixture.search.get());
+        }
+    }
+
+    @Test
+    public void missingCavePoolIsReportedAsNotFoundInGeneratedChunks() {
+        try (Fixture fixture = new Fixture()) {
+            fixture.queries.when(() -> GenerationSemanticQueries.nearestRiver(eq(fixture.engine), any(), eq(0), eq(0), anyInt()))
+                    .thenReturn(Optional.empty());
+            fixture.command.river("cave_pool", true);
+            fixture.search.get().run();
+
+            verify(fixture.sender).sendMessage(contains("Searching generated chunks for the nearest cave pool within 7168 blocks"));
+            verify(fixture.sender).sendMessage(contains("No cave pool found in generated chunks within 7168 blocks."));
+        }
+    }
+
+    @Test
+    public void missingFeatureIsReportedAsNotFound() {
+        try (Fixture fixture = new Fixture()) {
+            fixture.queries.when(() -> GenerationSemanticQueries.nearestRiver(eq(fixture.engine), any(), eq(0), eq(0), anyInt()))
+                    .thenReturn(Optional.empty());
+            fixture.command.river("sea_inlet", true);
+            fixture.search.get().run();
+
+            verify(fixture.sender).sendMessage(contains("No sea inlet found within 7168 blocks."));
+            fixture.platform.verify(() -> BukkitPlatform.chunkAtAsync(any(World.class), anyInt(), anyInt(), eq(true)), never());
+        }
+    }
+
+    @Test
+    public void plannerFailureIsReportedAsAnErrorNotAsNotFound() {
+        try (Fixture fixture = new Fixture()) {
+            IllegalStateException failure = new IllegalStateException("window planner exploded");
+            fixture.queries.when(() -> GenerationSemanticQueries.nearestRiver(eq(fixture.engine), any(), eq(0), eq(0), anyInt()))
+                    .thenThrow(failure);
+            fixture.command.river("lake", true);
+            fixture.search.get().run();
+
+            verify(fixture.sender).sendMessage(contains("Could not search for lake: IllegalStateException - window planner exploded"));
+            verify(fixture.sender, never()).sendMessage(contains("No lake found"));
+            fixture.logging.verify(() -> Iris.reportError(any(String.class), eq(failure)));
+        }
+    }
+
     private static final class Fixture implements AutoCloseable {
         private final CommandFind command = mock(CommandFind.class, CALLS_REAL_METHODS);
         private final Engine engine = mock(Engine.class);
@@ -132,7 +199,7 @@ public class CommandFindHydrologyTest {
         private final CompletableFuture<Boolean> teleport = new CompletableFuture<>();
         private final MockedStatic<J> scheduler = mockStatic(J.class);
         private final MockedStatic<BukkitPlatform> platform = mockStatic(BukkitPlatform.class);
-        private final MockedStatic<GenerationSemanticQueries> queries = mockStatic(GenerationSemanticQueries.class);
+        private final MockedStatic<GenerationSemanticQueries> queries = mockStatic(GenerationSemanticQueries.class, CALLS_REAL_METHODS);
         private final MockedStatic<IrisLanguage> language = mockStatic(IrisLanguage.class, invocation -> "teleported");
         private final MockedStatic<Iris> logging = mockStatic(Iris.class);
 
@@ -160,10 +227,10 @@ public class CommandFindHydrologyTest {
             });
             platform.when(() -> BukkitPlatform.chunkAtAsync(any(World.class), anyInt(), anyInt(), eq(true))).thenReturn(chunk);
             platform.when(() -> BukkitPlatform.teleportAsync(eq(player), any(Location.class))).thenReturn(teleport);
-            queries.when(() -> GenerationSemanticQueries.nearestRiver(eq(engine), any(), eq(0), eq(0), anyInt(), any()))
+            queries.when(() -> GenerationSemanticQueries.nearestRiver(eq(engine), any(), eq(0), eq(0), anyInt()))
                     .thenReturn(Optional.of(new GenerationSemanticQueries.RiverResult(
                             GenerationSemanticQueries.RiverSource.ACTIVE_PREDICTION,
-                            HydrologyFeatureType.RIFFLE, Optional.empty(), 1L, 32, 63, 32, OptionalLong.empty())));
+                            HydrologyFeatureType.RIVER, 1L, 32, 63, 32, OptionalLong.empty())));
         }
 
         @Override

adapters/bukkit/plugin/src/test/java/art/arcane/iris/command/CommandObjectFluidHeightTest.java

@@ -20,26 +20,26 @@ import static org.mockito.Mockito.when;
 
 public class CommandObjectFluidHeightTest {
     @Test
-    public void absoluteObjectPlacementShiftsTheColumnRiverHeadFromNegativeMinY() {
+    public void absoluteObjectPlacementShiftsTheColumnWaterHeadFromNegativeMinY() {
         World world = mock(World.class);
         Engine engine = mock(Engine.class);
         IrisDimension dimension = mock(IrisDimension.class);
         IrisComplex complex = mock(IrisComplex.class);
         @SuppressWarnings("unchecked")
-        ProceduralStream<Double> riverHead = mock(ProceduralStream.class);
+        ProceduralStream<Double> waterHead = mock(ProceduralStream.class);
         Map<Block, BlockData> future = new HashMap<>();
 
         when(engine.getMinHeight()).thenReturn(-64);
         when(engine.getDimension()).thenReturn(dimension);
         when(engine.getComplex()).thenReturn(complex);
         when(dimension.getFluidHeight()).thenReturn(127);
-        when(complex.getRiverWaterSurfaceStream()).thenReturn(riverHead);
+        when(complex.getWaterHeadStream()).thenReturn(waterHead);
-        when(riverHead.get(12, -7)).thenReturn(131D);
+        when(waterHead.get(12, -7)).thenReturn(131D);
 
         IObjectPlacer placer = CommandObject.createPlacer(world, future, engine);
 
         assertEquals(63, placer.getFluidHeight());
         assertEquals(67, placer.getFluidHeight(12, -7));
-        verify(riverHead).get(12, -7);
+        verify(waterHead).get(12, -7);
     }
 }

adapters/bukkit/plugin/src/test/java/art/arcane/iris/command/StudioMapPositionTest.java

@@ -0,0 +1,99 @@
+package art.arcane.iris.command;
+
+import art.arcane.iris.configuration.IrisSettings;
+import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.iris.platform.bukkit.plugin.VolmitSender;
+import art.arcane.iris.platform.generation.PlatformChunkGenerator;
+import art.arcane.iris.studio.map.MapWindow;
+import art.arcane.iris.studio.map.PaletteExplorerStart;
+import art.arcane.iris.studio.view.GuiHost;
+import art.arcane.iris.world.IrisToolbelt;
+import art.arcane.iris.world.task.J;
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.junit.Test;
+import org.mockito.MockedStatic;
+
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.ArgumentMatchers.same;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.when;
+
+public class StudioMapPositionTest {
+    @Test
+    public void mapCapturesItsStartingPositionOnThePlayerScheduler() {
+        IrisSettings previous = IrisSettings.settings;
+        IrisSettings.settings = new IrisSettings();
+        IrisSettings.settings.getGui().setUseServerLaunchedGuis(true);
+        World world = mock(World.class);
+        Player player = mock(Player.class);
+        VolmitSender sender = mock(VolmitSender.class);
+        PlatformChunkGenerator generator = mock(PlatformChunkGenerator.class);
+        Engine engine = mock(Engine.class);
+        UUID playerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        AtomicBoolean owned = new AtomicBoolean();
+        AtomicReference<Runnable> task = new AtomicReference<>();
+        AtomicReference<PaletteExplorerStart> start = new AtomicReference<>();
+        when(world.getUID()).thenReturn(worldId);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.isOnline()).thenReturn(true);
+        when(player.getWorld()).thenAnswer(invocation -> {
+            assertTrue("world read must use the player scheduler", owned.get());
+            return world;
+        });
+        when(player.getLocation()).thenAnswer(invocation -> {
+            assertTrue("location read must use the player scheduler", owned.get());
+            return new Location(world, 33.25D, 91D, -72.5D);
+        });
+        when(sender.isPlayer()).thenReturn(true);
+        when(sender.player()).thenReturn(player);
+        when(generator.getEngine()).thenReturn(engine);
+        CommandStudio command = new CommandStudio() {
+            @Override
+            public VolmitSender sender() {
+                return sender;
+            }
+        };
+        try (MockedStatic<GuiHost> host = mockStatic(GuiHost.class);
+             MockedStatic<IrisToolbelt> toolbelt = mockStatic(IrisToolbelt.class);
+             MockedStatic<J> scheduling = mockStatic(J.class);
+             MockedStatic<MapWindow> windows = mockStatic(MapWindow.class)) {
+            host.when(GuiHost::isAvailable).thenReturn(true);
+            toolbelt.when(() -> IrisToolbelt.isIrisWorld(world)).thenReturn(true);
+            toolbelt.when(() -> IrisToolbelt.access(world)).thenReturn(generator);
+            scheduling.when(() -> J.runEntity(same(player), any(Runnable.class), eq(0), any(Runnable.class)))
+                    .thenAnswer(invocation -> {
+                        task.set(invocation.getArgument(1));
+                        return true;
+                    });
+            windows.when(() -> MapWindow.openMap(any(PaletteExplorerStart.class))).thenAnswer(invocation -> {
+                start.set(invocation.getArgument(0));
+                return null;
+            });
+
+            command.map(world);
+            assertNull(start.get());
+            owned.set(true);
+            task.get().run();
+
+            assertEquals(engine, start.get().engine());
+            assertEquals(playerId, start.get().playerId());
+            assertEquals(worldId, start.get().worldId());
+            assertEquals(33.25D, start.get().centerX(), 0D);
+            assertEquals(-72.5D, start.get().centerZ(), 0D);
+        } finally {
+            IrisSettings.settings = previous;
+        }
+    }
+}

adapters/bukkit/plugin/src/test/java/art/arcane/iris/platform/bukkit/api/IrisTerrainSVCTest.java

@@ -9,16 +9,18 @@ import art.arcane.iris.configuration.IrisSettings;
 import art.arcane.iris.generation.biome.IrisBiome;
 import art.arcane.iris.generation.runtime.BiomeEnvironment;
 import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.iris.generation.runtime.IrisComplex;
+import art.arcane.iris.generation.terrain.InferredType;
 import art.arcane.iris.generation.terrain.IrisDimension;
 import art.arcane.iris.generation.terrain.IrisRegion;
 import art.arcane.iris.pack.loading.IrisData;
 import art.arcane.iris.platform.generation.PlatformChunkGenerator;
 import art.arcane.iris.spi.IrisLogging;
 import art.arcane.iris.world.history.SavedBiomeUnavailableException;
-import art.arcane.iris.generation.hydrology.HydrologyColumnLayer;
+import art.arcane.volmlib.util.stream.ProceduralStream;
-import art.arcane.iris.generation.hydrology.HydrologyColumnSample;
+import art.arcane.volmlib.util.stream.interpolation.Interpolated;
-import art.arcane.iris.generation.hydrology.HydrologyFeatureRef;
+import art.arcane.iris.api.terrain.IrisColumnSample;
-import art.arcane.iris.generation.hydrology.HydrologyFeatureType;
+import art.arcane.iris.generation.hydrology.raster.WaterRole;
 import art.arcane.iris.platform.bukkit.plugin.IrisService;
 import org.bukkit.World;
 import org.bukkit.generator.ChunkGenerator;
@@ -26,6 +28,7 @@ import org.junit.Test;
 import org.mockito.MockedStatic;
 
 import java.lang.reflect.Field;
+import java.util.ArrayList;
 import java.util.EnumSet;
 import java.util.List;
 import java.util.Optional;
@@ -112,10 +115,32 @@ public class IrisTerrainSVCTest {
     }
 
     @Test
-    public void acceptedHydrologyMapsToThePublicDiagnosticStates() {
+    public void waterRolesMapToThePublicRiverFields() {
-        assertEquals(IrisRiverState.NONE, IrisTerrainSVC.riverState(null));
+        for (WaterRole role : WaterRole.values()) {
-        assertEquals(IrisRiverState.WET, IrisTerrainSVC.riverState(river(true)));
+            assertEquals(role.name(), role.wet() ? IrisRiverState.WET : IrisRiverState.NONE, IrisTerrainSVC.riverState(role));
-        assertEquals(IrisRiverState.DRY, IrisTerrainSVC.riverState(river(false)));
+            double distance = switch (role) {
+                case NONE -> IrisColumnSample.UNAVAILABLE_RIVER_DISTANCE;
+                case CHANNEL, POND, MOUTH, CASCADE, WATERFALL, INLET -> 0D;
+                case SHORE, POND_SHORE -> 1D;
+                case BANK, DAM -> 2D;
+            };
+            assertEquals(role.name(), distance, IrisTerrainSVC.riverDistance(role), 0D);
+            int flow = switch (role) {
+                case NONE, SHORE, POND_SHORE, BANK, DAM -> IrisColumnSample.UNAVAILABLE_RIVER_FLOW;
+                case CHANNEL, MOUTH, CASCADE, WATERFALL -> 1;
+                case POND, INLET -> 0;
+            };
+            assertEquals(role.name(), flow, IrisTerrainSVC.riverFlow(role));
+        }
+    }
+
+    @Test
+    public void columnSamplesReportTheWaterRoleOfEachColumn() throws Exception {
+        assertEquals(List.of("RIVER", "WET", "0.0", "1", "6"), sampled(WaterRole.CHANNEL, 70));
+        assertEquals(List.of("RIVER", "WET", "0.0", "0", "6"), sampled(WaterRole.POND, 70));
+        assertEquals(List.of("RIVER_SHORE", "NONE", "1.0", "-1", "unavailable"), sampled(WaterRole.SHORE, 50));
+        assertEquals(List.of("LAND", "NONE", "2.0", "-1", "unavailable"), sampled(WaterRole.BANK, 50));
+        assertEquals(List.of("LAND", "NONE", "NaN", "-1", "unavailable"), sampled(WaterRole.NONE, 50));
     }
 
     @Test
@@ -219,6 +244,33 @@ public class IrisTerrainSVCTest {
         }
     }
 
+    private static List<String> sampled(WaterRole role, int head) throws Exception {
+        Engine engine = mock(Engine.class);
+        IrisComplex complex = mock(IrisComplex.class);
+        IrisBiome biome = mock(IrisBiome.class);
+        when(biome.getInferredType()).thenReturn(InferredType.LAND);
+        when(engine.getComplex()).thenReturn(complex);
+        when(engine.getDimension()).thenReturn(mock(IrisDimension.class));
+        when(engine.getHeight(0, 0)).thenReturn(60);
+        when(engine.getMinHeight()).thenReturn(-64);
+        when(engine.getSurfaceBiome(0, 0)).thenReturn(biome);
+        when(complex.getWaterRoleStream()).thenReturn(ProceduralStream.of((x, z) -> role, Interpolated.of(value -> 0D, value -> role)));
+        when(complex.getWaterHeadStream()).thenReturn(ProceduralStream.ofDouble((x, z) -> (double) head));
+        IrisColumnQuery query = IrisColumnQuery.rect(0, 0, 0, 0, 1, EnumSet.of(IrisColumnField.SURFACE_KIND,
+                IrisColumnField.RIVER_STATE, IrisColumnField.RIVER_DISTANCE, IrisColumnField.RIVER_FLOW,
+                IrisColumnField.RIVER_WATER_SURFACE_Y));
+        List<IrisColumnSample> samples = new ArrayList<>();
+        try (MockedStatic<IrisSettings> settings = mockStatic(IrisSettings.class)) {
+            settings.when(IrisSettings::get).thenReturn(new IrisSettings());
+            assertTrue(enabledService().sampleColumns(world(engine), query, samples::add));
+        }
+        assertEquals(1, samples.size());
+        IrisColumnSample sample = samples.get(0);
+        return List.of(sample.surfaceKind().name(), sample.riverState().name(), String.valueOf(sample.riverDistance()),
+                String.valueOf(sample.riverFlow()),
+                sample.riverWaterSurfaceY() == IrisColumnSample.UNAVAILABLE_HEIGHT ? "unavailable" : String.valueOf(sample.riverWaterSurfaceY()));
+    }
+
     private static World world(Engine engine) {
         World world = mock(World.class);
         ChunkGenerator generator = mock(ChunkGenerator.class, withSettings().extraInterfaces(PlatformChunkGenerator.class));
@@ -235,41 +287,4 @@ public class IrisTerrainSVCTest {
         ((AtomicBoolean) enabled.get(service)).set(true);
         return service;
     }
-
-    private static HydrologyColumnSample river(boolean connectedFluid) {
-        HydrologyFeatureRef feature = new HydrologyFeatureRef(
-                1L,
-                HydrologyFeatureType.SURFACE_POOL,
-                2L,
-                3L,
-                0,
-                63,
-                0,
-                1,
-                0,
-                false
-        );
-        HydrologyColumnLayer layer = new HydrologyColumnLayer(
-                feature,
-                60,
-                63,
-                63,
-                true,
-                false,
-                false,
-                connectedFluid,
-                false,
-                false,
-                true,
-                connectedFluid,
-                false,
-                "water",
-                "river",
-                "mouth",
-                "shore",
-                "dry",
-                "cave"
-        );
-        return new HydrologyColumnSample(0, 0, 70, 63, false, "parent", List.of(layer));
-    }
 }

adapters/bukkit/plugin/src/test/java/art/arcane/iris/platform/bukkit/terrain/IrisSurfaceClassifierTest.java

@@ -1,15 +1,10 @@
 package art.arcane.iris.platform.bukkit.terrain;
 
 import art.arcane.iris.api.terrain.IrisSurfaceKind;
-import art.arcane.iris.generation.hydrology.HydrologyColumnLayer;
+import art.arcane.iris.generation.hydrology.raster.WaterRole;
-import art.arcane.iris.generation.hydrology.HydrologyColumnSample;
-import art.arcane.iris.generation.hydrology.HydrologyFeatureRef;
-import art.arcane.iris.generation.hydrology.HydrologyFeatureType;
 import art.arcane.iris.generation.terrain.InferredType;
 import org.junit.Test;
 
-import java.util.List;
-
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
@@ -69,98 +64,28 @@ public class IrisSurfaceClassifierTest {
     }
 
     @Test
-    public void acceptedSurfaceRolesOverrideGenericOceanAndLandKinds() {
+    public void waterRolesOverrideGenericOceanAndLandKinds() {
-        assertEquals(IrisSurfaceKind.RIVER, IrisSurfaceClassifier.classify(
+        for (WaterRole role : WaterRole.values()) {
-                60,
+            IrisSurfaceKind expected = switch (role) {
-                63,
+                case NONE -> IrisSurfaceKind.OCEAN;
-                InferredType.SEA,
+                case SHORE, POND_SHORE -> IrisSurfaceKind.RIVER_SHORE;
-                hydrology(HydrologyFeatureType.SURFACE_POOL, true, false, true)
+                case BANK, DAM -> IrisSurfaceKind.LAND;
-        ));
+                case CHANNEL, POND, MOUTH, CASCADE, WATERFALL, INLET -> IrisSurfaceKind.RIVER;
-        assertEquals(IrisSurfaceKind.RIVER, IrisSurfaceClassifier.classify(
+            };
-                60,
+            assertEquals(role.name(), expected, IrisSurfaceClassifier.classify(60, 63, InferredType.SEA, role));
-                63,
+        }
-                InferredType.SEA,
-                hydrology(HydrologyFeatureType.MOUTH, true, false, true)
-        ));
-        assertEquals(IrisSurfaceKind.RIVER_SHORE, IrisSurfaceClassifier.classify(
-                64,
-                63,
-                InferredType.SHORE,
-                hydrology(HydrologyFeatureType.SURFACE_POOL, false, true, false)
-        ));
-        assertEquals(IrisSurfaceKind.DRY_CHANNEL, IrisSurfaceClassifier.classify(
-                60,
-                60,
-                InferredType.LAND,
-                hydrology(HydrologyFeatureType.SURFACE_POOL, true, false, false)
-        ));
-        assertEquals(IrisSurfaceKind.LAND, IrisSurfaceClassifier.classify(
-                60,
-                60,
-                InferredType.LAND,
-                hydrology(HydrologyFeatureType.SURFACE_POOL, false, false, false)
-        ));
     }
 
     @Test
-    public void voidClassificationWinsOverAcceptedRiverGeometry() {
+    public void voidClassificationWinsOverWaterRoles() {
-        assertEquals(IrisSurfaceKind.VOID, IrisSurfaceClassifier.classify(
+        for (WaterRole role : WaterRole.values()) {
-                0,
+            assertEquals(role.name(), IrisSurfaceKind.VOID, IrisSurfaceClassifier.classify(0, 63, InferredType.LAND, role));
-                63,
+        }
-                InferredType.LAND,
-                hydrology(HydrologyFeatureType.SURFACE_POOL, true, false, true)
-        ));
     }
 
     @Test
-    public void absentRejectedCandidatesDoNotCreatePublicRiverKinds() {
+    public void columnsWithoutAWaterRoleKeepTheGenericKinds() {
-        assertEquals(IrisSurfaceKind.LAND, IrisSurfaceClassifier.classify(
+        assertEquals(IrisSurfaceKind.LAND, IrisSurfaceClassifier.classify(64, 63, InferredType.LAND, WaterRole.NONE));
-                64,
+        assertEquals(IrisSurfaceKind.SHORE, IrisSurfaceClassifier.classify(64, 63, InferredType.SHORE, WaterRole.NONE));
-                63,
-                InferredType.LAND,
-                null
-        ));
-    }
-
-    private static HydrologyColumnSample hydrology(
-            HydrologyFeatureType type,
-            boolean channel,
-            boolean shore,
-            boolean connectedFluid
-    ) {
-        HydrologyFeatureRef feature = new HydrologyFeatureRef(
-                1L,
-                type,
-                2L,
-                3L,
-                0,
-                63,
-                0,
-                1,
-                0,
-                false
-        );
-        HydrologyColumnLayer layer = new HydrologyColumnLayer(
-                feature,
-                60,
-                63,
-                63,
-                channel,
-                shore,
-                !channel && !shore,
-                connectedFluid,
-                false,
-                false,
-                true,
-                connectedFluid && channel,
-                false,
-                "water",
-                "river",
-                "mouth",
-                "shore",
-                "dry",
-                "cave"
-        );
-        return new HydrologyColumnSample(0, 0, 70, 63, false, "parent", List.of(layer));
     }
 }

adapters/bukkit/plugin/src/test/java/art/arcane/iris/studio/view/BukkitOpenerPositionTest.java

@@ -0,0 +1,165 @@
+package art.arcane.iris.studio.view;
+
+import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.iris.platform.bukkit.BukkitWorldBinding;
+import art.arcane.iris.world.IrisWorld;
+import art.arcane.iris.world.task.J;
+import org.bukkit.Bukkit;
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.junit.Test;
+import org.mockito.MockedStatic;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.ArgumentMatchers.same;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.when;
+
+public class BukkitOpenerPositionTest {
+    @Test
+    public void playerMarkersAreCapturedOnTheirEntitySchedulers() {
+        try (Harness harness = new Harness()) {
+            harness.binding.when(() -> BukkitWorldBinding.players(harness.target)).thenReturn(List.of(harness.player));
+            when(harness.player.getName()).thenReturn("Explorer");
+            assertTrue(harness.overlay.players().isEmpty());
+
+            harness.runEntity();
+
+            List<GuiMarker> markers = harness.overlay.players();
+            assertEquals(1, markers.size());
+            assertEquals("Explorer", markers.getFirst().label());
+            assertEquals(18.5D, markers.getFirst().worldX(), 0D);
+            assertEquals(-4.25D, markers.getFirst().worldZ(), 0D);
+        }
+    }
+
+    @Test
+    public void positionIsCapturedOnlyOnTheOwningEntityTask() {
+        try (Harness harness = new Harness()) {
+            harness.overlay.requestOpenerPosition(harness.results::add);
+            assertTrue(harness.results.isEmpty());
+
+            harness.runEntity();
+
+            assertEquals(List.of(OpenerPosition.inWorld(18.5D, 72D, -4.25D)), harness.results);
+        }
+    }
+
+    @Test
+    public void retiredEntityCompletesTheRequestOnce() {
+        try (Harness harness = new Harness()) {
+            harness.overlay.requestOpenerPosition(harness.results::add);
+            assertTrue("retirement callback must be registered", harness.retired != null);
+
+            harness.retired.run();
+            harness.retired.run();
+
+            assertEquals(List.of(OpenerPosition.OFFLINE), harness.results);
+        }
+    }
+
+    @Test
+    public void disconnectBeforeCaptureCompletesAsOfflineAndReconnectCanRefresh() {
+        try (Harness harness = new Harness()) {
+            harness.overlay.requestOpenerPosition(harness.results::add);
+            when(harness.player.isOnline()).thenReturn(false);
+            harness.runEntity();
+            assertEquals(List.of(OpenerPosition.OFFLINE), harness.results);
+
+            when(harness.player.isOnline()).thenReturn(true);
+            harness.overlay.requestOpenerPosition(harness.results::add);
+            harness.runEntity();
+            assertEquals(List.of(OpenerPosition.OFFLINE, OpenerPosition.inWorld(18.5D, 72D, -4.25D)), harness.results);
+        }
+    }
+
+    @Test
+    public void rejectedEntityTaskCompletesOnceEvenIfRetirementAlreadyRan() {
+        try (Harness harness = new Harness()) {
+            harness.reject = true;
+            harness.overlay.requestOpenerPosition(harness.results::add);
+            assertEquals(List.of(OpenerPosition.OFFLINE), harness.results);
+        }
+    }
+
+    @Test
+    public void changingWorldBeforeCaptureReportsOtherWorld() {
+        try (Harness harness = new Harness()) {
+            harness.overlay.requestOpenerPosition(harness.results::add);
+            when(harness.player.getWorld()).thenReturn(mock(World.class));
+            harness.runEntity();
+            assertEquals(List.of(OpenerPosition.IN_OTHER_WORLD), harness.results);
+        }
+    }
+
+    private static final class Harness implements AutoCloseable {
+        private final Player player = mock(Player.class);
+        private final World world = mock(World.class);
+        private final Engine engine = mock(Engine.class);
+        private final IrisWorld target = mock(IrisWorld.class);
+        private final UUID opener = UUID.randomUUID();
+        private final List<OpenerPosition> results = new ArrayList<>();
+        private final MockedStatic<J> scheduling = mockStatic(J.class);
+        private final MockedStatic<Bukkit> bukkit = mockStatic(Bukkit.class);
+        private final MockedStatic<BukkitWorldBinding> binding = mockStatic(BukkitWorldBinding.class);
+        private final BukkitVisionOverlay overlay = new BukkitVisionOverlay(engine, opener);
+        private Runnable task;
+        private Runnable retired;
+        private boolean entityOwned;
+        private boolean reject;
+
+        private Harness() {
+            when(engine.getWorld()).thenReturn(target);
+            when(player.isOnline()).thenReturn(true);
+            when(player.getWorld()).thenReturn(world);
+            when(player.getLocation()).thenAnswer(invocation -> {
+                assertTrue("location read outside owning entity task", entityOwned);
+                return new Location(world, 18.5D, 72D, -4.25D);
+            });
+            bukkit.when(() -> Bukkit.getPlayer(opener)).thenReturn(player);
+            binding.when(() -> BukkitWorldBinding.world(target)).thenReturn(world);
+            scheduling.when(() -> J.runGlobal(any(Runnable.class))).thenAnswer(invocation -> {
+                invocation.getArgument(0, Runnable.class).run();
+                return true;
+            });
+            scheduling.when(() -> J.runEntity(same(player), any(Runnable.class))).thenAnswer(invocation -> {
+                task = invocation.getArgument(1);
+                return !reject;
+            });
+            scheduling.when(() -> J.runEntity(same(player), any(Runnable.class), eq(0), any(Runnable.class)))
+                    .thenAnswer(invocation -> {
+                        task = invocation.getArgument(1);
+                        retired = invocation.getArgument(3);
+                        if (reject) {
+                            retired.run();
+                        }
+                        return !reject;
+                    });
+        }
+
+        private void runEntity() {
+            entityOwned = true;
+            try {
+                task.run();
+            } finally {
+                entityOwned = false;
+            }
+        }
+
+        @Override
+        public void close() {
+            binding.close();
+            bukkit.close();
+            scheduling.close();
+        }
+    }
+}

adapters/bukkit/plugin/src/test/java/art/arcane/iris/world/PendingWorldReplacementAdmissionTest.java

@@ -11,12 +11,16 @@ import art.arcane.iris.platform.bukkit.plugin.VolmitSender;
 import org.bukkit.NamespacedKey;
 import org.junit.Test;
 
+import java.io.IOException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.assertThrows;
 import static org.mockito.Mockito.mock;
 
@@ -42,4 +46,55 @@ public class PendingWorldReplacementAdmissionTest {
             executor.awaitTermination(5L, TimeUnit.SECONDS);
         }
     }
+
+    @Test
+    public void shutdownRejectsReplacementsThatStartAfterIt() {
+        PendingWorldReplacementManager manager = new PendingWorldReplacementManager(mock(Iris.class));
+        manager.awaitStagingForShutdown();
+
+        IOException rejected = assertThrows(IOException.class, () -> manager.stageReplacement(
+                mock(VolmitSender.class), NamespacedKey.minecraft("overworld"), mock(IrisDimension.class), null));
+
+        assertTrue(rejected.getMessage().contains("shutting down"));
+        assertTrue(LifecycleOperationCoordinator.get().isIdle());
+    }
+
+    @Test
+    public void shutdownWaitsForTheReplacementBeingStaged() throws Exception {
+        PendingWorldReplacementManager manager = new PendingWorldReplacementManager(mock(Iris.class));
+        AtomicReference<Throwable> stagingFailure = new AtomicReference<>();
+        Thread staging = new Thread(() -> {
+            try {
+                manager.stageReplacement(mock(VolmitSender.class), NamespacedKey.minecraft("overworld"),
+                        mock(IrisDimension.class), null);
+            } catch (Throwable failure) {
+                stagingFailure.set(failure);
+            }
+        });
+        Thread shutdown = new Thread(manager::awaitStagingForShutdown);
+        synchronized (manager) {
+            staging.start();
+            awaitState(staging, Thread.State.BLOCKED);
+            shutdown.start();
+            awaitState(shutdown, Thread.State.WAITING);
+            assertTrue(staging.isAlive());
+        }
+        shutdown.join(TimeUnit.SECONDS.toMillis(10L));
+        staging.join(TimeUnit.SECONDS.toMillis(10L));
+
+        assertFalse(shutdown.isAlive());
+        assertFalse(staging.isAlive());
+        assertTrue(stagingFailure.get() instanceof Exception);
+        assertTrue(LifecycleOperationCoordinator.get().isIdle());
+    }
+
+    private static void awaitState(Thread thread, Thread.State state) throws InterruptedException {
+        long deadline = System.nanoTime() + TimeUnit.SECONDS.toNanos(5L);
+        while (thread.getState() != state) {
+            if (System.nanoTime() > deadline) {
+                throw new AssertionError(thread.getName() + " never reached " + state + "; it is " + thread.getState());
+            }
+            Thread.sleep(5L);
+        }
+    }
 }

adapters/fabric/build.gradle

@@ -58,6 +58,7 @@ IrisFileOperations irisFileOperations = objects.newInstance(IrisFileOperations)
 
 apply from: file('../../gradle/modded-generation-build-revision.gradle')
 apply from: file('../../gradle/volmlib-stamp.gradle')
+apply from: file('../../gradle/java21-runtime-exclusions.gradle')
 
 Properties rootProperties = new Properties()
 file('../../gradle.properties').withInputStream { InputStream stream -> rootProperties.load(stream) }
@@ -130,6 +131,8 @@ configurations.named('bundle').configure {
     exclude(group: 'de.crazydev22.slimjar.helper')
     exclude(group: 'de.crazydev22.slimjar')
     exclude(group: 'io.github.slimjar')
+    // The game ships its own LWJGL; without the modules it leaves out, the map's 3D views draw in software.
+    exclude(group: 'org.lwjgl')
 }
 
 configurations.compileClasspath.extendsFrom(configurations.devBundle)
@@ -152,7 +155,7 @@ dependencies {
     String modConfiguration = irisModTarget.fabricRemap ? 'modImplementation' : 'implementation'
     add(modConfiguration, "net.fabricmc:fabric-loader:${fabricLoaderVersion}")
     testImplementation('junit:junit:4.13.2')
-    testImplementation('org.mockito:mockito-core:5.23.0')
+    testImplementation(libs.mockito.core)
     testImplementation(testFixtures('art.arcane:core'))
     testImplementation(libs.spigot) {
         transitive = false
@@ -215,7 +218,9 @@ dependencies {
         libs.caffeine,
         'com.fulcrumgenomics:jlibdeflate:0.2.0',
         libs.dom4j,
-        libs.jaxen
+        libs.jaxen,
+        libs.flatlaf,
+        libs.flatlaf.extras
     ]
     shared.each { Object notation ->
         ['bundle', 'devBundle'].each { String configuration ->
@@ -235,6 +240,8 @@ tasks.named('compileJava', JavaCompile).configure {
     options.release.set((int) irisModTarget.java)
 }
 
+apply from: file('../../gradle/mockito-agent.gradle')
+
 tasks.named('test').configure {
 }
 
@@ -322,8 +329,7 @@ tasks.named('shadowJar', ShadowJar).configure {
     configurations = [project.configurations.named('bundle').get()]
     mergeServiceFiles()
     if ((int) irisModTarget.java == 21) {
-        exclude('art/arcane/volmlib/util/noise/NativeBillowLoader*.class')
+        exclude(java21RuntimeExclusions)
-        exclude('art/arcane/volmlib/util/noise/BillowBatch*.class')
     }
     exclude('META-INF/maven/**')
     exclude('META-INF/proguard/**')

adapters/forge/build.gradle

@@ -57,6 +57,7 @@ IrisFileOperations irisFileOperations = objects.newInstance(IrisFileOperations)
 
 apply from: file('../../gradle/modded-generation-build-revision.gradle')
 apply from: file('../../gradle/volmlib-stamp.gradle')
+apply from: file('../../gradle/java21-runtime-exclusions.gradle')
 
 Properties rootProperties = new Properties()
 file('../../gradle.properties').withInputStream { InputStream stream -> rootProperties.load(stream) }
@@ -151,12 +152,16 @@ configurations.named('bundle').configure {
     exclude(group: 'de.crazydev22.slimjar.helper')
     exclude(group: 'de.crazydev22.slimjar')
     exclude(group: 'io.github.slimjar')
+    // The game ships its own LWJGL; without the modules it leaves out, the map's 3D views draw in software.
+    exclude(group: 'org.lwjgl')
 }
 
 configurations.named('runBundle').configure {
     exclude(group: 'de.crazydev22.slimjar.helper')
     exclude(group: 'de.crazydev22.slimjar')
     exclude(group: 'io.github.slimjar')
+    // The game ships its own LWJGL; without the modules it leaves out, the map's 3D views draw in software.
+    exclude(group: 'org.lwjgl')
 }
 
 configurations.compileClasspath.extendsFrom(configurations.devBundle)
@@ -177,7 +182,7 @@ dependencies {
         ? minecraft.dependency("net.minecraftforge:forge:${forgeVersion}")
         : minecraft.dependency("iris-${buildLane}", "net.minecraftforge:forge:${forgeVersion}"))
     testImplementation('junit:junit:4.13.2')
-    testImplementation('org.mockito:mockito-core:5.23.0')
+    testImplementation(libs.mockito.core)
     testImplementation(testFixtures('art.arcane:core'))
     testImplementation(libs.spigot) {
         transitive = false
@@ -214,7 +219,9 @@ dependencies {
         libs.caffeine,
         'com.fulcrumgenomics:jlibdeflate:0.2.0',
         libs.dom4j,
-        libs.jaxen
+        libs.jaxen,
+        libs.flatlaf,
+        libs.flatlaf.extras
     ]
     shared.each { Object notation ->
         ['bundle', 'devBundle', 'runBundle'].each { String configuration ->
@@ -271,6 +278,8 @@ tasks.named('compileJava', JavaCompile).configure {
     options.release.set((int) irisModTarget.java)
 }
 
+apply from: file('../../gradle/mockito-agent.gradle')
+
 tasks.named('test').configure {
 }
 
@@ -309,8 +318,7 @@ tasks.named('shadowJar', ShadowJar).configure {
     from(sourceSets.main.output)
     mergeServiceFiles()
     if ((int) irisModTarget.java == 21) {
-        exclude('art/arcane/volmlib/util/noise/NativeBillowLoader*.class')
+        exclude(java21RuntimeExclusions)
-        exclude('art/arcane/volmlib/util/noise/BillowBatch*.class')
     }
     exclude('META-INF/maven/**')
     exclude('META-INF/proguard/**')

adapters/modded-common/src/main/java/art/arcane/iris/modded/ModdedEngineBootstrap.java

@@ -227,6 +227,7 @@ public final class ModdedEngineBootstrap {
         failure = runStopStage(failure, "wand service", ModdedWandService::clearAll);
         failure = runStopStage(failure, "block break handler", ModdedBlockBreakHandler::clear);
         failure = runStopStage(failure, "studio commands", ModdedStudioCommands::clear);
+        failure = runStopStage(failure, "gui windows", GuiHost::shutdown);
         failure = runStopStage(failure, "gui host", ModdedGuiHost::clear);
         failure = runStopStage(failure, "services", () -> services().disableAll());
         reportStopFailure("stopping", failure);

adapters/modded-common/src/main/java/art/arcane/iris/modded/command/ModdedCommandSuggestions.java

@@ -25,7 +25,7 @@ import art.arcane.iris.generation.runtime.Engine;
 import art.arcane.iris.structure.placement.IrisStructureLocator;
 import art.arcane.iris.structure.nativegen.NativeStructureGenerationPolicy;
 import art.arcane.iris.structure.placement.StructureReachability;
-import art.arcane.iris.generation.hydrology.HydrologyFeatureQuery;
+import art.arcane.iris.generation.hydrology.query.HydrologyFeatureType;
 import art.arcane.iris.world.history.GenerationFindCatalog;
 import art.arcane.iris.generation.biome.IrisBiome;
 import art.arcane.iris.structure.nativegen.IrisNativeStructureDecision;
@@ -61,7 +61,7 @@ final class ModdedCommandSuggestions {
     static final SuggestionProvider<NativeCommandSource> OBJECT_KEYS = (CommandContext<NativeCommandSource> context, SuggestionsBuilder builder) -> suggestObjectKeys(context, builder);
     static final SuggestionProvider<NativeCommandSource> STRUCTURE_KEYS = (CommandContext<NativeCommandSource> context, SuggestionsBuilder builder) -> suggestStructureKeys(context, builder);
     static final SuggestionProvider<NativeCommandSource> POI_TYPES = (CommandContext<NativeCommandSource> context, SuggestionsBuilder builder) -> NativeCommandRegistration.suggest(List.of("buried_treasure"), builder);
-    static final SuggestionProvider<NativeCommandSource> HYDROLOGY_TYPES = (CommandContext<NativeCommandSource> context, SuggestionsBuilder builder) -> suggestHydrologyTypes(context, builder);
+    static final SuggestionProvider<NativeCommandSource> HYDROLOGY_TYPES = (CommandContext<NativeCommandSource> context, SuggestionsBuilder builder) -> NativeCommandRegistration.suggest(HydrologyFeatureType.keys(), builder);
     static final SuggestionProvider<NativeCommandSource> PACK_NAMES = (CommandContext<NativeCommandSource> context, SuggestionsBuilder builder) -> suggestPackNames(context, builder);
     static final SuggestionProvider<NativeCommandSource> DIMENSION_NAMES = (CommandContext<NativeCommandSource> context, SuggestionsBuilder builder) -> suggestDimensionNames(context, builder);
 
@@ -87,24 +87,6 @@ final class ModdedCommandSuggestions {
         return builder.buildFuture();
     }
 
-    private static CompletableFuture<Suggestions> suggestHydrologyTypes(
-            CommandContext<NativeCommandSource> context,
-            SuggestionsBuilder builder
-    ) {
-        ModdedCommandFeedback.tab(context.getSource());
-        try {
-            Engine engine = IrisModdedCommands.engineFor(context.getSource().world());
-            if (engine != null && engine.getComplex().getHydrologyRuntime() != null) {
-                return NativeCommandRegistration.suggest(
-                        engine.getComplex().getHydrologyRuntime().featureQueryKeys(), builder);
-            }
-        } catch (Throwable error) {
-            warnTabFailure("hydrology types", context.getSource(), error);
-        }
-        return NativeCommandRegistration.suggest(
-                HydrologyFeatureQuery.suggestions(List.of()), builder);
-    }
-
     static Set<String> reachableBiomeKeys(Engine engine) {
         return reachableBiomeKeys(GenerationFindCatalog.biomes(engine));
     }

adapters/modded-common/src/main/java/art/arcane/iris/modded/command/ModdedLocateCommands.java

@@ -39,8 +39,7 @@ import art.arcane.iris.structure.placement.StructureReachability;
 import art.arcane.iris.generation.runtime.WrongEngineBroException;
 import art.arcane.iris.world.history.GenerationSemanticQueries;
 import art.arcane.iris.world.history.GenerationFindCatalog;
-import art.arcane.iris.generation.hydrology.HydrologyFeatureQuery;
+import art.arcane.iris.generation.hydrology.query.HydrologyFeatureType;
-import art.arcane.iris.generation.hydrology.runtime.IrisHydrologyRuntime;
 import art.arcane.iris.generation.biome.IrisBiome;
 import art.arcane.iris.structure.nativegen.IrisNativeStructureDecision;
 import art.arcane.iris.generation.terrain.IrisRegion;
@@ -143,39 +142,31 @@ final class ModdedLocateCommands {
             IrisModdedCommands.fail(source, "This dimension is not generated by Iris.");
             return 0;
         }
-        IrisHydrologyRuntime runtime = engine.getComplex().getHydrologyRuntime();
+        HydrologyFeatureType featureType;
-        HydrologyFeatureQuery query;
         try {
-            query = HydrologyFeatureQuery.parse(type);
+            featureType = HydrologyFeatureType.parse(type);
         } catch (IllegalArgumentException error) {
             IrisModdedCommands.fail(source, error.getMessage());
             return 0;
         }
+        String label = featureType.key().replace('_', ' ');
         int originX = player.blockX();
         int originZ = player.blockZ();
-        int requestedDistance = runtime == null
+        int maximumDistance = GenerationSemanticQueries.RIVER_SEARCH_DISTANCE;
-                ? 8192
-                : Math.min(8192, runtime.settings().routing().tileSize() * 15);
-        int maximumDistance = runtime == null
-                ? requestedDistance
-                : runtime.maximumFeatureSearchDistance(originX, originZ, requestedDistance);
         NativeModdedServer server = source.server();
-        IrisModdedCommands.ok(source, "Searching accepted hydrology plans for " + type + "...");
+        IrisModdedCommands.ok(source, GenerationSemanticQueries.riverSearchMessage(featureType, maximumDistance));
         MultiBurst.burst.completeValueAsync(() -> GenerationSemanticQueries.nearestRiver(
-                        engine, query, originX, originZ, maximumDistance,
+                        engine, featureType, originX, originZ, maximumDistance).orElse(null))
-                        (int visited) -> server.execute(() -> IrisModdedCommands.ok(source,
-                                "Searched " + visited + " hydrology tiles for " + type + "..."))).orElse(null))
                 .whenComplete((GenerationSemanticQueries.RiverResult feature, Throwable error) -> server.execute(() -> {
                     if (error != null) {
-                        ModdedIrisLog.error("Hydrology locate failed for {}", type, error);
+                        Throwable cause = error instanceof CompletionException && error.getCause() != null ? error.getCause() : error;
-                        IrisModdedCommands.fail(source,
+                        ModdedIrisLog.error("Hydrology locate failed for {}", featureType.key(), cause);
-                                "Could not locate " + type + " hydrology: " + error.getClass().getSimpleName());
+                        IrisModdedCommands.fail(source, "Could not search for " + label + ": " + cause.getClass().getSimpleName()
+                                + (cause.getMessage() == null ? "" : " - " + cause.getMessage()));
                         return;
                     }
                     if (feature == null) {
-                        IrisModdedCommands.fail(source,
+                        IrisModdedCommands.fail(source, GenerationSemanticQueries.riverNotFoundMessage(featureType, maximumDistance));
-                                "No accepted " + type + " hydrology feature found within "
-                                        + maximumDistance + " blocks.");
                         return;
                     }
                     teleportToStructure(
@@ -185,7 +176,7 @@ final class ModdedLocateCommands {
                             feature.x(),
                             feature.y() + 2,
                             feature.z(),
-                            type + " hydrology feature"
+                            label
                     );
                 }));
         return 1;

adapters/modded-common/src/main/java/art/arcane/iris/modded/command/ModdedPregenMethod.java

@@ -23,6 +23,7 @@ import art.arcane.volmlib.nativelib.terrain.NativePregenRuntime;
 import art.arcane.volmlib.nativelib.terrain.NativePregenRuntime.ChunkLoad;
 import art.arcane.iris.configuration.IrisSettings;
 import art.arcane.iris.world.pregen.MantleHeapPressure;
+import art.arcane.iris.world.pregen.PregenHydrology;
 import art.arcane.iris.world.pregen.PregenListener;
 import art.arcane.iris.world.pregen.PregenMantleBackpressure;
 import art.arcane.iris.world.pregen.PregeneratorMethod;
@@ -30,6 +31,7 @@ import art.arcane.iris.generation.runtime.Engine;
 import art.arcane.iris.modded.ModdedGenPool;
 import art.arcane.volmlib.util.mantle.runtime.Mantle;
 
+import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
@@ -71,6 +73,8 @@ public final class ModdedPregenMethod implements PregeneratorMethod {
     private final PregenMantleBackpressure backpressure;
     private final PauseWhenEmptyGuard pauseGuard;
     private final LongSupplier clock;
+    private final AtomicBoolean closing = new AtomicBoolean();
+    private final PregenHydrology hydrology;
 
     public ModdedPregenMethod(Configuration configuration) {
         this(configuration, System::nanoTime);
@@ -80,6 +84,7 @@ public final class ModdedPregenMethod implements PregeneratorMethod {
         this.clock = Objects.requireNonNull(clock);
         runtime = configuration.runtime();
         engine = configuration.engine();
+        hydrology = new PregenHydrology(() -> engine);
         sync = configuration.sync();
         pauseGuard = new PauseWhenEmptyGuard(runtime);
         IrisSettings.IrisSettingsPregen pregen = IrisSettings.get().getPregen();
@@ -121,6 +126,8 @@ public final class ModdedPregenMethod implements PregeneratorMethod {
 
     @Override
     public void close() {
+        closing.set(true);
+        hydrology.close();
         try {
             awaitPendingChunks();
             ModdedIrisLog.info("Iris modded pregen closing: dim={} completed={} pending={} peakInFlight={} finalLimit={}",
@@ -341,6 +348,13 @@ public final class ModdedPregenMethod implements PregeneratorMethod {
         return false;
     }
 
+    @Override
+    public void onRegionsAhead(List<long[]> regions) {
+        if (!closing.get()) {
+            hydrology.prepare(regions);
+        }
+    }
+
     @Override
     public String getMethod(int x, int z) {
         return "Modded";

adapters/modded-common/src/main/java/art/arcane/iris/modded/command/ModdedStudioCommands.java

@@ -23,10 +23,9 @@ import art.arcane.volmlib.nativelib.minecraft26_2.modded.NativeWorldView;
 
 import art.arcane.iris.modded.ModdedIrisLog;
 import art.arcane.iris.configuration.IrisSettings;
+import art.arcane.iris.studio.map.MapWindow;
+import art.arcane.iris.studio.map.PaletteExplorerStart;
 import art.arcane.iris.studio.view.GuiHost;
-import art.arcane.iris.studio.view.ImageMapStudioGUI;
-import art.arcane.iris.studio.view.NoiseExplorerGUI;
-import art.arcane.iris.studio.view.VisionGUI;
 import art.arcane.iris.pack.loading.IrisData;
 import art.arcane.iris.pack.StructurePackageClosure;
 import art.arcane.iris.pack.ImageMapPackageClosure;
@@ -38,6 +37,7 @@ import art.arcane.iris.generation.biome.IrisBiome;
 import art.arcane.iris.generation.biome.IrisBiomeGeneratorLink;
 import art.arcane.iris.generation.terrain.IrisDimension;
 import art.arcane.iris.world.entity.IrisEntitySpawn;
+import art.arcane.iris.world.IrisWorld;
 import art.arcane.iris.generation.noise.IrisGenerator;
 import art.arcane.iris.pack.PackExportClosure;
 import art.arcane.iris.world.entity.IrisEntity;
@@ -247,8 +247,9 @@ public final class ModdedStudioCommands {
             NativeProtocolPlayer player = source.player();
             ModdedGuiHost.bindContext(worldView(source.server(), level), engine, player == null ? null : player.id());
         }
-        if (generatorKey == null || generatorKey.isBlank()) {
+        Engine mapEngine = engine != null ? engine : GuiHost.get().findActiveEngine();
-            NoiseExplorerGUI.launch();
+        if ((generatorKey == null || generatorKey.isBlank()) && mapEngine != null) {
+            MapWindow.openNoise(mapStart(mapEngine, source.player()), new MapWindow.NoiseSelection(null, null, seed));
             IrisModdedCommands.ok(source, IrisLanguage.plain(ModdedCommandMessages.MODDED_STUDIO_COMMANDS_OPENING_NOISE_EXPLORER_ON_SERVER_DISPLAY));
             return 1;
         }
@@ -262,7 +263,7 @@ public final class ModdedStudioCommands {
             return 0;
         }
         String selectedGeneratorKey = generatorKey.trim();
-        NoiseExplorerGUI.launchGeneratorKey(selectedGeneratorKey, generator, seed);
+        MapWindow.openNoise(mapStart(engine, source.player()), new MapWindow.NoiseSelection(selectedGeneratorKey, generator, seed));
         IrisModdedCommands.ok(source, IrisLanguage.plain(ModdedCommandMessages.MODDED_STUDIO_COMMANDS_OPENING_NOISE_EXPLORER_GENERATOR_SEED, MessageArgument.untrusted("value", generatorKey.trim()), MessageArgument.untrusted("seed", seed)));
         return 1;
     }
@@ -280,11 +281,20 @@ public final class ModdedStudioCommands {
         }
         NativeProtocolPlayer player = source.player();
         ModdedGuiHost.bindContext(worldView(source.server(), level), engine, player == null ? null : player.id());
-        VisionGUI.launch(engine, player == null ? null : player.id());
+        MapWindow.openMap(mapStart(engine, player));
         IrisModdedCommands.ok(source, IrisLanguage.plain(ModdedCommandMessages.MODDED_STUDIO_COMMANDS_OPENING_VISION_MAP_ON_SERVER_DISPLAY, MessageArgument.untrusted("value", level.name())));
         return 1;
     }
 
+    // Modded worlds have no Bukkit world id; the map finds the engine again through the bound GUI context.
+    private static PaletteExplorerStart mapStart(Engine engine, NativeProtocolPlayer player) {
+        IrisWorld world = engine.getWorld();
+        NativeWorld level = world == null ? null : world.platformWorld();
+        boolean inWorld = player != null && player.connected() && level != null && player.inWorld(level);
+        return new PaletteExplorerStart(engine, null, player == null ? null : player.id(), null,
+                inWorld ? player.x() : 0D, inWorld ? player.z() : 0D);
+    }
+
     private static int imageMap(NativeCommandSource source) {
         NativeWorld level = source.world();
         Engine engine = IrisModdedCommands.engineFor(level);
@@ -294,13 +304,13 @@ public final class ModdedStudioCommands {
             ));
             return 0;
         }
-        if (!ImageMapStudioGUI.isAvailable()) {
+        if (!GuiHost.isAvailable() || !IrisSettings.get().getGui().isUseServerLaunchedGuis()) {
             IrisModdedCommands.fail(source, guiUnavailableMessage());
             return 0;
         }
         NativeProtocolPlayer player = source.player();
         ModdedGuiHost.bindContext(worldView(source.server(), level), engine, player == null ? null : player.id());
-        ImageMapStudioGUI.launch(engine);
+        MapWindow.openImageMaps(mapStart(engine, player));
         IrisModdedCommands.ok(source, IrisLanguage.plain(
                 ModdedCommandMessages.MODDED_STUDIO_COMMANDS_OPENING_IMAGE_MAP_STUDIO_ON_SERVER_DISPLAY,
                 MessageArgument.untrusted("value", level.name())

adapters/modded-common/src/main/java/art/arcane/iris/modded/command/ModdedVisionOverlay.java

@@ -18,21 +18,22 @@
 
 package art.arcane.iris.modded.command;
 
-import art.arcane.iris.studio.view.GuiHost;
+import art.arcane.iris.studio.view.GuiMarker;
-import art.arcane.volmlib.nativelib.view.WorldMarker;
 import art.arcane.iris.studio.view.GuiOverlay;
-import art.arcane.iris.generation.runtime.IrisComplex;
+import art.arcane.iris.studio.view.OpenerPosition;
 import art.arcane.iris.generation.runtime.Engine;
-import art.arcane.iris.studio.render.RenderType;
 import art.arcane.iris.modded.ModdedIrisLog;
 import art.arcane.iris.modded.ModdedTeleportDeadline;
+import art.arcane.iris.world.IrisWorld;
+import art.arcane.volmlib.nativelib.minecraft26_2.modded.NativeModdedServer;
+import art.arcane.volmlib.nativelib.minecraft26_2.modded.NativeProtocolPlayer;
+import art.arcane.volmlib.nativelib.terrain.NativeWorld;
+import art.arcane.volmlib.nativelib.view.WorldView;
 
-import java.awt.Desktop;
-import java.io.File;
 import java.util.List;
 import java.util.Optional;
-import art.arcane.volmlib.nativelib.view.WorldView;
 import java.util.UUID;
+import java.util.concurrent.RejectedExecutionException;
 import java.util.function.Consumer;
 
 public final class ModdedVisionOverlay implements GuiOverlay {
@@ -46,14 +47,33 @@ public final class ModdedVisionOverlay implements GuiOverlay {
         opener = context.opener();
     }
 
+    // WorldView doesn't report which way a player faces, so their markers all face south.
     @Override
-    public List<WorldMarker> players() {
+    public List<GuiMarker> players() {
-        return world.players();
+        return world.players().stream()
+                .map(player -> GuiMarker.player(player.label(), player.worldX(), player.worldZ(), 0F))
+                .toList();
     }
 
     @Override
-    public void requestEntities(Consumer<List<WorldMarker>> sink) {
+    public void requestEntities(Consumer<List<GuiMarker>> sink) {
-        world.requestEntities(sink);
+        world.requestEntities(entities -> sink.accept(entities.stream()
+                .map(entity -> GuiMarker.entity(entity.label(), entity.worldX(), entity.worldY(), entity.worldZ(),
+                        entity.health(), entity.maxHealth()))
+                .toList()));
+    }
+
+    @Override
+    public void requestOpenerPosition(Consumer<OpenerPosition> sink) {
+        if (opener == null) {
+            sink.accept(OpenerPosition.OFFLINE);
+            return;
+        }
+        try {
+            world.execute(() -> sink.accept(openerPosition()));
+        } catch (RejectedExecutionException failure) {
+            sink.accept(OpenerPosition.OFFLINE);
+        }
     }
 
     @Override
@@ -80,23 +100,25 @@ public final class ModdedVisionOverlay implements GuiOverlay {
         });
     }
 
-    @Override
+    private OpenerPosition openerPosition() {
-    public String openInEditor(double worldX, double worldZ, RenderType type) {
+        IrisWorld target = engine.getWorld();
-        if (!GuiHost.isAvailable() || !Desktop.isDesktopSupported()) {
+        if (target == null || engine.isClosing() || engine.isClosed()) {
-            return null;
+            return OpenerPosition.OFFLINE;
         }
-        IrisComplex complex = engine.getComplex();
+        NativeWorld level = target.platformWorld();
-        File file = switch (type) {
+        if (level == null) {
-            case BIOME, LAYER_LOAD, DECORATOR_LOAD, OBJECT_LOAD, HEIGHT, RIVER ->
+            return OpenerPosition.OFFLINE;
-                    complex.getTrueBiomeStream().get(worldX, worldZ).openInVSCode();
-            case BIOME_LAND -> complex.getLandBiomeStream().get(worldX, worldZ).openInVSCode();
-            case BIOME_SEA -> complex.getSeaBiomeStream().get(worldX, worldZ).openInVSCode();
-            case REGION -> complex.getRegionStream().get(worldX, worldZ).openInVSCode();
-            case CAVE_LAND -> complex.getCaveBiomeStream().get(worldX, worldZ).openInVSCode();
-            default -> null;
-        };
-        return file == null ? null : file.getName();
         }
+        NativeProtocolPlayer player = NativeModdedServer.forWorld(level).player(opener);
+        if (player == null || !player.connected()) {
+            return OpenerPosition.OFFLINE;
+        }
+        if (!player.inWorld(level)) {
+            return OpenerPosition.IN_OTHER_WORLD;
+        }
+        return OpenerPosition.inWorld(player.x(), player.y(), player.z());
+    }
+
     public record Context(WorldView world, Engine engine, UUID opener) {
     }
 

adapters/modded-common/src/test/java/art/arcane/iris/modded/command/ModdedLocateRiverTest.java

@@ -0,0 +1,149 @@
+package art.arcane.iris.modded.command;
+
+import art.arcane.iris.generation.hydrology.engine.HydrologyRuntime;
+import art.arcane.iris.generation.hydrology.query.HydrologyFeatureQuery;
+import art.arcane.iris.generation.hydrology.query.HydrologyFeatureRef;
+import art.arcane.iris.generation.hydrology.query.HydrologyFeatureType;
+import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.iris.generation.runtime.IrisComplex;
+import art.arcane.iris.generation.terrain.IrisDimension;
+import art.arcane.iris.world.history.GenerationSemanticQueries;
+import art.arcane.volmlib.nativelib.minecraft26_2.modded.NativeCommandSource;
+import art.arcane.volmlib.nativelib.minecraft26_2.modded.NativeModdedServer;
+import art.arcane.volmlib.nativelib.minecraft26_2.modded.NativeProtocolPlayer;
+import art.arcane.volmlib.nativelib.minecraft26_2.modded.NativeStructureQueries;
+import art.arcane.volmlib.nativelib.terrain.NativeWorld;
+import org.junit.Test;
+import org.mockito.ArgumentCaptor;
+import org.mockito.MockedConstruction;
+import org.mockito.MockedStatic;
+
+import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyDouble;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockConstruction;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class ModdedLocateRiverTest {
+    private static final int DISTANCE = GenerationSemanticQueries.RIVER_SEARCH_DISTANCE;
+
+    @Test
+    public void unknownTypeFailsBeforeSearching() {
+        Fixture fixture = new Fixture();
+        try (MockedStatic<IrisModdedCommands> commands = fixture.commands()) {
+            assertEquals(0, ModdedLocateCommands.gotoRiver(fixture.source, "ocean_trench"));
+
+            commands.verify(() -> IrisModdedCommands.fail(eq(fixture.source), anyString()));
+            commands.verify(() -> IrisModdedCommands.ok(eq(fixture.source), anyString()), never());
+            verify(fixture.server, never()).execute(any());
+            verify(fixture.runtime, never()).nearestFeature(anyInt(), anyInt(), any(), anyInt(), any());
+        }
+    }
+
+    @Test
+    public void missingFeatureReportsNotFound() throws Exception {
+        Fixture fixture = new Fixture();
+        when(fixture.runtime.nearestFeature(anyInt(), anyInt(), any(), anyInt(), any())).thenReturn(Optional.empty());
+        try (MockedStatic<IrisModdedCommands> commands = fixture.commands()) {
+            assertEquals(1, ModdedLocateCommands.gotoRiver(fixture.source, "river"));
+            fixture.finishOnServerThread();
+
+            commands.verify(() -> IrisModdedCommands.fail(fixture.source, "No river found within " + DISTANCE + " blocks."));
+            verify(fixture.player, never()).teleport(any(), anyDouble(), anyDouble(), anyDouble());
+        }
+    }
+
+    @Test
+    public void plannerFailureIsReportedAsAnErrorNotAsNotFound() throws Exception {
+        Fixture fixture = new Fixture();
+        when(fixture.runtime.nearestFeature(anyInt(), anyInt(), any(), anyInt(), any()))
+                .thenThrow(new IllegalStateException("window planner exploded"));
+        try (MockedStatic<IrisModdedCommands> commands = fixture.commands()) {
+            assertEquals(1, ModdedLocateCommands.gotoRiver(fixture.source, "major_river"));
+            fixture.finishOnServerThread();
+
+            commands.verify(() -> IrisModdedCommands.fail(fixture.source,
+                    "Could not search for major river: IllegalStateException - window planner exploded"));
+            commands.verify(() -> IrisModdedCommands.fail(eq(fixture.source), eq("No major river found within " + DISTANCE + " blocks.")),
+                    never());
+            verify(fixture.player, never()).teleport(any(), anyDouble(), anyDouble(), anyDouble());
+        }
+    }
+
+    @Test
+    public void foundFeatureTeleportsAboveItFromThePlayersPosition() throws Exception {
+        Fixture fixture = new Fixture();
+        when(fixture.runtime.nearestFeature(anyInt(), anyInt(), any(), anyInt(), any()))
+                .thenReturn(Optional.of(new HydrologyFeatureRef(9L, HydrologyFeatureType.WATERFALL, 400, 130, -250)));
+        when(fixture.player.teleport(fixture.world, 400.5D, 68D, -249.5D)).thenReturn(true);
+        try (MockedStatic<IrisModdedCommands> commands = fixture.commands();
+             MockedConstruction<NativeStructureQueries> queries = mockConstruction(NativeStructureQueries.class)) {
+            assertEquals(1, ModdedLocateCommands.gotoRiver(fixture.source, "waterfall"));
+            fixture.finishOnServerThread();
+
+            ArgumentCaptor<HydrologyFeatureQuery> query = ArgumentCaptor.forClass(HydrologyFeatureQuery.class);
+            verify(fixture.runtime).nearestFeature(eq(120), eq(-75), query.capture(), eq(DISTANCE), any());
+            assertEquals(HydrologyFeatureQuery.of(HydrologyFeatureType.WATERFALL), query.getValue());
+            verify(queries.constructed().getFirst()).loadChunk(400 >> 4, -250 >> 4);
+            verify(fixture.player).teleport(fixture.world, 400.5D, 68D, -249.5D);
+            commands.verify(() -> IrisModdedCommands.ok(eq(fixture.source), anyString()), times(2));
+            commands.verify(() -> IrisModdedCommands.fail(eq(fixture.source), anyString()), never());
+        }
+    }
+
+    private static final class Fixture {
+        private final NativeCommandSource source = mock(NativeCommandSource.class);
+        private final NativeWorld world = mock(NativeWorld.class);
+        private final NativeProtocolPlayer player = mock(NativeProtocolPlayer.class);
+        private final NativeModdedServer server = mock(NativeModdedServer.class);
+        private final Engine engine = mock(Engine.class);
+        private final HydrologyRuntime runtime = mock(HydrologyRuntime.class);
+        private final CompletableFuture<Runnable> completion = new CompletableFuture<>();
+
+        private Fixture() {
+            IrisComplex complex = mock(IrisComplex.class);
+            IrisDimension dimension = mock(IrisDimension.class);
+            when(source.player()).thenReturn(player);
+            when(source.world()).thenReturn(world);
+            when(source.server()).thenReturn(server);
+            when(player.blockX()).thenReturn(120);
+            when(player.blockZ()).thenReturn(-75);
+            when(player.connected()).thenReturn(true);
+            when(player.inWorld(world)).thenReturn(true);
+            when(world.minHeight()).thenReturn(-64);
+            when(world.maxHeight()).thenReturn(320);
+            when(engine.getComplex()).thenReturn(complex);
+            when(engine.getDimension()).thenReturn(dimension);
+            when(dimension.getMinHeight()).thenReturn(-64);
+            when(complex.getHydrologyRuntime()).thenReturn(runtime);
+            when(runtime.enabled()).thenReturn(true);
+            doAnswer(invocation -> {
+                completion.complete(invocation.getArgument(0));
+                return null;
+            }).when(server).execute(any());
+        }
+
+        private MockedStatic<IrisModdedCommands> commands() {
+            MockedStatic<IrisModdedCommands> commands = mockStatic(IrisModdedCommands.class);
+            commands.when(() -> IrisModdedCommands.engineFor(world)).thenReturn(engine);
+            return commands;
+        }
+
+        private void finishOnServerThread() throws Exception {
+            completion.get(10L, TimeUnit.SECONDS).run();
+        }
+    }
+}

adapters/modded-common/src/test/java/art/arcane/iris/modded/command/ModdedPregenMethodLifecycleTest.java

@@ -1,6 +1,7 @@
 package art.arcane.iris.modded.command;
 
 import art.arcane.iris.configuration.IrisSettings;
+import art.arcane.iris.generation.hydrology.engine.HydrologyPregeneration;
 import art.arcane.iris.generation.runtime.Engine;
 import art.arcane.iris.modded.ModdedGenPool;
 import art.arcane.iris.world.pregen.MantleHeapPressure;
@@ -11,8 +12,10 @@ import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.ArgumentCaptor;
+import org.mockito.InOrder;
 import org.mockito.MockedStatic;
 
+import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
@@ -31,9 +34,11 @@ import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyList;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
 import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.mockStatic;
 import static org.mockito.Mockito.never;
@@ -89,6 +94,25 @@ public class ModdedPregenMethodLifecycleTest {
         verify(runtime, never()).execute(any());
     }
 
+    @Test
+    public void closeWithdrawsQueuedHydrologyPrefetchAndRefusesLaterAnnouncements() {
+        HydrologyPregeneration epoch = mock(HydrologyPregeneration.class);
+        when(engine.getComplex().getHydrologyRuntime().openPregeneration()).thenReturn(epoch);
+        when(runtime.isServerThread()).thenReturn(true);
+        assertTrue(method.deferFinalSaveToServerThread());
+        List<long[]> ahead = List.of(new long[]{0L, 0L}, new long[]{1L, 0L});
+
+        method.onRegionsAhead(ahead);
+        method.close();
+        method.onRegionsAhead(ahead);
+
+        InOrder order = inOrder(epoch);
+        order.verify(epoch).prepare(ahead);
+        order.verify(epoch).close();
+        verify(epoch, times(1)).prepare(anyList());
+        method.completeDeferredFinalSave();
+    }
+
     @Test
     public void asynchronousCallerCannotClaimTheShutdownSave() {
         assertFalse(method.deferFinalSaveToServerThread());

adapters/modded-common/src/test/java/art/arcane/iris/modded/command/ModdedVisionOverlayTest.java

@@ -1,25 +1,98 @@
 package art.arcane.iris.modded.command;
 
 import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.iris.studio.view.OpenerPosition;
+import art.arcane.iris.world.IrisWorld;
+import art.arcane.volmlib.nativelib.minecraft26_2.modded.NativeModdedServer;
+import art.arcane.volmlib.nativelib.minecraft26_2.modded.NativeProtocolPlayer;
+import art.arcane.volmlib.nativelib.terrain.NativeWorld;
 import art.arcane.volmlib.nativelib.view.WorldView;
 import org.junit.Test;
+import org.mockito.MockedStatic;
 import org.mockito.invocation.InvocationOnMock;
 
 import java.util.Optional;
 import java.util.UUID;
+import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertNull;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
 import static org.mockito.Mockito.when;
 
 public class ModdedVisionOverlayTest {
+    @Test
+    public void rejectedServerTaskCompletesThePositionRequestAsOffline() {
+        WorldView world = mock(WorldView.class);
+        doThrow(new RejectedExecutionException("Server stopped")).when(world).execute(any(Runnable.class));
+        ModdedVisionOverlay overlay = new ModdedVisionOverlay(new ModdedVisionOverlay.Context(world,
+                mock(Engine.class), UUID.randomUUID()));
+        AtomicReference<OpenerPosition> position = new AtomicReference<>();
+
+        overlay.requestOpenerPosition(position::set);
+
+        assertEquals(OpenerPosition.OFFLINE, position.get());
+    }
+
+    @Test
+    public void openerPositionRunsOnTheServerAndTracksDisconnectAndWorldChanges() {
+        WorldView world = mock(WorldView.class);
+        AtomicReference<Runnable> scheduled = new AtomicReference<>();
+        doAnswer(invocation -> {
+            scheduled.set(invocation.getArgument(0));
+            return null;
+        }).when(world).execute(any(Runnable.class));
+        Engine engine = mock(Engine.class);
+        IrisWorld irisWorld = mock(IrisWorld.class);
+        NativeWorld level = mock(NativeWorld.class);
+        NativeModdedServer server = mock(NativeModdedServer.class);
+        NativeProtocolPlayer player = mock(NativeProtocolPlayer.class);
+        UUID opener = UUID.randomUUID();
+        when(engine.getWorld()).thenReturn(irisWorld);
+        when(irisWorld.platformWorld()).thenReturn(level);
+        when(server.player(opener)).thenReturn(player);
+        when(player.connected()).thenReturn(true);
+        when(player.inWorld(level)).thenReturn(true);
+        when(player.x()).thenReturn(21.5D);
+        when(player.y()).thenReturn(85.25D);
+        when(player.z()).thenReturn(-39.5D);
+        ModdedVisionOverlay overlay = new ModdedVisionOverlay(new ModdedVisionOverlay.Context(world, engine, opener));
+        AtomicReference<OpenerPosition> position = new AtomicReference<>();
+        try (MockedStatic<NativeModdedServer> nativeServer = mockStatic(NativeModdedServer.class)) {
+            nativeServer.when(() -> NativeModdedServer.forWorld(level)).thenReturn(server);
+
+            overlay.requestOpenerPosition(position::set);
+            assertNull("position reads must wait for the server task", position.get());
+            scheduled.get().run();
+            assertEquals(OpenerPosition.inWorld(21.5D, 85.25D, -39.5D), position.get());
+
+            overlay.requestOpenerPosition(position::set);
+            when(player.connected()).thenReturn(false);
+            scheduled.get().run();
+            assertEquals(OpenerPosition.OFFLINE, position.get());
+
+            when(player.connected()).thenReturn(true);
+            when(player.inWorld(level)).thenReturn(false);
+            overlay.requestOpenerPosition(position::set);
+            scheduled.get().run();
+            assertEquals(OpenerPosition.IN_OTHER_WORLD, position.get());
+
+            when(player.inWorld(level)).thenReturn(true);
+            overlay.requestOpenerPosition(position::set);
+            scheduled.get().run();
+            assertEquals(OpenerPosition.inWorld(21.5D, 85.25D, -39.5D), position.get());
+        }
+    }
+
     /**
      * A Vision click can land anywhere in the world, so the destination chunk is usually cold and gets the same
      * bounded deadline as /iris tp.

adapters/neoforge/build.gradle

@@ -56,6 +56,7 @@ IrisFileOperations irisFileOperations = objects.newInstance(IrisFileOperations)
 
 apply from: file('../../gradle/modded-generation-build-revision.gradle')
 apply from: file('../../gradle/volmlib-stamp.gradle')
+apply from: file('../../gradle/java21-runtime-exclusions.gradle')
 
 Properties rootProperties = new Properties()
 file('../../gradle.properties').withInputStream { InputStream stream -> rootProperties.load(stream) }
@@ -131,6 +132,8 @@ configurations.named('bundle').configure {
     exclude(group: 'de.crazydev22.slimjar.helper')
     exclude(group: 'de.crazydev22.slimjar')
     exclude(group: 'io.github.slimjar')
+    // The game ships its own LWJGL; without the modules it leaves out, the map's 3D views draw in software.
+    exclude(group: 'org.lwjgl')
 }
 
 configurations.compileClasspath.extendsFrom(configurations.devBundle)
@@ -140,7 +143,7 @@ configurations.testRuntimeClasspath.extendsFrom(configurations.runtimeClasspath,
 
 dependencies {
     testImplementation('junit:junit:4.13.2')
-    testImplementation('org.mockito:mockito-core:5.23.0')
+    testImplementation(libs.mockito.core)
     testImplementation(testFixtures('art.arcane:core'))
     testImplementation(libs.spigot) {
         transitive = false
@@ -172,7 +175,9 @@ dependencies {
         libs.caffeine,
         'com.fulcrumgenomics:jlibdeflate:0.2.0',
         libs.dom4j,
-        libs.jaxen
+        libs.jaxen,
+        libs.flatlaf,
+        libs.flatlaf.extras
     ]
     add('bundle', libs.asm)
     add('devBundle', 'org.ow2.asm:asm') {
@@ -260,6 +265,8 @@ tasks.named('compileJava', JavaCompile).configure {
     options.release.set((int) irisModTarget.java)
 }
 
+apply from: file('../../gradle/mockito-agent.gradle')
+
 tasks.named('test').configure {
     useJUnitPlatform()
     classpath = classpath.minus(developmentModLibraries).plus(sourceSets.modLibraries.output)
@@ -295,8 +302,7 @@ tasks.named('shadowJar', ShadowJar).configure {
     from(sourceSets.main.output)
     mergeServiceFiles()
     if ((int) irisModTarget.java == 21) {
-        exclude('art/arcane/volmlib/util/noise/NativeBillowLoader*.class')
+        exclude(java21RuntimeExclusions)
-        exclude('art/arcane/volmlib/util/noise/BillowBatch*.class')
     }
     exclude('META-INF/maven/**')
     exclude('META-INF/proguard/**')

build.gradle

@@ -127,7 +127,7 @@ nmsBindings.each { String key ->
             compileOnly(rootProject.libs.annotations)
             compileOnly(rootProject.libs.byteBuddy.core)
             testImplementation('junit:junit:4.13.2')
-            testImplementation('org.mockito:mockito-core:5.23.0')
+            testImplementation(rootProject.libs.mockito.core)
             if (key == 'v26_3_R1') {
                 testImplementation(project(':probe'))
             }
@@ -230,6 +230,7 @@ List<Object> moddedSharedInputs = []
     'gradle/libs.versions.toml',
     'gradle/volmlib-resolution.settings.gradle',
     'gradle/volmlib-stamp.gradle',
+    'gradle/java21-runtime-exclusions.gradle',
     'gradle/generation-build-revision.gradle',
     'gradle/modded-generation-build-revision.gradle',
     'gradle/native-minecraft-sources.gradle',
@@ -245,7 +246,8 @@ List<Object> moddedSharedInputs = []
 ].each { String path -> moddedSharedInputs.add(layout.projectDirectory.file(path).asFile) }
 if (localVolmLibCheckout != null) {
     moddedSharedInputs.add(fileTree(localVolmLibCheckout) {
-        include('shared/src/main/**', 'native-api/src/main/**', 'native-terrain-api/src/main/**',
+        include('shared/src/main/**', 'shared/src/nativeNoise/**', 'shared/native/noise/prebuilt/**',
+            'native-api/src/main/**', 'native-terrain-api/src/main/**',
             'native/**/src/main/**',
             'native/minecraft-common/src/**', 'packaging/src/main/**',
             '**/build.gradle', 'settings.gradle', 'gradle.properties', 'gradle/libs.versions.toml')
@@ -437,6 +439,21 @@ if (selectedModdedBuilds.isEmpty()) {
     throw new GradleException("Minecraft ${minecraftVersion} is not a mod target in gradle/mod-targets.json")
 }
 
+tasks.register('prepareRelease', Sync) {
+    group = 'distribution'
+    description = 'Builds, verifies and stages one selected mod loader jar for publication.'
+    Provider<IrisModdedBuild> releaseBuild = providers.provider {
+        String releaseLoader = providers.gradleProperty('releaseLoader').orNull
+        if (!moddedLoaderLabels.containsKey(releaseLoader)) {
+            throw new GradleException('prepareRelease requires -PreleaseLoader=fabric, forge or neoforge')
+        }
+        return selectedModdedBuilds[releaseLoader].get()
+    }
+    dependsOn(releaseBuild)
+    from(releaseBuild.flatMap { IrisModdedBuild task -> task.artifactFile })
+    into(layout.buildDirectory.dir('release'))
+}
+
 tasks.register('buildFabric') {
     group = 'iris'
     description = "Builds and verifies the Fabric ${minecraftVersion} jar."
@@ -569,11 +586,14 @@ allprojects {
         layout.buildDirectory.set(layout.projectDirectory.dir("build/${runtimeOutputVariant}"))
     }
 
+    apply from: rootProject.file('gradle/mockito-agent.gradle')
+
     tasks.withType(Test).configureEach {
         int moduleForks = project.path.startsWith(':adapters:bukkit:') ? Math.min(2, testForks)
             : project.path == ':probe' ? Math.min(4, testForks) : testForks
         maxParallelForks = Math.min(gradle.startParameter.maxWorkerCount, moduleForks)
         jvmArgs('-XX:ParallelGCThreads=2', '-XX:ConcGCThreads=1', '-XX:CICompilerCount=2')
+        timeout = java.time.Duration.ofMinutes(60)
     }
 
     java {

core/build.gradle

@@ -39,6 +39,7 @@ plugins {
 }
 
 apply from: rootProject.file('gradle/runtime-relocations.gradle')
+apply from: rootProject.file('gradle/java21-runtime-exclusions.gradle')
 
 def lib = 'art.arcane.iris.util'
 
@@ -135,6 +136,13 @@ dependencies {
     implementation('com.moandjiezana.toml:toml4j:0.7.2') {
         transitive = false
     }
+    // Shaded: the runtime downloader can neither fetch the natives classifiers nor relocate lwjgl's own jar.
+    implementation(libs.lwjgl)
+    implementation(libs.lwjgl.opengl)
+    implementation(libs.lwjgl.egl)
+    implementation(libs.lwjgl.jawt)
+    runtimeOnly(variantOf(libs.lwjgl) { classifier('natives-linux') })
+    runtimeOnly(variantOf(libs.lwjgl.opengl) { classifier('natives-linux') })
     // Dynamically Loaded
     slim(libs.gson)
     slim(libs.lru)
@@ -160,13 +168,15 @@ dependencies {
     slim(libs.byteBuddy.agent)
     slim(libs.dom4j)
     slim(libs.jaxen)
+    slim(libs.flatlaf)
+    slim(libs.flatlaf.extras)
 
     testFixturesImplementation('junit:junit:4.13.2')
-    testFixturesImplementation('org.mockito:mockito-core:5.23.0')
+    testFixturesImplementation(libs.mockito.core)
     testFixturesCompileOnly(libs.paper.api)
 
     testImplementation('junit:junit:4.13.2')
-    testImplementation('org.mockito:mockito-core:5.23.0')
+    testImplementation(libs.mockito.core)
     testImplementation(libs.paper.api)
     testImplementation(libs.log4j.core)
     testRuntimeOnly(libs.paper.api)
@@ -176,8 +186,10 @@ dependencies {
 }
 
 tasks.named('test').configure {
-    maxHeapSize = '1g'
+    timeout = java.time.Duration.ofMinutes(60)
+    maxHeapSize = '2g'
     jvmArgs('-XX:+ExitOnOutOfMemoryError')
+    systemProperty('iris.generation.counters', 'true')
 }
 
 java {
@@ -474,8 +486,7 @@ tasks.named('shadowJar', ShadowJar).configure {
     dependsOn(embeddedAgentJar)
     mergeServiceFiles()
     if (providers.gradleProperty('irisRuntimeJava').getOrElse(rootProject.irisModTarget.java.toString()) == '21') {
-        exclude('art/arcane/volmlib/util/noise/NativeBillowLoader*.class')
+        exclude(java21RuntimeExclusions)
-        exclude('art/arcane/volmlib/util/noise/BillowBatch*.class')
     }
     // minimize() stays off. Caffeine reaches its 520 generated cache and node classes through
     // MethodHandles.Lookup.findClass on a computed name, and the VolmLib command, GUI and hotload

core/purity-allowlist.txt

@@ -16,8 +16,8 @@ art/arcane/iris/generation/block/IrisCustomData.java
 art/arcane/iris/generation/block/LegacyTileData.java
 art/arcane/iris/generation/block/TileData.java
 art/arcane/iris/generation/chunk/ChunkBiomeHunkView.java
-art/arcane/iris/generation/chunk/ChunkDataHunkHolder.java
 art/arcane/iris/generation/chunk/ChunkDataHunkView.java
+art/arcane/iris/generation/chunk/ChunkDataOutput.java
 art/arcane/iris/generation/chunk/ChunkHunkView.java
 art/arcane/iris/generation/chunk/LinkedTerrainChunk.java
 art/arcane/iris/generation/chunk/TerrainChunk.java

core/src/main/java/art/arcane/iris/command/specialhandlers/HydrologyTypeHandler.java

@@ -1,25 +1,14 @@
 package art.arcane.iris.command.specialhandlers;
 
-import art.arcane.iris.generation.runtime.Engine;
-import art.arcane.iris.generation.hydrology.HydrologyFeatureQuery;
-import art.arcane.iris.generation.hydrology.runtime.IrisHydrologyRuntime;
 import art.arcane.iris.command.DirectorParameterHandler;
+import art.arcane.iris.generation.hydrology.query.HydrologyFeatureType;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.director.exceptions.DirectorParsingException;
 
-import java.util.List;
-
 public final class HydrologyTypeHandler implements DirectorParameterHandler<String> {
     @Override
     public KList<String> getPossibilities() {
-        Engine activeEngine = engine();
+        return new KList<>(HydrologyFeatureType.keys());
-        if (activeEngine == null) {
-            return new KList<>(HydrologyFeatureQuery.suggestions(List.of()));
-        }
-        IrisHydrologyRuntime runtime = activeEngine.getComplex().getHydrologyRuntime();
-        return new KList<>(runtime == null
-                ? HydrologyFeatureQuery.suggestions(List.of())
-                : runtime.featureQueryKeys());
     }
 
     @Override
@@ -29,16 +18,11 @@ public final class HydrologyTypeHandler implements DirectorParameterHandler<Stri
 
     @Override
     public String parse(String input, boolean force) throws DirectorParsingException {
-        String normalized = input == null ? "" : input.trim();
+        try {
-        if (normalized.isEmpty()) {
+            return HydrologyFeatureType.parse(input).key();
-            throw new DirectorParsingException("Hydrology feature type must not be blank.");
+        } catch (IllegalArgumentException error) {
+            throw new DirectorParsingException(error.getMessage());
         }
-        for (String possibility : getPossibilities(normalized)) {
-            if (possibility.equalsIgnoreCase(normalized)) {
-                return possibility;
-            }
-        }
-        return normalized;
     }
 
     @Override
@@ -48,6 +32,6 @@ public final class HydrologyTypeHandler implements DirectorParameterHandler<Stri
 
     @Override
     public String getRandomDefault() {
-        return "surface";
+        return HydrologyFeatureType.RIVER.key();
     }
 }

core/src/main/java/art/arcane/iris/configuration/IrisSettings.java

@@ -373,6 +373,7 @@ public class IrisSettings {
         public boolean useServerLaunchedGuis = true;
         public boolean maximumPregenGuiFPS = false;
         public boolean colorMode = true;
+        public String theme = "auto";
     }
 
     @Data

core/src/main/java/art/arcane/iris/generation/bake/BakePlane.java

@@ -0,0 +1,26 @@
+package art.arcane.iris.generation.bake;
+
+public enum BakePlane {
+    REGION(false),
+    BASE_BIOME(false),
+    BASE_HEIGHT(true),
+    NATURAL_HEIGHT(true),
+    NATURAL_TRUE_BIOME(false),
+    HEIGHT(true),
+    TRUE_BIOME(false),
+    ROCK(false),
+    FLUID(false),
+    CAVE_BIOME(false);
+
+    static final BakePlane[] PLANES = values();
+
+    private final boolean doubles;
+
+    BakePlane(boolean doubles) {
+        this.doubles = doubles;
+    }
+
+    public boolean doubles() {
+        return doubles;
+    }
+}

core/src/main/java/art/arcane/iris/generation/bake/ChunkBakeCache.java

@@ -0,0 +1,152 @@
+package art.arcane.iris.generation.bake;
+
+import art.arcane.iris.generation.cache.ConcurrentClockCache;
+import art.arcane.iris.generation.stream.ProvisionalSampling;
+
+import java.util.Arrays;
+import java.util.Objects;
+
+public final class ChunkBakeCache {
+    public static final int MINIMUM_CAPACITY = 2_048;
+    static final int MAXIMUM_CAPACITY = 32_768;
+    static final long BYTES_PER_ENTRY = 13L * 1_024L;
+    static final int HEAP_SHARE = 32;
+    private static final int RECENT_SLOTS = 16;
+    private static final ThreadLocal<int[]> SPARSE = ThreadLocal.withInitial(() -> new int[1]);
+
+    private final PlaneSource source;
+    private final ConcurrentClockCache<ChunkPlanes> entries;
+    private final ThreadLocal<Recent> recent = ThreadLocal.withInitial(Recent::new);
+    private volatile int generation;
+
+    public ChunkBakeCache(PlaneSource source, int capacityChunks) {
+        this.source = Objects.requireNonNull(source, "Bake plane source");
+        this.entries = new ConcurrentClockCache<>(Math.max(16, capacityChunks));
+    }
+
+    public static int capacityFor(long maxMemory) {
+        long entries = Math.max(0L, maxMemory) / HEAP_SHARE / BYTES_PER_ENTRY;
+        return (int) Math.max(MINIMUM_CAPACITY, Math.min(MAXIMUM_CAPACITY, entries));
+    }
+
+    public int capacity() {
+        return entries.capacity();
+    }
+
+    public synchronized void clear() {
+        generation++;
+        entries.forEach(ChunkPlanes::release);
+        entries.clear();
+    }
+
+    public long[] census() {
+        long[] counts = new long[BakePlane.PLANES.length + 1];
+        entries.forEach(planes -> {
+            counts[BakePlane.PLANES.length]++;
+            for (BakePlane plane : BakePlane.PLANES) {
+                if (planes.planeIfPresent(plane) != null) {
+                    counts[plane.ordinal()]++;
+                }
+            }
+        });
+        return counts;
+    }
+
+    public ChunkPlanes.Plane planeIfPresent(BakePlane plane, int chunkX, int chunkZ) {
+        long key = key(chunkX, chunkZ);
+        int slot = Recent.slot(chunkX, chunkZ);
+        Recent last = recent.get();
+        int current = generation;
+        ChunkPlanes planes = last.get(key, slot, current);
+        if (planes == null) {
+            planes = entries.get(key);
+            if (planes == null) {
+                return null;
+            }
+            last.remember(key, slot, planes, current);
+        }
+        return planes.planeIfPresent(plane);
+    }
+
+    public ChunkPlanes.Plane plane(BakePlane plane, int chunkX, int chunkZ) {
+        return planes(chunkX, chunkZ).plane(plane);
+    }
+
+    public Object complete(BakePlane plane, int chunkX, int chunkZ) {
+        return remembered(chunkX, chunkZ).complete(plane, source);
+    }
+
+    public void fillColumns(BakePlane plane, int chunkX, int chunkZ, long[] columns, Object target) {
+        remembered(chunkX, chunkZ).plane(plane).fillColumns(source, chunkX, chunkZ, columns, target);
+    }
+
+    public boolean memoAllowed() {
+        return SPARSE.get()[0] == 0 && !source.mainThread();
+    }
+
+    public void storeDouble(BakePlane plane, int blockX, int blockZ, double value, long revision) {
+        if (revision != ProvisionalSampling.revision()) {
+            return;
+        }
+        remembered(blockX >> 4, blockZ >> 4).plane(plane).storeDouble(((blockZ & 15) << 4) | (blockX & 15), value);
+    }
+
+    public void storeObject(BakePlane plane, int blockX, int blockZ, Object value, long revision) {
+        if (revision != ProvisionalSampling.revision()) {
+            return;
+        }
+        remembered(blockX >> 4, blockZ >> 4).plane(plane).storeObject(((blockZ & 15) << 4) | (blockX & 15), value);
+    }
+
+    private ChunkPlanes planes(int chunkX, int chunkZ) {
+        long key = key(chunkX, chunkZ);
+        ChunkPlanes existing = entries.get(key);
+        return existing != null ? existing : entries.putIfAbsent(key, new ChunkPlanes(chunkX, chunkZ));
+    }
+
+    private ChunkPlanes remembered(int chunkX, int chunkZ) {
+        int current = generation;
+        ChunkPlanes planes = planes(chunkX, chunkZ);
+        recent.get().remember(key(chunkX, chunkZ), Recent.slot(chunkX, chunkZ), planes, current);
+        return planes;
+    }
+
+    public static void enterSparse() {
+        SPARSE.get()[0]++;
+    }
+
+    public static void exitSparse() {
+        SPARSE.get()[0]--;
+    }
+
+    public static boolean inSparseScope() {
+        return SPARSE.get()[0] > 0;
+    }
+
+    public static long key(int chunkX, int chunkZ) {
+        return ((long) chunkX << 32) ^ (chunkZ & 0xffffffffL);
+    }
+
+    private static final class Recent {
+        private final long[] keys = new long[RECENT_SLOTS];
+        private final ChunkPlanes[] planes = new ChunkPlanes[RECENT_SLOTS];
+        private int generation = -1;
+
+        private static int slot(int chunkX, int chunkZ) {
+            return ((chunkZ & 3) << 2) | (chunkX & 3);
+        }
+
+        private ChunkPlanes get(long key, int slot, int generation) {
+            return this.generation == generation && keys[slot] == key ? planes[slot] : null;
+        }
+
+        private void remember(long key, int slot, ChunkPlanes value, int generation) {
+            if (this.generation != generation) {
+                Arrays.fill(planes, null);
+                this.generation = generation;
+            }
+            keys[slot] = key;
+            planes[slot] = value;
+        }
+    }
+}

core/src/main/java/art/arcane/iris/generation/bake/ChunkPlanes.java

@@ -0,0 +1,245 @@
+package art.arcane.iris.generation.bake;
+
+import art.arcane.iris.generation.stream.ProvisionalSampling;
+
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.VarHandle;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.atomic.AtomicReferenceArray;
+
+public final class ChunkPlanes {
+    private static final VarHandle READY = MethodHandles.arrayElementVarHandle(long[].class);
+
+    private final int chunkX;
+    private final int chunkZ;
+    private final AtomicReferenceArray<Plane> planes = new AtomicReferenceArray<>(BakePlane.PLANES.length);
+
+    ChunkPlanes(int chunkX, int chunkZ) {
+        this.chunkX = chunkX;
+        this.chunkZ = chunkZ;
+    }
+
+    public int chunkX() {
+        return chunkX;
+    }
+
+    public int chunkZ() {
+        return chunkZ;
+    }
+
+    public Plane planeIfPresent(BakePlane kind) {
+        return planes.getAcquire(kind.ordinal());
+    }
+
+    public Plane plane(BakePlane kind) {
+        int slot = kind.ordinal();
+        Plane plane = planes.getAcquire(slot);
+        if (plane != null) {
+            return plane;
+        }
+        Plane created = new Plane(kind);
+        Plane witness = planes.compareAndExchangeRelease(slot, null, created);
+        return witness == null ? created : witness;
+    }
+
+    Object complete(BakePlane kind, PlaneSource source) {
+        Plane plane = plane(kind);
+        while (true) {
+            if (plane.complete) {
+                return plane.values;
+            }
+            Pending running = plane.filling.get();
+            if (running != null) {
+                if (running.owner == Thread.currentThread()) {
+                    return plane.unpublishedFill(source, chunkX, chunkZ);
+                }
+                running.await();
+                continue;
+            }
+            Pending pending = new Pending(Thread.currentThread());
+            if (!plane.filling.compareAndSet(null, pending)) {
+                continue;
+            }
+            try {
+                return plane.fill(source, chunkX, chunkZ);
+            } finally {
+                plane.filling.set(null);
+                pending.complete();
+            }
+        }
+    }
+
+    void release() {
+        for (int slot = 0; slot < planes.length(); slot++) {
+            planes.setRelease(slot, null);
+        }
+    }
+
+    public static final class Plane {
+        private final BakePlane kind;
+        private final Object values;
+        private final long[] ready = new long[4];
+        private final AtomicReference<Pending> filling = new AtomicReference<>();
+        private volatile boolean complete;
+
+        private Plane(BakePlane kind) {
+            this.kind = kind;
+            this.values = kind.doubles() ? new double[256] : new Object[256];
+        }
+
+        public boolean ready(int index) {
+            return complete || ((long) READY.getAcquire(ready, index >>> 6) & (1L << (index & 63))) != 0L;
+        }
+
+        public double doubleAt(int index) {
+            return ((double[]) values)[index];
+        }
+
+        public Object objectAt(int index) {
+            return ((Object[]) values)[index];
+        }
+
+        public void storeDouble(int index, double value) {
+            ((double[]) values)[index] = value;
+            markReady(index);
+        }
+
+        public void storeObject(int index, Object value) {
+            ((Object[]) values)[index] = value;
+            markReady(index);
+        }
+
+        private void markReady(int index) {
+            READY.getAndBitwiseOrRelease(ready, index >>> 6, 1L << (index & 63));
+        }
+
+        private long[] missing() {
+            long[] missing = new long[4];
+            for (int word = 0; word < 4; word++) {
+                missing[word] = ~(long) READY.getAcquire(ready, word);
+            }
+            return missing;
+        }
+
+        private Object fill(PlaneSource source, int chunkX, int chunkZ) {
+            long[] missing = missing();
+            Object computed = kind.doubles() ? new double[256] : new Object[256];
+            long revision = ProvisionalSampling.revision();
+            source.fill(kind, chunkX, chunkZ, missing, computed);
+            if (revision != ProvisionalSampling.revision()) {
+                return merge(missing, computed);
+            }
+            for (int index = 0; index < 256; index++) {
+                if ((missing[index >>> 6] & (1L << (index & 63))) != 0L) {
+                    if (kind.doubles()) {
+                        ((double[]) values)[index] = ((double[]) computed)[index];
+                    } else {
+                        ((Object[]) values)[index] = ((Object[]) computed)[index];
+                    }
+                }
+            }
+            for (int word = 0; word < 4; word++) {
+                READY.setRelease(ready, word, -1L);
+            }
+            complete = true;
+            return values;
+        }
+
+        void fillColumns(PlaneSource source, int chunkX, int chunkZ, long[] columns, Object target) {
+            long[] missing = new long[4];
+            boolean any = false;
+            if (!complete) {
+                for (int word = 0; word < 4; word++) {
+                    missing[word] = columns[word] & ~(long) READY.getAcquire(ready, word);
+                    any |= missing[word] != 0L;
+                }
+            }
+            if (!any) {
+                copyColumns(columns, values, target);
+                return;
+            }
+            long revision = ProvisionalSampling.revision();
+            source.fill(kind, chunkX, chunkZ, missing, target);
+            long[] known = new long[4];
+            for (int word = 0; word < 4; word++) {
+                known[word] = columns[word] & ~missing[word];
+            }
+            copyColumns(known, values, target);
+            if (revision == ProvisionalSampling.revision()) {
+                publish(missing, target);
+            }
+        }
+
+        private void publish(long[] missing, Object computed) {
+            copyColumns(missing, computed, values);
+            for (int word = 0; word < 4; word++) {
+                if (missing[word] != 0L) {
+                    READY.getAndBitwiseOrRelease(ready, word, missing[word]);
+                }
+            }
+        }
+
+        private void copyColumns(long[] columns, Object from, Object to) {
+            for (int word = 0; word < 4; word++) {
+                long bits = columns[word];
+                while (bits != 0L) {
+                    int index = (word << 6) | Long.numberOfTrailingZeros(bits);
+                    if (kind.doubles()) {
+                        ((double[]) to)[index] = ((double[]) from)[index];
+                    } else {
+                        ((Object[]) to)[index] = ((Object[]) from)[index];
+                    }
+                    bits &= bits - 1L;
+                }
+            }
+        }
+
+        private Object unpublishedFill(PlaneSource source, int chunkX, int chunkZ) {
+            long[] missing = missing();
+            Object computed = kind.doubles() ? new double[256] : new Object[256];
+            source.fill(kind, chunkX, chunkZ, missing, computed);
+            return merge(missing, computed);
+        }
+
+        private Object merge(long[] missing, Object computed) {
+            for (int index = 0; index < 256; index++) {
+                if ((missing[index >>> 6] & (1L << (index & 63))) == 0L) {
+                    if (kind.doubles()) {
+                        ((double[]) computed)[index] = ((double[]) values)[index];
+                    } else {
+                        ((Object[]) computed)[index] = ((Object[]) values)[index];
+                    }
+                }
+            }
+            return computed;
+        }
+    }
+
+    private static final class Pending {
+        private final Thread owner;
+        private boolean done;
+
+        private Pending(Thread owner) {
+            this.owner = owner;
+        }
+
+        private synchronized void complete() {
+            done = true;
+            notifyAll();
+        }
+
+        private synchronized void await() {
+            boolean interrupted = false;
+            while (!done) {
+                try {
+                    wait();
+                } catch (InterruptedException e) {
+                    interrupted = true;
+                }
+            }
+            if (interrupted) {
+                Thread.currentThread().interrupt();
+            }
+        }
+    }
+}

core/src/main/java/art/arcane/iris/generation/bake/GeneratorEvaluations.java

@@ -0,0 +1,59 @@
+package art.arcane.iris.generation.bake;
+
+import art.arcane.iris.generation.runtime.GenerationCounter;
+
+import java.util.concurrent.atomic.LongAdder;
+
+public final class GeneratorEvaluations {
+    private static final LongAdder BAKED_CHUNKS = new LongAdder();
+    private static final LongAdder BAKED = new LongAdder();
+    private static final LongAdder BATCHED = new LongAdder();
+    private static final LongAdder SCALAR = new LongAdder();
+
+    private GeneratorEvaluations() {
+    }
+
+    public static void bakedChunk(long evaluations) {
+        if (!GenerationCounter.ENABLED) {
+            return;
+        }
+        BAKED_CHUNKS.increment();
+        BAKED.add(evaluations);
+    }
+
+    public static void batched(long evaluations) {
+        if (!GenerationCounter.ENABLED) {
+            return;
+        }
+        BATCHED.add(evaluations);
+    }
+
+    public static void scalar(int evaluations) {
+        if (!GenerationCounter.ENABLED) {
+            return;
+        }
+        SCALAR.add(evaluations);
+    }
+
+    public static Snapshot snapshot() {
+        return new Snapshot(BAKED_CHUNKS.sum(), BAKED.sum(), BATCHED.sum(), SCALAR.sum());
+    }
+
+    public static void reset() {
+        BAKED_CHUNKS.reset();
+        BAKED.reset();
+        BATCHED.reset();
+        SCALAR.reset();
+    }
+
+    public record Snapshot(long bakedChunks, long bakedEvaluations, long batchedEvaluations, long scalarEvaluations) {
+        public double bakedEvaluationsPerChunk() {
+            return bakedChunks == 0L ? 0D : (double) bakedEvaluations / bakedChunks;
+        }
+
+        public Snapshot minus(Snapshot earlier) {
+            return new Snapshot(bakedChunks - earlier.bakedChunks, bakedEvaluations - earlier.bakedEvaluations,
+                    batchedEvaluations - earlier.batchedEvaluations, scalarEvaluations - earlier.scalarEvaluations);
+        }
+    }
+}

core/src/main/java/art/arcane/iris/generation/bake/PlaneSource.java

@@ -0,0 +1,7 @@
+package art.arcane.iris.generation.bake;
+
+public interface PlaneSource {
+    void fill(BakePlane plane, int chunkX, int chunkZ, long[] missing, Object values);
+
+    boolean mainThread();
+}

core/src/main/java/art/arcane/iris/generation/bake/TerrainProgram.java

@@ -0,0 +1,168 @@
+package art.arcane.iris.generation.bake;
+
+import art.arcane.iris.generation.noise.GeneratorProgram;
+import art.arcane.iris.generation.noise.IrisGenerator;
+import art.arcane.iris.generation.noise.TerrainBatchScratch;
+import art.arcane.volmlib.util.math.M;
+
+import java.util.Arrays;
+
+public final class TerrainProgram {
+    private static final int SKIPPED = 0;
+    private static final int CONSTANT = 1;
+    private static final int ACTIVE = 2;
+
+    private final IrisGenerator[][] generators;
+    private final GeneratorProgram[][] programs;
+    private final long heightSeed;
+
+    private TerrainProgram(IrisGenerator[][] generators, GeneratorProgram[][] programs, long heightSeed) {
+        this.generators = generators;
+        this.programs = programs;
+        this.heightSeed = heightSeed;
+    }
+
+    public static TerrainProgram compile(IrisGenerator[][] generators, long heightSeed) {
+        GeneratorProgram[][] programs = new GeneratorProgram[generators.length][];
+        for (int group = 0; group < generators.length; group++) {
+            programs[group] = new GeneratorProgram[generators[group].length];
+            for (int index = 0; index < generators[group].length; index++) {
+                IrisGenerator generator = generators[group][index];
+                programs[group][index] = generator.supportsBatch() ? generator.compileProgram(heightSeed) : null;
+            }
+        }
+        return new TerrainProgram(generators, programs, heightSeed);
+    }
+
+    public long heightSeed() {
+        return heightSeed;
+    }
+
+    public double average(int group, TerrainBatchScratch scratch, double low, double high, double x, double z) {
+        IrisGenerator[] members = generators[group];
+        if (members.length == 0) {
+            return 0D;
+        }
+        if (!Double.isFinite(low) || !Double.isFinite(high)) {
+            throw new IllegalStateException("Terrain generator bounds were not finite at " + x + "," + z
+                    + " (generator=" + members[0].getLoadKey() + ", bounds=" + low + ".." + high + ").");
+        }
+        double height = 0D;
+        if (low == high) {
+            for (int member = 0; member < members.length; member++) {
+                height += low;
+            }
+            return height / members.length;
+        }
+        GeneratorEvaluations.scalar(members.length);
+        GeneratorProgram[] compiled = programs[group];
+        for (int member = 0; member < members.length; member++) {
+            GeneratorProgram program = compiled[member];
+            double noise = program != null ? program.height(scratch, x, z) : members[member].getHeight(x, z, heightSeed);
+            if (!Double.isFinite(noise)) {
+                throw new IllegalStateException("Terrain generator noise was not finite at " + x + "," + z
+                        + " (generator=" + members[member].getLoadKey() + ", noise=" + noise
+                        + ", bounds=" + low + ".." + high + ").");
+            }
+            height += M.lerp(low, high, noise);
+        }
+        return height / members.length;
+    }
+
+    public int groups() {
+        return generators.length;
+    }
+
+    public int groupSize(int group) {
+        return generators[group].length;
+    }
+
+    public long accumulate(int group, TerrainBatchScratch scratch, double[] xs, double[] zs, int count,
+                           double[] lows, double[] highs, double[] heights) {
+        IrisGenerator[] members = generators[group];
+        if (members.length == 0 || count == 0) {
+            return 0L;
+        }
+        int mark = scratch.mark();
+        int indexMark = scratch.indexMark();
+        try {
+            return accumulate(members, group, scratch, xs, zs, count, lows, highs, heights);
+        } finally {
+            scratch.reset(mark);
+            scratch.resetIndices(indexMark);
+        }
+    }
+
+    private long accumulate(IrisGenerator[] members, int group, TerrainBatchScratch scratch, double[] xs, double[] zs,
+                            int count, double[] lows, double[] highs, double[] heights) {
+        int[] modes = scratch.indices(count);
+        int activeCount = 0;
+        for (int index = 0; index < count; index++) {
+            double low = lows[index];
+            double high = highs[index];
+            if (low == 0D && high == 0D) {
+                modes[index] = SKIPPED;
+                continue;
+            }
+            if (!Double.isFinite(low) || !Double.isFinite(high)) {
+                throw new IllegalStateException("Terrain generator bounds were not finite at " + xs[index] + "," + zs[index]
+                        + " (generator=" + members[0].getLoadKey() + ", bounds=" + low + ".." + high + ").");
+            }
+            if (low == high) {
+                modes[index] = CONSTANT;
+                double sum = 0D;
+                for (int member = 0; member < members.length; member++) {
+                    sum += low;
+                }
+                heights[index] += sum / members.length;
+                continue;
+            }
+            modes[index] = ACTIVE;
+            activeCount++;
+        }
+        if (activeCount == 0) {
+            return 0L;
+        }
+        double[] activeX = scratch.buffer(activeCount);
+        double[] activeZ = scratch.buffer(activeCount);
+        double[] activeLow = scratch.buffer(activeCount);
+        double[] activeHigh = scratch.buffer(activeCount);
+        int[] activeIndex = scratch.indices(activeCount);
+        int cursor = 0;
+        for (int index = 0; index < count; index++) {
+            if (modes[index] == ACTIVE) {
+                activeX[cursor] = xs[index];
+                activeZ[cursor] = zs[index];
+                activeLow[cursor] = lows[index];
+                activeHigh[cursor] = highs[index];
+                activeIndex[cursor++] = index;
+            }
+        }
+        double[] sums = scratch.buffer(activeCount);
+        double[] noise = scratch.buffer(activeCount);
+        Arrays.fill(sums, 0, activeCount, 0D);
+        GeneratorProgram[] compiled = programs[group];
+        for (int member = 0; member < members.length; member++) {
+            GeneratorProgram program = compiled[member];
+            if (program != null) {
+                program.heights(scratch, activeX, activeZ, activeCount, noise);
+            } else {
+                for (int index = 0; index < activeCount; index++) {
+                    noise[index] = members[member].getHeight(activeX[index], activeZ[index], heightSeed);
+                }
+            }
+            for (int index = 0; index < activeCount; index++) {
+                if (!Double.isFinite(noise[index])) {
+                    throw new IllegalStateException("Terrain generator noise was not finite at " + activeX[index] + "," + activeZ[index]
+                            + " (generator=" + members[member].getLoadKey() + ", noise=" + noise[index]
+                            + ", bounds=" + activeLow[index] + ".." + activeHigh[index] + ").");
+                }
+                sums[index] += M.lerp(activeLow[index], activeHigh[index], noise[index]);
+            }
+        }
+        for (int index = 0; index < activeCount; index++) {
+            heights[activeIndex[index]] += sums[index] / members.length;
+        }
+        return (long) activeCount * members.length;
+    }
+}

core/src/main/java/art/arcane/iris/generation/biome/IrisBiome.java

@@ -26,7 +26,7 @@ import art.arcane.iris.generation.decoration.IrisDepositVariant;
 import art.arcane.iris.generation.decoration.IrisOreGenerator;
 import art.arcane.iris.generation.decoration.IrisOreBands;
 import art.arcane.iris.generation.decoration.IrisProceduralObjects;
-import art.arcane.iris.generation.hydrology.IrisRiverPolicy;
+import art.arcane.iris.generation.hydrology.config.IrisHydrologyPolicy;
 import art.arcane.iris.generation.noise.IrisGeneratorStyle;
 import art.arcane.iris.generation.noise.NoiseStyle;
 import art.arcane.iris.generation.terrain.InferredType;
@@ -161,8 +161,8 @@ public class IrisBiome extends IrisRegistrant implements Rarity {
     private int lockLayersMax = 7;
     @Description("Profile-driven 3D cave configuration")
     private IrisCaveProfile caveProfile = new IrisCaveProfile();
-    @Description("Biome-level river placement, routing, profile, biome, and geometry policy. Omit to inherit region and dimension settings.")
+    @Description("Water settings for this biome: rainfall, pond density, where streams and ponds may form, and the fluid that fills them. A value left unset comes from the region, then from the dimension.")
-    private IrisRiverPolicy riverPolicy = null;
+    private IrisHydrologyPolicy hydrologyPolicy = null;
     @MinNumber(1)
     @MaxNumber(512)
     @Description("The rarity of this biome (integer)")
@@ -515,7 +515,10 @@ public class IrisBiome extends IrisRegistrant implements Rarity {
     }
 
     public CNG getChildrenGenerator(RNG random, int sig, double scale) {
-        long seed = deriveChildStyleSeed(random, sig).getSeed();
+        return getChildrenGenerator(deriveChildStyleSeed(random, sig).getSeed(), scale);
+    }
+
+    public CNG getChildrenGenerator(long seed, double scale) {
         IrisData data = getLoader();
         Engine engine = data == null ? null : data.getEngine();
         CachedChildGenerator recent = recentChildGenerator;
@@ -533,6 +536,10 @@ public class IrisBiome extends IrisRegistrant implements Rarity {
         return random.nextParallelRNG(signature * CHILDREN_SEED_SALT);
     }
 
+    public static long childStyleSeed(RNG random, int signature) {
+        return deriveChildStyleSeed(random, signature).getSeed();
+    }
+
     public KList<NativeBlockState> generateLayers(IrisDimension dim, double wx, double wz, RNG random, int maxDepth, int height, IrisData rdata, IrisComplex complex) {
         return IrisBiomeLayerGenerator.generateLayers(this, dim, wx, wz, random, maxDepth, height, rdata, complex);
     }
@@ -573,6 +580,10 @@ public class IrisBiome extends IrisRegistrant implements Rarity {
         return IrisBiomeLayerGenerator.getLayerSeaHeightGenerators(this, rng, data);
     }
 
+    public KList<CNG> getCaveCeilingLayerHeightGenerators(RNG rng, IrisData data) {
+        return IrisBiomeLayerGenerator.getCaveCeilingLayerHeightGenerators(this, rng, data);
+    }
+
     public NativeBlockState getSurfaceBlock(int x, int z, RNG rng, IrisData idm) {
         return IrisBiomeLayerGenerator.getSurfaceBlock(this, x, z, rng, idm);
     }

core/src/main/java/art/arcane/iris/generation/biome/IrisBiomeLayerGenerator.java

@@ -148,8 +148,7 @@ final class IrisBiomeLayerGenerator {
             return data;
         }
 
-        KList<CNG> heightGenerators = getHeightGenerators(
+        KList<CNG> heightGenerators = getCaveCeilingLayerHeightGenerators(biome, random, rdata);
-                biome.getLayerCeilingHeightGenerators(), ceilingLayers, 7235, random, rdata);
 
         for (int i = 0; i < layerCount; i++) {
             IrisBiomePaletteLayer layer = ceilingLayers.get(i);
@@ -317,6 +316,10 @@ final class IrisBiomeLayerGenerator {
         return getHeightGenerators(biome.getLayerSeaHeightGenerators(), biome.getSeaLayers(), 7735, rng, data);
     }
 
+    static KList<CNG> getCaveCeilingLayerHeightGenerators(IrisBiome biome, RNG rng, IrisData data) {
+        return getHeightGenerators(biome.getLayerCeilingHeightGenerators(), biome.getCaveCeilingLayers(), 7235, rng, data);
+    }
+
     private static KList<CNG> getHeightGenerators(IrisBiomeLayerHeightCache cache,
                                                   KList<IrisBiomePaletteLayer> layers,
                                                   int seedOffset, RNG rng, IrisData data) {

core/src/main/java/art/arcane/iris/generation/chunk/ChunkDataHunkHolder.java

@@ -1,169 +0,0 @@
-/*
- * Iris is a World Generator for Minecraft Bukkit Servers
- * Copyright (c) 2022 Arcane Arts (Volmit Software)
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-package art.arcane.iris.generation.chunk;
-
-import art.arcane.iris.platform.bukkit.nms.INMS;
-import art.arcane.volmlib.nativelib.terrain.NativeBlockVolume;
-import art.arcane.volmlib.nativelib.terrain.NativeBlockState;
-import art.arcane.iris.generation.block.BoundBlockState;
-import art.arcane.iris.generation.block.IrisCustomData;
-import art.arcane.volmlib.util.hunk.storage.StorageHunk;
-import org.bukkit.block.data.BlockData;
-import org.bukkit.generator.ChunkGenerator.ChunkData;
-
-import java.lang.invoke.MethodHandles;
-import java.lang.invoke.VarHandle;
-import java.util.Arrays;
-
-/**
- * Plain-array block buffer for one chunk. Stages write disjoint columns when they fan out and every hand-off
- * between threads is a join, so the cells need no per-access fences. Each column tracks its highest stored y;
- * a raise is a CAS so concurrent writers to one column can never lose the maximum.
- */
-public class ChunkDataHunkHolder extends StorageHunk<NativeBlockState> implements NativeBlockVolume, ColumnExtent {
-    private static final BoundBlockState AIR = BoundBlockState.of("AIR");
-    private static final VarHandle COLUMN_TOPS = MethodHandles.arrayElementVarHandle(int[].class);
-
-    private final ChunkData chunk;
-    private final NativeBlockState[] data;
-    private final int[] columnTops;
-    private final int zStride;
-
-    public ChunkDataHunkHolder(ChunkData chunk) {
-        super(16, chunk.getMaxHeight() - chunk.getMinHeight(), 16);
-        this.chunk = chunk;
-        this.zStride = 16 * getHeight();
-        this.data = new NativeBlockState[zStride * 16];
-        this.columnTops = new int[256];
-        Arrays.fill(columnTops, -1);
-    }
-
-    @Override
-    public int getWidth() {
-        return 16;
-    }
-
-    @Override
-    public int getDepth() {
-        return 16;
-    }
-
-    @Override
-    public void setRaw(int x, int y, int z, NativeBlockState t) {
-        // Block-hunk contract: null means "no write", never "erase" — ChunkDataHunkView and
-        // the modded ModdedBlockBuffer already discard nulls, and storing one here made the
-        // Bukkit output diverge from the modded loaders for the same engine emission.
-        if (t == null) {
-            return;
-        }
-        data[index(x, y, z)] = t;
-        int column = (z << 4) | x;
-        int top = (int) COLUMN_TOPS.getOpaque(columnTops, column);
-        while (y > top) {
-            int witness = (int) COLUMN_TOPS.compareAndExchange(columnTops, column, top, y);
-            if (witness == top) {
-                break;
-            }
-            top = witness;
-        }
-    }
-
-    @Override
-    public NativeBlockState getRaw(int x, int y, int z) {
-        if (y < 0 || y >= getHeight()) {
-            return AIR.get();
-        }
-
-        NativeBlockState b = data[index(x, y, z)];
-
-        return b != null ? b : AIR.get();
-    }
-
-    @Override
-    public NativeBlockState getStoredRaw(int x, int y, int z) {
-        return data[index(x, y, z)];
-    }
-
-    @Override
-    public int highestStoredY(int x, int z) {
-        return (int) COLUMN_TOPS.getOpaque(columnTops, (z << 4) | x);
-    }
-
-    private int index(int x, int y, int z) {
-        return (z * zStride) + (y << 4) + x;
-    }
-
-    public void apply() {
-        applyTo(chunk);
-    }
-
-    public void applyTo(ChunkData target) {
-        if (INMS.get().applyChunkDataBlocks(target, this)) {
-            return;
-        }
-
-        int height = getHeight();
-        for (int x = 0; x < getWidth(); x++) {
-            for (int z = 0; z < getDepth(); z++) {
-                BlockData activeBlock = null;
-                int runStart = -1;
-
-                for (int y = 0; y < height; y++) {
-                    NativeBlockState state = getStoredRaw(x, y, z);
-                    BlockData block = state == null ? null : (BlockData) state.nativeHandle();
-                    // Custom wrappers are not real Bukkit data; write the vanilla base like the
-                    // NMS fast path (NMSBinding.applyChunkDataBlocks) does.
-                    if (block instanceof IrisCustomData custom) {
-                        block = custom.getBase();
-                    }
-                    if (block == null) {
-                        flushRun(target, x, z, runStart, y, activeBlock);
-                        activeBlock = null;
-                        runStart = -1;
-                        continue;
-                    }
-
-                    if (activeBlock != null && activeBlock.equals(block)) {
-                        continue;
-                    }
-
-                    flushRun(target, x, z, runStart, y, activeBlock);
-                    activeBlock = block;
-                    runStart = y;
-                }
-
-                flushRun(target, x, z, runStart, height, activeBlock);
-            }
-        }
-    }
-
-    private void flushRun(ChunkData target, int x, int z, int startY, int endY, BlockData block) {
-        if (block == null || startY < 0 || endY <= startY) {
-            return;
-        }
-
-        int minY = target.getMinHeight();
-        if (endY - startY == 1) {
-            target.setBlock(x, startY + minY, z, block);
-            return;
-        }
-
-        target.setRegion(x, startY + minY, z, x + 1, endY + minY, z + 1, block);
-    }
-}

core/src/main/java/art/arcane/iris/generation/chunk/ChunkDataOutput.java

@@ -0,0 +1,82 @@
+/*
+ * Iris is a World Generator for Minecraft Bukkit Servers
+ * Copyright (c) 2026 Arcane Arts (Volmit Software)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package art.arcane.iris.generation.chunk;
+
+import art.arcane.iris.generation.block.IrisCustomData;
+import art.arcane.iris.platform.bukkit.nms.INMS;
+import art.arcane.volmlib.nativelib.terrain.NativeBlockState;
+import org.bukkit.block.data.BlockData;
+import org.bukkit.generator.ChunkGenerator.ChunkData;
+
+public final class ChunkDataOutput {
+    private ChunkDataOutput() {
+    }
+
+    public static void apply(ChunkData target, SectionBuffer blocks) {
+        if (INMS.get().applyChunkDataBlocks(target, blocks)) {
+            return;
+        }
+
+        int height = blocks.getHeight();
+        for (int x = 0; x < 16; x++) {
+            for (int z = 0; z < 16; z++) {
+                BlockData activeBlock = null;
+                int runStart = -1;
+
+                for (int y = 0; y < height; y++) {
+                    NativeBlockState state = blocks.getStoredRaw(x, y, z);
+                    BlockData block = state == null ? null : (BlockData) state.nativeHandle();
+                    if (block instanceof IrisCustomData custom) {
+                        block = custom.getBase();
+                    }
+                    if (block == null) {
+                        flushRun(target, x, z, runStart, y, activeBlock);
+                        activeBlock = null;
+                        runStart = -1;
+                        continue;
+                    }
+
+                    if (activeBlock != null && activeBlock.equals(block)) {
+                        continue;
+                    }
+
+                    flushRun(target, x, z, runStart, y, activeBlock);
+                    activeBlock = block;
+                    runStart = y;
+                }
+
+                flushRun(target, x, z, runStart, height, activeBlock);
+            }
+        }
+    }
+
+    private static void flushRun(ChunkData target, int x, int z, int startY, int endY, BlockData block) {
+        if (block == null || startY < 0 || endY <= startY) {
+            return;
+        }
+
+        int minY = target.getMinHeight();
+        if (endY - startY == 1) {
+            target.setBlock(x, startY + minY, z, block);
+            return;
+        }
+
+        target.setRegion(x, startY + minY, z, x + 1, endY + minY, z + 1, block);
+    }
+}

core/src/main/java/art/arcane/iris/generation/chunk/ColumnExtentListeningHunk.java

@@ -20,7 +20,7 @@ package art.arcane.iris.generation.chunk;
 
 import art.arcane.volmlib.util.hunk.Hunk;
 
-public final class ColumnExtentListeningHunk<T> implements Hunk<T>, ColumnExtent {
+public final class ColumnExtentListeningHunk<T> implements Hunk<T>, ColumnExtent, ColumnRunHunk<T> {
     private final Hunk<T> source;
     private final Listener<T> listener;
 
@@ -35,6 +35,12 @@ public final class ColumnExtentListeningHunk<T> implements Hunk<T>, ColumnExtent
         source.setRaw(x, y, z, t);
     }
 
+    @Override
+    public void fillColumnRun(int x, int z, int yFromInclusive, int yToInclusive, T value) {
+        listener.onRun(x, z, yFromInclusive, yToInclusive, value);
+        ColumnRunHunk.fillColumnRun(source, x, z, yFromInclusive, yToInclusive, value);
+    }
+
     @Override
     public T getRaw(int x, int y, int z) {
         return source.getRaw(x, y, z);
@@ -63,5 +69,11 @@ public final class ColumnExtentListeningHunk<T> implements Hunk<T>, ColumnExtent
     @FunctionalInterface
     public interface Listener<T> {
         void onWrite(int x, int y, int z, T value);
+
+        default void onRun(int x, int z, int yFromInclusive, int yToInclusive, T value) {
+            for (int y = yToInclusive; y >= yFromInclusive; y--) {
+                onWrite(x, y, z, value);
+            }
+        }
     }
 }

core/src/main/java/art/arcane/iris/generation/chunk/ColumnRunHunk.java

@@ -0,0 +1,36 @@
+/*
+ * Iris is a World Generator for Minecraft Bukkit Servers
+ * Copyright (c) 2026 Arcane Arts (Volmit Software)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package art.arcane.iris.generation.chunk;
+
+import art.arcane.volmlib.util.hunk.Hunk;
+
+public interface ColumnRunHunk<T> {
+    void fillColumnRun(int x, int z, int yFromInclusive, int yToInclusive, T value);
+
+    @SuppressWarnings("unchecked")
+    static <T> void fillColumnRun(Hunk<T> hunk, int x, int z, int yFromInclusive, int yToInclusive, T value) {
+        if (hunk instanceof ColumnRunHunk<?> runs) {
+            ((ColumnRunHunk<T>) runs).fillColumnRun(x, z, yFromInclusive, yToInclusive, value);
+            return;
+        }
+        for (int y = yToInclusive; y >= yFromInclusive; y--) {
+            hunk.setRaw(x, y, z, value);
+        }
+    }
+}

core/src/main/java/art/arcane/iris/generation/chunk/SectionBuffer.java

@@ -0,0 +1,268 @@
+/*
+ * Iris is a World Generator for Minecraft Bukkit Servers
+ * Copyright (c) 2026 Arcane Arts (Volmit Software)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package art.arcane.iris.generation.chunk;
+
+import art.arcane.iris.generation.block.BoundBlockState;
+import art.arcane.volmlib.nativelib.terrain.NativeBlockState;
+import art.arcane.volmlib.nativelib.terrain.NativeSectionVolume;
+import art.arcane.volmlib.util.hunk.Hunk;
+
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.VarHandle;
+import java.util.Arrays;
+
+public final class SectionBuffer implements Hunk<NativeBlockState>, NativeSectionVolume, ColumnExtent, ColumnRunHunk<NativeBlockState> {
+    private static final BoundBlockState AIR = BoundBlockState.of("AIR");
+    private static final VarHandle SECTIONS = MethodHandles.arrayElementVarHandle(short[][].class);
+    private static final VarHandle COLUMN_TOPS = MethodHandles.arrayElementVarHandle(int[].class);
+    private static final int SECTION_CELLS = 4096;
+    private static final int MAX_PALETTE_ID = 0xFFFF;
+    private static final int INITIAL_PALETTE_CAPACITY = 64;
+    private static final int COLUMN_SLICE_SHIFT = 5;
+
+    private final int height;
+    private final short[][] sections;
+    private final int[] columnTops;
+    private final Object paletteLock = new Object();
+    private PaletteEntry[] slots;
+    private NativeBlockState[] states;
+    private int paletteSize;
+
+    public SectionBuffer(int height) {
+        if (height <= 0) {
+            throw new IllegalArgumentException("Unsupported section buffer height " + height);
+        }
+        this.height = height;
+        this.sections = new short[(height + 15) >> 4][];
+        this.columnTops = new int[16 << COLUMN_SLICE_SHIFT];
+        Arrays.fill(columnTops, -1);
+        this.slots = new PaletteEntry[INITIAL_PALETTE_CAPACITY << 1];
+        this.states = new NativeBlockState[INITIAL_PALETTE_CAPACITY];
+        this.paletteSize = 1;
+    }
+
+    @Override
+    public int getWidth() {
+        return 16;
+    }
+
+    @Override
+    public int getHeight() {
+        return height;
+    }
+
+    @Override
+    public int getDepth() {
+        return 16;
+    }
+
+    public int paletteId(NativeBlockState state) {
+        if (state == null) {
+            return 0;
+        }
+        PaletteEntry[] table = slots;
+        int mask = table.length - 1;
+        int slot = System.identityHashCode(state) & mask;
+        PaletteEntry entry;
+        while ((entry = table[slot]) != null) {
+            if (entry.state == state) {
+                return entry.id;
+            }
+            slot = (slot + 1) & mask;
+        }
+        return insert(state);
+    }
+
+    @Override
+    public void setRaw(int x, int y, int z, NativeBlockState t) {
+        if (t == null) {
+            return;
+        }
+        writableSection(y >> 4)[((y & 15) << 8) | (z << 4) | x] = (short) paletteId(t);
+        raiseTop((x << COLUMN_SLICE_SHIFT) | z, y);
+    }
+
+    @Override
+    public NativeBlockState getRaw(int x, int y, int z) {
+        if (y < 0 || y >= height) {
+            return AIR.get();
+        }
+        short[] section = sections[y >> 4];
+        if (section != null) {
+            int id = section[((y & 15) << 8) | (z << 4) | x] & 0xFFFF;
+            if (id != 0) {
+                return state(id);
+            }
+        }
+        return AIR.get();
+    }
+
+    @Override
+    public NativeBlockState getStoredRaw(int x, int y, int z) {
+        if (y < 0 || y >= height) {
+            return null;
+        }
+        short[] section = sections[y >> 4];
+        if (section == null) {
+            return null;
+        }
+        int id = section[((y & 15) << 8) | (z << 4) | x] & 0xFFFF;
+        return id == 0 ? null : state(id);
+    }
+
+    @Override
+    public void fillColumnRun(int x, int z, int yFromInclusive, int yToInclusive, NativeBlockState value) {
+        if (value == null || yToInclusive < yFromInclusive) {
+            return;
+        }
+        fillColumnRun(x, z, yFromInclusive, yToInclusive, paletteId(value));
+    }
+
+    public void fillColumnRun(int localX, int localZ, int yFromInclusive, int yToInclusive, int paletteId) {
+        if (paletteId == 0 || yToInclusive < yFromInclusive) {
+            return;
+        }
+        short value = (short) paletteId;
+        int column = (localZ << 4) | localX;
+        int y = yFromInclusive;
+        while (y <= yToInclusive) {
+            int sectionIndex = y >> 4;
+            short[] section = writableSection(sectionIndex);
+            int last = Math.min(yToInclusive, (sectionIndex << 4) | 15);
+            int end = ((last & 15) << 8) | column;
+            for (int index = ((y & 15) << 8) | column; index <= end; index += 256) {
+                section[index] = value;
+            }
+            y = last + 1;
+        }
+        raiseTop((localX << COLUMN_SLICE_SHIFT) | localZ, yToInclusive);
+    }
+
+    @Override
+    public int highestStoredY(int x, int z) {
+        return (int) COLUMN_TOPS.getOpaque(columnTops, (x << COLUMN_SLICE_SHIFT) | z);
+    }
+
+    @Override
+    public int sectionCount() {
+        return sections.length;
+    }
+
+    @Override
+    public short[] section(int sectionIndex) {
+        return sections[sectionIndex];
+    }
+
+    @Override
+    public NativeBlockState[] palette() {
+        synchronized (paletteLock) {
+            return Arrays.copyOf(states, paletteSize);
+        }
+    }
+
+    private short[] writableSection(int sectionIndex) {
+        short[] section = sections[sectionIndex];
+        if (section != null) {
+            return section;
+        }
+        short[] created = new short[SECTION_CELLS];
+        short[] witness = (short[]) SECTIONS.compareAndExchange(sections, sectionIndex, (short[]) null, created);
+        return witness == null ? created : witness;
+    }
+
+    private void raiseTop(int column, int y) {
+        int top = (int) COLUMN_TOPS.getOpaque(columnTops, column);
+        while (y > top) {
+            int witness = (int) COLUMN_TOPS.compareAndExchange(columnTops, column, top, y);
+            if (witness == top) {
+                return;
+            }
+            top = witness;
+        }
+    }
+
+    private NativeBlockState state(int id) {
+        NativeBlockState[] current = states;
+        if (id < current.length) {
+            NativeBlockState state = current[id];
+            if (state != null) {
+                return state;
+            }
+        }
+        synchronized (paletteLock) {
+            return states[id];
+        }
+    }
+
+    private int insert(NativeBlockState state) {
+        synchronized (paletteLock) {
+            PaletteEntry[] table = slots;
+            int mask = table.length - 1;
+            int slot = System.identityHashCode(state) & mask;
+            PaletteEntry entry;
+            while ((entry = table[slot]) != null) {
+                if (entry.state == state) {
+                    return entry.id;
+                }
+                slot = (slot + 1) & mask;
+            }
+            int id = paletteSize;
+            if (id > MAX_PALETTE_ID) {
+                throw new IllegalStateException("A chunk wrote more than " + MAX_PALETTE_ID + " distinct block state instances");
+            }
+            NativeBlockState[] current = states;
+            if (id == current.length) {
+                current = Arrays.copyOf(current, current.length << 1);
+            }
+            current[id] = state;
+            states = current;
+            paletteSize = id + 1;
+            PaletteEntry created = new PaletteEntry(state, id);
+            if (id << 1 >= table.length) {
+                slots = rehash(table, created);
+            } else {
+                table[slot] = created;
+            }
+            return id;
+        }
+    }
+
+    private static PaletteEntry[] rehash(PaletteEntry[] table, PaletteEntry created) {
+        PaletteEntry[] grown = new PaletteEntry[table.length << 1];
+        for (PaletteEntry entry : table) {
+            if (entry != null) {
+                place(grown, entry);
+            }
+        }
+        place(grown, created);
+        return grown;
+    }
+
+    private static void place(PaletteEntry[] table, PaletteEntry entry) {
+        int mask = table.length - 1;
+        int slot = System.identityHashCode(entry.state) & mask;
+        while (table[slot] != null) {
+            slot = (slot + 1) & mask;
+        }
+        table[slot] = entry;
+    }
+
+    private record PaletteEntry(NativeBlockState state, int id) {
+    }
+}

core/src/main/java/art/arcane/iris/generation/concurrent/MultiBurst.java

@@ -26,7 +26,7 @@ public class MultiBurst extends MultiBurstSupport {
     private final AtomicInteger parallelismBaseline = new AtomicInteger();
 
     public MultiBurst() {
-        this("Iris");
+        this("Iris", Thread.MIN_PRIORITY, MultiBurstSupport::performanceProcessors);
     }
 
     public MultiBurst(String name) {
@@ -140,8 +140,15 @@ public class MultiBurst extends MultiBurstSupport {
 
     static final class HydrologyBurst extends MultiBurst {
         HydrologyBurst() {
-            super("Iris Hydrology", () -> Math.max(2,
+            super("Iris Hydrology", HydrologyBurst::plannerParallelism);
-                    IrisSettings.getThreadCount(IrisSettings.get().getConcurrency().getParallelism())));
+        }
+
+        static int plannerParallelism() {
+            return plannerParallelism(MultiBurstSupport.performanceProcessors(), Runtime.getRuntime().availableProcessors());
+        }
+
+        static int plannerParallelism(int performanceProcessors, int availableProcessors) {
+            return Math.max(2, Math.min(Math.max(4, performanceProcessors), availableProcessors));
         }
 
         @Override

core/src/main/java/art/arcane/iris/generation/context/ChunkContext.java

@@ -5,7 +5,7 @@ import art.arcane.iris.generation.runtime.DimensionStackLayout;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.generation.runtime.IrisComplex;
 import art.arcane.iris.generation.runtime.EngineMetrics;
-import art.arcane.iris.generation.hydrology.runtime.IrisHydrologyRuntime;
+import art.arcane.iris.generation.hydrology.raster.ChunkWaterRaster;
 import art.arcane.iris.generation.biome.FloatingIslandBoundarySampler;
 import art.arcane.iris.generation.biome.IrisBiome;
 import art.arcane.iris.generation.mantle.CaveTerrainSnapshot;
@@ -17,8 +17,6 @@ import art.arcane.volmlib.nativelib.terrain.NativeBiome;
 import art.arcane.volmlib.util.hunk.Hunk;
 import art.arcane.iris.generation.concurrent.MultiBurst;
 
-import java.util.ArrayList;
-import java.util.List;
 import java.util.concurrent.CompletableFuture;
 
 public class ChunkContext {
@@ -27,6 +25,7 @@ public class ChunkContext {
     private FloatingBiomeOverlay floatingBiomes;
     private CaveTerrainSnapshot caveTerrain;
     private TransitionTerrainColumn[] transitionTerrain;
+    private volatile ChunkWaterRaster waterRaster;
     private final int x;
     private final int z;
     private final IrisComplex complex;
@@ -91,42 +90,11 @@ public class ChunkContext {
             PrefillPlan resolvedPlan = prefillPlan == null ? PrefillPlan.NO_CAVE : prefillPlan;
             boolean capturePrefillMetric = metrics != null;
             long totalStartNanos = capturePrefillMetric ? System.nanoTime() : 0L;
-            IrisHydrologyRuntime hydrologyRuntime = complex.getHydrologyRuntime();
+            if (shouldPrefillAsync(resolvedPlan, complex.isPlatformMainThread())) {
-            if (hydrologyRuntime != null && (resolvedPlan.height || resolvedPlan.biome)) {
+                prefillAsync(resolvedPlan);
-                hydrologyRuntime.prepareChunkColumns(x, z);
-            }
-            List<Runnable> fillTasks = new ArrayList<>(6);
-            if (resolvedPlan.height) {
-                fillTasks.add(() -> height.fillRounded(roundedHeight));
-            }
-            if (resolvedPlan.biome) {
-                fillTasks.add(new PrefillFillTask(biome));
-            }
-            if (resolvedPlan.rock) {
-                fillTasks.add(new PrefillFillTask(rock));
-            }
-            if (resolvedPlan.fluid) {
-                fillTasks.add(new PrefillFillTask(fluid));
-            }
-            if (resolvedPlan.region) {
-                fillTasks.add(new PrefillFillTask(region));
-            }
-            if (resolvedPlan.cave) {
-                fillTasks.add(new PrefillFillTask(cave));
-            }
-
-            if (!shouldPrefillAsync(resolvedPlan, fillTasks.size())) {
-                for (Runnable fillTask : fillTasks) {
-                    fillTask.run();
-                }
             } else {
-                List<CompletableFuture<Void>> futures = new ArrayList<>(fillTasks.size());
+                prefillSurface(resolvedPlan);
-                for (Runnable fillTask : fillTasks) {
+                prefillPalettes(resolvedPlan);
-                    futures.add(CompletableFuture.runAsync(fillTask, MultiBurst.burst));
-                }
-                for (CompletableFuture<Void> future : futures) {
-                    future.join();
-                }
             }
             if (capturePrefillMetric) {
                 metrics.getContextPrefill().put((System.nanoTime() - totalStartNanos) / 1_000_000D);
@@ -134,14 +102,49 @@ public class ChunkContext {
         }
     }
 
-    static boolean shouldPrefillAsync(PrefillPlan prefillPlan, int fillTaskCount) {
+    static boolean shouldPrefillAsync(PrefillPlan prefillPlan, boolean platformMainThread) {
-        if (prefillPlan == PrefillPlan.NATURAL_TERRAIN || fillTaskCount <= 1 || !IrisPlatforms.isBound()) {
+        if (!platformMainThread || prefillPlan == PrefillPlan.NATURAL_TERRAIN || prefillPlan == PrefillPlan.NONE
+                || !IrisPlatforms.isBound()) {
             return false;
         }
 
         return !MultiBurst.burst.ownsCurrentThread();
     }
 
+    private void prefillSurface(PrefillPlan prefillPlan) {
+        if (prefillPlan.height || prefillPlan.biome) {
+            waterRaster();
+        }
+        if (prefillPlan.height) {
+            height.fillRounded(roundedHeight);
+        }
+        if (prefillPlan.biome) {
+            biome.fill();
+        }
+    }
+
+    private void prefillPalettes(PrefillPlan prefillPlan) {
+        if (prefillPlan.rock) {
+            rock.fill();
+        }
+        if (prefillPlan.fluid) {
+            fluid.fill();
+        }
+        if (prefillPlan.region) {
+            region.fill();
+        }
+        if (prefillPlan.cave) {
+            cave.fill();
+        }
+    }
+
+    private void prefillAsync(PrefillPlan prefillPlan) {
+        CompletableFuture<Void> surface = CompletableFuture.runAsync(() -> prefillSurface(prefillPlan), MultiBurst.burst);
+        CompletableFuture<Void> palettes = CompletableFuture.runAsync(() -> prefillPalettes(prefillPlan), MultiBurst.burst);
+        surface.join();
+        palettes.join();
+    }
+
     public void setTerrainBiomeOutput(Hunk<NativeBiome> terrainBiomes) {
         this.terrainBiomes = terrainBiomes;
     }
@@ -206,6 +209,18 @@ public class ChunkContext {
         return complex;
     }
 
+    public ChunkWaterRaster waterRaster() {
+        ChunkWaterRaster known = waterRaster;
+        if (known != null) {
+            return known;
+        }
+        ChunkWaterRaster raster = complex.getHydrologyRuntime().raster(x >> 4, z >> 4);
+        if (!raster.provisional()) {
+            waterRaster = raster;
+        }
+        return raster;
+    }
+
     public FloatingIslandBoundarySampler getFloatingIslandBoundarySampler() {
         return floatingIslandBoundarySampler;
     }
@@ -295,17 +310,4 @@ public class ChunkContext {
 
     public record TransitionTerrainColumn(Terrain3DColumn solids, int fluidHeight) {
     }
-
-    private static final class PrefillFillTask implements Runnable {
-        private final ChunkedDataCache<?> dataCache;
-
-        private PrefillFillTask(ChunkedDataCache<?> dataCache) {
-            this.dataCache = dataCache;
-        }
-
-        @Override
-        public void run() {
-            dataCache.fill();
-        }
-    }
 }

core/src/main/java/art/arcane/iris/generation/decoration/DecoratorCore.java

@@ -542,7 +542,7 @@ final class DecoratorCore {
         return stack;
     }
 
-    private static boolean allowsSurface(IrisDecorator decorator, NativeBlockState surface, IrisData data) {
+    static boolean allowsSurface(IrisDecorator decorator, NativeBlockState surface, IrisData data) {
         return decorator.isForcePlace()
                 || (decorator.getWhitelist() == null || matchesPalette(decorator.getWhitelistArray(data), surface))
                 && (decorator.getBlacklist() == null || !matchesPalette(decorator.getBlacklistArray(data), surface));

core/src/main/java/art/arcane/iris/generation/decoration/DepositRandom.java

@@ -0,0 +1,82 @@
+/*
+ * Iris is a World Generator for Minecraft Bukkit Servers
+ * Copyright (c) 2026 Arcane Arts (Volmit Software)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package art.arcane.iris.generation.decoration;
+
+import art.arcane.volmlib.util.math.RNG;
+
+public final class DepositRandom extends RNG {
+    private static final long MULTIPLIER = 0x5DEECE66DL;
+    private static final long ADDEND = 0xBL;
+    private static final long MASK = (1L << 48) - 1L;
+    private static final int JUMP_TABLE_SIZE = 48;
+    private static final long[] JUMP_MULTIPLIERS = new long[JUMP_TABLE_SIZE];
+    private static final long[] JUMP_ADDENDS = new long[JUMP_TABLE_SIZE];
+
+    static {
+        long multiplier = MULTIPLIER;
+        long addend = ADDEND;
+        for (int bit = 0; bit < JUMP_TABLE_SIZE; bit++) {
+            JUMP_MULTIPLIERS[bit] = multiplier;
+            JUMP_ADDENDS[bit] = addend;
+            addend = (addend * multiplier + addend) & MASK;
+            multiplier = (multiplier * multiplier) & MASK;
+        }
+    }
+
+    private long state;
+
+    public DepositRandom() {
+        super(0L);
+    }
+
+    public DepositRandom(long seed) {
+        super(seed);
+    }
+
+    @Override
+    public void setSeed(long seed) {
+        state = (seed ^ MULTIPLIER) & MASK;
+    }
+
+    @Override
+    protected int next(int bits) {
+        long advanced = (state * MULTIPLIER + ADDEND) & MASK;
+        state = advanced;
+        return (int) (advanced >>> (48 - bits));
+    }
+
+    public long state() {
+        return state;
+    }
+
+    public void restore(long state) {
+        this.state = state & MASK;
+    }
+
+    public void skip(long steps) {
+        long remaining = steps;
+        long advanced = state;
+        for (int bit = 0; remaining != 0L && bit < JUMP_TABLE_SIZE; bit++, remaining >>>= 1) {
+            if ((remaining & 1L) != 0L) {
+                advanced = (advanced * JUMP_MULTIPLIERS[bit] + JUMP_ADDENDS[bit]) & MASK;
+            }
+        }
+        state = advanced;
+    }
+}

core/src/main/java/art/arcane/iris/generation/decoration/HydrologyVegetation.java

@@ -0,0 +1,390 @@
+package art.arcane.iris.generation.decoration;
+
+import art.arcane.iris.generation.block.B;
+import art.arcane.iris.generation.block.IrisBlockData;
+import art.arcane.iris.generation.hydrology.plan.HydrologySettings;
+import art.arcane.iris.generation.hydrology.raster.WaterRole;
+import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.iris.pack.loading.IrisData;
+import art.arcane.volmlib.nativelib.terrain.NativeBlockState;
+import art.arcane.volmlib.util.hunk.Hunk;
+import art.arcane.volmlib.util.math.RNG;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public final class HydrologyVegetation {
+    private static final long SALT = 0x4859445256454745L;
+    private static final long GOLDEN = 0x9e3779b97f4a7c15L;
+    private static final int[][] SIDES = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
+
+    private final long seed;
+    private final Engine engine;
+    private final RNG floorRng;
+    private final RNG surfaceRng;
+    private final RNG shoreRng;
+
+    public HydrologyVegetation(long seed, Engine engine) {
+        this.seed = seed ^ SALT;
+        this.engine = engine;
+        this.floorRng = new RNG(DecoratorCore.partSeed(this.seed, IrisDecorationPart.SEA_FLOOR));
+        this.surfaceRng = new RNG(DecoratorCore.partSeed(this.seed, IrisDecorationPart.SEA_SURFACE));
+        this.shoreRng = new RNG(DecoratorCore.partSeed(this.seed, IrisDecorationPart.SHORE_LINE));
+    }
+
+    public void decorate(Hunk<NativeBlockState> output, int localX, int localZ, int x, int z, WaterRole role, Water water, IrisData data) {
+        Placement placement = placement(role);
+        if (placement == Placement.NONE) {
+            return;
+        }
+        Decorators decorators = water.decorators(x, z);
+        if (decorators.empty()) {
+            return;
+        }
+        int ground = water.ground(x, z);
+        if (ground < 0 || ground + 1 >= output.getHeight()) {
+            return;
+        }
+        Column column = new Column(output, localX, localZ, x, z, ground, water, data);
+        if (placement == Placement.SHORE) {
+            decorateShore(column, decorators.shore);
+            return;
+        }
+        int head = water.head(x, z);
+        if (head <= ground || head + 1 >= output.getHeight()) {
+            return;
+        }
+        decorateFloor(column, head, decorators.floor);
+        if (placement == Placement.STILL && decorators.surface.length > 0 && still(water, x, z, head)) {
+            decorateSurface(column, head, decorators.surface);
+        }
+    }
+
+    private static Placement placement(WaterRole role) {
+        return switch (role) {
+            case CHANNEL, POND -> Placement.STILL;
+            case CASCADE, WATERFALL -> Placement.FLOOR;
+            case BANK, SHORE, POND_SHORE -> Placement.SHORE;
+            case NONE, DAM, MOUTH, INLET -> Placement.NONE;
+        };
+    }
+
+    private void decorateFloor(Column column, int head, IrisDecorator[] bucket) {
+        int room = head - column.ground - 1;
+        if (room < 1 || bucket.length == 0) {
+            return;
+        }
+        IrisDecorator decorator = pick(bucket, floorRng, column, IrisDecorationPart.SEA_FLOOR);
+        NativeBlockState support = column.output.get(column.localX, column.ground, column.localZ);
+        if (decorator == null || !B.isSolid(support) || !column.accepts(decorator, support)) {
+            return;
+        }
+        column.place(decorator, floorRng, column.ground + 1, room, Slot.FLOOR, null);
+    }
+
+    private void decorateSurface(Column column, int head, IrisDecorator[] bucket) {
+        NativeBlockState support = column.output.get(column.localX, head, column.localZ);
+        if (!isWaterSource(support)) {
+            return;
+        }
+        IrisDecorator decorator = pick(bucket, surfaceRng, column, IrisDecorationPart.SEA_SURFACE);
+        if (decorator == null || !column.accepts(decorator, support)) {
+            return;
+        }
+        column.place(decorator, surfaceRng, head + 1, column.output.getHeight() - head - 1, Slot.SURFACE, null);
+    }
+
+    private void decorateShore(Column column, IrisDecorator[] bucket) {
+        NativeBlockState support = column.output.get(column.localX, column.ground, column.localZ);
+        if (bucket.length == 0 || support == null || !support.isSolid()) {
+            return;
+        }
+        IrisDecorator decorator = pick(bucket, shoreRng, column, IrisDecorationPart.SHORE_LINE);
+        if (decorator == null || !column.accepts(decorator, support)) {
+            return;
+        }
+        column.place(decorator, shoreRng, column.ground + 1, column.output.getHeight() - column.ground - 1, Slot.SHORE, support);
+    }
+
+    private IrisDecorator pick(IrisDecorator[] bucket, RNG partRng, Column column, IrisDecorationPart part) {
+        IrisDecorator picked = null;
+        long choice = seed + part.ordinal();
+        int count = 0;
+        for (IrisDecorator decorator : bucket) {
+            if (!decorator.passesChanceGate(partRng, column.x, column.z, column.data)) {
+                continue;
+            }
+            count++;
+            choice = mix(choice ^ mix(column.x * 0x632be59bd9b4e019L + column.z * 0x8cb92ba72f3d8dd7L + count));
+            if (count == 1 || Long.remainderUnsigned(choice, count) == 0L) {
+                picked = decorator;
+            }
+        }
+        if (picked == null || picked.isForcePlace() || picked.getSlopeCondition().isDefault()
+                || picked.getSlopeCondition().isValid(column.water.slope(column.x, column.z))) {
+            return picked;
+        }
+        return null;
+    }
+
+    static boolean still(Water water, int x, int z, int head) {
+        for (int[] side : SIDES) {
+            int neighbourX = x + side[0];
+            int neighbourZ = z + side[1];
+            int neighbourHead = water.head(neighbourX, neighbourZ);
+            if (neighbourHead != head && water.ground(neighbourX, neighbourZ) < neighbourHead) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    static boolean isWaterSource(NativeBlockState state) {
+        if (state == null || !state.isWater()) {
+            return false;
+        }
+        String level = IrisProceduralBlocks.propertyValue(state, "level");
+        return level == null || level.equals("0");
+    }
+
+    static boolean holdsWater(NativeBlockState state) {
+        return B.isFluid(state) || B.isWaterLogged(state) || IrisSurfaceDecorator.isAquaticPlacement(state);
+    }
+
+    static boolean plannedWater(Water water, int x, int z, int y) {
+        int ground = water.ground(x, z);
+        int top = water.head(x, z);
+        if (y <= ground || top <= ground) {
+            return false;
+        }
+        for (int[] side : SIDES) {
+            int neighbourHead = water.head(x + side[0], z + side[1]);
+            if (neighbourHead > top && water.ground(x + side[0], z + side[1]) < neighbourHead) {
+                top = neighbourHead;
+            }
+        }
+        return y <= top;
+    }
+
+    private static boolean twoBlock(NativeBlockState state) {
+        String half = IrisProceduralBlocks.propertyValue(state, "half");
+        return "lower".equals(half) || "upper".equals(half);
+    }
+
+    private static long mix(long value) {
+        long mixed = (value + GOLDEN ^ (value + GOLDEN >>> 30)) * 0xbf58476d1ce4e5b9L;
+        mixed = (mixed ^ (mixed >>> 27)) * 0x94d049bb133111ebL;
+        return mixed ^ (mixed >>> 31);
+    }
+
+    public interface Water {
+        int ground(int x, int z);
+
+        int head(int x, int z);
+
+        double slope(int x, int z);
+
+        Decorators decorators(int x, int z);
+    }
+
+    private enum Placement {
+        NONE,
+        SHORE,
+        FLOOR,
+        STILL
+    }
+
+    private enum Slot {
+        FLOOR,
+        SURFACE,
+        SHORE
+    }
+
+    private final class Column {
+        private final Hunk<NativeBlockState> output;
+        private final int localX;
+        private final int localZ;
+        private final int x;
+        private final int z;
+        private final int ground;
+        private final Water water;
+        private final IrisData data;
+
+        private Column(Hunk<NativeBlockState> output, int localX, int localZ, int x, int z, int ground, Water water, IrisData data) {
+            this.output = output;
+            this.localX = localX;
+            this.localZ = localZ;
+            this.x = x;
+            this.z = z;
+            this.ground = ground;
+            this.water = water;
+            this.data = data;
+        }
+
+        private boolean accepts(IrisDecorator decorator, NativeBlockState support) {
+            return decorator.isForcePlace() || DecoratorCore.allowsSurface(decorator, support, data);
+        }
+
+        private int stack(IrisDecorator decorator, RNG rng, int room) {
+            return decorator.isStacking() ? Math.min(room, DecoratorCore.computeStack(decorator, rng, x, z, data, room)) : 1;
+        }
+
+        private void place(IrisDecorator decorator, RNG rng, int baseY, int room, Slot slot, NativeBlockState support) {
+            NativeBlockState first = decorator.pickBlockData(rng, data, x, z);
+            if (first == null) {
+                return;
+            }
+            if (twoBlock(first)) {
+                if (room >= 2) {
+                    placePair(decorator, first, baseY, slot, support);
+                }
+                return;
+            }
+            int stack = stack(decorator, rng, room);
+            NativeBlockState sampled = first;
+            boolean sampledTop = false;
+            for (int index = 0; index < stack; index++) {
+                int y = baseY + index;
+                boolean top = (stack == 1 ? 1D : (double) index / (stack - 1)) >= decorator.getTopThreshold();
+                if (top != sampledTop) {
+                    sampled = top ? decorator.pickBlockDataTop(rng, data, x, z) : decorator.pickBlockData(rng, data, x, z);
+                    sampledTop = top;
+                }
+                NativeBlockState block = sampled == null ? null : fit(sampled, y, slot, decorator, index == 0 ? support : null);
+                if (block == null) {
+                    return;
+                }
+                output.set(localX, y, localZ, block);
+            }
+        }
+
+        private void placePair(IrisDecorator decorator, NativeBlockState block, int y, Slot slot, NativeBlockState support) {
+            NativeBlockState lower = fit(block.withProperty("half", "lower"), y, slot, decorator, support);
+            NativeBlockState upper = lower == null ? null : fit(block.withProperty("half", "upper"), y + 1, slot, decorator, null);
+            if (upper != null) {
+                output.set(localX, y, localZ, lower);
+                output.set(localX, y + 1, localZ, upper);
+            }
+        }
+
+        private NativeBlockState fit(NativeBlockState block, int y, Slot slot, IrisDecorator decorator, NativeBlockState support) {
+            NativeBlockState existing = output.get(localX, y, localZ);
+            if (slot == Slot.FLOOR) {
+                NativeBlockState placed = IrisProceduralBlocks.normalizeWaterlogging(block, existing, true);
+                return isWaterSource(existing) && IrisSurfaceDecorator.isAquaticPlacement(placed) ? placed : null;
+            }
+            if (!B.isAir(existing) || holdsWater(block)) {
+                return null;
+            }
+            if (slot == Slot.SURFACE) {
+                return block;
+            }
+            if (besideWater(y) || support != null && !DecoratorCore.isValidShorelineSupport(decorator, block, support)) {
+                return null;
+            }
+            return IrisSugarCane.canPlace(block, output, localX, y, localZ, x, z, engine) ? block : null;
+        }
+
+        private boolean besideWater(int y) {
+            for (int[] side : SIDES) {
+                int neighbourX = localX + side[0];
+                int neighbourZ = localZ + side[1];
+                if (neighbourX >= 0 && neighbourX < output.getWidth() && neighbourZ >= 0 && neighbourZ < output.getDepth()) {
+                    if (holdsWater(output.get(neighbourX, y, neighbourZ))) {
+                        return true;
+                    }
+                } else if (plannedWater(water, x + side[0], z + side[1], y)) {
+                    return true;
+                }
+            }
+            return false;
+        }
+    }
+
+    public static final class Decorators {
+        public static final Decorators EMPTY = new Decorators(new IrisDecorator[0], new IrisDecorator[0], new IrisDecorator[0]);
+
+        private final IrisDecorator[] floor;
+        private final IrisDecorator[] surface;
+        private final IrisDecorator[] shore;
+
+        private Decorators(IrisDecorator[] floor, IrisDecorator[] surface, IrisDecorator[] shore) {
+            this.floor = floor;
+            this.surface = surface;
+            this.shore = shore;
+        }
+
+        public static Decorators compile(List<IrisDecorator> decorators, IrisData data, String path) {
+            HydrologySettings.requireDecorators(decorators, path);
+            if (decorators == null || decorators.isEmpty()) {
+                return EMPTY;
+            }
+            List<IrisDecorator> floor = new ArrayList<>();
+            List<IrisDecorator> surface = new ArrayList<>();
+            List<IrisDecorator> shore = new ArrayList<>();
+            for (int index = 0; index < decorators.size(); index++) {
+                IrisDecorator decorator = decorators.get(index);
+                String field = path + "[" + index + "]";
+                IrisDecorationPart part = decorator.getPartOf();
+                requirePlaced(decorator.getPalette(), data, field + ".palette", part);
+                requirePlaced(decorator.getTopPalette(), data, field + ".topPalette", part);
+                requireKnown(decorator.getWhitelist(), data, field + ".whitelist");
+                requireKnown(decorator.getBlacklist(), data, field + ".blacklist");
+                switch (part) {
+                    case SEA_FLOOR -> floor.add(decorator);
+                    case SEA_SURFACE -> surface.add(decorator);
+                    default -> shore.add(decorator);
+                }
+            }
+            return new Decorators(floor.toArray(new IrisDecorator[0]), surface.toArray(new IrisDecorator[0]), shore.toArray(new IrisDecorator[0]));
+        }
+
+        public boolean empty() {
+            return floor.length == 0 && surface.length == 0 && shore.length == 0;
+        }
+
+        private static void requirePlaced(List<IrisBlockData> blocks, IrisData data, String path, IrisDecorationPart part) {
+            if (blocks == null) {
+                return;
+            }
+            for (int index = 0; index < blocks.size(); index++) {
+                String field = path + "[" + index + "]";
+                String name = blocks.get(index).getBlock();
+                NativeBlockState state = requireKnown(blocks.get(index), data, field);
+                if (state.isFluid()) {
+                    throw new IllegalArgumentException(field + " names the fluid '" + name + "'; water decorators never place fluids");
+                }
+                if (part == IrisDecorationPart.SEA_FLOOR && !waterCompatible(state)) {
+                    throw new IllegalArgumentException(field + " names '" + name + "', which cannot stand in water; SEA_FLOOR decorators place"
+                            + " only waterloggable or water plants such as seagrass, kelp, coral and sea pickles");
+                }
+                if (part != IrisDecorationPart.SEA_FLOOR && holdsWater(state)) {
+                    throw new IllegalArgumentException(field + " names '" + name + "', which holds water; " + part
+                            + " decorators grow in air and place only blocks without water, never waterlogged blocks, seagrass, kelp, sea pickles or coral");
+                }
+            }
+        }
+
+        private static void requireKnown(List<IrisBlockData> blocks, IrisData data, String path) {
+            if (blocks == null) {
+                return;
+            }
+            for (int index = 0; index < blocks.size(); index++) {
+                requireKnown(blocks.get(index), data, path + "[" + index + "]");
+            }
+        }
+
+        private static NativeBlockState requireKnown(IrisBlockData block, IrisData data, String path) {
+            NativeBlockState state = block.getBlockData(data);
+            if (state == null || state.isAir()) {
+                throw new IllegalArgumentException(path + " names the block '" + block.getBlock()
+                        + "', which does not exist on this server; water decorators never place air");
+            }
+            return state;
+        }
+
+        private static boolean waterCompatible(NativeBlockState state) {
+            return IrisSurfaceDecorator.isAquaticPlacement(state) || IrisProceduralBlocks.propertyValue(state, "waterlogged") != null;
+        }
+    }
+}

core/src/main/java/art/arcane/iris/generation/decoration/IrisDepositGenerator.java

@@ -39,6 +39,7 @@ import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.collection.KSet;
 import art.arcane.volmlib.util.math.BlockPosition;
 import art.arcane.volmlib.util.math.RNG;
+import java.util.Arrays;
 import java.util.LinkedHashSet;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
@@ -57,6 +58,7 @@ import lombok.experimental.Accessors;
 public class IrisDepositGenerator {
     private static final int FOOTPRINT_MAXIMUM_SIZE = 64;
     private static final ThreadLocal<FootprintCells> FOOTPRINT_CELLS = ThreadLocal.withInitial(FootprintCells::new);
+    private static final double[][] NODE_SINES = nodeSines();
     private static final long FNV_OFFSET_BASIS = 0xcbf29ce484222325L;
     private static final long FNV_PRIME = 0x100000001b3L;
 
@@ -282,28 +284,52 @@ public class IrisDepositGenerator {
      * only for clumps it keeps. Returns null without drawing when the shape has no footprint path.
      */
     public ClumpFootprint sampleClumpFootprint(RNG rng, IrisData rdata) {
-        if (shape != IrisDepositShape.VANILLA_ELLIPSOID || minSize > FOOTPRINT_MAXIMUM_SIZE
+        if (!usesClumpFootprints(rdata)) {
-                || maxSize > FOOTPRINT_MAXIMUM_SIZE) {
-            return null;
-        }
-        int paletteSize = getBlockData(rdata).size();
-        if (paletteSize == 0) {
             return null;
         }
+        KList<NativeBlockState> resolvedPalette = getBlockData(rdata);
+        int paletteSize = resolvedPalette.size();
         int size = rng.i(minSize, maxSize + 1);
         if (size <= 0) {
             return ClumpFootprint.EMPTY;
         }
         FootprintCells cells = FOOTPRINT_CELLS.get();
         cells.reset();
-        vanillaEllipsoidCells(rng, size, cells);
+        if (paletteSize == 1) {
+            emitEllipsoidRows(rng, size, cells);
+            if (cells.count == 0) {
+                return ClumpFootprint.EMPTY;
+            }
+            skipUniformPicks(rng, cells.count);
+        } else {
+            emitEllipsoidCells(rng, size, cells, cells.scratch);
             if (cells.count == 0) {
                 return ClumpFootprint.EMPTY;
             }
             for (int cell = 0; cell < cells.count; cell++) {
-            rng.i(0, paletteSize);
+                cells.picks[cell] = rng.i(0, paletteSize);
+            }
+        }
+        return new ClumpFootprint(cells.extentX * 2 + 1, cells.minY, cells, cells.stamp, resolvedPalette);
+    }
+
+    public boolean usesClumpFootprints(IrisData rdata) {
+        return shape == IrisDepositShape.VANILLA_ELLIPSOID && minSize <= FOOTPRINT_MAXIMUM_SIZE
+                && maxSize <= FOOTPRINT_MAXIMUM_SIZE && !getBlockData(rdata).isEmpty();
+    }
+
+    public static int lowestFootprintOffset(int size) {
+        return -4 - (Math.max(0, size) + 15) / 16;
+    }
+
+    private static void skipUniformPicks(RNG rng, int count) {
+        if (rng instanceof DepositRandom random) {
+            random.skip(2L * count);
+            return;
+        }
+        for (int cell = 0; cell < count; cell++) {
+            rng.nextDouble();
         }
-        return new ClumpFootprint(cells.extentX * 2 + 1, cells.minY, false);
     }
 
     /**
@@ -312,15 +338,87 @@ public class IrisDepositGenerator {
      * test is bit-identical to evaluating {@code nx * nx + ny * ny + nz * nz} in place.
      */
     static void vanillaEllipsoidCells(RNG rng, int size, CellSink sink) {
+        emitEllipsoidCells(rng, size, sink, new EllipsoidScratch());
+    }
+
+    private static void emitEllipsoidCells(RNG rng, int size, CellSink sink, EllipsoidScratch scratch) {
+        double[] nodes = ellipsoidNodes(rng, size, scratch);
+        for (int node = 0; node < size; node++) {
+            if (!scratch.sphere(nodes, node)) {
+                continue;
+            }
+            double[] squaredY = scratch.squaredY;
+            double[] squaredZ = scratch.squaredZ;
+            for (int x = scratch.minX; x <= scratch.maxX; x++) {
+                double nx = (x + 0.5D - scratch.centerX) / scratch.radius;
+                double squaredX = nx * nx;
+                if (squaredX >= 1D) {
+                    continue;
+                }
+                for (int y = 0; y < scratch.spanY; y++) {
+                    double squaredXY = squaredX + squaredY[y];
+                    if (squaredXY >= 1D) {
+                        continue;
+                    }
+                    for (int z = 0; z < scratch.spanZ; z++) {
+                        if (squaredXY + squaredZ[z] < 1D) {
+                            sink.add(x, scratch.minY + y, scratch.minZ + z);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    private static void emitEllipsoidRows(RNG rng, int size, FootprintCells cells) {
+        EllipsoidScratch scratch = cells.scratch;
+        double[] nodes = ellipsoidNodes(rng, size, scratch);
+        for (int node = 0; node < size; node++) {
+            if (!scratch.sphere(nodes, node)) {
+                continue;
+            }
+            double[] squaredY = scratch.squaredY;
+            double[] squaredZ = scratch.squaredZ;
+            int zShift = scratch.minZ + FootprintCells.OFFSET;
+            for (int x = scratch.minX; x <= scratch.maxX; x++) {
+                double nx = (x + 0.5D - scratch.centerX) / scratch.radius;
+                double squaredX = nx * nx;
+                if (squaredX >= 1D) {
+                    continue;
+                }
+                for (int y = 0; y < scratch.spanY; y++) {
+                    double squaredXY = squaredX + squaredY[y];
+                    if (squaredXY >= 1D) {
+                        continue;
+                    }
+                    long row = 0L;
+                    for (int z = 0; z < scratch.spanZ; z++) {
+                        if (squaredXY + squaredZ[z] < 1D) {
+                            row |= 1L << (zShift + z);
+                        }
+                    }
+                    if (row != 0L) {
+                        cells.addRow(x, scratch.minY + y, row);
+                    }
+                }
+            }
+        }
+        cells.finishRows();
+    }
+
+    private static double[] ellipsoidNodes(RNG rng, int size, EllipsoidScratch scratch) {
         float angle = rng.nextFloat() * (float) Math.PI;
         float reach = size / 8F;
-        double startX = Math.sin(angle) * reach;
+        double sine = Math.sin(angle);
-        double endX = -Math.sin(angle) * reach;
+        double cosine = Math.cos(angle);
-        double startZ = Math.cos(angle) * reach;
+        double startX = sine * reach;
-        double endZ = -Math.cos(angle) * reach;
+        double endX = -sine * reach;
+        double startZ = cosine * reach;
+        double endZ = -cosine * reach;
         double startY = rng.nextInt(3) - 2;
         double endY = rng.nextInt(3) - 2;
-        double[] nodes = new double[size * 4];
+        double[] nodes = scratch.nodes(size * 4);
+        double[] sines = size < NODE_SINES.length ? NODE_SINES[size] : null;
 
         for (int i = 0; i < size; i++) {
             float progress = (float) i / size;
@@ -328,7 +426,8 @@ public class IrisDepositGenerator {
             nodes[i * 4] = startX + (endX - startX) * progress;
             nodes[i * 4 + 1] = startY + (endY - startY) * progress;
             nodes[i * 4 + 2] = startZ + (endZ - startZ) * progress;
-            nodes[i * 4 + 3] = ((Math.sin(Math.PI * progress) + 1D) * radiusNoise + 1D) / 2D;
+            double arc = sines == null ? Math.sin(Math.PI * progress) : sines[i];
+            nodes[i * 4 + 3] = ((arc + 1D) * radiusNoise + 1D) / 2D;
         }
 
         for (int i = 0; i < size - 1; i++) {
@@ -353,59 +452,20 @@ public class IrisDepositGenerator {
                 }
             }
         }
+        return nodes;
+    }
 
-        double[] squaredY = new double[16];
+    private static double[][] nodeSines() {
-        double[] squaredZ = new double[16];
+        double[][] sines = new double[FOOTPRINT_MAXIMUM_SIZE + 1][];
+        for (int size = 1; size <= FOOTPRINT_MAXIMUM_SIZE; size++) {
+            double[] values = new double[size];
             for (int i = 0; i < size; i++) {
-            double radius = nodes[i * 4 + 3];
+                float progress = (float) i / size;
-            if (radius < 0D) {
+                values[i] = Math.sin(Math.PI * progress);
-                continue;
-            }
-            double centerX = nodes[i * 4];
-            double centerY = nodes[i * 4 + 1];
-            double centerZ = nodes[i * 4 + 2];
-            int minX = (int) Math.floor(centerX - radius);
-            int maxX = Math.max((int) Math.floor(centerX + radius), minX);
-            int minY = (int) Math.floor(centerY - radius);
-            int maxY = Math.max((int) Math.floor(centerY + radius), minY);
-            int minZ = (int) Math.floor(centerZ - radius);
-            int maxZ = Math.max((int) Math.floor(centerZ + radius), minZ);
-            int spanY = maxY - minY + 1;
-            int spanZ = maxZ - minZ + 1;
-            if (spanY > squaredY.length) {
-                squaredY = new double[spanY];
-            }
-            if (spanZ > squaredZ.length) {
-                squaredZ = new double[spanZ];
-            }
-            for (int y = 0; y < spanY; y++) {
-                double ny = (minY + y + 0.5D - centerY) / radius;
-                squaredY[y] = ny * ny;
-            }
-            for (int z = 0; z < spanZ; z++) {
-                double nz = (minZ + z + 0.5D - centerZ) / radius;
-                squaredZ[z] = nz * nz;
-            }
-
-            for (int x = minX; x <= maxX; x++) {
-                double nx = (x + 0.5D - centerX) / radius;
-                double squaredX = nx * nx;
-                if (squaredX >= 1D) {
-                    continue;
-                }
-                for (int y = 0; y < spanY; y++) {
-                    double squaredXY = squaredX + squaredY[y];
-                    if (squaredXY >= 1D) {
-                        continue;
-                    }
-                    for (int z = 0; z < spanZ; z++) {
-                        if (squaredXY + squaredZ[z] < 1D) {
-                            sink.add(x, minY + y, minZ + z);
-                        }
-                    }
-                }
             }
+            sines[size] = values;
         }
+        return sines;
     }
 
     IrisObject generateVanillaScattered(RNG rng, IrisData rdata, int size) {
@@ -630,8 +690,134 @@ public class IrisDepositGenerator {
         void add(int x, int y, int z);
     }
 
-    public record ClumpFootprint(int width, int minY, boolean empty) {
+    public static final class ClumpFootprint {
-        static final ClumpFootprint EMPTY = new ClumpFootprint(1, 0, true);
+        static final ClumpFootprint EMPTY = new ClumpFootprint(1, 0, null, 0L, null);
+
+        private final int width;
+        private final int minY;
+        private final FootprintCells source;
+        private final long stamp;
+        private final KList<NativeBlockState> palette;
+
+        private ClumpFootprint(int width, int minY, FootprintCells source, long stamp, KList<NativeBlockState> palette) {
+            this.width = width;
+            this.minY = minY;
+            this.source = source;
+            this.stamp = stamp;
+            this.palette = palette;
+        }
+
+        public int width() {
+            return width;
+        }
+
+        public int minY() {
+            return minY;
+        }
+
+        public boolean empty() {
+            return source == null;
+        }
+
+        public ClumpCells cells() {
+            if (source == null) {
+                return ClumpCells.EMPTY;
+            }
+            if (source.stamp != stamp) {
+                throw new IllegalStateException("Deposit footprint cells were resampled before they were read");
+            }
+            return source.toCells(palette);
+        }
+    }
+
+    public static final class ClumpCells {
+        static final ClumpCells EMPTY = new ClumpCells(new int[0], new NativeBlockState[0], null);
+
+        private final int[] positions;
+        private final NativeBlockState[] blocks;
+        private final NativeBlockState uniform;
+
+        private ClumpCells(int[] positions, NativeBlockState[] blocks, NativeBlockState uniform) {
+            this.positions = positions;
+            this.blocks = blocks;
+            this.uniform = uniform;
+        }
+
+        public int size() {
+            return positions.length;
+        }
+
+        public int x(int cell) {
+            return (positions[cell] >> 12) - FootprintCells.OFFSET;
+        }
+
+        public int y(int cell) {
+            return ((positions[cell] >> 6) & (FootprintCells.AXIS - 1)) - FootprintCells.OFFSET;
+        }
+
+        public int z(int cell) {
+            return (positions[cell] & (FootprintCells.AXIS - 1)) - FootprintCells.OFFSET;
+        }
+
+        public NativeBlockState block(int cell) {
+            return blocks == null ? uniform : blocks[cell];
+        }
+    }
+
+    private static final class EllipsoidScratch {
+        private double[] nodes = new double[256];
+        private double[] squaredY = new double[16];
+        private double[] squaredZ = new double[16];
+        private double centerX;
+        private double radius;
+        private int minX;
+        private int maxX;
+        private int minY;
+        private int spanY;
+        private int minZ;
+        private int spanZ;
+
+        private double[] nodes(int length) {
+            if (nodes.length < length) {
+                nodes = new double[length];
+            }
+            return nodes;
+        }
+
+        private boolean sphere(double[] values, int node) {
+            double sphereRadius = values[node * 4 + 3];
+            if (sphereRadius < 0D) {
+                return false;
+            }
+            double sphereX = values[node * 4];
+            double sphereY = values[node * 4 + 1];
+            double sphereZ = values[node * 4 + 2];
+            minX = (int) Math.floor(sphereX - sphereRadius);
+            maxX = Math.max((int) Math.floor(sphereX + sphereRadius), minX);
+            minY = (int) Math.floor(sphereY - sphereRadius);
+            int maxY = Math.max((int) Math.floor(sphereY + sphereRadius), minY);
+            minZ = (int) Math.floor(sphereZ - sphereRadius);
+            int maxZ = Math.max((int) Math.floor(sphereZ + sphereRadius), minZ);
+            spanY = maxY - minY + 1;
+            spanZ = maxZ - minZ + 1;
+            if (spanY > squaredY.length) {
+                squaredY = new double[spanY];
+            }
+            if (spanZ > squaredZ.length) {
+                squaredZ = new double[spanZ];
+            }
+            for (int y = 0; y < spanY; y++) {
+                double ny = (minY + y + 0.5D - sphereY) / sphereRadius;
+                squaredY[y] = ny * ny;
+            }
+            for (int z = 0; z < spanZ; z++) {
+                double nz = (minZ + z + 0.5D - sphereZ) / sphereRadius;
+                squaredZ[z] = nz * nz;
+            }
+            centerX = sphereX;
+            radius = sphereRadius;
+            return true;
+        }
     }
 
     private static final class FootprintCells implements CellSink {
@@ -639,10 +825,16 @@ public class IrisDepositGenerator {
         private static final int AXIS = 64;
         private final long[] occupied = new long[AXIS * AXIS * AXIS / 64];
         private final int[] touched = new int[AXIS * AXIS * AXIS / 64];
+        private final EllipsoidScratch scratch = new EllipsoidScratch();
+        private int[] order = new int[256];
+        private int[] picks = new int[256];
+        private long[] sortKeys = new long[256];
         private int touchedCount;
         private int count;
         private int extentX;
         private int minY;
+        private boolean uniform;
+        private long stamp;
 
         private void reset() {
             for (int index = 0; index < touchedCount; index++) {
@@ -652,6 +844,8 @@ public class IrisDepositGenerator {
             count = 0;
             extentX = 0;
             minY = Integer.MAX_VALUE;
+            uniform = false;
+            stamp++;
         }
 
         @Override
@@ -667,9 +861,72 @@ public class IrisDepositGenerator {
                 touched[touchedCount++] = word;
             }
             occupied[word] = current | bit;
-            count++;
+            if (count == order.length) {
+                order = Arrays.copyOf(order, count * 2);
+                picks = Arrays.copyOf(picks, count * 2);
+                sortKeys = new long[count * 2];
+            }
+            order[count++] = index;
             extentX = Math.max(extentX, Math.abs(x));
             minY = Math.min(minY, y);
         }
+
+        private void addRow(int x, int y, long row) {
+            int word = (x + OFFSET) * AXIS + (y + OFFSET);
+            long current = occupied[word];
+            if (current == 0L) {
+                touched[touchedCount++] = word;
+            }
+            occupied[word] = current | row;
+        }
+
+        private void finishRows() {
+            int cells = 0;
+            int extent = 0;
+            int lowest = Integer.MAX_VALUE;
+            for (int index = 0; index < touchedCount; index++) {
+                int word = touched[index];
+                cells += Long.bitCount(occupied[word]);
+                extent = Math.max(extent, Math.abs(word / AXIS - OFFSET));
+                lowest = Math.min(lowest, word % AXIS - OFFSET);
+            }
+            count = cells;
+            extentX = extent;
+            minY = lowest;
+            uniform = true;
+        }
+
+        private ClumpCells toCells(KList<NativeBlockState> palette) {
+            if (uniform) {
+                return toUniformCells(palette.get(0));
+            }
+            for (int cell = 0; cell < count; cell++) {
+                sortKeys[cell] = ((long) order[cell] << 32) | picks[cell];
+            }
+            Arrays.sort(sortKeys, 0, count);
+            int[] positions = new int[count];
+            NativeBlockState[] blocks = new NativeBlockState[count];
+            for (int cell = 0; cell < count; cell++) {
+                long key = sortKeys[cell];
+                positions[cell] = (int) (key >>> 32);
+                blocks[cell] = palette.get((int) key);
+            }
+            return new ClumpCells(positions, blocks, null);
+        }
+
+        private ClumpCells toUniformCells(NativeBlockState block) {
+            Arrays.sort(touched, 0, touchedCount);
+            int[] positions = new int[count];
+            int cell = 0;
+            for (int index = 0; index < touchedCount; index++) {
+                int word = touched[index];
+                long row = occupied[word];
+                while (row != 0L) {
+                    positions[cell++] = (word << 6) | Long.numberOfTrailingZeros(row);
+                    row &= row - 1L;
+                }
+            }
+            return new ClumpCells(positions, null, block);
+        }
     }
 }

core/src/main/java/art/arcane/iris/generation/decoration/IrisOreBands.java

@@ -1,5 +1,6 @@
 package art.arcane.iris.generation.decoration;
 
+import art.arcane.iris.generation.runtime.Engine;
 import art.arcane.iris.pack.loading.IrisData;
 import art.arcane.iris.pack.value.IrisRange;
 import art.arcane.volmlib.nativelib.terrain.NativeBlockState;
@@ -79,6 +80,14 @@ public final class IrisOreBands {
         return minY <= maxY;
     }
 
+    public int lowestY() {
+        return minY;
+    }
+
+    public int highestY() {
+        return maxY;
+    }
+
     public boolean contains(int y) {
         return y >= minY && y <= maxY;
     }
@@ -86,10 +95,10 @@ public final class IrisOreBands {
     /**
      * The ore placed at a Y inside {@link #contains(int)}, or null when no generator places one.
      */
-    public NativeBlockState generate(int x, int y, int z, RNG rng, IrisData data) {
+    public NativeBlockState generate(int x, int y, int z, RNG rng, IrisData data, Engine engine) {
         IrisOreGenerator[] candidates = byY == null ? generators : byY[y - minY];
         for (IrisOreGenerator candidate : candidates) {
-            NativeBlockState ore = candidate.generate(x, y, z, rng, data);
+            NativeBlockState ore = candidate.generate(x, y, z, rng, data, engine);
             if (ore != null) {
                 return ore;
             }

core/src/main/java/art/arcane/iris/generation/decoration/IrisOreGenerator.java

@@ -65,6 +65,10 @@ public class IrisOreGenerator {
     }
 
     public NativeBlockState generate(int x, int y, int z, RNG rng, IrisData data) {
+        return generate(x, y, z, rng, data, data == null ? null : data.getEngine());
+    }
+
+    public NativeBlockState generate(int x, int y, int z, RNG rng, IrisData data, Engine engine) {
         if (threshold <= 0 || !range.contains(y)) {
             return null;
         }
@@ -73,7 +77,7 @@ public class IrisOreGenerator {
             return null;
         }
 
-        if (chance(rng, data).sample(x, y, z) > threshold) {
+        if (chance(rng, data, engine).sample(x, y, z) > threshold) {
             return null;
         }
 
@@ -81,8 +85,11 @@ public class IrisOreGenerator {
     }
 
     private OreChance chance(RNG rng, IrisData data) {
+        return chance(rng, data, data == null ? null : data.getEngine());
+    }
+
+    private OreChance chance(RNG rng, IrisData data, Engine engine) {
         long seed = rng.getSeed();
-        Engine engine = data == null ? null : data.getEngine();
         CachedChance recent = recentChance;
         if (recent != null && recent.key.seed == seed && recent.key.data == data && recent.key.engine == engine) {
             return recent.chance;

core/src/main/java/art/arcane/iris/generation/decoration/IrisSugarCane.java

@@ -2,8 +2,6 @@ package art.arcane.iris.generation.decoration;
 
 import art.arcane.iris.generation.runtime.IrisComplex;
 import art.arcane.iris.generation.runtime.Engine;
-import art.arcane.iris.generation.hydrology.HydrologyColumnLayer;
-import art.arcane.iris.generation.hydrology.HydrologyColumnSample;
 import art.arcane.iris.generation.biome.IrisBiome;
 import art.arcane.volmlib.nativelib.terrain.NativeBlockState;
 import art.arcane.volmlib.util.hunk.Hunk;
@@ -71,21 +69,18 @@ final class IrisSugarCane {
 
     private static boolean plannedWater(Engine engine, int x, int y, int z) {
         IrisComplex complex = engine.getComplex();
-        HydrologyColumnSample sample = complex.sampleHydrologyColumn(x, z);
-        HydrologyColumnLayer fluid = sample == null ? null : sample.primarySurfaceFluidLayerOrNull();
-        if (fluid != null) {
-            return y > fluid.bedY() && y <= fluid.fluidHeadY()
-                    && supportsAdjacent(complex.resolveHydrologyFluid(fluid.profileKey(), x, z));
-        }
         int terrainHeight = (int) Math.round(complex.getHeightStream().getDouble(x, z));
-        int fluidHeight = (int) Math.round(complex.getRiverWaterSurfaceStream().getDouble(x, z));
+        int fluidHeight = (int) Math.round(complex.getWaterHeadStream().getDouble(x, z));
         if (y <= terrainHeight || y > fluidHeight) {
             return false;
         }
+        if (complex.getWaterRoleStream().get(x, z).wet()) {
+            return supportsAdjacent(complex.resolveWaterFluid(x, z));
+        }
         IrisBiome biome = complex.getTrueBiomeStream().get(x, z);
         KList<NativeBlockState> layers = biome.generateSeaLayers(x, z,
                 new RNG(engine.getSeedManager().getTerrain()), fluidHeight - terrainHeight, engine.getData());
         int depth = fluidHeight - y;
-        return supportsAdjacent(layers.hasIndex(depth) ? layers.get(depth) : complex.resolveSurfaceFluid(x, z));
+        return supportsAdjacent(layers.hasIndex(depth) ? layers.get(depth) : complex.resolveSeaFluid(x, z));
     }
 }

core/src/main/java/art/arcane/iris/generation/hydrology/CaveCandidateBounds.java

@@ -1,35 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import art.arcane.iris.generation.hydrology.cave.CavePosition;
-
-record CaveCandidateBounds(
-        int entryX,
-        int entryY,
-        int entryZ,
-        int waterHeadY,
-        int horizontalRadius,
-        int maximumDepth,
-        int dryHeadroom
-) {
-    boolean containsColumn(int x, int z) {
-        long deltaX = (long) x - entryX;
-        long deltaZ = (long) z - entryZ;
-        long radiusSquared = (long) horizontalRadius * horizontalRadius;
-        return deltaX * deltaX + deltaZ * deltaZ <= radiusSquared;
-    }
-
-    int minimumY() {
-        return Math.toIntExact((long) entryY - maximumDepth);
-    }
-
-    int maximumY() {
-        return Math.max(entryY, Math.addExact(waterHeadY, dryHeadroom + 1));
-    }
-
-    boolean contains(CavePosition position) {
-        if (!containsColumn(position.x(), position.z())) {
-            return false;
-        }
-        return position.y() >= minimumY() && position.y() <= maximumY();
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CaveCandidateBuilder.java

@@ -1,202 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import art.arcane.iris.generation.hydrology.cave.CavePosition;
-import art.arcane.iris.generation.hydrology.cave.CavePositionIndex;
-import art.arcane.iris.generation.hydrology.cave.HydrologyCaveAction;
-import art.arcane.iris.generation.hydrology.cave.HydrologyCaveCandidate;
-import art.arcane.iris.generation.hydrology.cave.HydrologyCaveFluidPolicy;
-import art.arcane.iris.generation.hydrology.cave.HydrologyCaveMode;
-import art.arcane.iris.generation.hydrology.cave.HydrologyCavePlannerSettings;
-import art.arcane.iris.generation.hydrology.cave.HydrologyCaveSource;
-
-import java.util.ArrayList;
-import java.util.LinkedHashMap;
-import java.util.LinkedHashSet;
-import java.util.List;
-
-final class CaveCandidateBuilder {
-    private final RiverCourse course;
-    private final HydraulicSegment representative;
-    private final LinkedHashMap<CavePosition, HydrologyCaveAction> actions;
-    private final LinkedHashSet<CavePosition> openings;
-    private final CavePositionIndex openingIndex;
-    private final List<CaveSurfaceOpening> surfaceOpenings;
-    private int minimumX;
-    private int maximumX;
-    private int minimumY;
-    private int maximumY;
-    private int minimumZ;
-    private int maximumZ;
-
-    CaveCandidateBuilder(RiverCourse course, HydraulicSegment representative) {
-        this.course = course;
-        this.representative = representative;
-        this.actions = new LinkedHashMap<>();
-        this.openings = new LinkedHashSet<>();
-        this.openingIndex = new CavePositionIndex();
-        this.surfaceOpenings = HydrologyCaveCourseFilter.surfaceOpenings(course);
-        this.minimumX = Integer.MAX_VALUE;
-        this.maximumX = Integer.MIN_VALUE;
-        this.minimumY = Integer.MAX_VALUE;
-        this.maximumY = Integer.MIN_VALUE;
-        this.minimumZ = Integer.MAX_VALUE;
-        this.maximumZ = Integer.MIN_VALUE;
-    }
-
-    RiverCourse course() {
-        return course;
-    }
-
-    private HydraulicSegment representative() {
-        return representative;
-    }
-
-    boolean isEmpty() {
-        return actions.isEmpty();
-    }
-
-    void addAction(CavePosition position, HydrologyCaveAction action) {
-        HydrologyCaveAction existing = actions.get(position);
-        if (existing == null || actionPriority(action) < actionPriority(existing)) {
-            actions.put(position, action);
-        }
-        include(position);
-    }
-
-    void addOpening(CavePosition position) {
-        if (openingIndex.add(position.x(), position.y(), position.z())) {
-            openings.add(position);
-        }
-        include(position);
-    }
-
-    void addOpening(int x, int y, int z) {
-        if (openingIndex.add(x, y, z)) {
-            openings.add(new CavePosition(x, y, z));
-        }
-        include(x, y, z);
-    }
-
-    void addOpeningNeighborhood(CavePosition position) {
-        addOpening(position);
-        for (int[] offset : HydrologyCaveCourseFilter.NEIGHBORS) {
-            addOpening(
-                    position.x() + offset[0],
-                    position.y() + offset[1],
-                    position.z() + offset[2]
-            );
-        }
-    }
-
-    void addAdjacentSurfaceOpenings(
-            HydrologyFootprintCompiler.ValidationRaster validation
-    ) {
-        ArrayList<CavePosition> actionPositions = new ArrayList<>(actions.keySet());
-        for (CavePosition position : actionPositions) {
-            for (int[] offset : HydrologyCaveCourseFilter.HORIZONTAL_NEIGHBORS) {
-                int neighborX = position.x() + offset[0];
-                int neighborZ = position.z() + offset[1];
-                if (actions.containsKey(new CavePosition(neighborX, position.y(), neighborZ))) {
-                    continue;
-                }
-                HydrologyColumnSample neighbor = validation.surfaceColumnAt(neighborX, neighborZ);
-                if (neighbor == null) {
-                    continue;
-                }
-                for (HydrologyColumnLayer layer : neighbor.layers()) {
-                    if (layer.feature().courseId() == course.id() && layer.channel() && layer.fluidOwned()
-                            && layer.bedY() < position.y() && position.y() <= layer.fluidHeadY()) {
-                        addOpening(neighborX, position.y(), neighborZ);
-                        break;
-                    }
-                }
-            }
-        }
-    }
-
-    void addSurfaceOpening(HydrologyColumnLayer layer, CavePosition position) {
-        for (CaveSurfaceOpening opening : surfaceOpenings) {
-            if (!opening.matches(layer, position)) {
-                continue;
-            }
-            if (opening.includeNeighborhood()) {
-                addOpening(position);
-                for (int[] offset : HydrologyCaveCourseFilter.NEIGHBORS) {
-                    int y = position.y() + offset[1];
-                    if (y >= opening.minimumY()) {
-                        addOpening(position.x() + offset[0], y, position.z() + offset[2]);
-                    }
-                }
-            } else {
-                addOpening(position);
-            }
-        }
-    }
-
-    private void include(CavePosition position) {
-        include(position.x(), position.y(), position.z());
-    }
-
-    private void include(int x, int y, int z) {
-        minimumX = Math.min(minimumX, x);
-        maximumX = Math.max(maximumX, x);
-        minimumY = Math.min(minimumY, y);
-        maximumY = Math.max(maximumY, y);
-        minimumZ = Math.min(minimumZ, z);
-        maximumZ = Math.max(maximumZ, z);
-    }
-
-    HydrologyCaveCandidate build(HydrologyCaveCourseFilter.Options options) {
-        HydrologyPoint start = representative.start();
-        int waterHead = representative.upstreamHeadY();
-        int entryY = Math.max(waterHead, maximumY);
-        CavePosition entry = new CavePosition(start.x(), entryY, start.z());
-        CavePosition target = new CavePosition(start.x(), waterHead, start.z());
-        int horizontalRadius = HydrologyCaveCourseFilter.horizontalRadius(
-                entry.x(),
-                entry.z(),
-                minimumX,
-                maximumX,
-                minimumZ,
-                maximumZ
-        );
-        int maximumDepth = Math.max(1, entryY - minimumY + 2);
-        int dryHeadroom = Math.max(0, maximumY - waterHead);
-        int volume = Math.max(1, actions.size());
-        HydrologyCavePlannerSettings settings = new HydrologyCavePlannerSettings(
-                horizontalRadius,
-                maximumDepth,
-                volume,
-                1,
-                1,
-                dryHeadroom,
-                HydrologyCaveFluidPolicy.REJECT_EXISTING,
-                horizontalRadius,
-                maximumDepth
-        );
-        return new HydrologyCaveCandidate(
-                new HydrologyCaveSource(
-                        course.id(),
-                        entry,
-                        target,
-                        waterHead,
-                        HydrologyCaveMode.GENERATED_GROTTO
-                ),
-                course.profileKey(),
-                settings,
-                options.connectToExistingCaves() && course.type() == RiverCourseType.UNDERGROUND,
-                actions,
-                openings
-        );
-    }
-
-    private static int actionPriority(HydrologyCaveAction action) {
-        return switch (action) {
-            case WET_SOURCE -> 0;
-            case FALLING_FLUID -> 1;
-            case DRY_AIR -> 2;
-            case SEAL_GUARD -> 3;
-        };
-    }
-
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CaveCandidateSpanBuilder.java

@@ -1,395 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import art.arcane.iris.generation.hydrology.cave.CavePosition;
-import art.arcane.iris.generation.hydrology.cave.CaveVoxelView;
-
-import java.util.LinkedHashMap;
-import java.util.List;
-import java.util.Map;
-
-final class CaveCandidateSpanBuilder {
-    private final RiverCourse course;
-    private final HydraulicSegment representative;
-    private final LinkedHashMap<Long, CaveSpanSet> actions;
-    private final LinkedHashMap<Long, CaveSpanSet> openings;
-    private final LinkedHashMap<Long, CaveSpanSet> coastalGrottoActions;
-    private final LinkedHashMap<Long, CaveSpanSet> inlandGrottoActions;
-    private final List<CaveSurfaceOpening> surfaceOpenings;
-    private int minimumX;
-    private int maximumX;
-    private int minimumY;
-    private int maximumY;
-    private int minimumZ;
-    private int maximumZ;
-
-    CaveCandidateSpanBuilder(RiverCourse course, HydraulicSegment representative) {
-        this.course = course;
-        this.representative = representative;
-        this.actions = new LinkedHashMap<>();
-        this.openings = new LinkedHashMap<>();
-        this.coastalGrottoActions = new LinkedHashMap<>();
-        this.inlandGrottoActions = new LinkedHashMap<>();
-        this.surfaceOpenings = HydrologyCaveCourseFilter.surfaceOpenings(course);
-        this.minimumX = Integer.MAX_VALUE;
-        this.maximumX = Integer.MIN_VALUE;
-        this.minimumY = Integer.MAX_VALUE;
-        this.maximumY = Integer.MIN_VALUE;
-        this.minimumZ = Integer.MAX_VALUE;
-        this.maximumZ = Integer.MIN_VALUE;
-    }
-
-    RiverCourse course() {
-        return course;
-    }
-
-    HydraulicSegment representative() {
-        return representative;
-    }
-
-    boolean isEmpty() {
-        return actions.isEmpty();
-    }
-
-    boolean allowsIntentionalSurfaceExposure() {
-        return course.surfaceSinkholeContinuation();
-    }
-
-    void addAction(int x, int z, HydrologyColumnLayer layer) {
-        int minimumActionY = layer.bedY() + 1;
-        int maximumActionY = layer.ceilingY();
-        if (minimumActionY > maximumActionY) {
-            return;
-        }
-        addSpan(actions, x, z, minimumActionY, maximumActionY);
-        if (layer.feature().type() == HydrologyFeatureType.COASTAL_GROTTO) {
-            addSpan(coastalGrottoActions, x, z, minimumActionY, maximumActionY);
-        } else if (layer.feature().type() == HydrologyFeatureType.INLAND_GROTTO) {
-            addSpan(inlandGrottoActions, x, z, minimumActionY, maximumActionY);
-        }
-        include(x, minimumActionY, z);
-        include(x, maximumActionY, z);
-        for (CaveSurfaceOpening opening : surfaceOpenings) {
-            if (!opening.matchesColumn(layer, x, z)) {
-                continue;
-            }
-            int minimumOpeningY = Math.max(minimumActionY, opening.minimumY());
-            if (minimumOpeningY > maximumActionY) {
-                continue;
-            }
-            if (!opening.includeNeighborhood()) {
-                addOpening(x, z, minimumOpeningY, maximumActionY);
-                continue;
-            }
-            addOpening(x, z, Math.max(minimumOpeningY - 1, opening.minimumY()), maximumActionY + 1);
-            for (int[] offset : HydrologyCaveCourseFilter.HORIZONTAL_NEIGHBORS) {
-                addOpening(x + offset[0], z + offset[1], minimumOpeningY, maximumActionY);
-            }
-        }
-    }
-
-    void addOceanOpening(int x, int z, int minimumOpeningY, int maximumOpeningY) {
-        if (minimumOpeningY <= maximumOpeningY) {
-            addOpening(x, z, minimumOpeningY, maximumOpeningY);
-        }
-    }
-
-    void addOpeningNeighborhood(
-            int x,
-            int z,
-            int minimumOpeningY,
-            int maximumOpeningY
-    ) {
-        if (minimumOpeningY > maximumOpeningY) {
-            return;
-        }
-        addOpening(x, z, minimumOpeningY - 1, maximumOpeningY + 1);
-        for (int[] offset : HydrologyCaveCourseFilter.HORIZONTAL_NEIGHBORS) {
-            addOpening(x + offset[0], z + offset[1], minimumOpeningY, maximumOpeningY);
-        }
-    }
-
-    void addAdjacentSurfaceOpenings(
-            HydrologyFootprintCompiler.ValidationRaster validation
-    ) {
-        for (Map.Entry<Long, CaveSpanSet> entry : actions.entrySet()) {
-            int x = RiverFootprint.unpackX(entry.getKey());
-            int z = RiverFootprint.unpackZ(entry.getKey());
-            for (int[] offset : HydrologyCaveCourseFilter.HORIZONTAL_NEIGHBORS) {
-                int neighborX = x + offset[0];
-                int neighborZ = z + offset[1];
-                HydrologyColumnSample neighbor = validation.surfaceColumnAt(neighborX, neighborZ);
-                if (neighbor == null) {
-                    continue;
-                }
-                for (HydrologyColumnLayer layer : neighbor.layers()) {
-                    if (layer.feature().courseId() != course.id() || !layer.channel() || !layer.fluidOwned()) {
-                        continue;
-                    }
-                    for (CaveYSpan span : entry.getValue().spans()) {
-                        int minimumY = Math.max(span.minimumY(), layer.bedY() + 1);
-                        int maximumY = Math.min(span.maximumY(), layer.fluidHeadY());
-                        if (minimumY <= maximumY) {
-                            addAdjacentFluidOpening(neighborX, neighborZ, minimumY, maximumY);
-                        }
-                    }
-                }
-            }
-        }
-    }
-
-    private void addAdjacentFluidOpening(int x, int z, int minimumY, int maximumY) {
-        CaveSpanSet owned = actions.get(RiverFootprint.pack(x, z));
-        if (owned == null) {
-            addOpening(x, z, minimumY, maximumY);
-            return;
-        }
-        int cursor = minimumY;
-        for (CaveYSpan span : owned.spans()) {
-            if (span.maximumY() < cursor) {
-                continue;
-            }
-            if (span.minimumY() > maximumY) {
-                break;
-            }
-            if (cursor < span.minimumY()) {
-                addOpening(x, z, cursor, Math.min(maximumY, span.minimumY() - 1));
-            }
-            cursor = Math.max(cursor, span.maximumY() + 1);
-            if (cursor > maximumY) {
-                return;
-            }
-        }
-        addOpening(x, z, cursor, maximumY);
-    }
-
-    HydrologyFeatureType oversizedGrotto(HydrologyCaveCourseFilter.Options options) {
-        if (positionCount(coastalGrottoActions)
-                > options.maximumVolume(HydrologyFeatureType.COASTAL_GROTTO)) {
-            return HydrologyFeatureType.COASTAL_GROTTO;
-        }
-        if (positionCount(inlandGrottoActions)
-                > options.maximumVolume(HydrologyFeatureType.INLAND_GROTTO)) {
-            return HydrologyFeatureType.INLAND_GROTTO;
-        }
-        return null;
-    }
-
-    long positionCount() {
-        return positionCount(actions);
-    }
-
-    boolean exposed(CaveVoxelView view) {
-        CaveCandidateBounds bounds = bounds();
-        for (Map.Entry<Long, CaveSpanSet> entry : actions.entrySet()) {
-            int x = RiverFootprint.unpackX(entry.getKey());
-            int z = RiverFootprint.unpackZ(entry.getKey());
-            CaveSpanSet actionSpans = entry.getValue();
-            CaveSpanSet openingSpans = openings.get(entry.getKey());
-            if (exposedDifference(actionSpans, null, openingSpans, x, z, bounds, view)) {
-                return true;
-            }
-            for (CaveYSpan span : actionSpans.spans()) {
-                int lowerBoundary = span.minimumY() - 1;
-                if (!actionSpans.contains(lowerBoundary)
-                        && !contains(openingSpans, lowerBoundary)
-                        && exposed(x, lowerBoundary, z, bounds, view)) {
-                    return true;
-                }
-                int upperBoundary = span.maximumY() + 1;
-                if (!actionSpans.contains(upperBoundary)
-                        && !contains(openingSpans, upperBoundary)
-                        && exposed(x, upperBoundary, z, bounds, view)) {
-                    return true;
-                }
-            }
-            for (int[] offset : HydrologyCaveCourseFilter.HORIZONTAL_NEIGHBORS) {
-                int neighborX = x + offset[0];
-                int neighborZ = z + offset[1];
-                long neighborKey = RiverFootprint.pack(neighborX, neighborZ);
-                if (exposedDifference(
-                        actionSpans,
-                        actions.get(neighborKey),
-                        openings.get(neighborKey),
-                        neighborX,
-                        neighborZ,
-                        bounds,
-                        view
-                )) {
-                    return true;
-                }
-            }
-        }
-        return false;
-    }
-
-    private boolean exposedDifference(
-            CaveSpanSet source,
-            CaveSpanSet excludedActions,
-            CaveSpanSet excludedOpenings,
-            int x,
-            int z,
-            CaveCandidateBounds bounds,
-            CaveVoxelView view
-    ) {
-        for (CaveYSpan span : source.spans()) {
-            if (exposedDifference(
-                    span,
-                    excludedActions,
-                    excludedOpenings,
-                    x,
-                    z,
-                    bounds,
-                    view
-            )) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    private boolean exposedDifference(
-            CaveYSpan source,
-            CaveSpanSet excludedActions,
-            CaveSpanSet excludedOpenings,
-            int x,
-            int z,
-            CaveCandidateBounds bounds,
-            CaveVoxelView view
-    ) {
-        List<CaveYSpan> actionSpans = excludedActions == null ? List.of() : excludedActions.spans();
-        List<CaveYSpan> openingSpans = excludedOpenings == null ? List.of() : excludedOpenings.spans();
-        int actionIndex = 0;
-        int openingIndex = 0;
-        long cursor = source.minimumY();
-        while (cursor <= source.maximumY()) {
-            while (actionIndex < actionSpans.size()
-                    && actionSpans.get(actionIndex).maximumY() < cursor) {
-                actionIndex++;
-            }
-            while (openingIndex < openingSpans.size()
-                    && openingSpans.get(openingIndex).maximumY() < cursor) {
-                openingIndex++;
-            }
-            CaveYSpan action = actionIndex < actionSpans.size() ? actionSpans.get(actionIndex) : null;
-            CaveYSpan opening = openingIndex < openingSpans.size() ? openingSpans.get(openingIndex) : null;
-            CaveYSpan excluded = first(action, opening);
-            if (excluded == null || excluded.minimumY() > source.maximumY()) {
-                return exposed(x, (int) cursor, source.maximumY(), z, bounds, view);
-            }
-            if (cursor < excluded.minimumY()
-                    && exposed(x, (int) cursor, excluded.minimumY() - 1, z, bounds, view)) {
-                return true;
-            }
-            cursor = Math.max(cursor, (long) excluded.maximumY() + 1L);
-            if (excluded == action) {
-                actionIndex++;
-            } else {
-                openingIndex++;
-            }
-        }
-        return false;
-    }
-
-    private CaveYSpan first(CaveYSpan first, CaveYSpan second) {
-        if (first == null) {
-            return second;
-        }
-        if (second == null) {
-            return first;
-        }
-        return first.minimumY() <= second.minimumY() ? first : second;
-    }
-
-    boolean exposed(
-            int x,
-            int minimumY,
-            int maximumY,
-            int z,
-            CaveCandidateBounds bounds,
-            CaveVoxelView view
-    ) {
-        if (!bounds.containsColumn(x, z)) {
-            return false;
-        }
-        int boundedMinimumY = Math.max(minimumY, bounds.minimumY());
-        int boundedMaximumY = Math.min(maximumY, bounds.maximumY());
-        return boundedMinimumY <= boundedMaximumY
-                && view.hasAboveTerrainSurface(x, z, boundedMinimumY, boundedMaximumY);
-    }
-
-    boolean exposed(
-            int x,
-            int y,
-            int z,
-            CaveCandidateBounds bounds,
-            CaveVoxelView view
-    ) {
-        CavePosition position = new CavePosition(x, y, z);
-        return bounds.contains(position)
-                && view.isInWorld(position)
-                && view.isAboveTerrainSurface(position);
-    }
-
-    private CaveCandidateBounds bounds() {
-        HydrologyPoint start = representative.start();
-        int waterHead = representative.upstreamHeadY();
-        int entryY = Math.max(waterHead, maximumY);
-        int horizontalRadius = HydrologyCaveCourseFilter.horizontalRadius(
-                start.x(),
-                start.z(),
-                minimumX,
-                maximumX,
-                minimumZ,
-                maximumZ
-        );
-        int maximumDepth = Math.max(1, entryY - minimumY + 2);
-        int dryHeadroom = Math.max(0, maximumY - waterHead);
-        return new CaveCandidateBounds(
-                start.x(),
-                entryY,
-                start.z(),
-                waterHead,
-                horizontalRadius,
-                maximumDepth,
-                dryHeadroom
-        );
-    }
-
-    private void addOpening(int x, int z, int minimumOpeningY, int maximumOpeningY) {
-        addSpan(openings, x, z, minimumOpeningY, maximumOpeningY);
-        include(x, minimumOpeningY, z);
-        include(x, maximumOpeningY, z);
-    }
-
-    private void include(int x, int y, int z) {
-        minimumX = Math.min(minimumX, x);
-        maximumX = Math.max(maximumX, x);
-        minimumY = Math.min(minimumY, y);
-        maximumY = Math.max(maximumY, y);
-        minimumZ = Math.min(minimumZ, z);
-        maximumZ = Math.max(maximumZ, z);
-    }
-
-    private static void addSpan(
-            Map<Long, CaveSpanSet> spans,
-            int x,
-            int z,
-            int minimumY,
-            int maximumY
-    ) {
-        spans.computeIfAbsent(RiverFootprint.pack(x, z), (Long ignored) -> new CaveSpanSet())
-                .add(minimumY, maximumY);
-    }
-
-    private static boolean contains(CaveSpanSet spans, int y) {
-        return spans != null && spans.contains(y);
-    }
-
-    static long positionCount(Map<Long, CaveSpanSet> spans) {
-        long count = 0L;
-        for (CaveSpanSet spanSet : spans.values()) {
-            count += spanSet.positionCount();
-        }
-        return count;
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CaveCourseGraph.java

@@ -1,10 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.List;
-
-record CaveCourseGraph(
-        List<DrainageNode> nodes,
-        List<DrainageEdge> edges,
-        List<RiverOutlet> outlets
-) {
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CaveSpanSet.java

@@ -1,103 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-final class CaveSpanSet {
-    private int[] pending;
-    private int size;
-    private List<CaveYSpan> normalized;
-
-    CaveSpanSet() {
-        this.pending = new int[4];
-        this.normalized = null;
-    }
-
-    void add(int minimumY, int maximumY) {
-        if (minimumY > maximumY) {
-            return;
-        }
-        int requiredLength = Math.multiplyExact(size + 1, 2);
-        if (requiredLength > pending.length) {
-            pending = Arrays.copyOf(pending, Math.multiplyExact(pending.length, 2));
-        }
-        pending[size * 2] = minimumY;
-        pending[size * 2 + 1] = maximumY;
-        size++;
-        normalized = null;
-    }
-
-    List<CaveYSpan> spans() {
-        if (normalized != null) {
-            return normalized;
-        }
-        sortPending();
-        ArrayList<CaveYSpan> merged = new ArrayList<>(size);
-        for (int index = 0; index < size; index++) {
-            CaveYSpan span = new CaveYSpan(pending[index * 2], pending[index * 2 + 1]);
-            if (merged.isEmpty()) {
-                merged.add(span);
-                continue;
-            }
-            CaveYSpan previous = merged.getLast();
-            if ((long) span.minimumY() > (long) previous.maximumY() + 1L) {
-                merged.add(span);
-                continue;
-            }
-            merged.set(
-                    merged.size() - 1,
-                    new CaveYSpan(previous.minimumY(), Math.max(previous.maximumY(), span.maximumY()))
-            );
-        }
-        normalized = List.copyOf(merged);
-        return normalized;
-    }
-
-    private void sortPending() {
-        for (int index = 1; index < size; index++) {
-            int minimumY = pending[index * 2];
-            int maximumY = pending[index * 2 + 1];
-            int insertionIndex = index;
-            while (insertionIndex > 0) {
-                int previousMinimumY = pending[(insertionIndex - 1) * 2];
-                int previousMaximumY = pending[(insertionIndex - 1) * 2 + 1];
-                if (previousMinimumY < minimumY
-                        || previousMinimumY == minimumY && previousMaximumY <= maximumY) {
-                    break;
-                }
-                pending[insertionIndex * 2] = previousMinimumY;
-                pending[insertionIndex * 2 + 1] = previousMaximumY;
-                insertionIndex--;
-            }
-            pending[insertionIndex * 2] = minimumY;
-            pending[insertionIndex * 2 + 1] = maximumY;
-        }
-    }
-
-    boolean contains(int y) {
-        List<CaveYSpan> spans = spans();
-        int minimumIndex = 0;
-        int maximumIndex = spans.size() - 1;
-        while (minimumIndex <= maximumIndex) {
-            int index = (minimumIndex + maximumIndex) >>> 1;
-            CaveYSpan span = spans.get(index);
-            if (y < span.minimumY()) {
-                maximumIndex = index - 1;
-            } else if (y > span.maximumY()) {
-                minimumIndex = index + 1;
-            } else {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    long positionCount() {
-        long count = 0L;
-        for (CaveYSpan span : spans()) {
-            count += (long) span.maximumY() - span.minimumY() + 1L;
-        }
-        return count;
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CaveSurfaceComposition.java

@@ -1,18 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import art.arcane.iris.generation.hydrology.cave.HydrologyCaveCandidate;
-
-import java.util.Objects;
-
-record CaveSurfaceComposition(
-        HydrologyCaveCandidate candidate,
-        boolean accepted
-) {
-    static CaveSurfaceComposition accepted(HydrologyCaveCandidate candidate) {
-        return new CaveSurfaceComposition(Objects.requireNonNull(candidate), true);
-    }
-
-    static CaveSurfaceComposition rejected() {
-        return new CaveSurfaceComposition(null, false);
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CaveSurfaceOpening.java

@@ -1,79 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import art.arcane.iris.generation.hydrology.cave.CavePosition;
-
-import java.util.List;
-
-record CaveSurfaceOpening(
-        long segmentId,
-        HydrologyPoint point,
-        double interiorX,
-        double interiorZ,
-        long radiusSquared,
-        int minimumY,
-        boolean includeNeighborhood,
-        boolean surfaceFall
-) {
-    static CaveSurfaceOpening create(
-            HydraulicSegment segment,
-            boolean start,
-            long radiusSquared,
-            int minimumY,
-            boolean includeNeighborhood
-    ) {
-        List<HydrologyPoint> centerline = segment.centerline();
-        int boundaryIndex = start ? 0 : centerline.size() - 1;
-        int interiorIndex = start
-                ? Math.min(1, centerline.size() - 1)
-                : Math.max(0, centerline.size() - 2);
-        HydrologyPoint point = centerline.get(boundaryIndex);
-        HydrologyPoint interior = centerline.get(interiorIndex);
-        double deltaX = interior.x() - point.x();
-        double deltaZ = interior.z() - point.z();
-        double lengthSquared = deltaX * deltaX + deltaZ * deltaZ;
-        double scale = 0D;
-        if (includeNeighborhood) {
-            scale = lengthSquared <= radiusSquared
-                    ? 1D
-                    : StrictMath.sqrt(radiusSquared / lengthSquared);
-        }
-        return new CaveSurfaceOpening(
-                segment.id(),
-                point,
-                point.x() + deltaX * scale,
-                point.z() + deltaZ * scale,
-                radiusSquared,
-                minimumY,
-                includeNeighborhood,
-                segment.type().isSurface() && segment.fallingFluid()
-        );
-    }
-
-    boolean matches(HydrologyColumnLayer layer, CavePosition position) {
-        return matchesColumn(layer, position.x(), position.z())
-                && position.y() >= minimumY;
-    }
-
-    boolean matchesColumn(HydrologyColumnLayer layer, int x, int z) {
-        if (surfaceFall) {
-            return layer.fallingFluid() && layer.feature().segmentId() == segmentId;
-        }
-        return (includeNeighborhood || layer.feature().segmentId() == segmentId)
-                && distanceSquared(x, z) <= radiusSquared;
-    }
-
-    private double distanceSquared(int x, int z) {
-        double pathX = interiorX - point.x();
-        double pathZ = interiorZ - point.z();
-        double pathLengthSquared = pathX * pathX + pathZ * pathZ;
-        double positionX = x - point.x();
-        double positionZ = z - point.z();
-        double progress = pathLengthSquared == 0D
-                ? 0D
-                : (positionX * pathX + positionZ * pathZ) / pathLengthSquared;
-        double clampedProgress = Math.max(0D, Math.min(1D, progress));
-        double deltaX = positionX - pathX * clampedProgress;
-        double deltaZ = positionZ - pathZ * clampedProgress;
-        return deltaX * deltaX + deltaZ * deltaZ;
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CaveYSpan.java

@@ -1,4 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-record CaveYSpan(int minimumY, int maximumY) {
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CompiledGraph.java

@@ -1,12 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.List;
-import java.util.Map;
-
-record CompiledGraph(
-        List<DrainageNode> nodes,
-        List<DrainageEdge> edges,
-        List<RiverOutlet> outlets,
-        Map<Integer, DrainageEdge> edgeByUpstream
-) {
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CourseEdgeKey.java

@@ -1,9 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.Objects;
-
-record CourseEdgeKey(RiverCourseType type, long edgeId) {
-    CourseEdgeKey {
-        Objects.requireNonNull(type, "type");
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CrossTileBlockers.java

@@ -1,14 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.List;
-import java.util.Objects;
-
-record CrossTileBlockers(
-        List<HydrologyCrossTileCaveAdmission.RankedClaim> caveClaims,
-        List<HydrologyCrossTileSurfaceAdmission.RankedClaim> surfaceClaims
-) {
-    CrossTileBlockers {
-        caveClaims = List.copyOf(Objects.requireNonNull(caveClaims, "caveClaims"));
-        surfaceClaims = List.copyOf(Objects.requireNonNull(surfaceClaims, "surfaceClaims"));
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CrossTileDraftAdmission.java

@@ -1,7 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-interface CrossTileDraftAdmission {
-    void prepare();
-
-    CrossTilePublicationAdmission admit(HydrologyCaveCourseFilter.Result result);
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CrossTilePublicationAdmission.java

@@ -1,15 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.List;
-import java.util.Objects;
-
-record CrossTilePublicationAdmission(
-        HydrologyCaveCourseFilter.Result result,
-        List<HydrologyDiagnosticCandidate> diagnostics,
-        boolean rejectedCourses
-) {
-    CrossTilePublicationAdmission {
-        Objects.requireNonNull(result, "result");
-        diagnostics = List.copyOf(Objects.requireNonNull(diagnostics, "diagnostics"));
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CrossTileRejectedCourse.java

@@ -1,9 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.Objects;
-
-record CrossTileRejectedCourse(RiverCourse course, long winnerSourceId) {
-    CrossTileRejectedCourse {
-        Objects.requireNonNull(course, "course");
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CrossTileRejectionKey.java

@@ -1,4 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-record CrossTileRejectionKey(long courseId, long winnerCourseId) {
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CrossTileResolution.java

@@ -1,17 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.List;
-import java.util.Objects;
-
-record CrossTileResolution(
-        HydrologyOwnerDraft draft,
-        List<CrossTileRejectedCourse> observedRejections,
-        int iterations,
-        int ownerCount,
-        long resolutionNanos
-) {
-    CrossTileResolution {
-        Objects.requireNonNull(draft, "draft");
-        observedRejections = List.copyOf(Objects.requireNonNull(observedRejections, "observedRejections"));
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CrossTileResolutionContext.java

@@ -1,73 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
-
-final class CrossTileResolutionContext {
-    final Map<HydrologyTileKey, CrossTileResolvedOwner> resolved;
-    private final Set<HydrologyTileKey> resolving;
-    final HydrologyTileKey root;
-    private final long maximumTileOffset;
-    private final int maximumOwners;
-    int iterations;
-
-    CrossTileResolutionContext(
-            HydrologyTileKey root,
-            long maximumTileOffset,
-            int maximumOwners
-    ) {
-        this.resolved = new HashMap<>();
-        this.resolving = new HashSet<>();
-        this.root = Objects.requireNonNull(root, "root");
-        this.maximumTileOffset = maximumTileOffset;
-        this.maximumOwners = maximumOwners;
-    }
-
-    CrossTileResolvedOwner resolved(HydrologyTileKey key) {
-        return resolved.get(key);
-    }
-
-    void remember(HydrologyTileKey key, CrossTileResolvedOwner owner) {
-        long offsetX = Math.abs((long) key.tileX() - root.tileX());
-        long offsetZ = Math.abs((long) key.tileZ() - root.tileZ());
-        if (offsetX > maximumTileOffset || offsetZ > maximumTileOffset) {
-            throw new IllegalStateException("Cross-tile owner dependency exceeded its color-ranked geometry bound.");
-        }
-        CrossTileResolvedOwner existing = resolved.putIfAbsent(key, owner);
-        if (existing != null
-                && !existing.withoutFootprintCompiler().equals(owner.withoutFootprintCompiler())) {
-            throw new IllegalStateException("Cross-tile owner resolution produced inconsistent cached results for "
-                    + key.tileX() + "," + key.tileZ() + " while planning " + root.tileX() + "," + root.tileZ() + ".");
-        }
-        if (resolved.size() > maximumOwners) {
-            throw new IllegalStateException("Cross-tile owner dependencies exceeded their color-ranked count bound.");
-        }
-    }
-
-    boolean begin(HydrologyTileKey key) {
-        return resolving.add(key);
-    }
-
-    void end(HydrologyTileKey key) {
-        resolving.remove(key);
-    }
-
-    void recordIteration() {
-        iterations++;
-    }
-
-    int iterations() {
-        return iterations;
-    }
-
-    int ownerCount() {
-        return resolved.size();
-    }
-
-    HydrologyTileKey root() {
-        return root;
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/CrossTileResolvedOwner.java

@@ -1,21 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.List;
-import java.util.Objects;
-
-record CrossTileResolvedOwner(
-        HydrologyOwnerDraft draft,
-        List<CrossTileRejectedCourse> observedRejections
-) {
-    CrossTileResolvedOwner {
-        Objects.requireNonNull(draft, "draft");
-        observedRejections = List.copyOf(Objects.requireNonNull(observedRejections, "observedRejections"));
-    }
-
-    CrossTileResolvedOwner withoutFootprintCompiler() {
-        HydrologyOwnerDraft uncachedDraft = draft.withoutFootprintCompiler();
-        return uncachedDraft == draft
-                ? this
-                : new CrossTileResolvedOwner(uncachedDraft, observedRejections);
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/DraftPhase.java

@@ -1,8 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-enum DraftPhase {
-    CONTEXT,
-    SELECT,
-    SETTLE,
-    PUBLISH
-}

core/src/main/java/art/arcane/iris/generation/hydrology/DraftProfile.java

@@ -1,60 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import art.arcane.iris.spi.IrisLogging;
-
-/**
- * Wall-clock breakdown of one owner draft for the debug log: sampling and routing context, source
- * selection, settling, publication passes, and the time spent waiting on lower-rank neighbour drafts.
- */
-final class DraftProfile {
-    private final long[] phaseNanos = new long[DraftPhase.values().length];
-    private long dependencyNanos;
-    private int dependencies;
-    private int admissions;
-    int earlyOwners;
-    int routeCalls;
-    int routeSolves;
-    long routeSolveNanos;
-    int rasterCalls;
-    long rasterNanos;
-    int filterCalls;
-    long filterNanos;
-
-    long record(DraftPhase phase, long started) {
-        long now = System.nanoTime();
-        phaseNanos[phase.ordinal()] += now - started;
-        return now;
-    }
-
-    void recordDependencies(int count, long started) {
-        dependencyNanos += System.nanoTime() - started;
-        dependencies += count;
-        admissions++;
-    }
-
-    void log(HydrologyTileKey key, int rank, long totalNanos) {
-        IrisLogging.debug(
-                "Hydrology owner %d,%d rank=%d drafted in %dms: context=%dms select=%dms settle=%dms publish=%dms deps=%d wait=%dms admissions=%d earlyOwners=%d routes=%d reuses=%d routeSolve=%dms rasters=%d raster=%dms filters=%d filter=%dms on %s",
-                key.tileX(),
-                key.tileZ(),
-                rank,
-                totalNanos / 1_000_000L,
-                phaseNanos[DraftPhase.CONTEXT.ordinal()] / 1_000_000L,
-                phaseNanos[DraftPhase.SELECT.ordinal()] / 1_000_000L,
-                phaseNanos[DraftPhase.SETTLE.ordinal()] / 1_000_000L,
-                phaseNanos[DraftPhase.PUBLISH.ordinal()] / 1_000_000L,
-                dependencies,
-                dependencyNanos / 1_000_000L,
-                admissions,
-                earlyOwners,
-                routeCalls,
-                routeCalls - routeSolves,
-                routeSolveNanos / 1_000_000L,
-                rasterCalls,
-                rasterNanos / 1_000_000L,
-                filterCalls,
-                filterNanos / 1_000_000L,
-                Thread.currentThread().getName()
-        );
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/DrainageEdge.java

@@ -1,36 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.List;
-import java.util.Objects;
-
-public record DrainageEdge(
-        long id,
-        long upstreamNodeId,
-        long downstreamNodeId,
-        long outletId,
-        double cost,
-        int contributingSurfaceSources,
-        int contributingUndergroundSources,
-        List<HydrologyPoint> centerline
-) {
-    public DrainageEdge {
-        if (upstreamNodeId == downstreamNodeId) {
-            throw new IllegalArgumentException("A drainage edge cannot point to the same node.");
-        }
-        if (!Double.isFinite(cost) || cost <= 0D) {
-            throw new IllegalArgumentException("Drainage edge cost must be finite and positive.");
-        }
-        if (contributingSurfaceSources < 0 || contributingUndergroundSources < 0) {
-            throw new IllegalArgumentException("Contributing source counts cannot be negative.");
-        }
-        Objects.requireNonNull(centerline, "centerline");
-        centerline = List.copyOf(centerline);
-        if (centerline.size() < 2) {
-            throw new IllegalArgumentException("A drainage edge requires at least two centerline points.");
-        }
-    }
-
-    public int totalContributingSources() {
-        return contributingSurfaceSources + contributingUndergroundSources;
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/DrainageNode.java

@@ -1,26 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.Objects;
-
-public record DrainageNode(
-        long id,
-        int x,
-        int z,
-        HydrologyTerrainSample terrain,
-        double potential,
-        long outletId
-) {
-    public DrainageNode {
-        Objects.requireNonNull(terrain, "terrain");
-        if (!Double.isFinite(potential) || potential < 0D) {
-            throw new IllegalArgumentException("Drainage potential must be finite and non-negative.");
-        }
-        if (terrain.ocean()) {
-            throw new IllegalArgumentException("Drainage nodes must remain landward of the first ocean column.");
-        }
-    }
-
-    public HydrologyPoint naturalPoint() {
-        return new HydrologyPoint(x, terrain.naturalHeight(), z);
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/FootprintCenterlineProjection.java

@@ -1,11 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-record FootprintCenterlineProjection(
-        int pointIndex,
-        double x,
-        double z,
-        double distance,
-        int flowX,
-        int flowZ
-) {
-}

core/src/main/java/art/arcane/iris/generation/hydrology/FootprintCourseRasterKey.java

@@ -1,11 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.List;
-
-record FootprintCourseRasterKey(
-        long courseId,
-        RiverCourseType courseType,
-        String profileKey,
-        List<HydraulicSegment> segments
-) {
-}

core/src/main/java/art/arcane/iris/generation/hydrology/FootprintFeatureKey.java

@@ -1,11 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-record FootprintFeatureKey(
-        long courseId,
-        long segmentId,
-        HydrologyFeatureType type,
-        int role,
-        int flowX,
-        int flowZ
-) {
-}

core/src/main/java/art/arcane/iris/generation/hydrology/FootprintLayerShape.java

@@ -1,20 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-record FootprintLayerShape(
-        int channelRadius,
-        double shoreWidth,
-        double gradingWidth,
-        int bed,
-        int fluidHead,
-        int ceiling,
-        boolean ellipsoid,
-        boolean archedChannel,
-        boolean roundedSurfaceBed,
-        boolean organicBoundary,
-        boolean fallingThroat,
-        boolean inlet
-) {
-    double totalRadius() {
-        return channelRadius + shoreWidth + gradingWidth;
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/FootprintMutableColumn.java

@@ -1,173 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.LinkedHashMap;
-import java.util.List;
-
-final class FootprintMutableColumn {
-    private final int x;
-    private final int z;
-    private final int naturalHeight;
-    private final int seaLevel;
-    private final boolean ocean;
-    private final String parentBiomeKey;
-    private HydrologyColumnLayer singleLayer;
-    private LinkedHashMap<Long, HydrologyColumnLayer> layers;
-
-    FootprintMutableColumn(int x, int z, HydrologyTerrainSample terrain, int seaLevel) {
-        this.x = x;
-        this.z = z;
-        this.naturalHeight = terrain.naturalHeight();
-        this.seaLevel = seaLevel;
-        this.ocean = terrain.ocean();
-        this.parentBiomeKey = terrain.parentBiomeKey();
-    }
-
-    FootprintMutableColumn(HydrologyColumnSample sample) {
-        this.x = sample.x();
-        this.z = sample.z();
-        this.naturalHeight = sample.naturalHeight();
-        this.seaLevel = sample.seaLevel();
-        this.ocean = sample.ocean();
-        this.parentBiomeKey = sample.parentBiomeKey();
-        for (HydrologyColumnLayer layer : sample.layers()) {
-            add(layer);
-        }
-    }
-
-    void add(HydrologyColumnLayer layer) {
-        if (layers == null) {
-            if (singleLayer == null) {
-                singleLayer = layer;
-                return;
-            }
-            if (singleLayer.feature().id() == layer.feature().id()) {
-                singleLayer = merge(singleLayer, layer);
-                return;
-            }
-            layers = new LinkedHashMap<>();
-            layers.put(singleLayer.feature().id(), singleLayer);
-            singleLayer = null;
-        }
-        HydrologyColumnLayer existing = layers.get(layer.feature().id());
-        layers.put(layer.feature().id(), existing == null ? layer : merge(existing, layer));
-    }
-
-    HydrologyColumnSample build() {
-        List<HydrologyColumnLayer> builtLayers;
-        if (layers != null) {
-            builtLayers = resolveSurfaceHeadConflicts(new ArrayList<>(layers.values()));
-        } else if (singleLayer != null) {
-            builtLayers = List.of(singleLayer);
-        } else {
-            builtLayers = List.of();
-        }
-        return new HydrologyColumnSample(
-                x,
-                z,
-                naturalHeight,
-                seaLevel,
-                ocean,
-                parentBiomeKey,
-                builtLayers
-        );
-    }
-
-    private List<HydrologyColumnLayer> resolveSurfaceHeadConflicts(List<HydrologyColumnLayer> candidates) {
-        HashMap<Long, HydrologyColumnLayer> selectedByCourse = new HashMap<>();
-        for (HydrologyColumnLayer candidate : candidates) {
-            if (!conflictingSurfaceCandidate(candidate)) {
-                continue;
-            }
-            long courseId = candidate.feature().courseId();
-            HydrologyColumnLayer selected = selectedByCourse.get(courseId);
-            if (selected == null || prefersSurfaceLayer(candidate, selected)) {
-                selectedByCourse.put(courseId, candidate);
-            }
-        }
-        if (selectedByCourse.isEmpty()) {
-            return candidates;
-        }
-        ArrayList<HydrologyColumnLayer> resolved = new ArrayList<>(candidates.size());
-        for (HydrologyColumnLayer candidate : candidates) {
-            HydrologyColumnLayer selected = selectedByCourse.get(candidate.feature().courseId());
-            if (!conflictingSurfaceCandidate(candidate)
-                    || selected == null
-                    || candidate.fluidHeadY() == selected.fluidHeadY()) {
-                resolved.add(candidate);
-            }
-        }
-        return List.copyOf(resolved);
-    }
-
-    private boolean conflictingSurfaceCandidate(HydrologyColumnLayer layer) {
-        return layer.feature().type().isSurface()
-                && layer.channel()
-                && layer.connectedFluid()
-                && layer.fluidOwned()
-                && !layer.fallingFluid();
-    }
-
-    private boolean prefersSurfaceLayer(HydrologyColumnLayer candidate, HydrologyColumnLayer selected) {
-        if (candidate.receivingPool() != selected.receivingPool()) {
-            return candidate.receivingPool();
-        }
-        if (candidate.fluidHeadY() != selected.fluidHeadY()) {
-            return candidate.fluidHeadY() > selected.fluidHeadY();
-        }
-        return candidate.feature().id() < selected.feature().id();
-    }
-
-    void merge(HydrologyColumnSample sample) {
-        if (sample.x() != x
-                || sample.z() != z
-                || sample.naturalHeight() != naturalHeight
-                || sample.seaLevel() != seaLevel
-                || sample.ocean() != ocean
-                || !sample.parentBiomeKey().equals(parentBiomeKey)) {
-            throw new IllegalStateException("Hydrology course footprints disagree on terrain metadata at "
-                    + x + "," + z + ".");
-        }
-        for (HydrologyColumnLayer layer : sample.layers()) {
-            add(layer);
-        }
-    }
-
-    private HydrologyColumnLayer merge(HydrologyColumnLayer first, HydrologyColumnLayer second) {
-        if (first.equals(second)) {
-            return first;
-        }
-        HydrologyFeatureRef feature = first.feature().y() <= second.feature().y()
-                ? first.feature()
-                : second.feature();
-        boolean drySurfaceBlend = first.feature().type().isSurface()
-                && second.feature().type().isSurface()
-                && !first.channel()
-                && !second.channel();
-        int bedY = drySurfaceBlend
-                ? Math.max(first.bedY(), second.bedY())
-                : Math.min(first.bedY(), second.bedY());
-        return new HydrologyColumnLayer(
-                feature,
-                bedY,
-                Math.max(first.fluidHeadY(), second.fluidHeadY()),
-                Math.max(first.ceilingY(), second.ceilingY()),
-                first.channel() || second.channel(),
-                first.shore() || second.shore(),
-                first.grading() || second.grading(),
-                first.connectedFluid() || second.connectedFluid(),
-                first.fallingFluid() || second.fallingFluid(),
-                first.receivingPool() || second.receivingPool(),
-                (first.terrainOwned() || second.terrainOwned()) && (!drySurfaceBlend || bedY != naturalHeight),
-                first.fluidOwned() || second.fluidOwned(),
-                first.oceanApron() || second.oceanApron(),
-                first.profileKey(),
-                first.surfaceBiomeKey(),
-                first.mouthBiomeKey(),
-                first.shoreBiomeKey(),
-                first.bankBiomeKey(),
-                first.floodedCaveBiomeKey()
-        );
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/FootprintRasterStencil.java

@@ -1,11 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-record FootprintRasterStencil(
-        int[] deltaXs,
-        int[] deltaZs,
-        double[] distances
-) {
-    int size() {
-        return deltaXs.length;
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/FootprintRasterStencilBuilder.java

@@ -1,37 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.Arrays;
-
-final class FootprintRasterStencilBuilder {
-    private int[] deltaXs;
-    private int[] deltaZs;
-    private double[] distances;
-    private int size;
-
-    FootprintRasterStencilBuilder() {
-        this.deltaXs = new int[64];
-        this.deltaZs = new int[64];
-        this.distances = new double[64];
-    }
-
-    void add(int deltaX, int deltaZ, double distance) {
-        if (size == deltaXs.length) {
-            int expandedSize = Math.multiplyExact(size, 2);
-            deltaXs = Arrays.copyOf(deltaXs, expandedSize);
-            deltaZs = Arrays.copyOf(deltaZs, expandedSize);
-            distances = Arrays.copyOf(distances, expandedSize);
-        }
-        deltaXs[size] = deltaX;
-        deltaZs[size] = deltaZ;
-        distances[size] = distance;
-        size++;
-    }
-
-    FootprintRasterStencil build() {
-        return new FootprintRasterStencil(
-                Arrays.copyOf(deltaXs, size),
-                Arrays.copyOf(deltaZs, size),
-                Arrays.copyOf(distances, size)
-        );
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/FootprintRasterStencilKey.java

@@ -1,8 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-record FootprintRasterStencilKey(
-        int channelRadius,
-        double shoreWidth,
-        double gradingWidth
-) {
-}

core/src/main/java/art/arcane/iris/generation/hydrology/FootprintValidationCourseRaster.java

@@ -1,12 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import art.arcane.iris.generation.hydrology.surface.SurfaceFootprint;
-
-import java.util.List;
-
-record FootprintValidationCourseRaster(
-        long courseId,
-        List<HydrologyColumnSample> columns,
-        SurfaceFootprint surface
-) {
-}

core/src/main/java/art/arcane/iris/generation/hydrology/HydraulicChannelProfile.java

@@ -1,87 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.Arrays;
-import java.util.Objects;
-
-public record HydraulicChannelProfile(double[] widths, double[] depths) {
-    public HydraulicChannelProfile {
-        Objects.requireNonNull(widths, "widths");
-        Objects.requireNonNull(depths, "depths");
-        if (widths.length == 0 || widths.length != depths.length) {
-            throw new IllegalArgumentException("Channel dimensions require equally sized, nonempty station arrays.");
-        }
-        widths = widths.clone();
-        depths = depths.clone();
-        for (int station = 0; station < widths.length; station++) {
-            if (!Double.isFinite(widths[station]) || widths[station] <= 0D
-                    || !Double.isFinite(depths[station]) || depths[station] <= 0D) {
-                throw new IllegalArgumentException("Channel dimensions must be finite and positive.");
-            }
-        }
-    }
-
-    public static HydraulicChannelProfile uniform(double width, double depth) {
-        return new HydraulicChannelProfile(new double[]{width}, new double[]{depth});
-    }
-
-    public static HydraulicChannelProfile range(double[] widths, double[] depths, int from, int to) {
-        Objects.checkFromToIndex(from, to, widths.length);
-        Objects.checkFromToIndex(from, to, depths.length);
-        return new HydraulicChannelProfile(Arrays.copyOfRange(widths, from, to), Arrays.copyOfRange(depths, from, to));
-    }
-
-    @Override
-    public double[] widths() {
-        return widths.clone();
-    }
-
-    @Override
-    public double[] depths() {
-        return depths.clone();
-    }
-
-    public int size() {
-        return widths.length;
-    }
-
-    public double widthAt(int station) {
-        return widths[widths.length == 1 ? 0 : station];
-    }
-
-    public double depthAt(int station) {
-        return depths[depths.length == 1 ? 0 : station];
-    }
-
-    public double maximumWidth() {
-        double maximum = 0D;
-        for (double width : widths) {
-            maximum = Math.max(maximum, width);
-        }
-        return maximum;
-    }
-
-    public double maximumDepth() {
-        double maximum = 0D;
-        for (double depth : depths) {
-            maximum = Math.max(maximum, depth);
-        }
-        return maximum;
-    }
-
-    @Override
-    public boolean equals(Object other) {
-        return other instanceof HydraulicChannelProfile profile
-                && Arrays.equals(widths, profile.widths)
-                && Arrays.equals(depths, profile.depths);
-    }
-
-    @Override
-    public int hashCode() {
-        return 31 * Arrays.hashCode(widths) + Arrays.hashCode(depths);
-    }
-
-    @Override
-    public String toString() {
-        return "HydraulicChannelProfile[widths=" + Arrays.toString(widths) + ", depths=" + Arrays.toString(depths) + "]";
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/HydraulicSegment.java

@@ -1,74 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import java.util.List;
-import java.util.Objects;
-
-public record HydraulicSegment(
-        long id,
-        long courseId,
-        HydrologyFeatureType type,
-        int upstreamHeadY,
-        int downstreamHeadY,
-        int width,
-        int depth,
-        boolean fallingFluid,
-        boolean receivingPool,
-        List<HydrologyPoint> centerline,
-        HydraulicChannelProfile channelProfile
-) {
-    public HydraulicSegment {
-        Objects.requireNonNull(type, "type");
-        Objects.requireNonNull(centerline, "centerline");
-        Objects.requireNonNull(channelProfile, "channelProfile");
-        centerline = List.copyOf(centerline);
-        if (centerline.isEmpty()) {
-            throw new IllegalArgumentException("A hydraulic segment requires a centerline.");
-        }
-        if (upstreamHeadY < downstreamHeadY) {
-            throw new IllegalArgumentException("Hydraulic heads cannot rise downstream.");
-        }
-        if (width <= 0 || depth <= 0) {
-            throw new IllegalArgumentException("Hydraulic segment width and depth must be positive.");
-        }
-        if (channelProfile.size() != 1 && channelProfile.size() != centerline.size()) {
-            throw new IllegalArgumentException("Channel dimensions must cover every centerline station.");
-        }
-        if (channelProfile.maximumWidth() > width || channelProfile.maximumDepth() > depth) {
-            throw new IllegalArgumentException("Hydraulic segment bounds must contain its channel dimensions.");
-        }
-        int drop = upstreamHeadY - downstreamHeadY;
-        if (fallingFluid && drop == 0) {
-            throw new IllegalArgumentException("Falling fluid requires a positive head transition.");
-        }
-        if (drop > 0 && !type.isDrop()) {
-            throw new IllegalArgumentException("A positive head transition requires a drop segment type.");
-        }
-        if (drop == 0 && type.isDrop()) {
-            throw new IllegalArgumentException("A drop segment type requires a positive head transition.");
-        }
-        if (drop > 0 && !fallingFluid) {
-            if (centerline.getFirst().y() != upstreamHeadY || centerline.getLast().y() != downstreamHeadY) {
-                throw new IllegalArgumentException("A graded head transition must span its declared heads.");
-            }
-            int previousHead = upstreamHeadY;
-            for (HydrologyPoint point : centerline) {
-                if (point.y() > previousHead || point.y() < downstreamHeadY) {
-                    throw new IllegalArgumentException("A graded head transition must descend monotonically.");
-                }
-                previousHead = point.y();
-            }
-        }
-    }
-
-    public int drop() {
-        return upstreamHeadY - downstreamHeadY;
-    }
-
-    public HydrologyPoint start() {
-        return centerline.getFirst();
-    }
-
-    public HydrologyPoint end() {
-        return centerline.getLast();
-    }
-}

core/src/main/java/art/arcane/iris/generation/hydrology/HydrologyBasisCache.java

@@ -1,325 +0,0 @@
-package art.arcane.iris.generation.hydrology;
-
-import art.arcane.iris.generation.stream.ProvisionalSampling;
-import art.arcane.volmlib.util.cache.CacheKey;
-import it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap;
-import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
-import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
-
-import java.util.Objects;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.ForkJoinPool;
-import java.util.concurrent.RejectedExecutionException;
-
-final class HydrologyBasisCache {
-    private static final int MAXIMUM_ENTRIES = 32_768;
-    private static final int MAXIMUM_STRIPES = 64;
-    private final Stripe[] full;
-    private final Stripe[] withoutSlope;
-
-    HydrologyBasisCache() {
-        this(MAXIMUM_ENTRIES);
-    }
-
-    HydrologyBasisCache(int maximumEntries) {
-        if (maximumEntries < 1 || Integer.bitCount(maximumEntries) != 1) {
-            throw new IllegalArgumentException("Terrain basis cache size must be a positive power of two.");
-        }
-        int stripeCount = Math.min(MAXIMUM_STRIPES, maximumEntries);
-        full = new Stripe[stripeCount];
-        withoutSlope = new Stripe[stripeCount];
-        for (int index = 0; index < stripeCount; index++) {
-            full[index] = new Stripe(maximumEntries / stripeCount);
-            withoutSlope[index] = new Stripe(maximumEntries / stripeCount);
-        }
-    }
-
-    HydrologyTerrainSample sample(int x, int z, HydrologyNaturalTerrainSampler sampler) {
-        return sample(x, z, sampler, false);
-    }
-
-    HydrologyTerrainSample sampleWithoutSlope(int x, int z, HydrologyNaturalTerrainSampler sampler) {
-        return sample(x, z, sampler, true);
-    }
-
-    void seed(Long2ObjectMap<HydrologyTerrainSample> samples) {
-        seed(samples, full);
-    }
-
-    HydrologyTerrainSample[] sampleWithoutSlopeBatch(long[] coordinates, int count,
-                                                    HydrologyNaturalTerrainSampler sampler) {
-        Objects.checkFromIndexSize(0, count, coordinates.length);
-        if (count > HydrologyTerrainSampler.MAXIMUM_BATCH_SIZE) {
-            throw new IllegalArgumentException("Terrain basis batch exceeds its sample limit");
-        }
-        HydrologyTerrainSample[] samples = new HydrologyTerrainSample[count];
-        Pending[] pending = new Pending[count];
-        long[] ownedCoordinates = new long[count];
-        Pending[] owned = new Pending[count];
-        int ownedCount = count;
-        Completion completion = new Completion();
-        int[] next = new int[count];
-        int[] heads = groupByStripe(coordinates, count, next);
-        try {
-            for (int stripeIndex = 0; stripeIndex < withoutSlope.length; stripeIndex++) {
-                if (heads[stripeIndex] == 0) {
-                    continue;
-                }
-                Stripe stripe = withoutSlope[stripeIndex];
-                synchronized (stripe) {
-                    for (int position = heads[stripeIndex]; position != 0; position = next[position - 1]) {
-                        int index = position - 1;
-                        long packed = coordinates[index];
-                        HydrologyTerrainSample cached = stripe.samples.getAndMoveToFirst(packed);
-                        if (cached != null || stripe.samples.containsKey(packed)) {
-                            samples[index] = cached;
-                            continue;
-                        }
-                        Pending loading = stripe.pending.get(packed);
-                        if (loading == null) {
-                            loading = new Pending(completion);
-                            stripe.pending.put(packed, loading);
-                            ownedCoordinates[index] = packed;
-                            owned[index] = loading;
-                        }
-                        pending[index] = loading;
-                    }
-                }
-            }
-            int claimed = 0;
-            for (int index = 0; index < count; index++) {
-                if (owned[index] != null) {
-                    ownedCoordinates[claimed] = ownedCoordinates[index];
-                    owned[claimed++] = owned[index];
-                }
-            }
-            ownedCount = claimed;
-            if (ownedCount > 0) {
-                loadBatch(ownedCoordinates, owned, ownedCount, sampler);
-            }
-        } catch (RuntimeException | Error failure) {
-            for (int index = 0; index < ownedCount; index++) {
-                if (owned[index] != null) {
-                    fail(withoutSlope, ownedCoordinates[index], owned[index], failure);
-                }
-            }
-            completion.failure = failure;
-            throw failure;
-        } finally {
-            completion.complete.countDown();
-        }
-        for (int index = 0; index < count; index++) {
-            if (pending[index] != null) {
-                samples[index] = pending[index].await();
-            }
-        }
-        return samples;
-    }
-
-    void seedWithoutSlope(Long2ObjectMap<HydrologyTerrainSample> samples) {
-        seed(samples, withoutSlope);
-    }
-
-    private HydrologyTerrainSample sample(int x, int z, HydrologyNaturalTerrainSampler sampler, boolean omitSlope) {
-        long packed = RiverFootprint.pack(x, z);
-        Stripe[] stripes = omitSlope ? withoutSlope : full;
-        Stripe stripe = stripe(stripes, packed);
-        Pending loading;
-        boolean owner = false;
-        synchronized (stripe) {
-            HydrologyTerrainSample cached = stripe.samples.getAndMoveToFirst(packed);
-            if (cached != null || stripe.samples.containsKey(packed)) {
-                return cached;
-            }
-            loading = stripe.pending.get(packed);
-            if (loading == null) {
-                loading = new Pending(new Completion());
-                stripe.pending.put(packed, loading);
-                owner = true;
-            }
-        }
-        if (owner) {
-            try {
-                HydrologyTerrainSample sampled = ProvisionalSampling.memoizable(() -> omitSlope
-                        ? sampler.sampleBasisWithoutSlope(x, z) : sampler.sampleBasis(x, z));
-                complete(stripes, packed, loading, sampled, false);
-            } catch (ProvisionalSampling.Unmemoizable provisional) {
-                complete(stripes, packed, loading, provisional.value(), true);
-            } catch (RuntimeException | Error failure) {
-                fail(stripes, packed, loading, failure);
-                throw failure;
-            } finally {
-                loading.completion.complete.countDown();
-            }
-        }
-        return loading.await();
-    }
-
-    private void loadBatch(long[] coordinates, Pending[] pending, int count, HydrologyNaturalTerrainSampler sampler) {
-        HydrologyTerrainSample[] samples;
-        boolean provisional = false;
-        try {
-            samples = ProvisionalSampling.memoizable(() -> sampler.sampleBasisWithoutSlopeBatch(coordinates, count));
-        } catch (ProvisionalSampling.Unmemoizable value) {
-            samples = value.value();
-            provisional = true;
-        }
-        if (samples.length < count) {
-            throw new IllegalStateException("Terrain basis batch returned too few samples");
-        }
-        int[] next = new int[count];
-        int[] heads = groupByStripe(coordinates, count, next);
-        for (int stripeIndex = 0; stripeIndex < withoutSlope.length; stripeIndex++) {
-            if (heads[stripeIndex] == 0) {
-                continue;
-            }
-            Stripe stripe = withoutSlope[stripeIndex];
-            synchronized (stripe) {
-                for (int position = heads[stripeIndex]; position != 0; position = next[position - 1]) {
-                    int index = position - 1;
-                    complete(stripe, coordinates[index], pending[index], samples[index], provisional);
-                }
-            }
-        }
-    }
-
-    private int[] groupByStripe(long[] coordinates, int count, int[] next) {
-        int[] heads = new int[withoutSlope.length];
-        for (int index = count - 1; index >= 0; index--) {
-            int stripeIndex = (int) CacheKey.mix(coordinates[index]) & (withoutSlope.length - 1);
-            next[index] = heads[stripeIndex];
-            heads[stripeIndex] = index + 1;
-        }
-        return heads;
-    }
-
-    private void complete(Stripe[] stripes, long packed, Pending pending, HydrologyTerrainSample sample,
-                          boolean provisional) {
-        Stripe stripe = stripe(stripes, packed);
-        synchronized (stripe) {
-            complete(stripe, packed, pending, sample, provisional);
-        }
-    }
-
-    private void complete(Stripe stripe, long packed, Pending pending, HydrologyTerrainSample sample,
-                          boolean provisional) {
-        if (stripe.samples.containsKey(packed)) {
-            sample = stripe.samples.getAndMoveToFirst(packed);
-            provisional = false;
-        } else if (!provisional) {
-            stripe.put(packed, sample);
-        }
-        stripe.pending.remove(packed);
-        pending.sample = sample;
-        pending.provisional = provisional;
-    }
-
-    private void fail(Stripe[] stripes, long packed, Pending pending, Throwable failure) {
-        Stripe stripe = stripe(stripes, packed);
-        synchronized (stripe) {
-            if (stripe.pending.remove(packed, pending)) {
-                pending.completion.failure = failure;
-            }
-        }
-    }
-
-    private void seed(Long2ObjectMap<HydrologyTerrainSample> samples, Stripe[] stripes) {
-        for (Long2ObjectMap.Entry<HydrologyTerrainSample> entry : samples.long2ObjectEntrySet()) {
-            Stripe stripe = stripe(stripes, entry.getLongKey());
-            synchronized (stripe) {
-                stripe.put(entry.getLongKey(), entry.getValue());
-            }
-        }
-    }
-
-    private Stripe stripe(Stripe[] stripes, long packed) {
-        return stripes[(int) CacheKey.mix(packed) & (stripes.length - 1)];
-    }
-
-    private static final class Stripe {
-        private final int maximumEntries;
-        private final Long2ObjectLinkedOpenHashMap<HydrologyTerrainSample> samples;
-        private final Long2ObjectOpenHashMap<Pending> pending = new Long2ObjectOpenHashMap<>();
-
-        private Stripe(int maximumEntries) {
-            this.maximumEntries = maximumEntries;
-            samples = new Long2ObjectLinkedOpenHashMap<>(Math.min(16, maximumEntries));
-        }
-
-        private void put(long packed, HydrologyTerrainSample value) {
-            if (samples.size() >= maximumEntries && !samples.containsKey(packed)) {
-                samples.removeLast();
-            }
-            samples.putAndMoveToFirst(packed, value);
-        }
-    }
-
-    private static final class Pending {
-        private final Completion completion;
-        private HydrologyTerrainSample sample;
-        private boolean provisional;
-
-        private Pending(Completion completion) {
-            this.completion = completion;
-        }
-
-        private HydrologyTerrainSample await() {
-            completion.await();
-            if (provisional) {
-                ProvisionalSampling.mark();
-            }
-            return sample;
-        }
-    }
-
-    private static final class Completion implements ForkJoinPool.ManagedBlocker {
-        private final Thread owner = Thread.currentThread();
-        private final CountDownLatch complete = new CountDownLatch(1);
-        private Throwable failure;
-
-        private void await() {
-            if (!isReleasable() && owner == Thread.currentThread()) {
-                throw new IllegalStateException("Recursive terrain basis sampling");
-            }
-            boolean interrupted = false;
-            boolean managed = true;
-            try {
-                while (!isReleasable()) {
-                    try {
-                        if (managed) {
-                            ForkJoinPool.managedBlock(this);
-                        } else {
-                            complete.await();
-                        }
-                    } catch (InterruptedException interruption) {
-                        interrupted = true;
-                        managed = false;
-                    } catch (RejectedExecutionException unavailable) {
-                        managed = false;
-                    }
-                }
-            } finally {
-                if (interrupted) {
-                    Thread.currentThread().interrupt();
-                }
-            }
-            if (failure instanceof Error error) {
-                throw error;
-            }
-            if (failure instanceof RuntimeException runtime) {
-                throw runtime;
-            }
-        }
-
-        @Override
-        public boolean block() throws InterruptedException {
-            complete.await();
-            return true;
-        }
-
-        @Override
-        public boolean isReleasable() {
-            return complete.getCount() == 0;
-        }
-    }
-}