Hydrology fixes

probe/src/main/java/art/arcane/iris/probe/HydrologyBlockProbe.java

@@ -0,0 +1,523 @@
+package art.arcane.iris.probe;
+
+import art.arcane.iris.engine.IrisComplex;
+import art.arcane.iris.engine.framework.Engine;
+import art.arcane.iris.engine.hydrology.HydrologyColumnLayer;
+import art.arcane.iris.engine.hydrology.HydrologyColumnSample;
+import art.arcane.iris.engine.hydrology.HydrologyFeatureType;
+import art.arcane.iris.engine.hydrology.RiverFootprint;
+import art.arcane.iris.engine.object.InferredType;
+import art.arcane.iris.spi.PlatformBlockState;
+import com.google.gson.GsonBuilder;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeMap;
+
+public final class HydrologyBlockProbe {
+    private static final int MAXIMUM_CHUNKS = 64;
+    private static final long MAXIMUM_VOXELS = 16_777_216L;
+    private static final int MAXIMUM_EXAMPLES = 16;
+    private static final int[][] CARDINALS = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
+
+    private HydrologyBlockProbe() {
+    }
+
+    record Configuration(File pack, String dimension, long seed, int minimumChunkX, int maximumChunkX,
+                         int minimumChunkZ, int maximumChunkZ, Set<String> requiredCoverage, File output,
+                         boolean studio) {
+        Configuration {
+            if (pack == null || !pack.isAbsolute() || dimension == null || dimension.isBlank()
+                    || output == null || !output.isAbsolute()) {
+                throw new IllegalArgumentException("Absolute pack/output paths and a dimension key are required.");
+            }
+            long width = (long) maximumChunkX - minimumChunkX + 1;
+            long depth = (long) maximumChunkZ - minimumChunkZ + 1;
+            if (width < 1 || depth < 1 || width > MAXIMUM_CHUNKS || depth > MAXIMUM_CHUNKS
+                    || width * depth > MAXIMUM_CHUNKS
+                    || minimumChunkX < Integer.MIN_VALUE / 16 || minimumChunkZ < Integer.MIN_VALUE / 16
+                    || maximumChunkX > Integer.MAX_VALUE / 16 - 1 || maximumChunkZ > Integer.MAX_VALUE / 16 - 1) {
+                throw new IllegalArgumentException("Bounds must contain 1..64 chunks and fit block coordinates.");
+            }
+            requiredCoverage = Set.copyOf(requiredCoverage);
+            if (!Set.of("cane", "mouth", "channel", "bank").containsAll(requiredCoverage)) {
+                throw new IllegalArgumentException("Required coverage accepts cane,mouth,channel,bank or -.");
+            }
+        }
+
+        static Configuration parse(String[] args) {
+            if (args.length != 10) {
+                throw new IllegalArgumentException("Expected <pack> <dimension> <seed> <minChunkX> <maxChunkX> "
+                        + "<minChunkZ> <maxChunkZ> <requiredCoverage|-> <outputDir> <studio>.");
+            }
+            Set<String> required = new LinkedHashSet<>();
+            if (!args[7].equals("-")) {
+                for (String value : args[7].split(",", -1)) {
+                    required.add(value.trim());
+                }
+            }
+            return new Configuration(new File(args[0]), args[1], Long.parseLong(args[2]), Integer.parseInt(args[3]),
+                    Integer.parseInt(args[4]), Integer.parseInt(args[5]), Integer.parseInt(args[6]), required,
+                    new File(args[8]), RealPackProbeSupport.parseBoolean(args[9], "studio"));
+        }
+    }
+
+    record PlannedColumn(int naturalY, boolean ocean, HydrologyColumnLayer surface, PlatformBlockState fluid) {
+        boolean mouthAt(int seaLevel) {
+            return surface != null && fluid != null && fluid.isWater()
+                    && surface.feature().type() == HydrologyFeatureType.MOUTH
+                    && surface.channel() && (surface.fluidOwned() || surface.oceanApron())
+                    && surface.fluidHeadY() == seaLevel;
+        }
+    }
+
+    static final class Evidence {
+        long caneRoots;
+        long validCaneRoots;
+        long invalidCaneSubstrates;
+        long dryCaneRoots;
+        long censoredCaneRoots;
+        long plannedWetVoxels;
+        long missingWetVoxels;
+        long bankColumns;
+        long bankExcavation;
+        int maximumBankCut;
+        long oceanBedWrites;
+        long drySillCuts;
+        long invalidDrySillCuts;
+        int connectedMouthComponents;
+        int disconnectedMouthComponents;
+        int censoredMouthComponents;
+        final List<String> examples = new ArrayList<>();
+
+        void example(String value) {
+            if (examples.size() < MAXIMUM_EXAMPLES) {
+                examples.add(value);
+            }
+        }
+    }
+
+    record Result(String status, Configuration configuration, int worldMinimumY, int seaLevel,
+                  Evidence evidence, List<String> failures, List<String> artifacts) {
+    }
+
+    static final class Volume {
+        private final Map<Long, RealPackProbeSupport.GeneratedChunk> chunks;
+        private final int minimumX;
+        private final int maximumX;
+        private final int minimumZ;
+        private final int maximumZ;
+        private final int height;
+
+        Volume(Map<Long, RealPackProbeSupport.GeneratedChunk> chunks) {
+            if (chunks.isEmpty()) {
+                throw new IllegalArgumentException("Generated chunks are required.");
+            }
+            this.chunks = Map.copyOf(chunks);
+            int minX = Integer.MAX_VALUE;
+            int maxX = Integer.MIN_VALUE;
+            int minZ = Integer.MAX_VALUE;
+            int maxZ = Integer.MIN_VALUE;
+            int selectedHeight = chunks.values().iterator().next().height();
+            for (RealPackProbeSupport.GeneratedChunk chunk : chunks.values()) {
+                if (chunk.height() != selectedHeight) {
+                    throw new IllegalArgumentException("Generated chunks must have the same height.");
+                }
+                minX = Math.min(minX, chunk.chunkX() << 4);
+                maxX = Math.max(maxX, (chunk.chunkX() << 4) + 15);
+                minZ = Math.min(minZ, chunk.chunkZ() << 4);
+                maxZ = Math.max(maxZ, (chunk.chunkZ() << 4) + 15);
+            }
+            minimumX = minX;
+            maximumX = maxX;
+            minimumZ = minZ;
+            maximumZ = maxZ;
+            height = selectedHeight;
+        }
+
+        boolean contains(int x, int z) {
+            return chunks.containsKey(RiverFootprint.pack(Math.floorDiv(x, 16), Math.floorDiv(z, 16)));
+        }
+
+        PlatformBlockState block(int x, int y, int z) {
+            RealPackProbeSupport.GeneratedChunk chunk = chunks.get(
+                    RiverFootprint.pack(Math.floorDiv(x, 16), Math.floorDiv(z, 16)));
+            return chunk == null || y < 0 || y >= height ? null : chunk.blockAt(x, y, z);
+        }
+    }
+
+    public static void main(String[] args) {
+        int exitCode = 2;
+        try {
+            Result result = run(Configuration.parse(args));
+            Evidence evidence = result.evidence();
+            System.out.println("IRIS_HYDROLOGY_BLOCK_RESULT version=1 status=" + result.status()
+                    + " seed=" + result.configuration().seed() + " cane=" + evidence.validCaneRoots
+                    + " wetVoxels=" + evidence.plannedWetVoxels + " missingWet=" + evidence.missingWetVoxels
+                    + " mouths=" + evidence.connectedMouthComponents + " failures=" + result.failures().size()
+                    + " output=" + result.configuration().output().getAbsolutePath());
+            exitCode = result.failures().isEmpty() ? 0 : 1;
+        } catch (Throwable failure) {
+            failure.printStackTrace(System.out);
+        }
+        System.exit(exitCode);
+    }
+
+    static Result run(Configuration configuration) throws Exception {
+        try (RealPackProbeSupport.Workspace workspace = RealPackProbeSupport.openWorkspace(
+                configuration.pack(), configuration.dimension(), "[hydrology-blocks]");
+             RealPackProbeSupport.EngineSession session = workspace.openEngine(
+                     configuration.seed(), configuration.studio(), "hydrology-blocks")) {
+            Engine engine = session.engine();
+            IrisComplex complex = engine.getComplex();
+            if (complex.getHydrologyRuntime() == null) {
+                throw new IllegalStateException("The dimension must enable hydrology.");
+            }
+            long chunks = ((long) configuration.maximumChunkX() - configuration.minimumChunkX() + 1)
+                    * ((long) configuration.maximumChunkZ() - configuration.minimumChunkZ() + 1);
+            if (chunks * 256 * engine.getTarget().getHeight() > MAXIMUM_VOXELS) {
+                throw new IllegalArgumentException("Generated bounds exceed the 16777216 voxel limit.");
+            }
+            Map<Long, RealPackProbeSupport.GeneratedChunk> generated = new HashMap<>();
+            for (int z = configuration.minimumChunkZ(); z <= configuration.maximumChunkZ(); z++) {
+                for (int x = configuration.minimumChunkX(); x <= configuration.maximumChunkX(); x++) {
+                    generated.put(RiverFootprint.pack(x, z), RealPackProbeSupport.generateChunk(engine, x, z));
+                }
+            }
+            Volume volume = new Volume(generated);
+            Map<Long, PlannedColumn> planned = new HashMap<>();
+            for (int z = volume.minimumZ; z <= volume.maximumZ; z++) {
+                for (int x = volume.minimumX; x <= volume.maximumX; x++) {
+                    HydrologyColumnSample sample = complex.sampleHydrologyColumn(x, z);
+                    int natural = sample == null ? (int) Math.round(complex.getNaturalHeightStream().getDouble(x, z))
+                            : sample.naturalHeight();
+                    HydrologyColumnLayer layer = surfaceForInspection(sample);
+                    PlatformBlockState fluid = layer == null ? null : complex.resolveHydrologyFluid(
+                            layer.profileKey(), x, z);
+                    planned.put(RiverFootprint.pack(x, z), new PlannedColumn(natural, sample == null
+                            ? complex.getBridgeStream().get(x, z) == InferredType.SEA : sample.ocean(), layer, fluid));
+                }
+            }
+            int seaLevel = complex.getHydrologyRuntime().settings().seaLevel();
+            Evidence evidence = inspect(volume, planned, seaLevel);
+            int maximumCut = complex.getHydrologyRuntime().settings().surface().banks().erosion()
+                    .excavation().maximumDepth();
+            List<String> failures = failures(evidence, maximumCut, configuration.requiredCoverage());
+            List<Throwable> reports = RealPackProbeSupport.drainReported();
+            RealPackProbeSupport.printReports("[hydrology-blocks]", "generation", reports);
+            if (!reports.isEmpty()) {
+                failures.add("The engine reported " + reports.size() + " generation errors.");
+            }
+            Files.createDirectories(configuration.output().toPath());
+            List<String> artifacts = writeImages(configuration.output(), volume, planned, seaLevel);
+            Result result = new Result(failures.isEmpty() ? "PASS" : "FAIL", configuration, engine.getMinHeight(),
+                    seaLevel, evidence, List.copyOf(failures), artifacts);
+            Files.writeString(new File(configuration.output(), "hydrology-blocks.json").toPath(),
+                    json(result), StandardCharsets.UTF_8);
+            return result;
+        }
+    }
+
+    static String json(Result result) {
+        Configuration configuration = result.configuration();
+        Map<String, Object> settings = Map.ofEntries(
+                Map.entry("pack", configuration.pack().getAbsolutePath()),
+                Map.entry("dimension", configuration.dimension()),
+                Map.entry("seed", configuration.seed()),
+                Map.entry("minimumChunkX", configuration.minimumChunkX()),
+                Map.entry("maximumChunkX", configuration.maximumChunkX()),
+                Map.entry("minimumChunkZ", configuration.minimumChunkZ()),
+                Map.entry("maximumChunkZ", configuration.maximumChunkZ()),
+                Map.entry("requiredCoverage", configuration.requiredCoverage()),
+                Map.entry("output", configuration.output().getAbsolutePath()),
+                Map.entry("studio", configuration.studio()));
+        Map<String, Object> report = Map.of("status", result.status(), "configuration", settings,
+                "worldMinimumY", result.worldMinimumY(), "seaLevel", result.seaLevel(),
+                "evidence", result.evidence(), "failures", result.failures(), "artifacts", result.artifacts(),
+                "coordinateConvention", "Block X/Z are world coordinates; evidence Y and seaLevel are relative to worldMinimumY.",
+                "imageLegend", "air=light blue,water=blue,lava=orange,cane=lime,vegetation=green,sand=tan,soil=brown,other=gray");
+        return new GsonBuilder().setPrettyPrinting().create().toJson(report) + "\n";
+    }
+
+    static HydrologyColumnLayer surfaceForInspection(HydrologyColumnSample sample) {
+        if (sample == null) {
+            return null;
+        }
+        HydrologyColumnLayer primary = sample.primarySurfaceLayerOrNull();
+        if (primary != null) {
+            return primary;
+        }
+        for (HydrologyColumnLayer layer : sample.layers()) {
+            if (layer.oceanApron() && layer.feature().type() == HydrologyFeatureType.MOUTH) {
+                return layer;
+            }
+        }
+        return null;
+    }
+
+    static Evidence inspect(Volume volume, Map<Long, PlannedColumn> planned, int seaLevel) {
+        Evidence evidence = new Evidence();
+        for (int z = volume.minimumZ; z <= volume.maximumZ; z++) {
+            for (int x = volume.minimumX; x <= volume.maximumX; x++) {
+                if (!volume.contains(x, z)) {
+                    continue;
+                }
+                for (int y = 0; y < volume.height; y++) {
+                    PlatformBlockState block = volume.block(x, y, z);
+                    if (key(block).equals("minecraft:sugar_cane")
+                            && !key(volume.block(x, y - 1, z)).equals("minecraft:sugar_cane")) {
+                        inspectCane(volume, block, x, y, z, evidence);
+                    }
+                }
+                PlannedColumn column = planned.get(RiverFootprint.pack(x, z));
+                if (column == null || column.surface() == null) {
+                    continue;
+                }
+                HydrologyColumnLayer surface = column.surface();
+                int cut = Math.max(0, column.naturalY() - surface.bedY());
+                if (surface.terrainOwned() && (column.ocean() || column.naturalY() < seaLevel)) {
+                    evidence.oceanBedWrites++;
+                }
+                if (surface.terrainOwned() && column.naturalY() == seaLevel && cut > 0) {
+                    evidence.drySillCuts++;
+                    if (!surface.channel() || !surface.fluidOwned() || surface.fluidHeadY() != seaLevel) {
+                        evidence.invalidDrySillCuts++;
+                    }
+                }
+                if (surface.terrainOwned() && !surface.channel()) {
+                    evidence.bankColumns++;
+                    evidence.bankExcavation += cut;
+                    evidence.maximumBankCut = Math.max(evidence.maximumBankCut, cut);
+                }
+                if (!surface.fluidOwned() || !surface.channel() || column.fluid() == null) {
+                    continue;
+                }
+                for (int y = Math.max(0, surface.bedY() + 1); y <= surface.fluidHeadY() && y < volume.height; y++) {
+                    evidence.plannedWetVoxels++;
+                    PlatformBlockState actual = volume.block(x, y, z);
+                    boolean matches = column.fluid().isWater() ? water(actual)
+                            : key(column.fluid()).equals(key(actual));
+                    if (!matches) {
+                        evidence.missingWetVoxels++;
+                        evidence.example("missing wet voxel " + x + "," + y + "," + z + "=" + key(actual));
+                    }
+                }
+            }
+        }
+        inspectMouths(volume, planned, seaLevel, evidence);
+        return evidence;
+    }
+
+    private static void inspectCane(Volume volume, PlatformBlockState cane, int x, int y, int z, Evidence evidence) {
+        evidence.caneRoots++;
+        PlatformBlockState substrate = volume.block(x, y - 1, z);
+        if (substrate == null || !cane.canPlaceOnto(substrate)) {
+            evidence.invalidCaneSubstrates++;
+            evidence.example("unsupported cane " + x + "," + y + "," + z + " on " + key(substrate));
+            return;
+        }
+        boolean censored = false;
+        for (int[] offset : CARDINALS) {
+            int nx = x + offset[0];
+            int nz = z + offset[1];
+            if (!volume.contains(nx, nz)) {
+                censored = true;
+                continue;
+            }
+            PlatformBlockState adjacent = volume.block(nx, y - 1, nz);
+            if (water(adjacent) || key(adjacent).equals("minecraft:frosted_ice")) {
+                evidence.validCaneRoots++;
+                return;
+            }
+        }
+        if (censored) {
+            evidence.censoredCaneRoots++;
+        } else {
+            evidence.dryCaneRoots++;
+            evidence.example("dry cane root " + x + "," + y + "," + z);
+        }
+    }
+
+    private static void inspectMouths(Volume volume, Map<Long, PlannedColumn> planned, int seaLevel, Evidence evidence) {
+        Set<Long> visited = new HashSet<>();
+        TreeMap<Long, PlannedColumn> ordered = new TreeMap<>(planned);
+        for (Map.Entry<Long, PlannedColumn> entry : ordered.entrySet()) {
+            if (!entry.getValue().mouthAt(seaLevel) || !visited.add(entry.getKey())) {
+                continue;
+            }
+            int startX = (int) (entry.getKey() >> 32);
+            int startZ = (int) (long) entry.getKey();
+            if (!water(volume.block(startX, seaLevel, startZ))) {
+                evidence.disconnectedMouthComponents++;
+                evidence.example("dry mouth " + startX + "," + seaLevel + "," + startZ);
+                continue;
+            }
+            ArrayDeque<Long> queue = new ArrayDeque<>();
+            queue.add(entry.getKey());
+            long courseId = entry.getValue().surface().feature().courseId();
+            boolean ocean = false;
+            boolean channel = false;
+            boolean censored = false;
+            while (!queue.isEmpty()) {
+                long packed = queue.removeFirst();
+                int x = (int) (packed >> 32);
+                int z = (int) packed;
+                PlannedColumn column = planned.get(packed);
+                ocean |= column != null && column.ocean() && column.naturalY() < seaLevel
+                        && (column.surface() == null || !column.surface().terrainOwned());
+                channel |= column != null && column.surface() != null && column.surface().channel()
+                        && column.surface().fluidOwned() && !column.surface().oceanApron()
+                        && column.surface().fluidHeadY() == seaLevel
+                        && column.surface().feature().courseId() == courseId;
+                for (int[] offset : CARDINALS) {
+                    int nx = x + offset[0];
+                    int nz = z + offset[1];
+                    if (!volume.contains(nx, nz)) {
+                        censored = true;
+                        continue;
+                    }
+                    long next = RiverFootprint.pack(nx, nz);
+                    if (water(volume.block(nx, seaLevel, nz)) && visited.add(next)) {
+                        queue.addLast(next);
+                    }
+                }
+            }
+            if (ocean && channel) {
+                evidence.connectedMouthComponents++;
+            } else if (censored) {
+                evidence.censoredMouthComponents++;
+            } else {
+                evidence.disconnectedMouthComponents++;
+                evidence.example("mouth without connected course and ocean water "
+                        + startX + "," + seaLevel + "," + startZ);
+            }
+        }
+    }
+
+    static List<String> failures(Evidence evidence, int maximumBankCut, Set<String> required) {
+        List<String> failures = new ArrayList<>();
+        if (evidence.invalidCaneSubstrates > 0 || evidence.dryCaneRoots > 0) {
+            failures.add("Generated sugar cane has invalid substrate or no adjacent supporting water.");
+        }
+        if (evidence.missingWetVoxels > 0) {
+            failures.add("Generated blocks do not retain every planned surface channel fluid voxel.");
+        }
+        if (evidence.disconnectedMouthComponents > 0) {
+            failures.add("A fully sampled mouth water component does not connect to untouched natural ocean water.");
+        }
+        if (evidence.oceanBedWrites > 0 || evidence.invalidDrySillCuts > 0) {
+            failures.add("Hydrology owns ocean-bed terrain or an invalid dry shoreline sill cut.");
+        }
+        if (evidence.maximumBankCut > maximumBankCut) {
+            failures.add("Published dry-bank cut depth exceeds its configured budget.");
+        }
+        for (String coverage : required) {
+            boolean covered = switch (coverage) {
+                case "cane" -> evidence.validCaneRoots > 0;
+                case "mouth" -> evidence.connectedMouthComponents > 0;
+                case "channel" -> evidence.plannedWetVoxels > 0;
+                case "bank" -> evidence.bankColumns > 0;
+                default -> false;
+            };
+            if (!covered) {
+                failures.add("Required generated coverage is absent: " + coverage);
+            }
+        }
+        return failures;
+    }
+
+    private static List<String> writeImages(File output, Volume volume, Map<Long, PlannedColumn> planned, int seaLevel)
+            throws Exception {
+        int width = volume.maximumX - volume.minimumX + 1;
+        int depth = volume.maximumZ - volume.minimumZ + 1;
+        BufferedImage overhead = new BufferedImage(width, depth, BufferedImage.TYPE_INT_RGB);
+        int selectedX = volume.minimumX + width / 2;
+        int selectedZ = volume.minimumZ + depth / 2;
+        for (int z = volume.minimumZ; z <= volume.maximumZ; z++) {
+            for (int x = volume.minimumX; x <= volume.maximumX; x++) {
+                for (int y = volume.height - 1; y >= 0; y--) {
+                    PlatformBlockState block = volume.block(x, y, z);
+                    if (block != null && !block.isAir()) {
+                        overhead.setRGB(x - volume.minimumX, z - volume.minimumZ, color(block));
+                        break;
+                    }
+                }
+                PlannedColumn column = planned.get(RiverFootprint.pack(x, z));
+                if (column != null && column.mouthAt(seaLevel)) {
+                    selectedX = x;
+                    selectedZ = z;
+                }
+            }
+        }
+        File plan = new File(output, "generated-overhead.png");
+        ImageIO.write(overhead, "png", plan);
+        List<String> artifacts = new ArrayList<>();
+        artifacts.add(plan.getAbsolutePath());
+        for (boolean alongX : new boolean[]{true, false}) {
+            int span = alongX ? width : depth;
+            BufferedImage section = new BufferedImage(span, volume.height, BufferedImage.TYPE_INT_RGB);
+            for (int position = 0; position < span; position++) {
+                int x = alongX ? volume.minimumX + position : selectedX;
+                int z = alongX ? selectedZ : volume.minimumZ + position;
+                for (int y = 0; y < volume.height; y++) {
+                    section.setRGB(position, volume.height - y - 1, color(volume.block(x, y, z)));
+                }
+            }
+            File file = new File(output, alongX ? "generated-section-z-" + selectedZ + ".png"
+                    : "generated-section-x-" + selectedX + ".png");
+            ImageIO.write(section, "png", file);
+            artifacts.add(file.getAbsolutePath());
+        }
+        return List.copyOf(artifacts);
+    }
+
+    private static int color(PlatformBlockState block) {
+        if (block == null || block.isAir()) {
+            return 0xC9E3F0;
+        }
+        if (water(block)) {
+            return 0x247AC4;
+        }
+        String key = key(block);
+        if (key.equals("minecraft:lava")) {
+            return 0xEC6F20;
+        }
+        if (key.equals("minecraft:sugar_cane")) {
+            return 0x9BDD42;
+        }
+        if (key.contains("grass") || key.contains("moss") || key.contains("leaves")) {
+            return 0x4E7845;
+        }
+        if (key.contains("sand")) {
+            return 0xDCCFA5;
+        }
+        if (key.contains("dirt") || key.contains("mud")) {
+            return 0x82634D;
+        }
+        return 0x888C90;
+    }
+
+    private static boolean water(PlatformBlockState block) {
+        return block != null && (block.isWater() || block.isWaterLogged());
+    }
+
+    private static String key(PlatformBlockState block) {
+        if (block == null) {
+            return "minecraft:air";
+        }
+        String key = block.key();
+        int bracket = key.indexOf('[');
+        return bracket < 0 ? key : key.substring(0, bracket);
+    }
+}

probe/src/main/java/art/arcane/iris/probe/HydrologyPackProbe.java

@@ -35,6 +35,7 @@ import art.arcane.iris.engine.mantle.components.MantleHydrologyCaveVoxelView;
 import art.arcane.iris.engine.object.IrisBiome;
 import art.arcane.iris.engine.object.IrisBiomeCustom;
 import art.arcane.iris.engine.object.IrisDimension;
+import art.arcane.iris.engine.object.IrisRiverBlendStyle;
 import art.arcane.iris.spi.PlatformBiome;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.volmlib.util.matter.MatterUpdate;
@@ -1682,7 +1683,8 @@ public final class HydrologyPackProbe {
             uncontainedSurfaceBankEdges += bankEdges.total();
             missingSurfaceBankEdges += bankEdges.missing();
             lowSurfaceBankEdges += bankEdges.low();
-            BankContinuityMetrics bankContinuity = bankContinuityMetrics(tile.footprint());
+            BankContinuityMetrics bankContinuity = bankContinuityMetrics(tile.footprint(),
+                    settings.surface().banks().erosion().style() == IrisRiverBlendStyle.SMOOTH);
             bankStepViolations += bankContinuity.violations();
             maximumBankStep = Math.max(maximumBankStep, bankContinuity.maximumStep());
             observeSurfaceIncision(tile, settings, ownedCompleteSurfaceCourseIds);
@@ -1743,7 +1745,7 @@ public final class HydrologyPackProbe {
             TreeMap<Long, long[]> totals = new TreeMap<>();
             for (HydrologyColumnSample sample : footprint.columns().values()) {
                 HydrologyColumnLayer layer = sample.primarySurfaceLayer().orElse(null);
-                if (layer == null || !layer.channel()
+                if (layer == null || !layer.channel() || layer.oceanApron() || !layer.terrainOwned()
                         || !scopedCourseIds.contains(layer.feature().courseId())) {
                     continue;
                 }
@@ -1805,7 +1807,7 @@ public final class HydrologyPackProbe {
         }
 
         String machineLine() {
-            return "IRIS_HYDROLOGY_PACK_SHAPE version=15 " + summary()
+            return "IRIS_HYDROLOGY_PACK_SHAPE version=16 " + summary()
                     + " " + publishedMorphology.summary();
         }
 
@@ -1902,7 +1904,7 @@ public final class HydrologyPackProbe {
                     bankStepViolations == 0,
                     String.format(
                             Locale.ROOT,
-                            "bank_step_violations=%d maximum_bank_step=%d maximum_allowed_step=%d",
+                            "bank_step_violations=%d maximum_bank_step=%d maximum_added_step=%d",
                             bankStepViolations,
                             maximumBankStep,
                             MAXIMUM_GRADED_STEP
@@ -2126,9 +2128,9 @@ public final class HydrologyPackProbe {
             return Set.copyOf(ownedCourseIds);
         }
 
-        private void observeOceanIntegrity(HydrologyColumnSample sample) {
+        void observeOceanIntegrity(HydrologyColumnSample sample) {
             boolean ocean = sample.ocean();
-            boolean naturallySubmerged = sample.naturalHeight() <= sample.seaLevel();
+            boolean naturallySubmerged = sample.naturalHeight() < sample.seaLevel();
             if (!ocean && !naturallySubmerged) {
                 if (carriesOceanApron(sample)) {
                     oceanApronLandColumns++;
@@ -2173,11 +2175,11 @@ public final class HydrologyPackProbe {
             return false;
         }
 
-        static int bankContinuityViolations(RiverFootprint footprint) {
-            return bankContinuityMetrics(footprint).violations();
+        static int bankContinuityViolations(RiverFootprint footprint, boolean smoothBanks) {
+            return bankContinuityMetrics(footprint, smoothBanks).violations();
         }
 
-        private static BankContinuityMetrics bankContinuityMetrics(RiverFootprint footprint) {
+        private static BankContinuityMetrics bankContinuityMetrics(RiverFootprint footprint, boolean smoothBanks) {
             int violations = 0;
             int maximumStep = 0;
             int[] offsets = {1, 0, 0, 1};
@@ -2195,9 +2197,10 @@ public final class HydrologyPackProbe {
                         continue;
                     }
                     int step = Math.abs(height - neighbor.terrainHeight());
-                    if (step > MAXIMUM_GRADED_STEP) {
+                    int naturalStep = Math.abs(sample.naturalHeight() - neighbor.naturalHeight());
+                    maximumStep = Math.max(maximumStep, step);
+                    if (smoothBanks && step - naturalStep > MAXIMUM_GRADED_STEP) {
                         violations++;
-                        maximumStep = Math.max(maximumStep, step);
                     }
                 }
             }
@@ -2244,12 +2247,12 @@ public final class HydrologyPackProbe {
                     }
                     if (neighbor != null
                             && layer.fluidHeadY() <= neighbor.seaLevel()
-                            && (neighbor.ocean() || neighbor.naturalHeight() <= neighbor.seaLevel())) {
+                            && neighbor.ocean() && neighbor.naturalHeight() < neighbor.seaLevel()) {
                         continue;
                     }
                     if (neighbor == null) {
                         missing++;
-                    } else if (neighbor.terrainHeight() <= layer.fluidHeadY()) {
+                    } else if (neighbor.terrainHeight() < layer.fluidHeadY()) {
                         low++;
                     }
                 }

probe/src/main/java/art/arcane/iris/probe/HydrologyPlannerProbe.java

@@ -5,6 +5,7 @@ import art.arcane.iris.engine.hydrology.policy.SurfaceRiverPolicy;
 import art.arcane.iris.engine.hydrology.HydrologyColumnSample;
 import art.arcane.iris.engine.hydrology.HydrologyFeatureRef;
 import art.arcane.iris.engine.hydrology.HydrologyFeatureType;
+import art.arcane.iris.engine.hydrology.HydrologyGeometrySampler;
 import art.arcane.iris.engine.hydrology.HydrologyPlanner;
 import art.arcane.iris.engine.hydrology.HydrologyPlannerSettings;
 import art.arcane.iris.engine.hydrology.HydrologyTerrainSample;
@@ -31,6 +32,7 @@ public final class HydrologyPlannerProbe {
     private static final long SURFACE_INLAND_SEED = 7012L;
     private static final long UNDERGROUND_INLAND_SEED = 7013L;
     private static final long COASTAL_SEED = 7014L;
+    private static final long WATERFALL_SEED = 7015L;
     static final Set<HydrologyFeatureType> REQUIRED_FEATURE_TYPES =
             // The synthetic probe settings define no standing pools, so that type is not expected either.
             Set.copyOf(EnumSet.complementOf(EnumSet.of(HydrologyFeatureType.RIDGE_BORE, HydrologyFeatureType.STANDING_POOL)));
@@ -96,6 +98,7 @@ public final class HydrologyPlannerProbe {
         collectAccepted(firstFeatures, surfaceInlandTile());
         collectAccepted(firstFeatures, undergroundInlandTile());
         collectAccepted(firstFeatures, surfaceMouthTile());
+        collectAccepted(firstFeatures, surfaceWaterfallTile());
         collectAccepted(firstFeatures, coastalGrottoTile());
         requireCompleteCoverage(firstFeatures.keySet());
 
@@ -141,6 +144,7 @@ public final class HydrologyPlannerProbe {
         collectAccepted(coverage, surfaceInlandTile());
         collectAccepted(coverage, undergroundInlandTile());
         collectAccepted(coverage, surfaceMouthTile());
+        collectAccepted(coverage, surfaceWaterfallTile());
         collectAccepted(coverage, coastalGrottoTile());
         requireCompleteCoverage(coverage.keySet());
         return Map.copyOf(coverage);
@@ -167,7 +171,7 @@ public final class HydrologyPlannerProbe {
         return new HydrologyPlanner(
                 SURFACE_INLAND_SEED,
                 inlandSettings(0D, 0D),
-                inlandTerrain(true, false),
+                inlandTerrain(true, false, false),
                 solidCaveView()
         ).plan(ORIGIN);
     }
@@ -176,12 +180,12 @@ public final class HydrologyPlannerProbe {
         return new HydrologyPlanner(
                 UNDERGROUND_INLAND_SEED,
                 inlandSettings(0D, 1D),
-                inlandTerrain(false, true),
+                inlandTerrain(false, true, false),
                 solidCaveView()
         ).plan(ORIGIN);
     }
 
-    private static HydrologyTile surfaceMouthTile() {
+    static HydrologyTile surfaceMouthTile() {
         return new HydrologyPlanner(
                 COASTAL_SEED,
                 settings(false),
@@ -189,6 +193,16 @@ public final class HydrologyPlannerProbe {
         ).plan(ORIGIN);
     }
 
+    static HydrologyTile surfaceWaterfallTile() {
+        HydrologyGeometrySampler geometry = request -> switch (request.field()) {
+            case SURFACE_WIDTH -> Math.clamp(6, request.minimum(), request.maximum());
+            case SURFACE_DEPTH -> Math.clamp(3, request.minimum(), request.maximum());
+            default -> request.minimum();
+        };
+        return new HydrologyPlanner(WATERFALL_SEED, inlandSettings(0D, 0D), inlandTerrain(true, false, true),
+                geometry, -4096, surface -> solidCaveView()).plan(ORIGIN);
+    }
+
     private static HydrologyTile coastalGrottoTile() {
         return new HydrologyPlanner(
                 COASTAL_SEED,
@@ -232,7 +246,7 @@ public final class HydrologyPlannerProbe {
                         0.5D,
                         0.1D,
                         1D,
-                        0
+                        0, HydrologyPlannerSettings.Regional.disabled()
                 ),
                 new HydrologyPlannerSettings.Surface(
                         true,
@@ -281,12 +295,13 @@ public final class HydrologyPlannerProbe {
 
     private static HydrologyTerrainSampler inlandTerrain(
             boolean surfaceSource,
-            boolean undergroundSource
+            boolean undergroundSource,
+            boolean waterfall
     ) {
         return (int x, int z) -> {
             boolean source = x == 0 && z == 0;
             boolean outlet = x == 64 && z == 64;
-            int height = 120 - Math.floorDiv(x + z, 16);
+            int height = 120 - Math.floorDiv(x + z, 16) - (waterfall && x + z >= 64 ? 10 : 0);
             return new HydrologyTerrainSample(
                     height,
                     1D,
@@ -330,15 +345,15 @@ public final class HydrologyPlannerProbe {
             }
             int height;
             double slope;
-            if (x < 104) {
+            if (!cliffCoast) {
+                height = 100 - Math.floorDiv(x, 6);
+                slope = 1D;
+            } else if (x < 104) {
                 height = 100 - Math.floorDiv(x, 8);
                 slope = 1D;
-            } else if (cliffCoast) {
+            } else {
                 height = 84 - Math.floorDiv(x - 104, 26);
                 slope = 1D;
-            } else {
-                height = 79 - Math.floorDiv(x - 104, 12);
-                slope = x < 112 ? 4D : 1D;
             }
             boolean surfaceSource = x <= 40;
             boolean undergroundSource = x <= 64;
@@ -458,7 +473,7 @@ public final class HydrologyPlannerProbe {
                         0.5D,
                         0.2D,
                         1D,
-                        0
+                        0, HydrologyPlannerSettings.Regional.disabled()
                 ),
                 new HydrologyPlannerSettings.Surface(
                         true,

probe/src/main/java/art/arcane/iris/probe/RiverTransectProbe.java

@@ -9,7 +9,11 @@ import art.arcane.iris.engine.hydrology.HydrologyCandidateKind;
 import art.arcane.iris.engine.hydrology.HydrologyColumnLayer;
 import art.arcane.iris.engine.hydrology.HydrologyColumnSample;
 import art.arcane.iris.engine.hydrology.HydrologyDiagnosticCandidate;
+import art.arcane.iris.engine.hydrology.HydrologyFeatureType;
+import art.arcane.iris.engine.object.InferredType;
 import art.arcane.iris.engine.hydrology.HydrologyPoint;
+import art.arcane.iris.engine.hydrology.HydrologyPlannerSettings;
+import art.arcane.iris.engine.hydrology.surface.SurfaceExcavationMetrics;
 import art.arcane.iris.engine.hydrology.HydrologyTile;
 import art.arcane.iris.engine.hydrology.HydrologyTileKey;
 import art.arcane.iris.engine.hydrology.RiverCourse;
@@ -25,6 +29,7 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.HashMap;
@@ -68,12 +73,24 @@ public final class RiverTransectProbe {
         }
     }
 
-    record ColumnView(int x, int z, int natural, int terrain, int water, Role role) {
+    record ColumnPlan(boolean ocean, boolean terrainOwned, boolean fluidOwned, boolean mouth, int bedY, long courseId) {
+    }
+
+    record ColumnView(int x, int z, int natural, int terrain, int water, Role role, ColumnPlan plan) {
         int cut() {
             return natural - terrain;
         }
     }
 
+    record SummaryOptions(long courseId, SurfaceCenterline centerline, int seaLevel,
+                          HydrologyPlannerSettings.Excavation limits) {
+        SummaryOptions {
+            if (centerline == null || centerline.size() < 1 || limits == null) {
+                throw new IllegalArgumentException("A nonempty centerline and excavation limits are required.");
+            }
+        }
+    }
+
     record CourseSummary(
             long id,
             int stations,
@@ -83,17 +100,31 @@ public final class RiverTransectProbe {
             int maximumBankStep,
             int oceanWrites,
             int uncontainedWetCells,
+            int drySillCuts,
+            int invalidDrySillCuts,
+            int maximumBankCut,
+            long bankExcavation,
+            int estimatedBankVolumePerBlock,
+            int bankVolumeLimit,
+            int bankBudgetViolations,
+            int connectedMouthColumns,
+            int disconnectedMouthColumns,
             List<String> details
     ) {
         boolean passes() {
-            return oceanWrites == 0 && uncontainedWetCells == 0;
+            return oceanWrites == 0 && uncontainedWetCells == 0 && invalidDrySillCuts == 0
+                    && bankBudgetViolations == 0 && disconnectedMouthColumns == 0;
         }
 
         String line() {
             return String.format(Locale.ROOT,
-                    "%s course=%d %s stations=%d owned=%d cut=%d..%d bankStep=%d oceanWrites=%d uncontained=%d",
+                    "%s course=%d %s stations=%d owned=%d cut=%d..%d bankStep=%d oceanWrites=%d uncontained=%d "
+                            + "drySillCuts=%d invalidSills=%d bankCut=%d bankVolume=%d estimatedBankVolumePerBlock=%d bankVolumeLimit=%d bankBudgetViolations=%d "
+                            + "connectedMouthColumns=%d disconnectedMouthColumns=%d",
                     PREFIX, id, passes() ? "PASS" : "FAIL", stations, ownedColumns, minimumCut, maximumCut,
-                    maximumBankStep, oceanWrites, uncontainedWetCells);
+                    maximumBankStep, oceanWrites, uncontainedWetCells, drySillCuts, invalidDrySillCuts,
+                    maximumBankCut, bankExcavation, estimatedBankVolumePerBlock, bankVolumeLimit,
+                    bankBudgetViolations, connectedMouthColumns, disconnectedMouthColumns);
         }
     }
 
@@ -209,7 +240,8 @@ public final class RiverTransectProbe {
                 SurfaceCenterline centerline = SurfaceCenterline.densify(exposedPath);
                 Bounds bounds = Bounds.of(centerline, MARGIN);
                 Map<Long, ColumnView> columns = sampleColumns(complex, runtime, bounds);
-                CourseSummary summary = summarize(course.id(), centerline.size(), seaLevel, columns);
+                CourseSummary summary = summarize(new SummaryOptions(course.id(), centerline, seaLevel,
+                        runtime.settings().surface().banks().erosion().excavation()), columns);
                 summaries.add(summary);
                 writePlan(new File(configuration.output(), "course-" + course.id() + ".png"), bounds, columns);
                 writeSections(new File(configuration.output(), "course-" + course.id() + "-sections.png"),
@@ -222,7 +254,7 @@ public final class RiverTransectProbe {
                 }
             }
             writeSummary(new File(configuration.output(), "summary.txt"), configuration, tile, summaries);
-            boolean pass = summaries.stream().allMatch(CourseSummary::passes);
+            boolean pass = !summaries.isEmpty() && summaries.stream().allMatch(CourseSummary::passes);
             System.out.println(PREFIX + " " + (pass ? "PASS" : "FAIL")
                     + " surfaceCourses=" + summaries.size()
                     + " output=" + configuration.output().getAbsolutePath());
@@ -262,34 +294,57 @@ public final class RiverTransectProbe {
         return selected;
     }
 
-    static CourseSummary summarize(long id, int stations, int seaLevel, Map<Long, ColumnView> columns) {
+    static CourseSummary summarize(SummaryOptions options, Map<Long, ColumnView> columns) {
+        int seaLevel = options.seaLevel();
+        int bankCutLimit = options.limits().maximumDepth();
         int owned = 0;
         int minimumCut = Integer.MAX_VALUE;
         int maximumCut = Integer.MIN_VALUE;
         int maximumBankStep = 0;
         int oceanWrites = 0;
         int uncontained = 0;
+        int drySills = 0;
+        int invalidSills = 0;
+        int maximumBankCut = 0;
+        long bankExcavation = 0L;
+        int bankBudgetViolations = 0;
+        int connectedMouthColumns = 0;
+        int disconnectedMouthColumns = 0;
+        HashSet<Long> oceanConnected = oceanConnected(columns, seaLevel);
         ArrayList<String> details = new ArrayList<>();
         String worstStep = null;
         ArrayList<ColumnView> ordered = new ArrayList<>(columns.values());
         ordered.sort(Comparator.comparingInt(ColumnView::z).thenComparingInt(ColumnView::x));
         for (ColumnView column : ordered) {
-            boolean submerged = column.natural() <= seaLevel;
-            if (submerged && (column.terrain() != column.natural() || column.role().owned())) {
+            boolean submerged = column.natural() < seaLevel || column.plan().ocean();
+            if (submerged && (column.terrain() != column.natural() || column.plan().terrainOwned())) {
                 oceanWrites++;
                 if (details.size() < MAXIMUM_DETAILS) {
                     details.add("oceanWrite " + column.x() + "," + column.z()
                             + " natural=" + column.natural() + " terrain=" + column.terrain() + " role=" + column.role());
                 }
             }
-            if (!column.role().owned()) {
+            if (column.plan().mouth() && column.role() == Role.CHANNEL && column.water() == seaLevel) {
+                if (oceanConnected.contains(RiverFootprint.pack(column.x(), column.z()))) {
+                    connectedMouthColumns++;
+                } else {
+                    disconnectedMouthColumns++;
+                }
+            }
+            if (!column.plan().terrainOwned()) {
                 continue;
             }
+            if (column.natural() == seaLevel && column.cut() > 0) {
+                drySills++;
+                if (column.role() != Role.CHANNEL || !column.plan().fluidOwned() || column.water() != seaLevel) {
+                    invalidSills++;
+                }
+            }
             owned++;
             minimumCut = Math.min(minimumCut, column.cut());
             maximumCut = Math.max(maximumCut, column.cut());
             if (column.role() == Role.CHANNEL) {
-                if (column.water() != NO_WATER && spills(column, columns)) {
+                if (column.water() != NO_WATER && spills(column, columns, seaLevel)) {
                     uncontained++;
                     if (details.size() < MAXIMUM_DETAILS) {
                         details.add("uncontained " + column.x() + "," + column.z()
@@ -299,6 +354,10 @@ public final class RiverTransectProbe {
                 }
                 continue;
             }
+            int bankCut = Math.max(0, column.natural() - column.plan().bedY());
+            maximumBankCut = Math.max(maximumBankCut, bankCut);
+            bankExcavation += bankCut;
+            bankBudgetViolations += bankCut > bankCutLimit ? 1 : 0;
             for (int[] offset : new int[][] {{1, 0}, {0, 1}}) {
                 ColumnView neighbour = columns.get(RiverFootprint.pack(column.x() + offset[0], column.z() + offset[1]));
                 int step = bankStep(column, neighbour);
@@ -318,7 +377,70 @@ public final class RiverTransectProbe {
             minimumCut = 0;
             maximumCut = 0;
         }
-        return new CourseSummary(id, stations, owned, minimumCut, maximumCut, maximumBankStep, oceanWrites, uncontained, List.copyOf(details));
+        return new CourseSummary(options.courseId(), options.centerline().size(), owned, minimumCut, maximumCut, maximumBankStep, oceanWrites,
+                uncontained, drySills, invalidSills, maximumBankCut, bankExcavation,
+                estimatedBankVolumePerBlock(options, columns), options.limits().maximumVolumePerBlock(), bankBudgetViolations,
+                connectedMouthColumns, disconnectedMouthColumns, List.copyOf(details));
+    }
+
+    static int estimatedBankVolumePerBlock(SummaryOptions options, Map<Long, ColumnView> columns) {
+        SurfaceCenterline centerline = options.centerline();
+        Map<Long, List<Integer>> buckets = new HashMap<>();
+        for (int station = 0; station < centerline.size(); station++) {
+            long bucket = RiverFootprint.pack(Math.floorDiv(centerline.x()[station], 16),
+                    Math.floorDiv(centerline.z()[station], 16));
+            buckets.computeIfAbsent(bucket, ignored -> new ArrayList<>()).add(station);
+        }
+        int[] stationVolumes = new int[centerline.size()];
+        for (ColumnView column : columns.values()) {
+            if (!column.plan().terrainOwned() || column.role() == Role.CHANNEL
+                    || column.plan().courseId() != options.courseId()) {
+                continue;
+            }
+            int cut = Math.max(0, column.natural() - column.plan().bedY());
+            if (cut > 0) {
+                int station = nearestStation(centerline, buckets, column.x(), column.z());
+                stationVolumes[station] = Math.addExact(stationVolumes[station], cut);
+            }
+        }
+        return SurfaceExcavationMetrics.maximumVolumePerBlock(centerline, stationVolumes);
+    }
+
+    private static int nearestStation(SurfaceCenterline centerline, Map<Long, List<Integer>> buckets, int x, int z) {
+        int bucketX = Math.floorDiv(x, 16);
+        int bucketZ = Math.floorDiv(z, 16);
+        int bestStation = -1;
+        double bestDistance = Double.POSITIVE_INFINITY;
+        for (int ring = 0; bestStation < 0 || nearestOutsideDistance(x, z, bucketX, bucketZ, ring - 1) <= bestDistance + 2D; ring++) {
+            for (int dz = -ring; dz <= ring; dz++) {
+                for (int dx = -ring; dx <= ring; dx++) {
+                    if (ring > 0 && Math.abs(dx) != ring && Math.abs(dz) != ring) {
+                        continue;
+                    }
+                    List<Integer> stations = buckets.get(RiverFootprint.pack(bucketX + dx, bucketZ + dz));
+                    if (stations == null) {
+                        continue;
+                    }
+                    for (int station : stations) {
+                        double distance = centerline.distanceToSegment(station, x, z);
+                        if (distance < bestDistance - 1.0e-7D
+                                || Math.abs(distance - bestDistance) <= 1.0e-7D && station > bestStation) {
+                            bestDistance = distance;
+                            bestStation = station;
+                        }
+                    }
+                }
+            }
+        }
+        return bestStation;
+    }
+
+    private static double nearestOutsideDistance(int x, int z, int bucketX, int bucketZ, int ring) {
+        double minX = ((double) bucketX - ring) * 16D;
+        double minZ = ((double) bucketZ - ring) * 16D;
+        double maxX = ((double) bucketX + ring + 1) * 16D;
+        double maxZ = ((double) bucketZ + ring + 1) * 16D;
+        return Math.min(Math.min(x - minX, maxX - x), Math.min(z - minZ, maxZ - z));
     }
 
     private static String neighbourHeights(ColumnView channel, Map<Long, ColumnView> columns) {
@@ -333,13 +455,16 @@ public final class RiverTransectProbe {
         return text.toString();
     }
 
-    private static boolean spills(ColumnView channel, Map<Long, ColumnView> columns) {
+    private static boolean spills(ColumnView channel, Map<Long, ColumnView> columns, int seaLevel) {
         int[][] offsets = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
         for (int[] offset : offsets) {
             ColumnView neighbour = columns.get(RiverFootprint.pack(channel.x() + offset[0], channel.z() + offset[1]));
             if (neighbour == null || neighbour.role() == Role.CHANNEL) {
                 continue;
             }
+            if (neighbour.plan().ocean() && neighbour.natural() < seaLevel && channel.water() <= seaLevel) {
+                continue;
+            }
             if (neighbour.terrain() < channel.water()) {
                 return true;
             }
@@ -347,6 +472,29 @@ public final class RiverTransectProbe {
         return false;
     }
 
+    private static HashSet<Long> oceanConnected(Map<Long, ColumnView> columns, int seaLevel) {
+        HashSet<Long> visited = new HashSet<>();
+        ArrayDeque<Long> queue = new ArrayDeque<>();
+        for (Map.Entry<Long, ColumnView> entry : columns.entrySet()) {
+            ColumnView column = entry.getValue();
+            if (column.plan().ocean() && column.natural() < seaLevel && !column.plan().terrainOwned()) {
+                visited.add(entry.getKey());
+                queue.add(entry.getKey());
+            }
+        }
+        while (!queue.isEmpty()) {
+            ColumnView current = columns.get(queue.removeFirst());
+            for (int[] offset : new int[][]{{1, 0}, {-1, 0}, {0, 1}, {0, -1}}) {
+                long key = RiverFootprint.pack(current.x() + offset[0], current.z() + offset[1]);
+                ColumnView next = columns.get(key);
+                if (next != null && next.water() == seaLevel && next.terrain() < seaLevel && visited.add(key)) {
+                    queue.addLast(key);
+                }
+            }
+        }
+        return visited;
+    }
+
     private static int bankStep(ColumnView bank, ColumnView neighbour) {
         if (neighbour == null || neighbour.role() == Role.CHANNEL) {
             return 0;
@@ -395,7 +543,13 @@ public final class RiverTransectProbe {
         HydrologyColumnLayer surface = sample.flatMap(HydrologyColumnSample::primarySurfaceLayer).orElse(null);
         HydrologyColumnLayer fluid = sample.flatMap(HydrologyColumnSample::primarySurfaceFluidLayer).orElse(null);
         int water = fluid == null ? NO_WATER : fluid.fluidHeadY();
-        return new ColumnView(x, z, natural, terrain, water, role(surface));
+        boolean ocean = sample.map(HydrologyColumnSample::ocean)
+                .orElseGet(() -> complex.getBridgeStream().get(x, z) == InferredType.SEA);
+        ColumnPlan plan = new ColumnPlan(ocean, surface != null && surface.terrainOwned(),
+                surface != null && surface.fluidOwned(),
+                surface != null && surface.feature().type() == HydrologyFeatureType.MOUTH,
+                surface == null ? natural : surface.bedY(), surface == null ? 0L : surface.feature().courseId());
+        return new ColumnView(x, z, natural, terrain, water, role(surface), plan);
     }
 
     private static Role role(HydrologyColumnLayer layer) {

probe/src/main/java/art/arcane/iris/probe/StubPlatform.java

@@ -226,7 +226,19 @@ public final class StubPlatform implements IrisPlatform {
 
         @Override
         public boolean canPlaceOnto(PlatformBlockState onto) {
-            return true;
+            if (!blockKey.equals("minecraft:sugar_cane")) {
+                return true;
+            }
+            if (onto == null) {
+                return false;
+            }
+            return switch (ParsedState.parse(onto.key()).blockKey()) {
+                case "minecraft:sugar_cane", "minecraft:grass_block", "minecraft:dirt", "minecraft:coarse_dirt",
+                     "minecraft:podzol", "minecraft:mycelium", "minecraft:rooted_dirt", "minecraft:moss_block",
+                     "minecraft:pale_moss_block", "minecraft:mud", "minecraft:muddy_mangrove_roots",
+                     "minecraft:sand", "minecraft:red_sand", "minecraft:suspicious_sand" -> true;
+                default -> false;
+            };
         }
 
         @Override