Refine hydrology and Studio

- Add dimension-wide hydrology density controls.
- Validate pond containment and shorelines at block resolution.
- Prioritize requested water plans and deduplicate prefetch work.
- Keep completed water previews visible while details load.
- Add pregeneration map navigation and Studio theme controls.
- Reject pack mutations during generation-registry capture.

core/src/main/java/art/arcane/iris/generation/hydrology/config/IrisHydrology.java

@@ -17,6 +17,11 @@ public class IrisHydrology {
     @Description("Turns rivers, streams, ponds, lakes and underground water on for this dimension.")
     private boolean enabled = false;
 
+    @MinNumber(0)
+    @MaxNumber(1)
+    @Description("Fraction of eligible water features to keep after local placement probabilities. 0.5 keeps half the candidate river sources, ponds, lakes and underground water features without changing their configured sizes.")
+    private double density = 1D;
+
     @Description("How water drains across the terrain before rivers and ponds are placed.")
     private IrisHydrologyDrainage drainage = new IrisHydrologyDrainage();
 

core/src/main/java/art/arcane/iris/generation/hydrology/engine/HydrologyRuntime.java

@@ -60,6 +60,7 @@ public final class HydrologyRuntime {
     private static final int CHUNKS_PER_WINDOW = WindowKey.SIZE >> 4;
     public static final int MAX_PREGENERATION_REGIONS = 4096;
     private static final int MAX_PREVIEW_REQUESTS = 64;
+    private static final int PREFETCH_CAPACITY = 16;
     private static final HydrologyRuntime DISABLED = new HydrologyRuntime();
 
     private final HydrologySettings settings;
@@ -74,6 +75,7 @@ public final class HydrologyRuntime {
     private final RasterFailures windowPreviewFailures;
     private final RasterFailures regionPreviewFailures;
     private final Set<Object> previews;
+    private final LinkedHashMap<WindowKey, WindowPrefetch> prefetches;
     private final HydrologyBinding binding;
     private final Function<PreparedHydrologyCacheIdentity, HydrologyPlanStore> stores;
     private final boolean caveFluidPolicies;
@@ -94,6 +96,7 @@ public final class HydrologyRuntime {
         this.windowPreviewFailures = null;
         this.regionPreviewFailures = null;
         this.previews = null;
+        this.prefetches = null;
         this.binding = HydrologyBinding.UNBOUND;
         this.stores = identity -> null;
         this.caveFluidPolicies = false;
@@ -119,6 +122,7 @@ public final class HydrologyRuntime {
         this.windowPreviewFailures = new RasterFailures(ticker);
         this.regionPreviewFailures = new RasterFailures(ticker);
         this.previews = new HashSet<>();
+        this.prefetches = new LinkedHashMap<>(PREFETCH_CAPACITY * 2, 0.75f, true);
         this.binding = Objects.requireNonNull(binding, "binding");
         this.stores = Objects.requireNonNull(stores, "stores");
         this.caveFluidPolicies = caveFluidPolicies;
@@ -135,6 +139,9 @@ public final class HydrologyRuntime {
                 engine.getHeight());
         boolean caveFluidPolicies = settings.underground().cavePools().enabled()
                 && requireBiomeFluids(dimension.getReachableBiomes(engine), settings);
+        if (settings.density() == 0D) {
+            return DISABLED;
+        }
         HydrologyBinding binding = binding(engine, complex);
         IrisHydrologyTerrainSource source = new IrisHydrologyTerrainSource(complex, dimension, settings, MultiBurst.hydrology,
                 MultiBurst.hydrology.parallelism(), binding);
@@ -203,16 +210,24 @@ public final class HydrologyRuntime {
         return settings;
     }
 
+    public PreviewScope preview() {
+        return new PreviewScope(cache == null ? null : last.get());
+    }
+
     public ChunkWaterRaster raster(int chunkX, int chunkZ) {
         if (cache == null) {
             return ChunkWaterRaster.EMPTY;
         }
+        LastRaster slot = last.get();
+        if (slot.preview) {
+            return rasterPreview(chunkX, chunkZ);
+        }
         if (mainThread.getAsBoolean()) {
             return rasterSnapshot(chunkX, chunkZ);
         }
         requireOpen();
         long key = key(chunkX, chunkZ);
-        ChunkWaterRaster known = remembered(key);
+        ChunkWaterRaster known = remembered(key, slot);
         return known != null ? known : remember(key, planned(chunkX, chunkZ, key));
     }
 
@@ -224,7 +239,7 @@ public final class HydrologyRuntime {
             return ChunkWaterRaster.PROVISIONAL;
         }
         long key = key(chunkX, chunkZ);
-        ChunkWaterRaster known = remembered(key);
+        ChunkWaterRaster known = remembered(key, last.get());
         if (known == null) {
             ChunkWaterRaster landed = queue(chunkX, chunkZ, key, false);
             return landed == null ? ChunkWaterRaster.PROVISIONAL : landed;
@@ -240,7 +255,7 @@ public final class HydrologyRuntime {
             return ChunkWaterRaster.PROVISIONAL;
         }
         long key = key(chunkX, chunkZ);
-        ChunkWaterRaster known = remembered(key);
+        ChunkWaterRaster known = remembered(key, last.get());
         if (known == null) {
             ChunkWaterRaster landed = queue(chunkX, chunkZ, key, true);
             return landed == null ? ChunkWaterRaster.PROVISIONAL : landed;
@@ -426,6 +441,9 @@ public final class HydrologyRuntime {
         synchronized (rasters) {
             rasters.clear();
         }
+        synchronized (prefetches) {
+            prefetches.clear();
+        }
     }
 
     private static HydrologyBinding binding(Engine engine, IrisComplex complex) {
@@ -532,7 +550,7 @@ public final class HydrologyRuntime {
             queued.remove(key);
             return null;
         }
-        ChunkWaterRaster landed = remembered(key);
+        ChunkWaterRaster landed = remembered(key, last.get());
         if (landed != null) {
             finish(key, preview);
             return landed;
@@ -632,8 +650,22 @@ public final class HydrologyRuntime {
     }
 
     private void prefetch(int chunkX, int chunkZ) {
-        if (settings.prefetchRings() > 0) {
+        if (settings.prefetchRings() <= 0) {
-            cache.prepareWindowsAround(chunkX, chunkZ, chunkX, chunkZ, 1 + settings.prefetchRings());
+            return;
+        }
+        WindowKey owner = WindowKey.containing(chunkX << 4, chunkZ << 4);
+        synchronized (prefetches) {
+            long evictions = cache.windowEvictions();
+            WindowPrefetch known = prefetches.get(owner);
+            if (known != null && !known.prepared().isCompletedExceptionally()
+                    && (!known.prepared().isDone() || known.evictions() == evictions)) {
+                return;
+            }
+            CompletableFuture<Void> prepared = cache.prepareWindowsAround(chunkX, chunkZ, chunkX, chunkZ, 1 + settings.prefetchRings());
+            prefetches.put(owner, new WindowPrefetch(prepared, evictions));
+            if (prefetches.size() > PREFETCH_CAPACITY) {
+                prefetches.pollFirstEntry();
+            }
         }
     }
 
@@ -648,8 +680,7 @@ public final class HydrologyRuntime {
         return keys;
     }
 
-    private ChunkWaterRaster remembered(long key) {
+    private ChunkWaterRaster remembered(long key, LastRaster slot) {
-        LastRaster slot = last.get();
         if (slot.raster != null && slot.key == key) {
             return slot.raster;
         }
@@ -712,9 +743,13 @@ public final class HydrologyRuntime {
         }
     }
 
+    private record WindowPrefetch(CompletableFuture<Void> prepared, long evictions) {
+    }
+
     private static final class LastRaster {
         private long key;
         private ChunkWaterRaster raster;
+        private boolean preview;
 
         private void remember(long key, ChunkWaterRaster raster) {
             this.key = key;
@@ -722,6 +757,30 @@ public final class HydrologyRuntime {
         }
     }
 
+    public static final class PreviewScope implements AutoCloseable {
+        private final LastRaster slot;
+        private final boolean previous;
+        private boolean closed;
+
+        private PreviewScope(LastRaster slot) {
+            this.slot = slot;
+            this.previous = slot != null && slot.preview;
+            if (slot != null) {
+                slot.preview = true;
+            }
+        }
+
+        @Override
+        public void close() {
+            if (!closed) {
+                closed = true;
+                if (slot != null) {
+                    slot.preview = previous;
+                }
+            }
+        }
+    }
+
     private static final class RasterLru extends LinkedHashMap<Long, ChunkWaterRaster> {
         private RasterLru() {
             super(RASTER_CAPACITY * 2, 0.75f, true);

core/src/main/java/art/arcane/iris/generation/hydrology/grid/HeightLattice.java

@@ -225,8 +225,11 @@ public final class HeightLattice {
         }
     }
 
-    private static Long key(int cellX, int cellZ) {
+    static long key(int cellX, int cellZ) {
-        return ((long) cellX << 32) | (cellZ & 0xFFFFFFFFL);
+        long packed = ((long) cellX << 32) | (cellZ & 0xFFFFFFFFL);
+        long mixed = (packed ^ (packed >>> 30)) * 0xbf58476d1ce4e5b9L;
+        mixed = (mixed ^ (mixed >>> 27)) * 0x94d049bb133111ebL;
+        return mixed ^ (mixed >>> 31);
     }
 
     private record Slot(CompletableFuture<HydrologySampleBuffer> batch, int index) {

core/src/main/java/art/arcane/iris/generation/hydrology/plan/HydrologyPlanCache.java

@@ -1,5 +1,6 @@
 package art.arcane.iris.generation.hydrology.plan;
 
+import art.arcane.iris.generation.concurrent.MultiBurst;
 import art.arcane.iris.generation.hydrology.raster.ReachIndex;
 import art.arcane.iris.spi.IrisLogging;
 
@@ -20,7 +21,9 @@ import java.util.concurrent.CompletionException;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
+import java.util.concurrent.ForkJoinPool;
 import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
@@ -46,6 +49,7 @@ public final class HydrologyPlanCache {
     private volatile HydrologyPlanStore store;
     private int writing;
     private final ExecutorService pool;
+    private final int speculativeParallelism;
     private final BooleanSupplier mainThread;
     private final Object lock = new Object();
     private final PriorityQueue<Job> queue = new PriorityQueue<>(Comparator.comparingLong((Job job) -> job.priority).thenComparingLong(job -> job.order));
@@ -56,6 +60,7 @@ public final class HydrologyPlanCache {
     private final Shelf<RegionKey, RegionPlan> regions = new Shelf<>(REGION_CAPACITY, this::startRegion);
     private final Shelf<WindowKey, IndexedWindow> windows = new Shelf<>(WINDOW_CAPACITY, this::startWindow);
     private final Map<Object, Set<Slot<?, ?>>> epochSlots = new HashMap<>();
+    private int runningSpeculative;
     private volatile boolean closed;
 
     public HydrologyPlanCache(HydrologySettings settings, Function<RegionKey, RegionPlan> regionPlanner,
@@ -64,6 +69,7 @@ public final class HydrologyPlanCache {
         this.windowPlanner = Objects.requireNonNull(windowPlanner, "windowPlanner");
         this.persist = Objects.requireNonNull(settings, "settings").persist();
         this.pool = Objects.requireNonNull(pool, "pool");
+        this.speculativeParallelism = speculativeParallelism(pool);
         this.mainThread = Objects.requireNonNull(mainThread, "mainThread");
     }
 
@@ -102,6 +108,10 @@ public final class HydrologyPlanCache {
         return windows.ready(Objects.requireNonNull(key, "key"));
     }
 
+    public long windowEvictions() {
+        return windows.evictions.get();
+    }
+
     public RegionPlan region(RegionKey key) {
         Objects.requireNonNull(key, "key");
         requireOffMainThread("region " + key.rx() + "," + key.rz());
@@ -179,11 +189,7 @@ public final class HydrologyPlanCache {
             dropped.run();
             return;
         }
-        try {
+        dispatch();
-            pool.execute(this::runNext);
-        } catch (RejectedExecutionException rejected) {
-            abandonQueue(rejected);
-        }
     }
 
     private CompletableFuture<Void> prepare(int minChunkX, int minChunkZ, int maxChunkX, int maxChunkZ, int rings, Interest interest) {
@@ -288,7 +294,17 @@ public final class HydrologyPlanCache {
     }
 
     private long speculativePriority() {
-        return -(speculations.incrementAndGet() << SPECULATIVE_SHIFT);
+        return Long.MAX_VALUE - (speculations.incrementAndGet() << SPECULATIVE_SHIFT);
+    }
+
+    private static int speculativeParallelism(ExecutorService pool) {
+        int parallelism = switch (pool) {
+            case MultiBurst burst -> burst.parallelism();
+            case ForkJoinPool forkJoin -> forkJoin.getParallelism();
+            case ThreadPoolExecutor threads -> threads.getCorePoolSize();
+            default -> 1;
+        };
+        return Math.max(1, parallelism / 2);
     }
 
     private static int frontCells(int unit, int cell) {
@@ -457,29 +473,34 @@ public final class HydrologyPlanCache {
             slot.fail(new CancellationException("Hydrology plan cache is closed."));
             return;
         }
-        try {
+        dispatch();
-            pool.execute(this::runNext);
-        } catch (RejectedExecutionException rejected) {
-            abandonQueue(rejected);
-        }
     }
 
     private void runNext() {
         Job job;
+        boolean speculative;
         synchronized (lock) {
-            job = queue.poll();
+            job = queue.peek();
-            if (job != null && job.slot != null) {
+            if (job == null) {
+                return;
+            }
+            speculative = job.priority >= 0;
+            if (speculative && runningSpeculative >= speculativeParallelism) {
+                return;
+            }
+            queue.remove();
+            if (speculative) {
+                runningSpeculative++;
+            }
+            if (job.slot != null) {
                 job.slot.job = null;
             }
         }
-        if (job == null) {
-            return;
-        }
-        if (closed) {
-            job.drop(new CancellationException("Hydrology plan cache is closed."));
-            return;
-        }
         try {
+            if (closed) {
+                job.drop(new CancellationException("Hydrology plan cache is closed."));
+                return;
+            }
             job.body.run();
         } catch (Throwable failure) {
             if (job.slot != null) {
@@ -487,6 +508,25 @@ public final class HydrologyPlanCache {
             } else if (!closed) {
                 IrisLogging.reportError("A speculative hydrology task failed.", failure);
             }
+        } finally {
+            if (speculative) {
+                boolean pending;
+                synchronized (lock) {
+                    runningSpeculative--;
+                    pending = !closed && !queue.isEmpty();
+                }
+                if (pending) {
+                    dispatch();
+                }
+            }
+        }
+    }
+
+    private void dispatch() {
+        try {
+            pool.execute(this::runNext);
+        } catch (RejectedExecutionException rejected) {
+            abandonQueue(rejected);
         }
     }
 
@@ -513,8 +553,12 @@ public final class HydrologyPlanCache {
         slot.priority = priority;
         Job job = slot.job;
         if (job != null && queue.remove(job)) {
+            boolean demanded = job.priority >= 0 && priority < 0;
             job.priority = priority;
             queue.add(job);
+            if (demanded) {
+                dispatch();
+            }
         }
         for (Slot<RegionKey, RegionPlan> need : slot.needs) {
             promoteLocked(need, priority);
@@ -597,6 +641,7 @@ public final class HydrologyPlanCache {
 
     private final class Shelf<K, V> {
         private final ConcurrentHashMap<K, Slot<K, V>> slots = new ConcurrentHashMap<>();
+        private final AtomicLong evictions = new AtomicLong();
         private final int capacity;
         private final BiConsumer<K, Slot<K, V>> start;
 
@@ -658,7 +703,9 @@ public final class HydrologyPlanCache {
                 ready.sort(Comparator.comparingLong(Aged::used));
                 for (int index = 0; index < excess; index++) {
                     Slot<K, V> slot = ready.get(index).slot();
-                    slots.remove(slot.key, slot);
+                    if (slots.remove(slot.key, slot)) {
+                        evictions.incrementAndGet();
+                    }
                 }
             }
         }

core/src/main/java/art/arcane/iris/generation/hydrology/plan/HydrologySettings.java

@@ -50,6 +50,7 @@ public final class HydrologySettings {
     private final int minY;
     private final int maxY;
     private final boolean enabled;
+    private final float density;
     private final Drainage drainage;
     private final List<HydrologyTier> tiers;
     private final Ponds ponds;
@@ -67,6 +68,10 @@ public final class HydrologySettings {
         this.minY = minY;
         this.maxY = maxY;
         this.enabled = config.isEnabled();
+        if (!Double.isFinite(config.getDensity()) || config.getDensity() < 0D || config.getDensity() > 1D) {
+            throw new IllegalArgumentException("Hydrology density must be within 0..1, got " + config.getDensity());
+        }
+        this.density = (float) config.getDensity();
         this.drainage = drainage(config.getDrainage());
         this.tiers = tiers(config.getTiers());
         this.ponds = ponds(config.getPonds());
@@ -126,6 +131,10 @@ public final class HydrologySettings {
         return enabled;
     }
 
+    public float density() {
+        return density;
+    }
+
     public Drainage drainage() {
         return drainage;
     }
@@ -458,7 +467,7 @@ public final class HydrologySettings {
 
     private long computeFingerprint() {
         Fingerprint hash = new Fingerprint().add(seed).add(seaLevel).add(minY).add(maxY).add(enabled)
-                .add(prefetchRings).add(persist);
+                .add(density).add(prefetchRings).add(persist);
         addDrainage(hash);
         addTiers(hash);
         addPonds(hash);

core/src/main/java/art/arcane/iris/generation/hydrology/plan/RegionPlanner.java

@@ -3,6 +3,7 @@ package art.arcane.iris.generation.hydrology.plan;
 import art.arcane.iris.generation.hydrology.grid.Basin;
 import art.arcane.iris.generation.hydrology.grid.BasinExtractor;
 import art.arcane.iris.generation.hydrology.grid.Breacher;
+import art.arcane.iris.generation.hydrology.grid.CellHash;
 import art.arcane.iris.generation.hydrology.grid.ChannelHeads;
 import art.arcane.iris.generation.hydrology.grid.D8Router;
 import art.arcane.iris.generation.hydrology.grid.DemGrid;
@@ -28,6 +29,7 @@ public final class RegionPlanner {
     private static final int SPAN = 3 * REGION_CELLS;
     private static final float BASIN_DEPTH = 0.5f;
     private static final int BREACH_PASSES = 8;
+    private static final long SALT_HEAD = 0x4d414a4f524844L;
 
     private final HydrologySettings settings;
     private final HeightLattice lattice;
@@ -127,7 +129,7 @@ public final class RegionPlanner {
         float[] accumulation = FlowAccumulator.accumulate(receivers, filled, weights, settings.drainage().saturationCatchment());
         BitSet candidates = ChannelHeads.candidates(surface, accumulation, samples.permission(), settings.majorTier().minCatchment(), settings.seaLevel());
         BitSet channels = ChannelHeads.keep(surface, samples.height(), receivers, candidates, settings.drainage().headRelief(), cell -> false,
-                cell -> true);
+                cell -> CellHash.unit(CellHash.mix(settings.seed(), SALT_HEAD, surface.blockX(cell), surface.blockZ(cell))) < settings.density());
         return shaper.coarsePaths(surface, receivers, accumulation, channels, settings.seed());
     }
 

core/src/main/java/art/arcane/iris/generation/hydrology/plan/WindowPlanner.java

@@ -94,11 +94,18 @@ public final class WindowPlanner {
         BitSet seeds = seeds(samples.ocean(), trunks);
         DemGrid preliminary = new DemGrid(raw.originX(), raw.originZ(), CELL, SPAN, SPAN);
         System.arraycopy(raw.values(), 0, preliminary.values(), 0, SPAN * SPAN);
-        BitSet channelHint = drain(preliminary, seeds, samples, trunks, lakes).channels();
+        Drainage initial = drain(preliminary, seeds, samples, trunks, lakes);
+        BitSet channelHint = (BitSet) initial.channels().clone();
         channelHint.andNot(trunks.cells());
         CupSet cups = ponds.subtractCups(raw, key, samples, channelHint);
-        trunks.descend(raw.values());
+        Drainage drainage;
-        Drainage drainage = drain(raw, seeds, samples, trunks, lakes);
+        if (cups.size() == 0) {
+            raw = preliminary;
+            drainage = initial;
+        } else {
+            trunks.descend(raw.values());
+            drainage = drain(raw, seeds, samples, trunks, lakes);
+        }
         List<Pond> water = new ArrayList<>(ponds.ponds(raw, drainage.filled(), drainage.basins(), lakes, fine, cups));
         water.addAll(lakes);
         ShapedNetwork network = shaper.shape(drainage.surface(), drainage.receivers(), drainage.accumulation(), drainage.channels(), water,
@@ -231,10 +238,8 @@ public final class WindowPlanner {
 
     private boolean keepHead(DemGrid surface, int cell, float rainfall) {
         HydrologySettings.Drainage drainage = settings.drainage();
-        if (!drainage.wetnessThinning()) {
+        float keep = drainage.wetnessThinning() ? Math.clamp(Math.max(drainage.minimumHeadKeep(), rainfall), 0f, 1f) : 1f;
-            return true;
+        keep *= settings.density();
-        }
-        float keep = Math.max(drainage.minimumHeadKeep(), rainfall);
         return CellHash.unit(CellHash.mix(settings.seed(), SALT_HEAD, surface.blockX(cell), surface.blockZ(cell))) < keep;
     }
 

core/src/main/java/art/arcane/iris/generation/hydrology/raster/MaskEdges.java

@@ -28,13 +28,20 @@ final class MaskEdges {
         int firstJ = Math.max(-margin, Math.floorDiv(minZ - mask.originZ() + half, step));
         int lastJ = Math.min(mask.depth() - 1 + margin, Math.floorDiv(maxZ - mask.originZ() + half, step));
         for (int j = firstJ; j <= lastJ; j++) {
+            int start = Integer.MIN_VALUE;
             for (int i = firstI; i <= lastI; i++) {
                 if (edge(mask, i, j)) {
-                    int x = mask.originX() + i * step - half;
+                    if (start == Integer.MIN_VALUE) {
-                    int z = mask.originZ() + j * step - half;
+                        start = i;
-                    append(x, z, x + step - 1, z + step - 1);
+                    }
+                } else if (start != Integer.MIN_VALUE) {
+                    appendRun(mask, start, i, j);
+                    start = Integer.MIN_VALUE;
                 }
             }
+            if (start != Integer.MIN_VALUE) {
+                appendRun(mask, start, lastI + 1, j);
+            }
         }
         slots++;
         starts[slots] = count;
@@ -77,6 +84,14 @@ final class MaskEdges {
         squares[count++] = maxZ;
     }
 
+    private void appendRun(PondMask mask, int first, int end, int row) {
+        int step = mask.step();
+        int half = step >> 1;
+        int x = mask.originX() + first * step - half;
+        int z = mask.originZ() + row * step - half;
+        append(x, z, mask.originX() + end * step - half - 1, z + step - 1);
+    }
+
     enum Kind {
         WATER,
         BANK,

core/src/main/java/art/arcane/iris/generation/hydrology/underground/CavePoolFiller.java

@@ -19,6 +19,7 @@ public final class CavePoolFiller {
     private static final long SALT_COLUMN = 0x434156434f4c00L;
     private static final long SALT_FLOOR = 0x4341564652L << 20;
     private static final long SALT_FREEBOARD = 0x43415646524244L;
+    private static final long SALT_DENSITY = 0x43415644454e53L;
     private static final HydrologyCaveCell GUARD = HydrologyCaveCell.of(HydrologyCaveAction.SEAL_GUARD);
     private static final CaveVoxel[] VOXELS = CaveVoxel.values();
     private static final int[] DX = {1, -1, 0, 0, 0, 0};
@@ -31,18 +32,23 @@ public final class CavePoolFiller {
 
     private final HydrologySettings.CavePools pools;
     private final Set<String> fluids;
+    private final float density;
 
     public CavePoolFiller(HydrologySettings settings) {
         this.pools = settings.underground().cavePools();
         this.fluids = settings.fluids().keySet();
+        this.density = settings.density();
     }
 
     public void fill(int chunkX, int chunkZ, CarvedTerrain carved, MantleWriter writer, long seed) {
-        if (!pools.enabled()) {
+        if (!pools.enabled() || density == 0f) {
             return;
         }
         int attempts = attempts(seed, chunkX, chunkZ);
         for (int attempt = 0; attempt < attempts; attempt++) {
+            if (density < 1f && CellHash.unit(CellHash.mix(seed, SALT_DENSITY + attempt, chunkX, chunkZ)) >= density) {
+                continue;
+            }
             long column = CellHash.mix(seed, SALT_COLUMN + attempt, chunkX, chunkZ);
             int x = (chunkX << 4) + (int) (column & 15);
             int z = (chunkZ << 4) + (int) ((column >>> 4) & 15);

core/src/main/java/art/arcane/iris/generation/hydrology/underground/SeaInletPlanner.java

@@ -32,6 +32,7 @@ public final class SeaInletPlanner {
     private static final long SALT_RADIUS = 0x53454152414449L;
     private static final long SALT_HEADROOM = 0x53454148454144L;
     private static final long SALT_DEPTH = 0x53454144455054L;
+    private static final long SALT_DENSITY = 0x53454144454e53L;
 
     private final HydrologySettings settings;
 
@@ -42,7 +43,7 @@ public final class SeaInletPlanner {
     public List<SeaInlet> plan(DemGrid raw, HydrologySampleBuffer samples, int[] receivers, float[] accumulation, ShapedNetwork network,
                                long seed) {
         HydrologySettings.SeaInlets config = settings.underground().seaInlets();
-        if (!config.enabled()) {
+        if (!config.enabled() || settings.density() == 0f) {
             return List.of();
         }
         int count = raw.values().length;
@@ -101,6 +102,9 @@ public final class SeaInletPlanner {
     private SeaInlet site(Terrain terrain, HydrologySettings.SeaInlets config, long key, List<Integer> candidates) {
         int siteX = (int) (key >> 32);
         int siteZ = (int) key;
+        if (settings.density() < 1f && CellHash.unit(CellHash.mix(terrain.seed, SALT_DENSITY, siteX, siteZ)) >= settings.density()) {
+            return null;
+        }
         double targetX = (siteX + CellHash.unit(CellHash.mix(terrain.seed, SALT_SITE_X, siteX, siteZ))) * config.spacing();
         double targetZ = (siteZ + CellHash.unit(CellHash.mix(terrain.seed, SALT_SITE_Z, siteX, siteZ))) * config.spacing();
         DemGrid grid = terrain.grid;

core/src/main/java/art/arcane/iris/generation/hydrology/water/CupCarver.java

@@ -72,7 +72,8 @@ final class CupCarver {
                 }
                 float slope = slope(raw, samples, cell);
                 if (suitable(samples, cell, slope)
-                        && CellHash.unit(CellHash.mix(seed, SALT_SITE, siteX, siteZ)) < chance * samples.pondDensity()[cell]) {
+                        && CellHash.unit(CellHash.mix(seed, SALT_SITE, siteX, siteZ))
+                        < Math.clamp(chance * samples.pondDensity()[cell], 0D, 1D) * settings.density()) {
                     addCup(raw, samples, cell, slope, siteX, siteZ, false, out);
                 }
             }
@@ -89,7 +90,7 @@ final class CupCarver {
             }
             float slope = slope(raw, samples, cell);
             double roll = CellHash.unit(CellHash.mix(settings.seed(), SALT_CHAIN, raw.blockX(cell), raw.blockZ(cell)));
-            if (suitable(samples, cell, slope) && roll < chance * samples.pondDensity()[cell]) {
+            if (suitable(samples, cell, slope) && roll < Math.clamp(chance * samples.pondDensity()[cell], 0D, 1D) * settings.density()) {
                 sites.add(new Site(roll, cell, slope));
             }
         }

core/src/main/java/art/arcane/iris/generation/hydrology/water/PondPlanner.java

@@ -150,7 +150,7 @@ public final class PondPlanner {
                     }
                 }
                 return new Pond(pond.id(), pond.kind(), level, (int) Math.floor(lowest), pond.spillX(), pond.spillZ(), pond.spillHeight(),
-                        mask(box, wet), pond.outletReachId(), pond.damRaise(), pond.fluid(), pond.floorX(), pond.floorZ());
+                        mask(box, ground, wet, level), pond.outletReachId(), pond.damRaise(), pond.fluid(), pond.floorX(), pond.floorZ());
             }
         }
         return null;
@@ -223,13 +223,16 @@ public final class PondPlanner {
             return null;
         }
         if (kind == PondKind.NATURAL && CellHash.unit(CellHash.mix(settings.seed(), SALT_KEEP, floorX, floorZ))
-                >= settings.ponds().natural().keep() * floor.pondDensity()[0]) {
+                >= Math.clamp(settings.ponds().natural().keep() * floor.pondDensity()[0], 0f, 1f) * settings.density()) {
             return null;
         }
         return new Candidate(basin, kind, floorX, floorZ, floor.rainfall()[0], fluid(floor));
     }
 
     private Pond lake(LakeCandidate candidate, HeightLattice fine) {
+        if (CellHash.unit(CellHash.mix(settings.seed(), SALT_KEEP, candidate.floorX(), candidate.floorZ())) >= settings.density()) {
+            return null;
+        }
         HydrologySampleBuffer floor = sampleAt(fine, candidate.floorX(), candidate.floorZ());
         if ((floor.permission()[0] & HydrologySampleBuffer.ALLOW_PONDS) == 0) {
             return null;
@@ -347,36 +350,31 @@ public final class PondPlanner {
                 level--;
                 continue;
             }
-            int limit = rim == null ? level : Math.min(level, rimGround(rim, box, wet) + settings.deformation().maxFill());
+            PondMask mask = mask(box, ground, wet, level);
+            int limit = rim == null ? level : Math.min(level, rimGround(rim, mask) + settings.deformation().maxFill());
             if (limit >= level) {
-                return pond(site, level, box, ground, wet, spill, damRaise);
+                return pond(site, level, box, ground, wet, spill, damRaise, mask);
             }
             level = limit;
         }
         return null;
     }
 
-    private static int rimGround(HeightLattice lattice, Box box, boolean[] wet) {
+    private static int rimGround(HeightLattice lattice, PondMask mask) {
-        int half = box.step() >> 1;
         Set<Long> columns = new LinkedHashSet<>();
-        for (int node = 0; node < wet.length; node++) {
+        for (int j = 0; j < mask.depth(); j++) {
-            if (!wet[node]) {
+            for (int i = 0; i < mask.width(); i++) {
-                continue;
+                if (!mask.node(i, j)) {
-            }
-            int i = node % box.width();
-            int j = node / box.width();
-            int x = box.x(node);
-            int z = box.z(node);
-            for (int axis = 0; axis < AXIS_X.length; axis++) {
-                int ni = i + AXIS_X[axis];
-                int nj = j + AXIS_Z[axis];
-                if (ni >= 0 && nj >= 0 && ni < box.width() && nj < box.depth() && wet[nj * box.width() + ni]) {
                     continue;
                 }
-                for (int along = -half; along < half; along++) {
+                for (int axis = 0; axis < AXIS_X.length; axis++) {
-                    int columnX = AXIS_X[axis] == 0 ? x + along : AXIS_X[axis] > 0 ? x + half : x - half - 1;
+                    int ni = i + AXIS_X[axis];
-                    int columnZ = AXIS_Z[axis] == 0 ? z + along : AXIS_Z[axis] > 0 ? z + half : z - half - 1;
+                    int nj = j + AXIS_Z[axis];
-                    columns.add(((long) columnX << 32) | (columnZ & 0xFFFFFFFFL));
+                    if (!mask.node(ni, nj)) {
+                        int x = mask.originX() + ni;
+                        int z = mask.originZ() + nj;
+                        columns.add(((long) x << 32) | (z & 0xFFFFFFFFL));
+                    }
                 }
             }
         }
@@ -397,7 +395,7 @@ public final class PondPlanner {
         return xs.length == 0 ? Integer.MAX_VALUE : (int) Math.floor(lowest);
     }
 
-    private Pond pond(Site site, int level, Box box, float[] ground, boolean[] wet, Spill spill, int damRaise) {
+    private Pond pond(Site site, int level, Box box, float[] ground, boolean[] wet, Spill spill, int damRaise, PondMask mask) {
         float lowest = Float.POSITIVE_INFINITY;
         for (int node = 0; node < wet.length; node++) {
             if (wet[node]) {
@@ -406,7 +404,7 @@ public final class PondPlanner {
         }
         long id = CellHash.mix(settings.seed(), salt(site.kind()), site.floorX(), site.floorZ());
         return new Pond(id, site.kind(), level, (int) Math.floor(lowest), spill.x(), spill.z(), spill.height(),
-                mask(box, wet), 0L, damRaise, site.fluid(), site.floorX(), site.floorZ());
+                mask, 0L, damRaise, site.fluid(), site.floorX(), site.floorZ());
     }
 
     private static boolean covered(DemGrid raw, Basin basin, List<Pond> lakes) {
@@ -681,7 +679,7 @@ public final class PondPlanner {
         return true;
     }
 
-    private static PondMask mask(Box box, boolean[] wet) {
+    private static PondMask mask(Box box, float[] ground, boolean[] wet, int level) {
         int minI = Integer.MAX_VALUE;
         int minJ = Integer.MAX_VALUE;
         int maxI = Integer.MIN_VALUE;
@@ -698,6 +696,9 @@ public final class PondPlanner {
         minJ = Math.max(0, minJ - 1);
         maxI = Math.min(box.width() - 1, maxI + 1);
         maxJ = Math.min(box.depth() - 1, maxJ + 1);
+        if (box.step() < LAKE_STEP) {
+            return shorelineMask(box, ground, wet, level, minI, minJ, maxI, maxJ);
+        }
         int width = maxI - minI + 1;
         int depth = maxJ - minJ + 1;
         long[] bits = new long[(width * depth + 63) >>> 6];
@@ -712,6 +713,46 @@ public final class PondPlanner {
         return new PondMask(box.originX() + minI * box.step(), box.originZ() + minJ * box.step(), box.step(), width, depth, bits);
     }
 
+    private static PondMask shorelineMask(Box box, float[] ground, boolean[] wet, int level, int minI, int minJ, int maxI, int maxJ) {
+        int step = box.step();
+        int half = step >> 1;
+        int width = (maxI - minI + 1) * step;
+        int depth = (maxJ - minJ + 1) * step;
+        long[] bits = new long[(width * depth + 63) >>> 6];
+        for (int z = 0; z < depth; z++) {
+            int sampleZ = minJ * step + z - half;
+            int j = Math.floorDiv(sampleZ, step);
+            if (j < 0 || j + 1 >= box.depth()) {
+                continue;
+            }
+            float v = Math.floorMod(sampleZ, step) / (float) step;
+            for (int x = 0; x < width; x++) {
+                int sampleX = minI * step + x - half;
+                int i = Math.floorDiv(sampleX, step);
+                if (i < 0 || i + 1 >= box.width()) {
+                    continue;
+                }
+                float u = Math.floorMod(sampleX, step) / (float) step;
+                int node = j * box.width() + i;
+                if (!wet[node] && !wet[node + 1] && !wet[node + box.width()] && !wet[node + box.width() + 1]) {
+                    continue;
+                }
+                float first = lifted(box, ground, node) * (1f - u) + lifted(box, ground, node + 1) * u;
+                float second = lifted(box, ground, node + box.width()) * (1f - u)
+                        + lifted(box, ground, node + box.width() + 1) * u;
+                if (first * (1f - v) + second * v < level) {
+                    int index = z * width + x;
+                    bits[index >>> 6] |= 1L << index;
+                }
+            }
+        }
+        return new PondMask(box.originX() + minI * step - half, box.originZ() + minJ * step - half, 1, width, depth, bits);
+    }
+
+    private static float lifted(Box box, float[] ground, int node) {
+        return ground[node] - box.lift()[node];
+    }
+
     private int freeboard(Site site) {
         return CupCarver.pick(settings.ponds().freeboard(),
                 CellHash.mix(settings.seed(), SALT_FREEBOARD, site.floorX(), site.floorZ()));

core/src/main/java/art/arcane/iris/localization/DesktopUiMessages.java

@@ -119,6 +119,17 @@ public final class DesktopUiMessages {
     public static final TextKey PREGEN_EXISTING = TextKey.of("iris.desktop.pregen.existing", "Existing");
     public static final TextKey PREGEN_NETWORK = TextKey.of("iris.desktop.pregen.network", "Network");
     public static final TextKey PREGEN_TERRAIN_HINT = TextKey.of("iris.desktop.pregen.terrain_hint", "Finished chunks show terrain colors");
+    public static final TextKey PREGEN_GRID = TextKey.of("iris.desktop.pregen.grid", "Grid");
+    public static final TextKey PREGEN_GRID_HINT = TextKey.of("iris.desktop.pregen.grid_hint", "Show chunk and region borders (G)");
+    public static final TextKey PREGEN_FIT = TextKey.of("iris.desktop.pregen.fit", "Reset view");
+    public static final TextKey PREGEN_FIT_HINT = TextKey.of("iris.desktop.pregen.fit_hint", "Fit the whole generation area (R)");
+    public static final TextKey PREGEN_ZOOM_IN = TextKey.of("iris.desktop.pregen.zoom_in", "Zoom in (+)");
+    public static final TextKey PREGEN_ZOOM_OUT = TextKey.of("iris.desktop.pregen.zoom_out", "Zoom out (-)");
+    public static final TextKey PREGEN_ZOOM = TextKey.of("iris.desktop.pregen.zoom", "Zoom {zoom}");
+    public static final TextKey PREGEN_SHORTCUTS = TextKey.of("iris.desktop.pregen.shortcuts", "Shortcuts");
+    public static final TextKey PREGEN_SHORTCUTS_HINT = TextKey.of("iris.desktop.pregen.shortcuts_hint", "Show mouse and key shortcuts (/)");
+    public static final TextKey PREGEN_NAVIGATION_HINT = TextKey.of("iris.desktop.pregen.navigation_hint", "Drag to pan · Scroll to zoom · Hover to inspect chunks");
+    public static final TextKey PREGEN_SHORTCUT_DETAILS = TextKey.of("iris.desktop.pregen.shortcut_details", "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts");
     public static final TextKey IMAGEMAP_TITLE = TextKey.of("iris.desktop.imagemap.title", "Image Map Studio");
     public static final TextKey IMAGEMAP_PRESET = TextKey.of("iris.desktop.imagemap.preset", "Preset:");
     public static final TextKey IMAGEMAP_LOAD = TextKey.of("iris.desktop.imagemap.load", "Load");
@@ -216,7 +227,9 @@ public final class DesktopUiMessages {
             PREGEN_METHOD, PREGEN_CACHED, PREGEN_FAILED, PREGEN_MAP,
             PREGEN_CHUNK_COORDINATES, PREGEN_WINDOW_HINT,
             PREGEN_BOUNDS, PREGEN_WAITING, PREGEN_READY, PREGEN_EXISTING,
-            PREGEN_NETWORK, PREGEN_TERRAIN_HINT,
+            PREGEN_NETWORK, PREGEN_TERRAIN_HINT, PREGEN_GRID, PREGEN_GRID_HINT,
+            PREGEN_FIT, PREGEN_FIT_HINT, PREGEN_ZOOM_IN, PREGEN_ZOOM_OUT, PREGEN_ZOOM,
+            PREGEN_SHORTCUTS, PREGEN_SHORTCUTS_HINT, PREGEN_NAVIGATION_HINT, PREGEN_SHORTCUT_DETAILS,
             IMAGEMAP_TITLE, IMAGEMAP_PRESET, IMAGEMAP_LOAD, IMAGEMAP_IMPORT_PNG,
             IMAGEMAP_REPLACE_PNG, IMAGEMAP_PREVIEW, IMAGEMAP_EXPORT, IMAGEMAP_METADATA,
             IMAGEMAP_RESOURCE, IMAGEMAP_COORDINATES, IMAGEMAP_BINDING_KEY, IMAGEMAP_MAP_KEY,

core/src/main/java/art/arcane/iris/studio/StudioSVC.java

@@ -388,10 +388,6 @@ public class StudioSVC implements IrisService {
                     fingerprint,
                     aliasPolicy
             );
-            if (!fingerprint.equals(GenerationPackFingerprint.compute(
-                    packRoot, GenerationPackFingerprint.CURRENT_VERSION))) {
-                throw new IOException("Generation pack changed during validation: " + packRoot);
-            }
             return new GenerationCandidate(fingerprint, dimensionContract, registryContract);
         } finally {
             data.close();

core/src/main/java/art/arcane/iris/studio/map/IslandOverlay.java

@@ -29,7 +29,7 @@ import java.awt.event.MouseEvent;
  * Lays an island over content that fills the whole area behind it. Dragging the island's right edge resizes it,
  * always leaving the content some room beside it.
  */
-final class IslandOverlay extends JLayeredPane {
+public final class IslandOverlay extends JLayeredPane {
     private static final long serialVersionUID = -4182209135360718342L;
 
     private final IslandPanel island;
@@ -38,7 +38,7 @@ final class IslandOverlay extends JLayeredPane {
     private final int minimumUncoveredWidth;
     private int islandWidth;
 
-    IslandOverlay(IslandPanel island, JComponent background, int islandWidth, int minimumIslandWidth, int minimumUncoveredWidth) {
+    public IslandOverlay(IslandPanel island, JComponent background, int islandWidth, int minimumIslandWidth, int minimumUncoveredWidth) {
         this.island = island;
         this.background = background;
         this.islandWidth = islandWidth;

core/src/main/java/art/arcane/iris/studio/map/IslandPanel.java

@@ -34,13 +34,13 @@ import java.util.List;
  * islands theme. The gap belongs to the content behind it, except for the strip along the right edge, which grabs the
  * island to resize it.
  */
-final class IslandPanel extends JPanel implements FloatingPanels.PartlySeeThrough {
+public final class IslandPanel extends JPanel implements FloatingPanels.PartlySeeThrough {
     private static final long serialVersionUID = 7313084027614358519L;
     private static final int GAP = 6;
     private static final int CORNER_ARC = 12;
     private static final int INNER_PADDING = 4;
 
-    IslandPanel(JComponent content) {
+    public IslandPanel(JComponent content) {
         super(new BorderLayout());
         setOpaque(false);
         int inset = GAP + INNER_PADDING;

core/src/main/java/art/arcane/iris/studio/map/MapCanvas.java

@@ -724,10 +724,13 @@ final class MapCanvas extends JPanel {
             int tileHeight = Math.max(1, (int) Math.round(worldToScreenZ(worldZ + frameTileSpan)) - screenY);
             if (tile.tile() != null) {
                 canvas.drawImage(tile.tile().image(style), screenX, screenY, tileWidth, tileHeight, null);
-                continue;
+                if (!tile.provisional()) {
+                    continue;
+                }
+            } else {
+                canvas.setColor(((tile.tileX() ^ tile.tileZ()) & 1L) == 0L ? TILE_EMPTY_A : TILE_EMPTY_B);
+                canvas.fillRect(screenX, screenY, tileWidth, tileHeight);
             }
-            canvas.setColor(((tile.tileX() ^ tile.tileZ()) & 1L) == 0L ? TILE_EMPTY_A : TILE_EMPTY_B);
-            canvas.fillRect(screenX, screenY, tileWidth, tileHeight);
             drawFallback(canvas, controller.fallback(frame, tile), screenX, screenY, tileWidth, tileHeight);
         }
     }

core/src/main/java/art/arcane/iris/studio/map/MapHost.java

@@ -46,7 +46,7 @@ public final class MapHost {
         return GuiHost.isAvailable();
     }
 
-    static JFrame createFrame(String title) {
+    public static JFrame createFrame(String title) {
         XwaylandWindowManagerHint.apply();
         StudioTheme.install();
         JFrame frame = new JFrame(title);
@@ -73,7 +73,7 @@ public final class MapHost {
     }
 
     // A scaled-up default size can be bigger than a small or low resolution screen.
-    static Dimension fitToScreen(Dimension preferred) {
+    public static Dimension fitToScreen(Dimension preferred) {
         Rectangle usable = GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds();
         return new Dimension(Math.min(preferred.width, usable.width), Math.min(preferred.height, usable.height));
     }

core/src/main/java/art/arcane/iris/studio/map/StudioTheme.java

@@ -45,20 +45,20 @@ import java.util.concurrent.atomic.AtomicBoolean;
  * The colours of IntelliJ's "New UI", light and dark, shared by FlatLaf's controls and everything the studio windows
  * draw themselves. The theme follows the system unless the user picked light or dark.
  */
-final class StudioTheme {
+public final class StudioTheme {
-    static final Color EDITOR_BACKGROUND = new ThemeColor(0xFFFFFF, 0x1E1F22);
+    public static final Color EDITOR_BACKGROUND = new ThemeColor(0xFFFFFF, 0x1E1F22);
-    static final Color PANEL_BACKGROUND = new ThemeColor(0xF7F8FA, 0x2B2D30);
+    public static final Color PANEL_BACKGROUND = new ThemeColor(0xF7F8FA, 0x2B2D30);
     static final Color HOVER_BACKGROUND = new ThemeColor(0xDFE1E5, 0x393B40);
     static final Color INACTIVE_SELECTION = new ThemeColor(0xDFE1E5, 0x43454A);
     static final Color SELECTION = new ThemeColor(0xD4E2FF, 0x2E436E);
-    static final Color CONTROL_BORDER = new ThemeColor(0xC9CCD6, 0x4E5157);
+    public static final Color CONTROL_BORDER = new ThemeColor(0xC9CCD6, 0x4E5157);
     static final Color SEPARATOR = new ThemeColor(0xEBECF0, 0x1E1F22);
-    static final Color TEXT = new ThemeColor(0x000000, 0xDFE1E5);
+    public static final Color TEXT = new ThemeColor(0x000000, 0xDFE1E5);
-    static final ThemeColor SECONDARY_TEXT = new ThemeColor(0x6C707E, 0x9DA0A8);
+    public static final ThemeColor SECONDARY_TEXT = new ThemeColor(0x6C707E, 0x9DA0A8);
     static final Color MUTED_TEXT = new ThemeColor(0x818594, 0x6F737A);
-    static final Color ACCENT = new Color(0x3574F0);
+    public static final Color ACCENT = new Color(0x3574F0);
     static final Color LINK = new ThemeColor(0x315FBD, 0x548AF7);
-    static final Color ERROR = new ThemeColor(0xDB3B4B, 0xF75464);
+    public static final Color ERROR = new ThemeColor(0xDB3B4B, 0xF75464);
     static final Color WARNING = new ThemeColor(0xC27D04, 0xF2C55C);
     static final Color SUCCESS = new ThemeColor(0x208A3C, 0x5FB865);
     static final Color OVERLAY_BACKGROUND = new ThemeColor(new Color(0xFF, 0xFF, 0xFF, 240), new Color(0x2B, 0x2D, 0x30, 236));
@@ -231,7 +231,7 @@ final class StudioTheme {
     /**
      * FlatLaf grows fonts and its own controls to the screen's DPI; every size the studio sets itself has to grow with them.
      */
-    static int scale(int pixels) {
+    public static int scale(int pixels) {
         return Math.round(pixels * pixelScale);
     }
 
@@ -239,27 +239,27 @@ final class StudioTheme {
         return pixels * pixelScale;
     }
 
-    static Dimension scaledSize(int width, int height) {
+    public static Dimension scaledSize(int width, int height) {
         return new Dimension(scale(width), scale(height));
     }
 
-    static Border emptyBorder(int top, int left, int bottom, int right) {
+    public static Border emptyBorder(int top, int left, int bottom, int right) {
         return BorderFactory.createEmptyBorder(scale(top), scale(left), scale(bottom), scale(right));
     }
 
-    static Font font() {
+    public static Font font() {
         return themeFont("defaultFont", Font.PLAIN, 13);
     }
 
-    static Font smallFont() {
+    public static Font smallFont() {
         return themeFont("small.font", Font.PLAIN, 11);
     }
 
-    static Font boldFont() {
+    public static Font boldFont() {
         return font().deriveFont(Font.BOLD);
     }
 
-    static Font titleFont() {
+    public static Font titleFont() {
         return font().deriveFont(Font.BOLD, font().getSize2D() + 1F);
     }
 

core/src/main/java/art/arcane/iris/studio/map/StudioToolbar.java

@@ -40,13 +40,13 @@ import java.awt.Insets;
 /**
  * Builds the IntelliJ style controls the studio windows share: a flat main toolbar, borderless toolbar buttons and search boxes.
  */
-final class StudioToolbar {
+public final class StudioToolbar {
     private static final int TOOLBAR_HEIGHT_PADDING = 5;
 
     private StudioToolbar() {
     }
 
-    static JToolBar create() {
+    public static JToolBar create() {
         JToolBar toolbar = new JToolBar();
         toolbar.setFloatable(false);
         toolbar.setRollover(true);
@@ -65,7 +65,7 @@ final class StudioToolbar {
         return label;
     }
 
-    static JButton button(String text, String tooltip, Runnable action) {
+    public static JButton button(String text, String tooltip, Runnable action) {
         JButton button = toolbarButton(text, tooltip);
         button.addActionListener(event -> action.run());
         return button;
@@ -74,7 +74,7 @@ final class StudioToolbar {
     /**
      * Opens a menu to pick light, dark or the system's theme.
      */
-    static JButton themeButton() {
+    public static JButton themeButton() {
         JButton button = toolbarButton("Theme", "Light, dark, or whatever the system uses");
         button.addActionListener(event -> themeMenu().show(button, 0, button.getHeight()));
         return button;
@@ -102,7 +102,7 @@ final class StudioToolbar {
         return button;
     }
 
-    static JToggleButton toggle(String text, String tooltip) {
+    public static JToggleButton toggle(String text, String tooltip) {
         JToggleButton toggle = new JToggleButton(text);
         toggle.setToolTipText(tooltip);
         toggle.setFocusable(false);
@@ -134,7 +134,7 @@ final class StudioToolbar {
         return panel;
     }
 
-    static JScrollPane scroll(JComponent content) {
+    public static JScrollPane scroll(JComponent content) {
         JScrollPane scrollPane = new JScrollPane(content);
         scrollPane.setBorder(BorderFactory.createEmptyBorder());
         scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);

core/src/main/java/art/arcane/iris/studio/map/VisionRenderController.java

@@ -578,6 +578,10 @@ final class VisionRenderController implements AutoCloseable {
             return tile;
         }
 
+        boolean provisional() {
+            return provisional;
+        }
+
         private void setTile(MapTile tile) {
             this.tile = tile;
             provisional = false;

core/src/main/java/art/arcane/iris/studio/map/components/MapTileRenderer.java

@@ -20,6 +20,7 @@ package art.arcane.iris.studio.map.components;
 
 import art.arcane.iris.generation.runtime.IrisComplex;
 import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.iris.generation.hydrology.engine.HydrologyRuntime;
 import art.arcane.iris.generation.terrain.InferredType;
 import art.arcane.iris.generation.biome.IrisBiome;
 import art.arcane.iris.generation.terrain.IrisDimension;
@@ -166,7 +167,15 @@ public final class MapTileRenderer {
     }
 
     private double[] sampleHeights(TileGrid grid) {
-        return new HeightLattice(grid, engine.getComplex().getHeightStream()).interpolatedHeights();
+        IrisComplex complex = engine.getComplex();
+        IrisDimension dimension = engine.getDimension();
+        HydrologyRuntime water = complex.getHydrologyRuntime();
+        if (water == null || !water.enabled() || dimension != null && dimension.getTerrainTransform() != null) {
+            return new HeightLattice(grid, complex.getHeightStream()).interpolatedHeights();
+        }
+        try (HydrologyRuntime.PreviewScope ignored = water.preview()) {
+            return new HeightLattice(grid, complex.getHeightStream()).interpolatedHeights();
+        }
     }
 
     // Large uniform squares are filled after a few samples; squares stay small enough to not skip tiny biomes.

core/src/main/java/art/arcane/iris/studio/render/WaterMap.java

@@ -90,6 +90,7 @@ final class WaterMap {
             lakes.add(lake.id());
         }
         Map<Long, ChunkWaterRaster> rasters = new HashMap<>();
+        WaterMap planned = null;
         for (int pixelZ = 0; pixelZ < resolution; pixelZ++) {
             checkCancelled();
             int minimumZ = (int) Math.floor(startZ + pixelZ * step);
@@ -102,6 +103,11 @@ final class WaterMap {
                         ChunkWaterRaster raster = raster(rasters, x >> 4, z >> 4);
                         if (raster.provisional()) {
                             provisional = true;
+                            if (planned == null) {
+                                planned = new WaterMap(runtime, resolution, startX, startZ, step, cancelled);
+                                planned.drawPlans(plans);
+                            }
+                            stamp(pixelX, pixelZ, planned.at(pixelX, pixelZ));
                         } else if (!raster.empty()) {
                             stamp(pixelX, pixelZ, columnType(raster, x & 15, z & 15, lakes));
                         }

core/src/main/java/art/arcane/iris/studio/view/PregenMapPanel.java

@@ -2,32 +2,60 @@ package art.arcane.iris.studio.view;
 
 import art.arcane.iris.localization.DesktopUiMessages;
 import art.arcane.iris.localization.IrisLanguage;
+import art.arcane.iris.studio.map.StudioTheme;
 import art.arcane.volmlib.util.localization.MessageArgument;
 
 import javax.swing.JPanel;
+import javax.swing.SwingUtilities;
 import javax.swing.ToolTipManager;
 import java.awt.Color;
+import java.awt.Cursor;
+import java.awt.FontMetrics;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
+import java.awt.Point;
 import java.awt.Rectangle;
 import java.awt.RenderingHints;
+import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
+import java.awt.event.MouseWheelEvent;
+import java.awt.geom.AffineTransform;
+import java.awt.geom.Rectangle2D;
 import java.awt.image.BufferedImage;
 import java.awt.image.DataBufferInt;
 
 final class PregenMapPanel extends JPanel {
+    private static final double MIN_ZOOM = 0.25D;
+    private static final double MAX_ZOOM = 128D;
+    private static final double ZOOM_STEP = 1.25D;
+
     private final PregenRenderSnapshot.Bounds bounds;
     private final PregenMapState state;
     private final PregenMapState.View view;
     private final BufferedImage image;
+    private final String[] shortcuts;
     private volatile boolean disposed;
+    private Runnable viewListener;
+    private Point drag;
+    private Point hover;
+    private double centerX = 0.5D;
+    private double centerZ = 0.5D;
+    private double zoom = 1D;
+    private int coveredLeftWidth;
+    private boolean gridVisible;
+    private boolean helpVisible;
 
     PregenMapPanel(PregenMapState state) {
         this.state = state;
         bounds = state.bounds();
         image = new BufferedImage(state.width(), state.height(), BufferedImage.TYPE_INT_RGB);
+        image.setAccelerationPriority(0F);
         view = state.attach(((DataBufferInt) image.getRaster().getDataBuffer()).getData());
-        setBackground(PregenRenderer.BACKGROUND);
+        shortcuts = IrisLanguage.plain(DesktopUiMessages.PREGEN_SHORTCUT_DETAILS).split("\n");
+        setBackground(StudioTheme.EDITOR_BACKGROUND);
+        setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
+        setFocusable(true);
+        installNavigation();
         ToolTipManager.sharedInstance().registerComponent(this);
     }
 
@@ -43,23 +71,83 @@ final class PregenMapPanel extends JPanel {
 
     void disposeMap() {
         disposed = true;
+        viewListener = null;
         ToolTipManager.sharedInstance().unregisterComponent(this);
         view.close();
     }
 
+    void setViewListener(Runnable listener) {
+        viewListener = listener;
+    }
+
+    void setCoveredLeftWidth(int width) {
+        coveredLeftWidth = Math.max(0, width);
+        changed();
+    }
+
+    void resetView() {
+        centerX = 0.5D;
+        centerZ = 0.5D;
+        zoom = 1D;
+        changed();
+    }
+
+    double zoom() {
+        return zoom;
+    }
+
+    void zoomIn() {
+        zoomAt(ZOOM_STEP, (getWidth() + coveredLeftWidth) / 2D, getHeight() / 2D);
+    }
+
+    void zoomOut() {
+        zoomAt(1D / ZOOM_STEP, (getWidth() + coveredLeftWidth) / 2D, getHeight() / 2D);
+    }
+
+    void zoomAt(double factor, double anchorX, double anchorY) {
+        Rectangle2D.Double before = mapArea();
+        double mapX = (anchorX - before.x) / before.width;
+        double mapZ = (anchorY - before.y) / before.height;
+        zoom = Math.clamp(zoom * factor, MIN_ZOOM, MAX_ZOOM);
+        Rectangle2D.Double after = mapArea();
+        centerX += mapX - (anchorX - after.x) / after.width;
+        centerZ += mapZ - (anchorY - after.y) / after.height;
+        changed();
+    }
+
+    void panBy(double pixelsX, double pixelsY) {
+        Rectangle2D.Double area = mapArea();
+        centerX -= pixelsX / area.width;
+        centerZ -= pixelsY / area.height;
+        changed();
+    }
+
+    void toggleGrid() {
+        gridVisible = !gridVisible;
+        repaint();
+    }
+
+    boolean isGridVisible() {
+        return gridVisible;
+    }
+
+    void toggleHelp() {
+        helpVisible = !helpVisible;
+        repaint();
+    }
+
+    void dismissHelp() {
+        helpVisible = false;
+        repaint();
+    }
+
+    String hoverCoordinates() {
+        return hover == null ? null : coordinatesAt(hover.x, hover.y);
+    }
+
     @Override
     public String getToolTipText(MouseEvent event) {
-        if (disposed) {
+        return coordinatesAt(event.getX(), event.getY());
-            return null;
-        }
-        Rectangle area = fit(bounds, getWidth(), getHeight());
-        if (!area.contains(event.getX(), event.getY())) {
-            return null;
-        }
-        int chunkX = (int) (bounds.minX() + (long) (event.getX() - area.x) * bounds.width() / area.width);
-        int chunkZ = (int) (bounds.minZ() + (long) (event.getY() - area.y) * bounds.height() / area.height);
-        return IrisLanguage.plain(DesktopUiMessages.PREGEN_CHUNK_COORDINATES,
-                MessageArgument.trusted("x", chunkX), MessageArgument.trusted("z", chunkZ));
     }
 
     @Override
@@ -67,11 +155,20 @@ final class PregenMapPanel extends JPanel {
         super.paintComponent(graphics);
         Graphics2D canvas = (Graphics2D) graphics.create();
         try {
-            Rectangle area = fit(bounds, getWidth(), getHeight());
+            Rectangle2D.Double area = mapArea();
             canvas.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR);
-            canvas.drawImage(image, area.x, area.y, area.width, area.height, null);
+            AffineTransform transform = AffineTransform.getTranslateInstance(area.x, area.y);
-            canvas.setColor(PregenRenderer.BORDER);
+            transform.scale(area.width / image.getWidth(), area.height / image.getHeight());
-            canvas.drawRect(area.x, area.y, area.width - 1, area.height - 1);
+            canvas.drawImage(image, transform, null);
+            if (gridVisible) {
+                paintGrid(canvas, area);
+            }
+            canvas.setColor(StudioTheme.CONTROL_BORDER);
+            canvas.draw(area);
+            paintHover(canvas, area);
+            if (helpVisible) {
+                paintHelp(canvas);
+            }
         } finally {
             canvas.dispose();
         }
@@ -85,4 +182,150 @@ final class PregenMapPanel extends JPanel {
         int mapHeight = Math.max(1, (int) Math.floor(bounds.height() * scale));
         return new Rectangle((width - mapWidth) / 2, (height - mapHeight) / 2, mapWidth, mapHeight);
     }
+
+    private Rectangle2D.Double mapArea() {
+        Rectangle fit = fit(bounds, Math.max(1, getWidth() - coveredLeftWidth), getHeight());
+        double width = fit.width * zoom;
+        double height = fit.height * zoom;
+        return new Rectangle2D.Double(coveredLeftWidth + fit.getCenterX() - centerX * width,
+                fit.getCenterY() - centerZ * height, width, height);
+    }
+
+    private String coordinatesAt(int x, int y) {
+        if (disposed || x < coveredLeftWidth) {
+            return null;
+        }
+        Rectangle2D.Double area = mapArea();
+        if (!area.contains(x, y)) {
+            return null;
+        }
+        long chunkX = bounds.minX() + (long) Math.floor((x - area.x) * bounds.width() / area.width);
+        long chunkZ = bounds.minZ() + (long) Math.floor((y - area.y) * bounds.height() / area.height);
+        return IrisLanguage.plain(DesktopUiMessages.PREGEN_CHUNK_COORDINATES,
+                MessageArgument.trusted("x", chunkX), MessageArgument.trusted("z", chunkZ));
+    }
+
+    private void installNavigation() {
+        MouseAdapter navigation = new MouseAdapter() {
+            @Override
+            public void mousePressed(MouseEvent event) {
+                if (SwingUtilities.isLeftMouseButton(event)) {
+                    requestFocusInWindow();
+                    drag = event.getPoint();
+                    setCursor(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR));
+                }
+            }
+
+            @Override
+            public void mouseReleased(MouseEvent event) {
+                drag = null;
+                setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
+            }
+
+            @Override
+            public void mouseDragged(MouseEvent event) {
+                if (drag != null) {
+                    hover = event.getPoint();
+                    panBy(event.getX() - drag.x, event.getY() - drag.y);
+                    drag = hover;
+                }
+            }
+
+            @Override
+            public void mouseMoved(MouseEvent event) {
+                hover = event.getPoint();
+                changed();
+            }
+
+            @Override
+            public void mouseExited(MouseEvent event) {
+                hover = null;
+                changed();
+            }
+
+            @Override
+            public void mouseWheelMoved(MouseWheelEvent event) {
+                zoomAt(Math.pow(ZOOM_STEP, -event.getPreciseWheelRotation()), event.getX(), event.getY());
+            }
+        };
+        addMouseListener(navigation);
+        addMouseMotionListener(navigation);
+        addMouseWheelListener(navigation);
+    }
+
+    private void paintGrid(Graphics2D canvas, Rectangle2D.Double area) {
+        if (!area.intersects(0, 0, getWidth(), getHeight())) {
+            return;
+        }
+        double chunkWidth = area.width / bounds.width();
+        double chunkHeight = area.height / bounds.height();
+        long step = Math.min(chunkWidth, chunkHeight) >= 24D ? 1 : 32;
+        while (step * Math.min(chunkWidth, chunkHeight) < 24D) {
+            step *= 2;
+        }
+        canvas.setColor(StudioTheme.CONTROL_BORDER);
+        long minX = Math.max(bounds.minX(), (long) Math.floor(bounds.minX() - area.x / chunkWidth));
+        long maxX = Math.min((long) bounds.maxX() + 1, (long) Math.ceil(bounds.minX() + (getWidth() - area.x) / chunkWidth));
+        long minZ = Math.max(bounds.minZ(), (long) Math.floor(bounds.minZ() - area.y / chunkHeight));
+        long maxZ = Math.min((long) bounds.maxZ() + 1, (long) Math.ceil(bounds.minZ() + (getHeight() - area.y) / chunkHeight));
+        int top = (int) Math.max(0, area.y);
+        int bottom = (int) Math.min(getHeight(), area.getMaxY());
+        int left = (int) Math.max(0, area.x);
+        int right = (int) Math.min(getWidth(), area.getMaxX());
+        for (long x = Math.ceilDiv(minX, step) * step; x <= maxX; x += step) {
+            int screenX = (int) Math.round(area.x + (x - bounds.minX()) * chunkWidth);
+            canvas.drawLine(screenX, top, screenX, bottom);
+        }
+        for (long z = Math.ceilDiv(minZ, step) * step; z <= maxZ; z += step) {
+            int screenZ = (int) Math.round(area.y + (z - bounds.minZ()) * chunkHeight);
+            canvas.drawLine(left, screenZ, right, screenZ);
+        }
+    }
+
+    private void paintHover(Graphics2D canvas, Rectangle2D.Double area) {
+        if (hover == null || hover.x < coveredLeftWidth || !area.contains(hover)) {
+            return;
+        }
+        double chunkWidth = area.width / bounds.width();
+        double chunkHeight = area.height / bounds.height();
+        if (Math.min(chunkWidth, chunkHeight) < 4D) {
+            return;
+        }
+        double x = area.x + Math.floor((hover.x - area.x) / chunkWidth) * chunkWidth;
+        double y = area.y + Math.floor((hover.y - area.y) / chunkHeight) * chunkHeight;
+        canvas.setColor(StudioTheme.ACCENT);
+        canvas.draw(new Rectangle2D.Double(x, y, chunkWidth, chunkHeight));
+    }
+
+    private void paintHelp(Graphics2D canvas) {
+        canvas.setFont(StudioTheme.font());
+        FontMetrics metrics = canvas.getFontMetrics();
+        int padding = StudioTheme.scale(14);
+        int width = 0;
+        for (String line : shortcuts) {
+            width = Math.max(width, metrics.stringWidth(line));
+        }
+        width += padding * 2;
+        int height = metrics.getHeight() * shortcuts.length + padding * 2;
+        int x = Math.max(coveredLeftWidth + padding, getWidth() - width - padding);
+        int arc = StudioTheme.scale(10);
+        canvas.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+        canvas.setColor(StudioTheme.PANEL_BACKGROUND);
+        canvas.fillRoundRect(x, padding, width, height, arc, arc);
+        canvas.setColor(StudioTheme.CONTROL_BORDER);
+        canvas.drawRoundRect(x, padding, width, height, arc, arc);
+        canvas.setColor(StudioTheme.TEXT);
+        int baseline = padding * 2 + metrics.getAscent();
+        for (String line : shortcuts) {
+            canvas.drawString(line, x + padding, baseline);
+            baseline += metrics.getHeight();
+        }
+    }
+
+    private void changed() {
+        if (viewListener != null) {
+            viewListener.run();
+        }
+        repaint();
+    }
 }

core/src/main/java/art/arcane/iris/studio/view/PregenMapState.java

@@ -10,7 +10,7 @@ import java.util.concurrent.locks.ReentrantLock;
 
 public final class PregenMapState {
     private static final int MAX_RASTER_SIZE = 1024;
-    static final Color WAITING = new Color(29, 35, 46);
+    static final Color WAITING = new Color(57, 59, 64);
 
     private final PregenRenderSnapshot.Bounds bounds;
     private final int width;

core/src/main/java/art/arcane/iris/studio/view/PregenRenderer.java

@@ -22,13 +22,18 @@ import art.arcane.iris.configuration.IrisSettings;
 import art.arcane.iris.localization.DesktopUiMessages;
 import art.arcane.iris.localization.IrisLanguage;
 import art.arcane.iris.spi.IrisLogging;
+import art.arcane.iris.studio.map.IslandOverlay;
+import art.arcane.iris.studio.map.IslandPanel;
+import art.arcane.iris.studio.map.MapHost;
+import art.arcane.iris.studio.map.StudioTheme;
+import art.arcane.iris.studio.map.StudioToolbar;
 import art.arcane.volmlib.util.format.Form;
 import art.arcane.volmlib.util.localization.MessageArgument;
 import art.arcane.volmlib.util.localization.TextKey;
 
 import javax.swing.AbstractAction;
-import javax.swing.AbstractButton;
 import javax.swing.BorderFactory;
+import javax.swing.Box;
 import javax.swing.JButton;
 import javax.swing.JComponent;
 import javax.swing.JFrame;
@@ -36,30 +41,31 @@ import javax.swing.JLabel;
 import javax.swing.JPanel;
 import javax.swing.JProgressBar;
 import javax.swing.JScrollPane;
-import javax.swing.Scrollable;
 import javax.swing.JTextArea;
+import javax.swing.JToggleButton;
+import javax.swing.JToolBar;
 import javax.swing.KeyStroke;
+import javax.swing.Scrollable;
 import javax.swing.SwingUtilities;
 import javax.swing.Timer;
-import javax.swing.plaf.basic.BasicButtonUI;
+import javax.swing.text.DefaultCaret;
-import javax.swing.plaf.basic.BasicGraphicsUtils;
+import javax.swing.text.JTextComponent;
-import javax.swing.plaf.basic.BasicProgressBarUI;
-import javax.swing.plaf.basic.BasicScrollBarUI;
 import java.awt.BorderLayout;
 import java.awt.Color;
+import java.awt.Component;
 import java.awt.Dimension;
-import java.awt.GridBagConstraints;
-import java.awt.GridBagLayout;
-import java.awt.Insets;
 import java.awt.Font;
 import java.awt.Frame;
+import java.awt.GridBagConstraints;
+import java.awt.GridBagLayout;
 import java.awt.GridLayout;
-import java.awt.Graphics;
+import java.awt.Insets;
+import java.awt.KeyboardFocusManager;
 import java.awt.LayoutManager;
 import java.awt.Rectangle;
 import java.awt.event.ActionEvent;
-import java.awt.event.FocusAdapter;
+import java.awt.event.ComponentAdapter;
-import java.awt.event.FocusEvent;
+import java.awt.event.ComponentEvent;
 import java.awt.event.KeyEvent;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
@@ -67,43 +73,43 @@ import java.util.Objects;
 
 public final class PregenRenderer extends JPanel {
     private static final long serialVersionUID = 2094606939770332040L;
-    static final Color BACKGROUND = new Color(12, 15, 22);
+    private static final Color BACKGROUND = StudioTheme.EDITOR_BACKGROUND;
-    static final Color BORDER = new Color(105, 119, 139);
+    private static final Color BORDER = StudioTheme.CONTROL_BORDER;
-    private static final Color SURFACE = new Color(17, 20, 29);
+    private static final Color SURFACE = StudioTheme.PANEL_BACKGROUND;
-    private static final Color FIELD = new Color(29, 34, 47);
+    private static final Color TEXT = StudioTheme.TEXT;
-    private static final Color TEXT = new Color(230, 234, 242);
+    private static final Color MUTED = StudioTheme.SECONDARY_TEXT;
-    private static final Color MUTED = new Color(163, 173, 191);
+    private static final Color ACCENT = StudioTheme.ACCENT;
-    private static final Color ACCENT = new Color(101, 194, 149);
+    private static final Color ERROR = StudioTheme.ERROR;
-    private static final Color ERROR = new Color(255, 139, 139);
     static final Color GENERATING = new Color(204, 168, 107);
-    static final Color GENERATED = ACCENT;
+    static final Color GENERATED = new Color(101, 194, 149);
     static final Color EXISTS = new Color(93, 133, 112);
     static final Color NETWORK = new Color(157, 138, 176);
     static final Color NETWORK_GENERATING = new Color(129, 112, 145);
-    private static final Font BODY_FONT = new Font(Font.SANS_SERIF, Font.PLAIN, 13);
-    private static final Font LABEL_FONT = new Font(Font.SANS_SERIF, Font.PLAIN, 11);
-    private static final Font VALUE_FONT = new Font(Font.SANS_SERIF, Font.BOLD, 15);
 
     private final PregenRenderSource source;
     private final Runnable onPause;
     private final PregenMapPanel map;
     private final Timer repaintTimer;
-    private final JLabel worldLabel = label("", new Font(Font.SANS_SERIF, Font.BOLD, 21), TEXT);
+    private final JLabel worldLabel = label("", StudioTheme.titleFont(), TEXT);
-    private final JLabel phaseLabel = label("", BODY_FONT, MUTED);
+    private final JLabel phaseLabel = label("", StudioTheme.font(), MUTED);
-    private final JLabel countLabel = label("", BODY_FONT, TEXT);
+    private final JLabel countLabel = label("", StudioTheme.font(), TEXT);
-    private final JLabel percentLabel = label("", new Font(Font.SANS_SERIF, Font.BOLD, 24), TEXT);
+    private final JLabel percentLabel = label("", StudioTheme.titleFont(), TEXT);
-    private final JLabel currentValue = label("", VALUE_FONT, TEXT);
+    private final JLabel currentValue = label("", StudioTheme.boldFont(), TEXT);
-    private final JLabel overallValue = label("", VALUE_FONT, TEXT);
+    private final JLabel overallValue = label("", StudioTheme.boldFont(), TEXT);
-    private final JLabel thirtyValue = label("", VALUE_FONT, TEXT);
+    private final JLabel thirtyValue = label("", StudioTheme.boldFont(), TEXT);
-    private final JLabel sixtyValue = label("", VALUE_FONT, TEXT);
+    private final JLabel sixtyValue = label("", StudioTheme.boldFont(), TEXT);
-    private final JLabel etaValue = label("", VALUE_FONT, TEXT);
+    private final JLabel etaValue = label("", StudioTheme.boldFont(), TEXT);
-    private final JLabel elapsedValue = label("", VALUE_FONT, TEXT);
+    private final JLabel elapsedValue = label("", StudioTheme.boldFont(), TEXT);
-    private final JLabel memoryValue = label("", VALUE_FONT, TEXT);
+    private final JLabel memoryValue = label("", StudioTheme.boldFont(), TEXT);
-    private final JLabel pressureValue = label("", VALUE_FONT, TEXT);
+    private final JLabel pressureValue = label("", StudioTheme.boldFont(), TEXT);
-    private final JLabel methodLabel = label("", LABEL_FONT, MUTED);
+    private final JLabel methodLabel = label("", StudioTheme.smallFont(), MUTED);
-    private final JTextArea failureLabel = wrappedText("", BODY_FONT, ERROR, SURFACE);
+    private final JTextArea failureLabel = wrappedText("", StudioTheme.font(), ERROR, SURFACE);
     private String controlFailure;
-    private final JButton pauseButton = new JButton();
+    private final JButton pauseButton = StudioToolbar.button("", "", this::togglePause);
+    private final JToggleButton gridToggle = StudioToolbar.toggle(text(DesktopUiMessages.PREGEN_GRID),
+            text(DesktopUiMessages.PREGEN_GRID_HINT));
+    private final JLabel coordinatesLabel = label("", StudioTheme.smallFont(), MUTED);
+    private final JLabel zoomLabel = label("", StudioTheme.smallFont(), MUTED);
     private final JProgressBar progressBar = new JProgressBar(0, 10_000);
     private volatile boolean renderingEnabled;
     private volatile boolean disposed;
@@ -116,16 +122,23 @@ public final class PregenRenderer extends JPanel {
         failureLabel.setFocusable(true);
         PregenRenderSnapshot initial = source.renderSnapshot();
         map = new PregenMapPanel(source.renderMapState());
-        setLayout(new BorderLayout(0, 18));
+        setLayout(new BorderLayout());
         setBackground(BACKGROUND);
-        setBorder(BorderFactory.createEmptyBorder(20, 24, 18, 24));
+        map.getAccessibleContext().setAccessibleName(text(DesktopUiMessages.PREGEN_MAP));
-        add(header(), BorderLayout.NORTH);
+        map.setViewListener(this::updateMapStatus);
-        JPanel content = panel(new BorderLayout(18, 0), BACKGROUND);
+        IslandPanel sidebar = new IslandPanel(statusArea(initial.bounds()));
-        content.add(mapArea(initial.bounds()), BorderLayout.CENTER);
+        sidebar.addComponentListener(new ComponentAdapter() {
-        content.add(statusArea(), BorderLayout.EAST);
+            @Override
-        add(content, BorderLayout.CENTER);
+            public void componentResized(ComponentEvent event) {
-        add(wrappedText(text(DesktopUiMessages.PREGEN_WINDOW_HINT), LABEL_FONT, MUTED, BACKGROUND), BorderLayout.SOUTH);
+                map.setCoveredLeftWidth(sidebar.getWidth());
-        installPauseControl();
+            }
+        });
+        add(toolbar(), BorderLayout.NORTH);
+        add(new IslandOverlay(sidebar, map, StudioTheme.scale(300), StudioTheme.scale(260),
+                StudioTheme.scale(300)), BorderLayout.CENTER);
+        add(statusBar(), BorderLayout.SOUTH);
+        installControls();
+        updateMapStatus();
         repaintTimer = new Timer(IrisSettings.get().getGui().isMaximumPregenGuiFPS() ? 4 : 250,
                 event -> refresh());
         refresh();
@@ -135,14 +148,14 @@ public final class PregenRenderer extends JPanel {
         if (!SwingUtilities.isEventDispatchThread()) {
             throw new IllegalStateException("The pregeneration window must open on the Swing event thread");
         }
+        JFrame frame = MapHost.createFrame(title);
         PregenRenderer renderer = new PregenRenderer(source, onPause);
-        JFrame frame = new JFrame(title);
-        GuiHost.prepareFrame(frame);
         renderer.frame = frame;
         renderer.renderingEnabled = true;
         frame.setContentPane(renderer);
-        frame.setSize(1040, 760);
+        frame.setSize(MapHost.fitToScreen(StudioTheme.scaledSize(1240, 800)));
-        frame.setMinimumSize(new Dimension(760, 620));
+        frame.setMinimumSize(StudioTheme.scaledSize(820, 520));
+        frame.setLocationRelativeTo(null);
         frame.addWindowListener(new WindowAdapter() {
             @Override
             public void windowClosed(WindowEvent event) {
@@ -172,67 +185,80 @@ public final class PregenRenderer extends JPanel {
         }
     }
 
-    private JPanel header() {
+    private JToolBar toolbar() {
-        JPanel heading = panel(new BorderLayout(16, 0), BACKGROUND);
+        JToolBar toolbar = StudioToolbar.create();
-        JPanel identity = panel(new GridLayout(2, 1, 0, 4), BACKGROUND);
+        worldLabel.setBorder(StudioTheme.emptyBorder(0, 6, 0, 14));
-        identity.add(worldLabel);
+        worldLabel.setMaximumSize(StudioTheme.scaledSize(220, 36));
-        identity.add(phaseLabel);
+        worldLabel.setMinimumSize(StudioTheme.scaledSize(80, 24));
-        heading.add(identity, BorderLayout.CENTER);
+        toolbar.add(worldLabel);
-        heading.add(pauseButton, BorderLayout.EAST);
+        toolbar.add(pauseButton);
-        JPanel counts = panel(new BorderLayout(), BACKGROUND);
+        toolbar.addSeparator();
-        counts.add(countLabel, BorderLayout.WEST);
+        toolbar.add(StudioToolbar.button(text(DesktopUiMessages.PREGEN_FIT),
-        counts.add(percentLabel, BorderLayout.EAST);
+                text(DesktopUiMessages.PREGEN_FIT_HINT), map::resetView));
-        progressBar.setUI(new BasicProgressBarUI());
+        toolbar.add(StudioToolbar.button("−", text(DesktopUiMessages.PREGEN_ZOOM_OUT), map::zoomOut));
-        progressBar.setForeground(ACCENT);
+        toolbar.add(StudioToolbar.button("+", text(DesktopUiMessages.PREGEN_ZOOM_IN), map::zoomIn));
-        progressBar.setBackground(FIELD);
+        gridToggle.addActionListener(event -> toggleGrid());
-        progressBar.setBorderPainted(false);
+        toolbar.add(gridToggle);
-        progressBar.setPreferredSize(new Dimension(1, 6));
+        toolbar.add(Box.createHorizontalGlue());
-        progressBar.setFocusable(false);
+        toolbar.add(StudioToolbar.themeButton());
-        JPanel progress = panel(new BorderLayout(0, 9), BACKGROUND);
+        toolbar.add(StudioToolbar.button(text(DesktopUiMessages.PREGEN_SHORTCUTS),
-        progress.add(counts, BorderLayout.NORTH);
+                text(DesktopUiMessages.PREGEN_SHORTCUTS_HINT), map::toggleHelp));
-        progress.add(progressBar, BorderLayout.SOUTH);
+        for (Component control : toolbar.getComponents()) {
-        JPanel header = panel(new BorderLayout(0, 18), BACKGROUND);
+            if (control instanceof JButton || control instanceof JToggleButton) {
-        header.add(heading, BorderLayout.NORTH);
+                control.setFocusable(true);
-        header.add(progress, BorderLayout.SOUTH);
+            }
-        return header;
+        }
+        return toolbar;
     }
 
-    private JPanel mapArea(PregenRenderSnapshot.Bounds bounds) {
+    private JPanel statusBar() {
-        JPanel area = panel(new BorderLayout(0, 8), BACKGROUND);
+        JPanel status = panel(new BorderLayout(12, 0), SURFACE);
-        map.getAccessibleContext().setAccessibleName(text(DesktopUiMessages.PREGEN_MAP));
+        status.setBorder(StudioTheme.emptyBorder(5, 12, 5, 12));
-        area.add(map, BorderLayout.CENTER);
+        status.add(coordinatesLabel, BorderLayout.CENTER);
-        JLabel coordinates = label(text(DesktopUiMessages.PREGEN_BOUNDS,
+        status.add(zoomLabel, BorderLayout.EAST);
-                MessageArgument.trusted("minX", Form.f(bounds.minX())),
+        status.setToolTipText(text(DesktopUiMessages.PREGEN_WINDOW_HINT));
-                MessageArgument.trusted("maxX", Form.f(bounds.maxX())),
+        return status;
-                MessageArgument.trusted("minZ", Form.f(bounds.minZ())),
-                MessageArgument.trusted("maxZ", Form.f(bounds.maxZ()))), LABEL_FONT, MUTED);
-        JPanel mapFooter = panel(new BorderLayout(0, 10), BACKGROUND);
-        mapFooter.add(coordinates, BorderLayout.NORTH);
-        mapFooter.add(legend(), BorderLayout.CENTER);
-        area.add(mapFooter, BorderLayout.SOUTH);
-        return area;
     }
 
-    private JScrollPane statusArea() {
+    private void updateMapStatus() {
+        String coordinates = map.hoverCoordinates();
+        coordinatesLabel.setText(coordinates == null ? text(DesktopUiMessages.PREGEN_NAVIGATION_HINT) : coordinates);
+        zoomLabel.setText(text(DesktopUiMessages.PREGEN_ZOOM,
+                MessageArgument.trusted("zoom", Form.pc(map.zoom(), 0))));
+    }
+
+    private JScrollPane statusArea(PregenRenderSnapshot.Bounds bounds) {
         JPanel status = new StatusPanel();
         status.setBackground(SURFACE);
-        status.setBorder(BorderFactory.createEmptyBorder(18, 16, 16, 16));
+        status.setBorder(StudioTheme.emptyBorder(14, 12, 12, 12));
         GridBagConstraints constraints = new GridBagConstraints();
         constraints.gridx = 0;
         constraints.gridy = 0;
         constraints.weightx = 1;
         constraints.fill = GridBagConstraints.HORIZONTAL;
         constraints.anchor = GridBagConstraints.NORTHWEST;
-        constraints.insets = new Insets(0, 0, 18, 0);
+        constraints.insets = new Insets(0, 0, StudioTheme.scale(12), 0);
+        status.add(label(text(DesktopUiMessages.PREGEN_TITLE), StudioTheme.titleFont(), TEXT), constraints);
+        constraints.gridy++;
+        status.add(phaseLabel, constraints);
+        constraints.gridy++;
+        JPanel progress = panel(new BorderLayout(0, StudioTheme.scale(8)), SURFACE);
+        progress.add(percentLabel, BorderLayout.NORTH);
+        progressBar.setForeground(ACCENT);
+        progressBar.setBackground(BACKGROUND);
+        progressBar.setBorderPainted(false);
+        progressBar.setPreferredSize(StudioTheme.scaledSize(1, 4));
+        progressBar.setFocusable(false);
+        progress.add(progressBar, BorderLayout.CENTER);
+        progress.add(countLabel, BorderLayout.SOUTH);
+        status.add(progress, constraints);
+        constraints.gridy++;
         status.add(failureLabel, constraints);
         constraints.gridy++;
-        currentValue.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 25));
+        status.add(metricRow(DesktopUiMessages.PREGEN_CURRENT, currentValue), constraints);
-        etaValue.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 23));
-        status.add(metric(DesktopUiMessages.PREGEN_CURRENT, currentValue), constraints);
         constraints.gridy++;
-        status.add(metric(DesktopUiMessages.PREGEN_ETA, etaValue), constraints);
+        status.add(metricRow(DesktopUiMessages.PREGEN_ETA, etaValue), constraints);
         constraints.gridy++;
-        constraints.insets = new Insets(0, 0, 10, 0);
         status.add(metricRow(DesktopUiMessages.PREGEN_OVERALL, overallValue), constraints);
         constraints.gridy++;
         status.add(metricRow(DesktopUiMessages.PREGEN_THIRTY, thirtyValue), constraints);
@@ -247,47 +273,26 @@ public final class PregenRenderer extends JPanel {
         constraints.gridy++;
         status.add(methodLabel, constraints);
         constraints.gridy++;
+        status.add(legend(), constraints);
+        constraints.gridy++;
+        status.add(wrappedText(text(DesktopUiMessages.PREGEN_BOUNDS,
+                MessageArgument.trusted("minX", Form.f(bounds.minX())),
+                MessageArgument.trusted("maxX", Form.f(bounds.maxX())),
+                MessageArgument.trusted("minZ", Form.f(bounds.minZ())),
+                MessageArgument.trusted("maxZ", Form.f(bounds.maxZ()))), StudioTheme.smallFont(), MUTED, SURFACE), constraints);
+        constraints.gridy++;
+        status.add(wrappedText(text(DesktopUiMessages.PREGEN_WINDOW_HINT), StudioTheme.smallFont(), MUTED, SURFACE), constraints);
+        constraints.gridy++;
         constraints.weighty = 1;
         status.add(panel(new BorderLayout(), SURFACE), constraints);
-        JScrollPane scroll = new JScrollPane(status);
+        JScrollPane scroll = StudioToolbar.scroll(status);
-        scroll.setBorder(BorderFactory.createLineBorder(BORDER));
         scroll.getViewport().setBackground(SURFACE);
-        scroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
-        scroll.setPreferredSize(new Dimension(276, 1));
-        scroll.setMinimumSize(new Dimension(260, 0));
-        scroll.getVerticalScrollBar().setUnitIncrement(16);
-        scroll.getVerticalScrollBar().setUI(new BasicScrollBarUI() {
-            @Override
-            protected void configureScrollBarColors() {
-                thumbColor = BORDER;
-                thumbDarkShadowColor = BORDER;
-                thumbHighlightColor = BORDER;
-                thumbLightShadowColor = BORDER;
-                trackColor = FIELD;
-            }
-
-            @Override
-            protected JButton createDecreaseButton(int orientation) {
-                return scrollEnd();
-            }
-
-            @Override
-            protected JButton createIncreaseButton(int orientation) {
-                return scrollEnd();
-            }
-
-            private JButton scrollEnd() {
-                JButton button = new JButton();
-                button.setPreferredSize(new Dimension(0, 0));
-                button.setFocusable(false);
-                return button;
-            }
-        });
         return scroll;
     }
 
     private JPanel legend() {
-        JPanel legend = panel(new GridLayout(0, 2, 12, 7), BACKGROUND);
+        JPanel legend = panel(new GridLayout(0, 2, StudioTheme.scale(12), StudioTheme.scale(7)), SURFACE);
+        legend.setBorder(StudioTheme.emptyBorder(8, 0, 4, 0));
         legend.add(legendItem(DesktopUiMessages.PREGEN_WAITING, PregenMapState.WAITING));
         legend.add(legendItem(DesktopUiMessages.PREGEN_GENERATING, GENERATING));
         legend.add(legendItem(DesktopUiMessages.PREGEN_READY, GENERATED));
@@ -298,64 +303,27 @@ public final class PregenRenderer extends JPanel {
     }
 
     private JPanel legendItem(TextKey key, Color color) {
-        JPanel item = panel(new BorderLayout(7, 0), BACKGROUND);
+        JPanel item = panel(new BorderLayout(StudioTheme.scale(7), 0), SURFACE);
         JPanel swatch = panel(new BorderLayout(), color);
-        swatch.setPreferredSize(new Dimension(10, 10));
+        swatch.setPreferredSize(StudioTheme.scaledSize(10, 10));
         swatch.setBorder(BorderFactory.createLineBorder(BORDER));
-        JPanel marker = panel(new BorderLayout(), BACKGROUND);
+        JPanel marker = panel(new BorderLayout(), SURFACE);
         marker.add(swatch, BorderLayout.NORTH);
         item.add(marker, BorderLayout.WEST);
-        item.add(wrappedText(text(key), LABEL_FONT, MUTED, BACKGROUND), BorderLayout.CENTER);
+        item.add(wrappedText(text(key), StudioTheme.smallFont(), MUTED, SURFACE), BorderLayout.CENTER);
         return item;
     }
 
-    private JPanel metric(TextKey title, JLabel value) {
-        JPanel metric = panel(new BorderLayout(0, 5), SURFACE);
-        metric.add(wrappedText(text(title), LABEL_FONT, MUTED, SURFACE), BorderLayout.NORTH);
-        metric.add(value, BorderLayout.CENTER);
-        return metric;
-    }
-
     private JPanel metricRow(TextKey title, JLabel value) {
-        JPanel row = panel(new BorderLayout(8, 0), SURFACE);
+        JPanel row = panel(new BorderLayout(StudioTheme.scale(8), 0), SURFACE);
-        value.setFont(BODY_FONT);
+        row.add(wrappedText(text(title), StudioTheme.smallFont(), MUTED, SURFACE), BorderLayout.CENTER);
-        row.add(wrappedText(text(title), LABEL_FONT, MUTED, SURFACE), BorderLayout.CENTER);
         row.add(value, BorderLayout.EAST);
         return row;
     }
 
-    private void installPauseControl() {
+    private void installControls() {
-        pauseButton.setUI(new BasicButtonUI() {
+        pauseButton.setFocusable(true);
-            @Override
-            protected void paintText(Graphics graphics, AbstractButton button, Rectangle bounds, String text) {
-                if (button.isEnabled()) {
-                    super.paintText(graphics, button, bounds, text);
-                    return;
-                }
-                graphics.setColor(MUTED);
-                BasicGraphicsUtils.drawStringUnderlineCharAt(graphics, text, button.getDisplayedMnemonicIndex(),
-                        bounds.x, bounds.y + graphics.getFontMetrics().getAscent());
-            }
-        });
-        pauseButton.setBackground(FIELD);
-        pauseButton.setForeground(TEXT);
-        pauseButton.setFont(BODY_FONT);
         pauseButton.putClientProperty("html.disable", Boolean.TRUE);
-        pauseButton.setFocusPainted(false);
-        pauseButton.setPreferredSize(new Dimension(108, 46));
-        setPauseBorder(false);
-        pauseButton.addFocusListener(new FocusAdapter() {
-            @Override
-            public void focusGained(FocusEvent event) {
-                setPauseBorder(true);
-            }
-
-            @Override
-            public void focusLost(FocusEvent event) {
-                setPauseBorder(false);
-            }
-        });
-        pauseButton.addActionListener(event -> togglePause());
         pauseButton.getInputMap(JComponent.WHEN_FOCUSED).put(
                 KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0), "activatePause");
         pauseButton.getActionMap().put("activatePause", new AbstractAction() {
@@ -364,19 +332,39 @@ public final class PregenRenderer extends JPanel {
                 pauseButton.doClick();
             }
         });
-        getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_P, 0, true), "pause");
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_P, 0, true), "pause", this::togglePause);
-        getActionMap().put("pause", new AbstractAction() {
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_R, 0), "reset-view", map::resetView);
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_BACK_SLASH, 0), "reset-zoom", map::resetView);
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_EQUALS, 0), "zoom-in", map::zoomIn);
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_EQUALS, KeyEvent.SHIFT_DOWN_MASK), "zoom-in-plus", map::zoomIn);
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_ADD, 0), "zoom-in-keypad", map::zoomIn);
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_MINUS, 0), "zoom-out", map::zoomOut);
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_SUBTRACT, 0), "zoom-out-keypad", map::zoomOut);
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_G, 0), "grid", this::toggleGrid);
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0), "pan-left", () -> map.panBy(64, 0));
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0), "pan-right", () -> map.panBy(-64, 0));
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0), "pan-up", () -> map.panBy(0, 64));
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0), "pan-down", () -> map.panBy(0, -64));
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_SLASH, 0), "help", map::toggleHelp);
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_SLASH, KeyEvent.SHIFT_DOWN_MASK), "help-question", map::toggleHelp);
+        bind(KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), "dismiss", map::dismissHelp);
+    }
+
+    private void bind(KeyStroke key, String name, Runnable action) {
+        getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(key, name);
+        getActionMap().put(name, new AbstractAction() {
             @Override
             public void actionPerformed(ActionEvent event) {
-                togglePause();
+                if (!(KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner() instanceof JTextComponent)) {
+                    action.run();
+                }
             }
         });
     }
 
-    private void setPauseBorder(boolean focused) {
+    private void toggleGrid() {
-        pauseButton.setBorder(BorderFactory.createCompoundBorder(
+        map.toggleGrid();
-                BorderFactory.createLineBorder(focused ? ACCENT : BORDER, 2),
+        gridToggle.setSelected(map.isGridVisible());
-                BorderFactory.createEmptyBorder(8, 14, 8, 14)));
     }
 
     private void togglePause() {
@@ -512,7 +500,10 @@ public final class PregenRenderer extends JPanel {
     }
 
     private static JTextArea wrappedText(String text, Font font, Color foreground, Color background) {
-        JTextArea area = new JTextArea(text);
+        JTextArea area = new JTextArea();
+        DefaultCaret caret = (DefaultCaret) area.getCaret();
+        caret.setUpdatePolicy(DefaultCaret.NEVER_UPDATE);
+        area.setText(text);
         area.setEditable(false);
         area.setFocusable(false);
         area.setLineWrap(true);

core/src/main/java/art/arcane/iris/world/history/GenerationRegistryContractFactory.java

@@ -158,13 +158,6 @@ public final class GenerationRegistryContractFactory {
         CustomBiomeAliasPolicy requiredAliasPolicy = Objects.requireNonNull(aliasPolicy, "aliasPolicy");
         requireRuntimeIdentity(requiredGenerationRegistry);
         Path packRoot = requiredData.getDataFolder().toPath().toAbsolutePath().normalize();
-        String actualPackFingerprint = GenerationPackFingerprint.compute(
-                packRoot,
-                GenerationPackFingerprint.CURRENT_VERSION
-        );
-        if (!requiredPackFingerprint.equals(actualPackFingerprint)) {
-            throw new IOException("Iris generation registry capture rejected a changed pack.");
-        }
 
         Map<GenerationRegistryContract.PhysicalResourceKey, PlatformGenerationRegistry.Definition> definitions =
                 new LinkedHashMap<>();
@@ -221,7 +214,15 @@ public final class GenerationRegistryContractFactory {
         ReferencedPlatformKeys referenced = referencedPlatformKeys(packRoot, requiredRegistries);
         addPlatformDefinitions(definitions, BLOCK_REGISTRY, referenced.blockKeys(), requiredGenerationRegistry);
         addPlatformDefinitions(definitions, ENTITY_TYPE_REGISTRY, referenced.entityKeys(), requiredGenerationRegistry);
-        return contract(definitions, generatedSources, requiredGenerationRegistry).withBiomeTags(biomeTags);
+        GenerationRegistryContract captured = contract(definitions, generatedSources, requiredGenerationRegistry).withBiomeTags(biomeTags);
+        String actualPackFingerprint = GenerationPackFingerprint.compute(
+                packRoot,
+                GenerationPackFingerprint.CURRENT_VERSION
+        );
+        if (!requiredPackFingerprint.equals(actualPackFingerprint)) {
+            throw new IOException("Iris generation registry capture rejected a changed pack.");
+        }
+        return captured;
     }
 
     public static CustomBiomeDefinition customBiomeDefinition(

core/src/main/resources/languages/de_DE.toml

@@ -1937,6 +1937,17 @@ ready = "Bereit"
 existing = "Vorhanden"
 network = "Netzwerk"
 terrain_hint = "Fertige Chunks zeigen Geländefarben"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/es_ES.toml

@@ -1937,6 +1937,17 @@ ready = "Listo"
 existing = "Existente"
 network = "Red"
 terrain_hint = "Los chunks terminados muestran los colores del terreno"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/fi_FI.toml

@@ -1942,6 +1942,17 @@ ready = "Valmis"
 existing = "Olemassa"
 network = "Verkko"
 terrain_hint = "Valmiit lohkot näyttävät maaston värit"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/fr_FR.toml

@@ -1937,6 +1937,17 @@ ready = "Prêt"
 existing = "Existant"
 network = "Réseau"
 terrain_hint = "Les chunks terminés affichent les couleurs du terrain"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/he_IL.toml

@@ -1942,6 +1942,17 @@ ready = "מוכן"
 existing = "קיים"
 network = "רשת"
 terrain_hint = "צ׳אנקים שהושלמו מציגים את צבעי השטח"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/it_IT.toml

@@ -1937,6 +1937,17 @@ ready = "Pronto"
 existing = "Esistente"
 network = "Rete"
 terrain_hint = "I chunk completati mostrano i colori del terreno"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/ja-JP.toml

@@ -1940,6 +1940,17 @@ ready = "準備完了"
 existing = "既存"
 network = "ネットワーク"
 terrain_hint = "完了したチャンクは地形の色で表示されます"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/ko_KR.toml

@@ -1940,6 +1940,17 @@ ready = "준비됨"
 existing = "기존"
 network = "네트워크"
 terrain_hint = "완료된 청크는 지형 색상으로 표시됩니다"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/lt_LT.toml

@@ -1942,6 +1942,17 @@ ready = "Paruošta"
 existing = "Esamos"
 network = "Tinklas"
 terrain_hint = "Baigtos sritys rodo reljefo spalvas"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/nl_NL.toml

@@ -1937,6 +1937,17 @@ ready = "Gereed"
 existing = "Bestaand"
 network = "Netwerk"
 terrain_hint = "Voltooide chunks tonen terreinkleuren"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/pl_PL.toml

@@ -1942,6 +1942,17 @@ ready = "Gotowe"
 existing = "Istniejące"
 network = "Sieć"
 terrain_hint = "Gotowe chunki pokazują kolory terenu"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/pt_PT.toml

@@ -1937,6 +1937,17 @@ ready = "Pronto"
 existing = "Existente"
 network = "Rede"
 terrain_hint = "Os chunks concluídos mostram as cores do terreno"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/ru_RU.toml

@@ -1942,6 +1942,17 @@ ready = "Готово"
 existing = "Существующие"
 network = "Сеть"
 terrain_hint = "Готовые чанки отображают цвета ландшафта"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/tr_TR.toml

@@ -1942,6 +1942,17 @@ ready = "Hazır"
 existing = "Mevcut"
 network = "Ağ"
 terrain_hint = "Tamamlanan chunklar arazi renklerini gösterir"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/vi_VI.toml

@@ -1940,6 +1940,17 @@ ready = "Sẵn sàng"
 existing = "Có sẵn"
 network = "Mạng"
 terrain_hint = "Chunk hoàn tất hiển thị màu địa hình"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/zh_CN.toml

@@ -1940,6 +1940,17 @@ ready = "就绪"
 existing = "已有"
 network = "网络"
 terrain_hint = "已完成的区块显示地形颜色"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/main/resources/languages/zh_TW.toml

@@ -1940,6 +1940,17 @@ ready = "就緒"
 existing = "既有"
 network = "網路"
 terrain_hint = "已完成的區塊顯示地形顏色"
+grid = "Grid"
+grid_hint = "Show chunk and region borders (G)"
+fit = "Reset view"
+fit_hint = "Fit the whole generation area (R)"
+zoom_in = "Zoom in (+)"
+zoom_out = "Zoom out (-)"
+zoom = "Zoom {zoom}"
+shortcuts = "Shortcuts"
+shortcuts_hint = "Show mouse and key shortcuts (/)"
+navigation_hint = "Drag to pan · Scroll to zoom · Hover to inspect chunks"
+shortcut_details = "Drag or arrow keys: pan\nScroll or + / -: zoom\nR or \\: fit generation area\nG: chunk and region grid\nP: pause or resume generation\n/ or Escape: close shortcuts"
 
 [iris.runtime.what]
 material = "Material: {material}"

core/src/test/java/art/arcane/iris/generation/hydrology/engine/HydrologyRuntimeTest.java

@@ -53,6 +53,7 @@ import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.AbstractExecutorService;
 import java.util.concurrent.CancellationException;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
@@ -79,8 +80,10 @@ import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.argThat;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.clearInvocations;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoInteractions;
@@ -296,6 +299,31 @@ public class HydrologyRuntimeTest {
         }
     }
 
+    @Test(timeout = 180_000L)
+    public void chunksSharePrefetchAndRetryAfterEvictionOrFailure() {
+        FakePlanners planners = new FakePlanners(settings());
+        HydrologyPlanCache cache = spy(new HydrologyPlanCache(planners.settings, planners::region, planners::window,
+                pool(planners, 2), () -> false));
+        AtomicInteger prefetches = new AtomicInteger();
+        doAnswer(invocation -> prefetches.incrementAndGet() == 2
+                ? CompletableFuture.failedFuture(new IllegalStateException("prefetch failed")) : CompletableFuture.completedFuture(null))
+                .when(cache).prepareWindowsAround(anyInt(), anyInt(), anyInt(), anyInt(), anyInt());
+        AtomicLong evictions = new AtomicLong();
+        doAnswer(invocation -> evictions.get()).when(cache).windowEvictions();
+        HydrologyRuntime runtime = new HydrologyRuntime(planners.settings, cache, planners::natural, () -> false, planners.ticker::get);
+        runtimes.add(runtime);
+        runtime.raster(0, 0);
+        runtime.raster(1, 0);
+        assertEquals(1, prefetches.get());
+        evictions.incrementAndGet();
+        runtime.raster(2, 0);
+        assertEquals(2, prefetches.get());
+        runtime.raster(3, 0);
+        assertEquals(3, prefetches.get());
+        runtime.raster(4, 0);
+        assertEquals(3, prefetches.get());
+    }
+
     @Test(timeout = 180_000L)
     public void preparePregenerationPlansRegionsInOrder() throws Exception {
         FakePlanners planners = new FakePlanners(settings());
@@ -702,6 +730,44 @@ public class HydrologyRuntimeTest {
         verify(engine, never()).getComplex();
     }
 
+    @Test
+    public void zeroDensitySkipsRuntimePlanningAfterValidatingSettings() {
+        Engine engine = mock(Engine.class);
+        IrisComplex complex = mock(IrisComplex.class);
+        IrisDimension dimension = new IrisDimension();
+        dimension.setHydrology(new IrisHydrology().setEnabled(true).setDensity(0D));
+        when(engine.getDimension()).thenReturn(dimension);
+        when(engine.getSeedManager()).thenReturn(new SeedManager(1337L));
+        when(engine.getHeight()).thenReturn(384);
+
+        assertDisabled(HydrologyRuntime.create(engine, complex));
+        verifyNoInteractions(complex);
+        verify(engine, never()).getPlatformHooks();
+
+        dimension.getHydrology().setDensity(-1D);
+        assertThrows(IllegalArgumentException.class, () -> HydrologyRuntime.create(engine, complex));
+    }
+
+    @Test(timeout = 15_000L)
+    public void nestedPreviewScopesStayNonblockingAndRestoreDemandSampling() throws Exception {
+        try (FakeHydrology water = new FakeHydrology(() -> false, (x, z) -> 60, 40, 63)) {
+            HydrologyRuntime runtime = spy(water.runtime);
+            water.hold();
+            try (HydrologyRuntime.PreviewScope outer = runtime.preview()) {
+                assertTrue(runtime.raster(0, 0).provisional());
+                try (HydrologyRuntime.PreviewScope inner = runtime.preview()) {
+                    assertTrue(runtime.raster(1, 0).provisional());
+                }
+                assertTrue(runtime.raster(0, 1).provisional());
+            }
+            water.release();
+            clearInvocations(runtime);
+
+            assertFalse(runtime.raster(400, 400).provisional());
+            verify(runtime, never()).rasterPreview(anyInt(), anyInt());
+        }
+    }
+
     @Test(timeout = 300_000L)
     public void createSavesPlansUnderTheWorldFolder() throws Exception {
         Path worldFolder = temporaryFolder.newFolder("world").toPath();

core/src/test/java/art/arcane/iris/generation/hydrology/grid/HeightLatticeTest.java

@@ -4,6 +4,7 @@ import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Random;
 import java.util.Set;
@@ -32,6 +33,35 @@ public class HeightLatticeTest {
     private static final int AREA = 3 * WINDOW;
     private static final int DISTINCT_ACROSS_NINE = 25 * WINDOW * WINDOW;
 
+    @Test
+    public void neighbouringCellsSpreadAcrossConcurrentMapBuckets() {
+        int[] buckets = new int[65_536];
+        int occupied = 0;
+        int largest = 0;
+        Set<Long> identities = new HashSet<>();
+        for (int z = -96; z < 96; z++) {
+            for (int x = -96; x < 96; x++) {
+                long key = HeightLattice.key(x, z);
+                assertTrue(identities.add(key));
+                int hash = Long.hashCode(key);
+                int bucket = (hash ^ (hash >>> 16)) & (buckets.length - 1);
+                if (buckets[bucket]++ == 0) {
+                    occupied++;
+                }
+                largest = Math.max(largest, buckets[bucket]);
+            }
+        }
+        assertTrue("occupied buckets " + occupied, occupied > 25_000);
+        assertTrue("largest collision chain " + largest, largest < 12);
+        identities.clear();
+        int[] extremes = {Integer.MIN_VALUE, Integer.MIN_VALUE + 1, -1, 0, 1, Integer.MAX_VALUE - 1, Integer.MAX_VALUE};
+        for (int x : extremes) {
+            for (int z : extremes) {
+                assertTrue("distinct coordinate " + x + "," + z, identities.add(HeightLattice.key(x, z)));
+            }
+        }
+    }
+
     @Test
     public void samplesEachCellOnceAcrossNineOverlappingWindows() {
         CountingSource source = new CountingSource();

core/src/test/java/art/arcane/iris/generation/hydrology/plan/HydrologyPlanCacheTest.java

@@ -317,6 +317,41 @@ public class HydrologyPlanCacheTest {
         assertEquals(26, planners.windowCalls.size());
     }
 
+    @Test
+    public void speculativePlanningLeavesWorkersForNewAndPromotedDemand() throws Exception {
+        for (int threads : List.of(2, 4)) {
+            FakePlanners planners = new FakePlanners(unpersisted());
+            Gate gate = new Gate();
+            planners.hook = key -> {
+                if (key instanceof RegionKey region && Math.abs(region.rx()) < 10 && Math.abs(region.rz()) < 10) {
+                    gate.pass();
+                }
+            };
+            ExecutorService workers = pool(threads);
+            HydrologyPlanCache cache = cache(planners, workers, () -> false);
+            CompletableFuture<Void> prepared = cache.prepareWindowsAround(0, 0, 31, 31, 2);
+            try {
+                await(() -> gate.arrivals() >= threads / 2, "speculative planning reaches its concurrency limit");
+                WindowKey demanded = new WindowKey(400, 400);
+                assertEquals(demanded, cache.demandWindow(demanded).get(5L, TimeUnit.SECONDS).plan().key());
+                assertEquals("prefetch leaves workers available for demand", threads / 2, gate.arrivals());
+
+                WindowKey promoted = new WindowKey(800, 800);
+                CompletableFuture<IndexedWindow> prefetched = cache.prefetchWindow(promoted);
+                workers.submit(() -> null).get(5L, TimeUnit.SECONDS);
+                assertFalse("the prefetch waits for speculative capacity", prefetched.isDone());
+                IndexedWindow ready = cache.demandWindow(promoted).get(5L, TimeUnit.SECONDS);
+                assertEquals(promoted, ready.plan().key());
+                assertSame("demand promotes the queued prefetch", ready, prefetched.get(5L, TimeUnit.SECONDS));
+                assertEquals(threads / 2, gate.arrivals());
+            } finally {
+                gate.release();
+            }
+            prepared.get(TIMEOUT_SECONDS, TimeUnit.SECONDS);
+            assertEquals("all prepared windows finish after demand", 27, planners.windowCalls.size());
+        }
+    }
+
     @Test
     public void plansWithRealPlannersAndReloadsFromStore() throws Exception {
         HydrologySettings settings = settings(new IrisHydrology());
@@ -412,13 +447,14 @@ public class HydrologyPlanCacheTest {
     }
 
     @Test
-    public void leastRecentlyUsedWindowIsEvicted() {
+    public void leastRecentlyUsedWindowIsEvicted() throws Exception {
         FakePlanners planners = new FakePlanners(unpersisted());
         HydrologyPlanCache cache = cache(planners, pool(4), () -> false);
         WindowKey kept = new WindowKey(0, 0);
         WindowKey stale = new WindowKey(1, 0);
         IndexedWindow keptWindow = cache.window(kept);
         cache.window(stale);
+        assertEquals(0L, cache.windowEvictions());
         List<WindowKey> requested = new ArrayList<>(List.of(kept, stale));
         for (int index = 0; index < 300; index++) {
             WindowKey key = new WindowKey(index, 7);
@@ -435,8 +471,13 @@ public class HydrologyPlanCacheTest {
             }
         }
         assertTrue("the cache stays bounded: " + ready, ready < requested.size() / 2);
+        await(() -> cache.windowEvictions() == requested.size() - 128, "all excess windows are evicted");
+        long evictions = cache.windowEvictions();
+        assertSame(keptWindow, cache.window(kept));
+        assertEquals("a resident cache hit does not evict a window", evictions, cache.windowEvictions());
         cache.window(stale);
         assertEquals("an evicted window is planned again on demand", 2, planners.windowCalls(stale));
+        await(() -> cache.windowEvictions() == evictions + 1, "replanning an evicted window advances the eviction count");
     }
 
     @Test

core/src/test/java/art/arcane/iris/generation/hydrology/plan/HydrologySettingsTest.java

@@ -30,7 +30,20 @@ public class HydrologySettingsTest {
     private static final int SEA_LEVEL = 62;
     private static final int MIN_Y = -64;
     private static final int MAX_Y = 320;
-    private static final long DEFAULT_FINGERPRINT = 3973071586549334460L;
+    private static final long DEFAULT_FINGERPRINT = 8818472145657699942L;
+
+    @Test
+    public void densityIsBoundedAndChangesThePlanIdentity() {
+        HydrologySettings full = compile(new IrisHydrology());
+        HydrologySettings half = compile(new IrisHydrology().setDensity(0.5D));
+        assertEquals(1f, full.density(), 0f);
+        assertEquals(0.5f, half.density(), 0f);
+        assertTrue(full.fingerprint() != half.fingerprint());
+        assertEquals(full.tiers(), half.tiers());
+        for (double invalid : new double[]{-0.01D, 1.01D, Double.NaN, Double.POSITIVE_INFINITY}) {
+            assertRejected(new IrisHydrology().setDensity(invalid), "density");
+        }
+    }
 
     @Rule
     public final TemporaryFolder temporary = new TemporaryFolder();

core/src/test/java/art/arcane/iris/generation/hydrology/plan/RegionPlannerTest.java

@@ -34,6 +34,14 @@ public class RegionPlannerTest {
     private static final RegionKey ORIGIN = new RegionKey(0, 0);
     private static final RegionKey EAST = new RegionKey(1, 0);
 
+    @Test
+    public void zeroDensityRemovesMajorChannelsAndLakes() {
+        HydrologySettings settings = HydrologySettings.compile(new IrisHydrology().setDensity(0D), SEED, SEA_LEVEL,
+                SyntheticTerrain.MIN_Y, SyntheticTerrain.MAX_Y);
+        assertTrue(planner(settings, SyntheticTerrain.coneIsland(2048D, 2048D, 1700D, 240D, 6)).plan(ORIGIN).majorReaches().isEmpty());
+        assertTrue(planner(settings, SyntheticTerrain.crater(2048D, 2048D, 150, 700D)).plan(ORIGIN).lakes().isEmpty());
+    }
+
     @Test
     public void coneIslandMajorReachesEndInOcean() {
         HydrologySettings settings = settings();

core/src/test/java/art/arcane/iris/generation/hydrology/plan/WindowPlannerTest.java

@@ -41,6 +41,14 @@ public class WindowPlannerTest {
     private static final WindowKey LAND = new WindowKey(4, 4);
     private static final int SEAM_DISTANCE = 256;
 
+    @Test
+    public void zeroDensityRemovesLocalChannelsAndPonds() {
+        HydrologySettings settings = settings(new IrisHydrology().setDensity(0D));
+        WindowPlan plan = planner(settings, SyntheticTerrain.trunkValley()).plan(LAND, noRegions(LAND));
+        assertTrue(plan.reaches().isEmpty());
+        assertTrue(plan.ponds().isEmpty());
+    }
+
     @Test
     public void burnedTrunkCapturesLocalDrainage() {
         HydrologySettings settings = settings(new IrisHydrology());

core/src/test/java/art/arcane/iris/generation/hydrology/underground/CavePoolFillerTest.java

@@ -28,12 +28,51 @@ import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.when;
 
 public class CavePoolFillerTest {
     private static final long SEED = 1337L;
     private static final int FLOOR = 50;
 
+    @Test
+    public void globalDensityThinsCandidateColumnsBeforeSamplingCaves() {
+        IrisHydrology config = new IrisHydrology().setDensity(0.5D);
+        config.getUnderground().getCavePools().setDensity(8D);
+        CavePoolFiller filler = new CavePoolFiller(HydrologySettings.compile(config, SEED, 63, 0, 384));
+        CarvedTerrain carved = mock(CarvedTerrain.class);
+        MantleWriter writer = mock(MantleWriter.class);
+        Set<Long> columns = new HashSet<>();
+        when(carved.surface(anyInt(), anyInt())).thenAnswer(invocation -> {
+            int x = invocation.getArgument(0);
+            int z = invocation.getArgument(1);
+            columns.add(key(x, 0, z));
+            return 0;
+        });
+        for (int chunkX = 0; chunkX < 1024; chunkX++) {
+            filler.fill(chunkX, 0, carved, writer, SEED);
+        }
+        assertTrue("half density samples approximately half the candidate columns", columns.size() > 3600 && columns.size() < 4500);
+        Set<Long> repeated = new HashSet<>(columns);
+        columns.clear();
+        for (int chunkX = 1023; chunkX >= 0; chunkX--) {
+            filler.fill(chunkX, 0, carved, writer, SEED);
+        }
+        assertEquals(repeated, columns);
+        verifyNoInteractions(writer);
+    }
+
+    @Test
+    public void zeroGlobalDensityDoesNotReadCaves() {
+        IrisHydrology config = new IrisHydrology().setDensity(0D);
+        config.getUnderground().getCavePools().setDensity(8D);
+        CavePoolFiller filler = new CavePoolFiller(HydrologySettings.compile(config, SEED, 63, 0, 384));
+        CarvedTerrain carved = mock(CarvedTerrain.class);
+        MantleWriter writer = mock(MantleWriter.class);
+        filler.fill(0, 0, carved, writer, SEED);
+        verifyNoInteractions(carved, writer);
+    }
+
     @Test
     public void poolLevelIsHighestContainedLevelMinusFreeboard() {
         VoxelWorld world = roomWithSill();

core/src/test/java/art/arcane/iris/generation/hydrology/underground/SeaInletPlannerTest.java

@@ -21,6 +21,31 @@ import static org.junit.Assert.assertTrue;
 public class SeaInletPlannerTest {
     private static final int SEA = InletTerrain.SEA;
 
+    @Test
+    public void globalDensityThinsInletSitesWithoutChangingTheirGeometry() {
+        InletTerrain terrain = InletTerrain.cliff(30D);
+        IrisHydrology full = new IrisHydrology();
+        IrisHydrology half = new IrisHydrology().setDensity(0.5D);
+        full.getUnderground().getSeaInlets().setSpacing(256);
+        half.getUnderground().getSeaInlets().setSpacing(256);
+        int baseline = 0;
+        int retained = 0;
+        for (int offset = 0; offset < 32; offset++) {
+            InletTerrain shifted = terrain.shifted(0, offset * 512);
+            List<SeaInlet> all = shifted.plan(InletTerrain.settings(full));
+            List<SeaInlet> reduced = shifted.plan(InletTerrain.settings(half));
+            baseline += all.size();
+            retained += reduced.size();
+            for (SeaInlet inlet : reduced) {
+                assertTrue("retained inlets keep the same full passage", all.contains(inlet));
+            }
+            assertEquals(reduced, shifted.plan(InletTerrain.settings(half)));
+        }
+        assertTrue("cliff provides enough candidates", baseline >= 32);
+        assertTrue("half density retains approximately half the sites", retained > baseline * 0.3 && retained < baseline * 0.7);
+        assertTrue(terrain.plan(InletTerrain.settings(new IrisHydrology().setDensity(0D))).isEmpty());
+    }
+
     @Test
     public void inletStartsAtOceanCell() {
         InletTerrain terrain = InletTerrain.cliff(30D);

core/src/test/java/art/arcane/iris/generation/hydrology/water/PondPlannerTest.java

@@ -10,15 +10,24 @@ import art.arcane.iris.generation.hydrology.grid.HydrologySampleBuffer;
 import art.arcane.iris.generation.hydrology.grid.HydrologyTerrainSource;
 import art.arcane.iris.generation.hydrology.grid.PriorityFlood;
 import art.arcane.iris.generation.hydrology.plan.HydrologySettings;
+import art.arcane.iris.generation.hydrology.plan.IndexedWindow;
+import art.arcane.iris.generation.hydrology.plan.RegionKey;
+import art.arcane.iris.generation.hydrology.plan.RegionPlan;
 import art.arcane.iris.generation.hydrology.plan.WindowKey;
+import art.arcane.iris.generation.hydrology.plan.WindowPlan;
+import art.arcane.iris.generation.hydrology.raster.ChunkRasterizer;
+import art.arcane.iris.generation.hydrology.raster.ChunkWaterRaster;
+import art.arcane.iris.generation.hydrology.raster.ReachIndex;
 import art.arcane.volmlib.util.collection.KList;
 import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.BitSet;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.function.Consumer;
 import java.util.function.DoubleBinaryOperator;
@@ -38,6 +47,77 @@ public class PondPlannerTest {
     private static final float BOWL_SPILL = 112f;
     private static final WindowKey ORIGIN = new WindowKey(0, 0);
 
+    @Test
+    public void smallSeededPondFollowsItsBowlAtBlockResolution() {
+        HydrologySettings settings = settings(config -> {
+            seededOnly(config);
+            config.getPonds().getSeeded().setDensity(1D).setRadius(new KList<>(8, 8)).setDepth(new KList<>(6, 6))
+                    .setAlongChannels(false);
+            config.getPonds().setFreeboard(new KList<>(1, 1));
+            config.getPonds().getShore().setRoundness(0D);
+        }, MIN_Y, MAX_Y);
+        List<Pond> ponds = plan(settings, new Terrain((x, z) -> 100D, 1f, ALLOW_ALL, null, MIN_Y, MAX_Y),
+                0, 0, 64, 64, new BitSet(), List.of());
+        Pond pond = single(ponds);
+        PondMask mask = pond.mask();
+        assertEquals(1, mask.step());
+        int wet = 0;
+        int minX = Integer.MAX_VALUE;
+        int minZ = Integer.MAX_VALUE;
+        int maxX = Integer.MIN_VALUE;
+        int maxZ = Integer.MIN_VALUE;
+        for (int j = 0; j < mask.depth(); j++) {
+            for (int i = 0; i < mask.width(); i++) {
+                if (mask.node(i, j)) {
+                    wet++;
+                    minX = Math.min(minX, i);
+                    minZ = Math.min(minZ, j);
+                    maxX = Math.max(maxX, i);
+                    maxZ = Math.max(maxZ, j);
+                }
+            }
+        }
+        int rectangle = (maxX - minX + 1) * (maxZ - minZ + 1);
+        assertTrue("rounded bowl occupies " + wet + " of " + rectangle + " bounding blocks", wet < rectangle * 0.9D);
+        assertFalse(mask.node(minX, minZ));
+        assertFalse(mask.node(maxX, maxZ));
+        assertTrue(mask.contains(pond.floorX(), pond.floorZ()));
+    }
+
+    @Test
+    public void globalDensityHalvesSaturatedSeededSiteAcceptance() {
+        HydrologySettings full = settings(config -> {
+            seededOnly(config);
+            config.getPonds().getSeeded().setDensity(16D).setAlongChannels(false);
+        }, MIN_Y, MAX_Y);
+        HydrologySettings half = settings(config -> {
+            seededOnly(config);
+            config.setDensity(0.5D);
+            config.getPonds().getSeeded().setDensity(16D).setAlongChannels(false);
+        }, MIN_Y, MAX_Y);
+        Terrain terrain = new Terrain((x, z) -> 100D, 1f, ALLOW_ALL, null, MIN_Y, MAX_Y);
+        Set<Long> all = seededSites(full, terrain);
+        Set<Long> reduced = seededSites(half, terrain);
+        assertTrue("full candidates " + all.size(), all.size() >= 450);
+        assertTrue(all.containsAll(reduced));
+        double fraction = reduced.size() / (double) all.size();
+        assertTrue("retained fraction " + fraction, fraction > 0.44D && fraction < 0.56D);
+    }
+
+    private static Set<Long> seededSites(HydrologySettings settings, Terrain terrain) {
+        Set<Long> sites = new HashSet<>();
+        for (int window = 0; window < 32; window++) {
+            int x = window * WindowKey.SIZE;
+            Sampled sampled = sample(terrain, 8, x, 0, 64, 64);
+            Arrays.fill(sampled.samples().pondDensity(), 100f);
+            CupSet cups = new PondPlanner(settings).subtractCups(sampled.grid(), new WindowKey(window, 0), sampled.samples(), new BitSet());
+            for (CupSet.Cup cup : cups.within(x, 0, x + WindowKey.SIZE, WindowKey.SIZE)) {
+                sites.add(((long) cup.x() << 32) | (cup.z() & 0xFFFFFFFFL));
+            }
+        }
+        return sites;
+    }
+
     @Test
     public void naturalBasinPondSitsBelowSpill() {
         HydrologySettings settings = settings(PondPlannerTest::naturalOnly, MIN_Y, MAX_Y);
@@ -187,6 +267,7 @@ public class PondPlannerTest {
         assertTrue(pond.mask().contains(200, 256));
         assertTrue(pond.mask().contains(312, 256));
         assertContained(pond, terrain);
+        assertRasterRimContained(settings, pond, terrain);
     }
 
     @Test
@@ -527,6 +608,43 @@ public class PondPlannerTest {
         return new PondMask(x, 208, 16, 1, 7, new long[]{0b1111111L});
     }
 
+    private static void assertRasterRimContained(HydrologySettings settings, Pond pond, DoubleBinaryOperator natural) {
+        Map<Long, ChunkWaterRaster> rasters = new HashMap<>();
+        ChunkRasterizer rasterizer = new ChunkRasterizer(settings);
+        int raised = 0;
+        int[][] sides = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
+        for (int[] wet : wetNodes(pond.mask())) {
+            for (int[] side : sides) {
+                int x = wet[0] + side[0];
+                int z = wet[1] + side[1];
+                if (pond.mask().contains(x, z)) {
+                    continue;
+                }
+                long key = ((long) (x >> 4) << 32) | ((z >> 4) & 0xFFFFFFFFL);
+                ChunkWaterRaster raster = rasters.get(key);
+                if (raster == null) {
+                    WindowPlan window = new WindowPlan(WindowKey.containing(x, z), List.of(), List.of(pond), List.of());
+                    IndexedWindow indexed = new IndexedWindow(window, ReachIndex.build(List.of(), List.of(pond)));
+                    List<RegionPlan> regions = new ArrayList<>();
+                    for (RegionKey region : ChunkRasterizer.lakeRegions(x >> 4, z >> 4)) {
+                        regions.add(new RegionPlan(region, List.of(), List.of()));
+                    }
+                    raster = rasterizer.rasterize(x >> 4, z >> 4, (px, pz) -> (int) Math.round(natural.applyAsDouble(px, pz)),
+                            List.of(indexed), regions);
+                    rasters.put(key, raster);
+                }
+                int ground = (int) Math.round(natural.applyAsDouble(x, z));
+                int actual = raster.terrainHeight(x & 15, z & 15);
+                assertTrue("dry rim contains the water at " + x + "," + z, actual >= pond.level());
+                assertTrue("rim fill remains bounded at " + x + "," + z, actual <= ground + settings.deformation().maxFill());
+                if (actual > ground) {
+                    raised++;
+                }
+            }
+        }
+        assertTrue("sub-lattice rim needs real raster berms", raised > 0);
+    }
+
     private static Pond lake(PondMask mask) {
         return new Pond(42L, PondKind.LAKE, 110, 100, mask.originX(), mask.originZ(), 111f, mask, 0L, 0, "water", mask.originX(), mask.originZ());
     }
@@ -548,6 +666,7 @@ public class PondPlannerTest {
     private static void assertContained(Pond pond, DoubleBinaryOperator natural) {
         PondMask mask = pond.mask();
         int step = mask.step();
+        int maxFill = new IrisHydrology().getDeformation().getMaxFill();
         List<int[]> nodes = wetNodes(mask);
         assertFalse(nodes.isEmpty());
         assertTrue("floor " + pond.floor() + " level " + pond.level(), pond.floor() < pond.level());
@@ -557,8 +676,8 @@ public class PondPlannerTest {
                 int x = node[0] + direction[0];
                 int z = node[1] + direction[1];
                 if (!mask.contains(x, z)) {
-                    float edge = (float) natural.applyAsDouble(x, z);
+                    long edge = Math.round(natural.applyAsDouble(x, z));
-                    assertTrue("edge " + x + "," + z + " natural " + edge + " level " + pond.level(), edge >= pond.level());
+                    assertTrue("edge " + x + "," + z + " natural " + edge + " level " + pond.level(), edge + maxFill >= pond.level());
                 }
             }
         }

core/src/test/java/art/arcane/iris/generation/runtime/IrisComplexHeightStreamTest.java

@@ -23,6 +23,10 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.IrisLogging;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.studio.map.components.MapLayer;
+import art.arcane.iris.studio.map.components.MapTile;
+import art.arcane.iris.studio.map.components.MapTileRenderer;
+import art.arcane.iris.studio.map.components.TileType;
 import art.arcane.iris.structure.object.IObjectPlacer;
 import art.arcane.iris.testsupport.FakeHydrology;
 import art.arcane.iris.testsupport.PlatformLeakGuard;
@@ -44,12 +48,14 @@ import java.util.EnumSet;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.CancellationException;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
@@ -208,6 +214,35 @@ public class IrisComplexHeightStreamTest {
         }
     }
 
+    @Test(timeout = 15_000L)
+    public void mapHeightPreviewReturnsWhilePlanningAndRefreshesToFinalTerrain() throws Exception {
+        try (HydrologyFixture fixture = new HydrologyFixture(hydrologyPack())) {
+            fixture.hydrology.hold();
+            MapTileRenderer renderer = new MapTileRenderer(fixture.engine);
+            MapLayer layer = MapLayer.of(TileType.HEIGHT);
+            long before = ProvisionalSampling.revision();
+
+            MapTile preview = renderer.renderTile(0D, 0D, 1D, 16, layer, true, () -> false);
+
+            assertEquals(HydrologyFixture.NATURAL, preview.heightAt(8, 8), 0D);
+            assertNotEquals(before, ProvisionalSampling.revision());
+            fixture.hydrology.release();
+            long deadline = System.nanoTime() + TimeUnit.SECONDS.toNanos(10L);
+            MapTile settled;
+            do {
+                assertTrue("Map height preview never settled", System.nanoTime() < deadline);
+                Thread.sleep(10L);
+                before = ProvisionalSampling.revision();
+                settled = renderer.renderTile(0D, 0D, 1D, 16, layer, true, () -> false);
+            } while (before != ProvisionalSampling.revision());
+
+            double terrain = fixture.complex.getHeightStream().getDouble(8D, 8D);
+            assertNotEquals(HydrologyFixture.NATURAL, terrain, 0D);
+            assertEquals(terrain, settled.heightAt(8, 8), 0D);
+            assertEquals(before, ProvisionalSampling.revision());
+        }
+    }
+
     @Test(timeout = 120_000L)
     public void waterStreamsFollowTheRaster() throws Exception {
         try (HydrologyFixture fixture = new HydrologyFixture(hydrologyPack())) {

core/src/test/java/art/arcane/iris/pack/schema/SchemaBuilderIdentityTest.java

@@ -83,7 +83,7 @@ public class SchemaBuilderIdentityTest {
     @ClassRule
     public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
 
-    private static final String EXPECTED_SCHEMA_DIGEST = "dd1ea7f0361dfad24c4800e75f1e26e951b4f775aa1b541328724a8635afeeca";
+    private static final String EXPECTED_SCHEMA_DIGEST = "6935e8d3914e5cde852522151d87fe898f79de3b394826e544c5c5bfbfceba57";
 
     private static final List<Class<?>> SCHEMA_ROOTS = List.of(
             IrisDimension.class,

core/src/test/java/art/arcane/iris/studio/map/VisionRenderControllerTest.java

@@ -13,6 +13,8 @@ import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.BooleanSupplier;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
@@ -102,6 +104,42 @@ public class VisionRenderControllerTest {
         }
     }
 
+    @Test
+    public void zoomRetainsCompleteWaterTilesWhileDetailedTilesAreProvisional() throws Exception {
+        MapTileRenderer renderer = mock(MapTileRenderer.class);
+        MapTile overview = mock(MapTile.class);
+        MapTile incomplete = mock(MapTile.class);
+        when(renderer.renderTile(anyDouble(), anyDouble(), anyDouble(), anyInt(), any(), anyBoolean(), any()))
+                .thenAnswer(invocation -> {
+                    double scale = invocation.getArgument(2);
+                    if (scale < 4D) {
+                        ProvisionalSampling.mark();
+                        return incomplete;
+                    }
+                    return overview;
+                });
+        try (VisionRenderController controller = new VisionRenderController(() -> { })) {
+            VisionRenderController.Frame coarse = controller.request(new VisionRenderController.RenderSpec(renderer,
+                    MapLayer.of(TileType.RIVER), 1L, 128D, 128D, 4D, 64, 64, false));
+            await(() -> controller.progress(coarse).ready() == 1);
+
+            VisionRenderController.Frame fine = controller.request(spec(renderer, 1L));
+            await(() -> fine.tiles().getFirst().tile() != null);
+            VisionRenderController.VisibleTile visible = fine.tiles().getFirst();
+            assertTrue(visible.provisional());
+            assertEquals(0, controller.progress(fine).ready());
+            VisionRenderController.Fallback retained = controller.fallback(fine, visible);
+            assertNotNull(retained);
+            assertSame(overview, retained.pieces().getFirst().tile());
+            assertEquals(16, retained.pieces().getFirst().sourceSize());
+
+            VisionRenderController.Frame returned = controller.request(new VisionRenderController.RenderSpec(renderer,
+                    MapLayer.of(TileType.RIVER), 1L, 128D, 128D, 4D, 64, 64, false));
+            assertSame(overview, returned.tiles().getFirst().tile());
+            assertFalse(returned.tiles().getFirst().provisional());
+        }
+    }
+
     @Test
     public void closeRejectsLatePublication() throws Exception {
         MapTileRenderer renderer = mock(MapTileRenderer.class);

core/src/test/java/art/arcane/iris/studio/render/IrisRendererRiverTest.java

@@ -2,8 +2,10 @@ package art.arcane.iris.studio.render;
 
 import art.arcane.iris.generation.biome.IrisBiome;
 import art.arcane.iris.generation.hydrology.engine.HydrologyRuntime;
+import art.arcane.iris.generation.hydrology.engine.HydrologyPlanPreview;
 import art.arcane.iris.generation.hydrology.plan.HydrologySettings;
 import art.arcane.iris.generation.hydrology.query.HydrologyFeatureType;
+import art.arcane.iris.generation.hydrology.raster.ChunkWaterRaster;
 import art.arcane.iris.generation.hydrology.water.Pond;
 import art.arcane.iris.generation.hydrology.water.Reach;
 import art.arcane.iris.generation.runtime.Engine;
@@ -93,6 +95,34 @@ public class IrisRendererRiverTest {
         }
     }
 
+    @Test
+    public void zoomKeepsResidentWaterPlansUntilDetailedRastersAreReady() {
+        HydrologyRuntime runtime = mock(HydrologyRuntime.class);
+        Pond pond = WaterScene.pond(32L, 62, 16, 16, 10);
+        when(runtime.enabled()).thenReturn(true);
+        when(runtime.planPreview(anyInt(), anyInt(), anyInt(), anyInt()))
+                .thenReturn(new HydrologyPlanPreview(List.of(), List.of(pond), List.of(), List.of(), true));
+        when(runtime.rasterPreview(anyInt(), anyInt())).thenReturn(ChunkWaterRaster.PROVISIONAL);
+        IrisRenderer renderer = new IrisRenderer(engine(runtime));
+
+        BufferedImage overview = renderer.renderStudio(0D, 0D, 256D, 64, RenderType.RIVER, () -> false);
+        int water = IrisRenderer.hydrologyFeatureColor(HydrologyFeatureType.POND);
+        assertEquals(water, overview.getRGB(4, 4));
+
+        for (int step : new int[]{2, 1}) {
+            long before = ProvisionalSampling.revision();
+            BufferedImage detailed = renderer.renderStudio(0D, 0D, step * 64D, 64, RenderType.RIVER, () -> false);
+            assertEquals(water, detailed.getRGB(16 / step, 16 / step));
+            assertNotEquals(before, ProvisionalSampling.revision());
+        }
+
+        when(runtime.rasterPreview(anyInt(), anyInt())).thenReturn(ChunkWaterRaster.EMPTY);
+        long before = ProvisionalSampling.revision();
+        BufferedImage settled = renderer.renderStudio(0D, 0D, 64D, 64, RenderType.RIVER, () -> false);
+        assertEquals(NO_RIVER, settled.getRGB(16, 16));
+        assertEquals(before, ProvisionalSampling.revision());
+    }
+
     @Test
     public void channelPixelsShowTheirTier() throws Exception {
         HydrologySettings settings = FakeHydrology.settings(SEA_LEVEL);

core/src/test/java/art/arcane/iris/studio/view/PregenMapPanelTest.java

@@ -6,8 +6,10 @@ import org.junit.Test;
 
 import javax.swing.SwingUtilities;
 import java.awt.Color;
+import java.awt.Graphics2D;
 import java.awt.Rectangle;
 import java.awt.event.MouseEvent;
+import java.awt.event.MouseWheelEvent;
 import java.awt.image.BufferedImage;
 import java.lang.reflect.Field;
 
@@ -125,6 +127,82 @@ public class PregenMapPanelTest {
         SwingUtilities.invokeAndWait(extreme::disposeMap);
     }
 
+    @Test
+    public void wheelZoomPreservesTheChunkUnderThePointerAndRetainedPixels() throws Exception {
+        PregenMapPanel panel = panel(new PregenRenderSnapshot.Bounds(-32, -32, 31, 31));
+        SwingUtilities.invokeAndWait(() -> panel.setSize(802, 602));
+        panel.submit(-7, -19, Color.GREEN);
+        flush(panel);
+        BufferedImage retained = image(panel);
+        String before = tooltip(panel, 337, 123);
+        SwingUtilities.invokeAndWait(() -> panel.dispatchEvent(new MouseWheelEvent(panel,
+                MouseEvent.MOUSE_WHEEL, 1L, 0, 337, 123, 0, false,
+                MouseWheelEvent.WHEEL_UNIT_SCROLL, 3, -4)));
+        assertEquals(before, tooltip(panel, 337, 123));
+        assertTrue(panel.zoom() > 1D);
+        assertTrue(retained == image(panel));
+        assertEquals(Color.GREEN.getRGB(), image(panel).getRGB(25, 13));
+        SwingUtilities.invokeAndWait(panel::disposeMap);
+    }
+
+    @Test
+    public void draggingPansTheMapAndResetFitsBesideTheSidebar() throws Exception {
+        PregenMapPanel panel = panel(new PregenRenderSnapshot.Bounds(-32, -32, 31, 31));
+        SwingUtilities.invokeAndWait(() -> {
+            panel.setSize(1000, 600);
+            panel.setCoveredLeftWidth(300);
+        });
+        String initial = tooltip(panel, 650, 300);
+        assertNull(tooltip(panel, 250, 300));
+        SwingUtilities.invokeAndWait(() -> {
+            panel.dispatchEvent(new MouseEvent(panel, MouseEvent.MOUSE_PRESSED, 1L,
+                    MouseEvent.BUTTON1_DOWN_MASK, 650, 300, 1, false, MouseEvent.BUTTON1));
+            panel.dispatchEvent(new MouseEvent(panel, MouseEvent.MOUSE_DRAGGED, 2L,
+                    MouseEvent.BUTTON1_DOWN_MASK, 710, 350, 0, false, MouseEvent.NOBUTTON));
+            panel.dispatchEvent(new MouseEvent(panel, MouseEvent.MOUSE_RELEASED, 3L,
+                    0, 710, 350, 1, false, MouseEvent.BUTTON1));
+        });
+        assertEquals(initial, tooltip(panel, 710, 350));
+        assertFalse(initial.equals(tooltip(panel, 650, 300)));
+        SwingUtilities.invokeAndWait(() -> {
+            panel.zoomIn();
+            panel.resetView();
+        });
+        assertEquals(1D, panel.zoom(), 0D);
+        assertEquals(initial, tooltip(panel, 650, 300));
+        SwingUtilities.invokeAndWait(panel::disposeMap);
+    }
+
+    @Test
+    public void zoomBoundsAndGridPaintingHandleExtremeMapCoordinates() throws Exception {
+        PregenMapPanel panel = panel(new PregenRenderSnapshot.Bounds(
+                Integer.MIN_VALUE, Integer.MIN_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE));
+        SwingUtilities.invokeAndWait(() -> {
+            panel.setSize(820, 520);
+            panel.toggleGrid();
+            for (int index = 0; index < 100; index++) {
+                panel.zoomIn();
+            }
+            assertEquals(128D, panel.zoom(), 0D);
+            BufferedImage target = new BufferedImage(820, 520, BufferedImage.TYPE_INT_RGB);
+            Graphics2D canvas = target.createGraphics();
+            try {
+                panel.paint(canvas);
+                panel.panBy(1_000_000, -1_000_000);
+                panel.paint(canvas);
+                for (int index = 0; index < 100; index++) {
+                    panel.zoomOut();
+                }
+                assertEquals(0.25D, panel.zoom(), 0D);
+                panel.resetView();
+                panel.paint(canvas);
+            } finally {
+                canvas.dispose();
+                panel.disposeMap();
+            }
+        });
+    }
+
     private static String tooltip(PregenMapPanel panel, int x, int y) throws Exception {
         String[] result = new String[1];
         SwingUtilities.invokeAndWait(() -> result[0] = panel.getToolTipText(

core/src/test/java/art/arcane/iris/studio/view/PregenRendererTest.java

@@ -11,8 +11,12 @@ import javax.swing.JButton;
 import javax.swing.JComponent;
 import javax.swing.JLabel;
 import javax.swing.JTextArea;
+import javax.swing.JToggleButton;
+import javax.swing.JViewport;
 import javax.swing.KeyStroke;
 import javax.swing.SwingUtilities;
+import java.awt.Component;
+import java.awt.Container;
 import java.awt.event.ActionEvent;
 import java.awt.event.KeyEvent;
 import java.lang.reflect.Constructor;
@@ -27,6 +31,50 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mockStatic;
 
 public class PregenRendererTest {
+    @Test
+    public void smallWindowOpensAtTheProgressHeaderWithoutScrollingAway() throws Exception {
+        PregenRenderer[] result = new PregenRenderer[1];
+        onEdt(() -> {
+            result[0] = renderer(new Source(), () -> { });
+            result[0].setSize(820, 520);
+            layout(result[0]);
+        });
+        try {
+            onEdt(() -> layout(result[0]));
+            onEdt(() -> assertScrollAtTop(result[0]));
+        } finally {
+            onEdt(result[0]::close);
+        }
+    }
+
+    @Test
+    public void mapShortcutsZoomPanResetAndKeepGridControlSynchronized() throws Exception {
+        onEdt(() -> {
+            PregenRenderer renderer = renderer(new Source(), () -> { });
+            try {
+                PregenMapPanel map = field(renderer, "map", PregenMapPanel.class);
+                map.setSize(1000, 600);
+                map.setCoveredLeftWidth(300);
+                shortcut(renderer, KeyEvent.VK_EQUALS);
+                assertTrue(map.zoom() > 1D);
+                shortcut(renderer, KeyEvent.VK_LEFT);
+                shortcut(renderer, KeyEvent.VK_R);
+                assertEquals(1D, map.zoom(), 0D);
+                shortcut(renderer, KeyEvent.VK_G);
+                assertTrue(map.isGridVisible());
+                JToggleButton grid = field(renderer, "gridToggle", JToggleButton.class);
+                assertTrue(grid.isSelected());
+                grid.doClick(0);
+                assertFalse(map.isGridVisible());
+                assertFalse(grid.isSelected());
+                shortcut(renderer, KeyEvent.VK_SLASH);
+                shortcut(renderer, KeyEvent.VK_ESCAPE);
+            } finally {
+                renderer.close();
+            }
+        });
+    }
+
     @Test
     public void keyboardAndButtonActivationToggleExactlyOnceAndTerminalControlsAreDisabled() throws Exception {
         onEdt(() -> {
@@ -155,6 +203,32 @@ public class PregenRendererTest {
         refresh.invoke(renderer);
     }
 
+    private static void shortcut(PregenRenderer renderer, int keyCode) {
+        Object action = renderer.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW)
+                .get(KeyStroke.getKeyStroke(keyCode, 0));
+        renderer.getActionMap().get(action).actionPerformed(new ActionEvent(renderer, 0, "shortcut"));
+    }
+
+    private static void layout(Container container) {
+        container.doLayout();
+        for (Component component : container.getComponents()) {
+            if (component instanceof Container child) {
+                layout(child);
+            }
+        }
+    }
+
+    private static void assertScrollAtTop(Container container) {
+        for (Component component : container.getComponents()) {
+            if (component instanceof JViewport viewport) {
+                assertEquals(0, viewport.getViewPosition().y);
+            }
+            if (component instanceof Container child) {
+                assertScrollAtTop(child);
+            }
+        }
+    }
+
     private static <T> T field(PregenRenderer renderer, String name, Class<T> type) throws Exception {
         Field field = PregenRenderer.class.getDeclaredField(name);
         field.setAccessible(true);

core/src/test/java/art/arcane/iris/studio/workspace/IrisRiverSchemaTest.java

@@ -68,6 +68,11 @@ public class IrisRiverSchemaTest {
         JSONObject fluid = referencedProperties(definitions, properties.getJSONObject("fluids").getJSONObject("items"));
 
         assertEquals("boolean", properties.getJSONObject("enabled").getString("type"));
+        JSONObject density = properties.getJSONObject("density");
+        assertEquals("number", density.getString("type"));
+        assertEquals(0D, density.getDouble("minimum"), 0D);
+        assertEquals(1D, density.getDouble("maximum"), 0D);
+        assertTrue(density.getString("description").contains("Default Value is 1.0"));
         assertEquals("boolean", properties.getJSONObject("persist").getString("type"));
         assertEquals(0, properties.getJSONObject("prefetchRings").getInt("minimum"));
         assertEquals(4, properties.getJSONObject("prefetchRings").getInt("maximum"));

core/src/test/java/art/arcane/iris/world/history/GenerationRegistryContractFactoryTest.java

@@ -34,6 +34,8 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.FileTime;
 import java.util.Collection;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -895,7 +897,7 @@ public class GenerationRegistryContractFactoryTest {
     }
 
     @Test
-    public void rejectsAChangedPackBeforeCapture() throws Exception {
+    public void rejectsAPackChangedBeforeCapture() throws Exception {
         File pack = temporary.newFolder("changed-pack");
         String original = GenerationPackFingerprint.compute(
                 pack.toPath(),
@@ -904,20 +906,58 @@ public class GenerationRegistryContractFactoryTest {
         Files.writeString(pack.toPath().resolve("dimension.json"), "{}", StandardCharsets.UTF_8);
         IrisData data = mock(IrisData.class);
         when(data.getDataFolder()).thenReturn(pack);
+        IrisDimension dimension = spy(new IrisDimension());
+        dimension.setLoadKey("overworld");
+        stubDimensions(data, dimension);
+        doReturn(new KList<>()).when(dimension).getReachableBiomes(any());
+        doReturn(new KList<>()).when(dimension).getAllRegions(any());
+        PlatformRegistries registries = mock(PlatformRegistries.class);
+        when(registries.blockTypeKeys()).thenReturn(new KList<>());
+        when(registries.entityKeys()).thenReturn(new KList<>());
 
         assertThrows(
                 IOException.class,
                 () -> GenerationRegistryContractFactory.create(
                         data,
-                        new IrisDimension(),
+                        dimension,
                         original,
                         DataVersion.getLatest().get(),
-                        mock(PlatformRegistries.class),
+                        registries,
                         new FakeGenerationRegistry("runtime")
                 )
         );
     }
 
+    @Test
+    public void rejectsSameSizePackMutationDuringCaptureWithPreservedTimestamp() throws Exception {
+        File pack = temporary.newFolder("mutating-pack");
+        Path content = pack.toPath().resolve("content.json");
+        Files.writeString(content, "{\"version\":1}", StandardCharsets.UTF_8);
+        FileTime modified = Files.getLastModifiedTime(content);
+        String original = GenerationPackFingerprint.compute(pack.toPath(), GenerationPackFingerprint.CURRENT_VERSION);
+        IrisData data = mock(IrisData.class);
+        when(data.getDataFolder()).thenReturn(pack);
+        IrisDimension dimension = spy(new IrisDimension());
+        dimension.setLoadKey("overworld");
+        stubDimensions(data, dimension);
+        doReturn(new KList<>()).when(dimension).getReachableBiomes(any());
+        doReturn(new KList<>()).when(dimension).getAllRegions(any());
+        PlatformRegistries registries = mock(PlatformRegistries.class);
+        when(registries.blockTypeKeys()).thenAnswer(ignored -> {
+            Files.writeString(content, "{\"version\":2}", StandardCharsets.UTF_8);
+            Files.setLastModifiedTime(content, modified);
+            return new KList<>();
+        });
+        when(registries.entityKeys()).thenReturn(new KList<>());
+
+        IOException failure = assertThrows(IOException.class, () -> GenerationRegistryContractFactory.create(
+                data, dimension, original, DataVersion.getLatest().get(), registries, new FakeGenerationRegistry("runtime")));
+
+        assertEquals("Iris generation registry capture rejected a changed pack.", failure.getMessage());
+        assertEquals(modified, Files.getLastModifiedTime(content));
+        assertEquals("{\"version\":2}", Files.readString(content));
+    }
+
     @Test
     public void rejectsAnUnloadableAdditionalDimensionBeforeCapturingItsRegistry() throws Exception {
         File pack = temporary.newFolder("missing-secondary-dimension");