perfpass

core/build.gradle

@@ -112,6 +112,11 @@ dependencies {
     // Script Engine
     slim(libs.kotlin.stdlib)
     slim(libs.kotlin.coroutines)
+
+    testImplementation('junit:junit:4.13.2')
+    testImplementation('org.mockito:mockito-core:5.16.1')
+    testImplementation(libs.spigot)
+    testRuntimeOnly(libs.spigot)
 }
 
 java {

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

@@ -152,11 +152,21 @@ public class IrisSettings {
         public boolean useVirtualThreads = false;
         public boolean useTicketQueue = true;
         public int maxConcurrency = 256;
+        public int chunkLoadTimeoutSeconds = 15;
+        public int timeoutWarnIntervalMs = 500;
         public boolean startupNoisemapPrebake = true;
         public boolean enablePregenPerformanceProfile = true;
         public int pregenProfileNoiseCacheSize = 4_096;
         public boolean pregenProfileEnableFastCache = true;
         public boolean pregenProfileLogJvmHints = true;
+
+        public int getChunkLoadTimeoutSeconds() {
+            return Math.max(5, Math.min(chunkLoadTimeoutSeconds, 120));
+        }
+
+        public int getTimeoutWarnIntervalMs() {
+            return Math.max(timeoutWarnIntervalMs, 250);
+        }
     }
 
     @Data

core/src/main/java/art/arcane/iris/core/pregenerator/methods/AsyncPregenMethod.java

@@ -45,13 +45,23 @@ import java.util.concurrent.atomic.AtomicLong;
 public class AsyncPregenMethod implements PregeneratorMethod {
     private static final AtomicInteger THREAD_COUNT = new AtomicInteger();
     private static final int FOLIA_MAX_CONCURRENCY = 32;
-    private static final long CHUNK_LOAD_TIMEOUT_SECONDS = 15L;
+    private static final int NON_FOLIA_MAX_CONCURRENCY = 96;
+    private static final int NON_FOLIA_CONCURRENCY_FACTOR = 2;
+    private static final int ADAPTIVE_TIMEOUT_STEP = 3;
     private final World world;
     private final Executor executor;
     private final Semaphore semaphore;
     private final int threads;
+    private final int timeoutSeconds;
+    private final int timeoutWarnIntervalMs;
     private final boolean urgent;
     private final Map<Chunk, Long> lastUse;
+    private final AtomicInteger adaptiveInFlightLimit;
+    private final int adaptiveMinInFlightLimit;
+    private final AtomicInteger timeoutStreak = new AtomicInteger();
+    private final AtomicLong lastTimeoutLogAt = new AtomicLong(0L);
+    private final AtomicInteger suppressedTimeoutLogs = new AtomicInteger();
+    private final AtomicLong lastAdaptiveLogAt = new AtomicLong(0L);
     private final AtomicInteger inFlight = new AtomicInteger();
     private final AtomicLong submitted = new AtomicLong();
     private final AtomicLong completed = new AtomicLong();
@@ -71,14 +81,21 @@ public class AsyncPregenMethod implements PregeneratorMethod {
             boolean useTicketQueue = IrisSettings.get().getPregen().isUseTicketQueue();
             this.executor = useTicketQueue ? new TicketExecutor() : new ServiceExecutor();
         }
-        int configuredThreads = IrisSettings.get().getPregen().getMaxConcurrency();
+        IrisSettings.IrisSettingsPregen pregen = IrisSettings.get().getPregen();
+        int configuredThreads = pregen.getMaxConcurrency();
         if (J.isFolia()) {
             configuredThreads = Math.min(configuredThreads, FOLIA_MAX_CONCURRENCY);
+        } else {
+            configuredThreads = Math.min(configuredThreads, resolveNonFoliaConcurrencyCap());
         }
         this.threads = Math.max(1, configuredThreads);
         this.semaphore = new Semaphore(this.threads, true);
+        this.timeoutSeconds = pregen.getChunkLoadTimeoutSeconds();
+        this.timeoutWarnIntervalMs = pregen.getTimeoutWarnIntervalMs();
         this.urgent = IrisSettings.get().getPregen().useHighPriority;
         this.lastUse = new ConcurrentHashMap<>();
+        this.adaptiveInFlightLimit = new AtomicInteger(this.threads);
+        this.adaptiveMinInFlightLimit = Math.max(4, Math.min(16, Math.max(1, this.threads / 4)));
     }
 
     private void unloadAndSaveAllChunks() {
@@ -121,7 +138,7 @@ public class AsyncPregenMethod implements PregeneratorMethod {
         }
 
         if (root instanceof java.util.concurrent.TimeoutException) {
-            Iris.warn("Timed out async pregen chunk load at " + x + "," + z + " after " + CHUNK_LOAD_TIMEOUT_SECONDS + "s. " + metricsSnapshot());
+            onTimeout(x, z);
         } else {
             Iris.warn("Failed async pregen chunk load at " + x + "," + z + ". " + metricsSnapshot());
         }
@@ -130,10 +147,93 @@ public class AsyncPregenMethod implements PregeneratorMethod {
         return null;
     }
 
+    private void onTimeout(int x, int z) {
+        int streak = timeoutStreak.incrementAndGet();
+        if (streak % ADAPTIVE_TIMEOUT_STEP == 0) {
+            lowerAdaptiveInFlightLimit();
+        }
+
+        long now = M.ms();
+        long last = lastTimeoutLogAt.get();
+        if (now - last < timeoutWarnIntervalMs || !lastTimeoutLogAt.compareAndSet(last, now)) {
+            suppressedTimeoutLogs.incrementAndGet();
+            return;
+        }
+
+        int suppressed = suppressedTimeoutLogs.getAndSet(0);
+        String suppressedText = suppressed <= 0 ? "" : " suppressed=" + suppressed;
+        Iris.warn("Timed out async pregen chunk load at " + x + "," + z
+                + " after " + timeoutSeconds + "s."
+                + " adaptiveLimit=" + adaptiveInFlightLimit.get()
+                + suppressedText + " " + metricsSnapshot());
+    }
+
+    private void onSuccess() {
+        int streak = timeoutStreak.get();
+        if (streak > 0) {
+            timeoutStreak.compareAndSet(streak, streak - 1);
+            return;
+        }
+
+        if ((completed.get() & 31L) == 0L) {
+            raiseAdaptiveInFlightLimit();
+        }
+    }
+
+    private void lowerAdaptiveInFlightLimit() {
+        while (true) {
+            int current = adaptiveInFlightLimit.get();
+            if (current <= adaptiveMinInFlightLimit) {
+                return;
+            }
+
+            int next = Math.max(adaptiveMinInFlightLimit, current - 1);
+            if (adaptiveInFlightLimit.compareAndSet(current, next)) {
+                logAdaptiveLimit("decrease", next);
+                return;
+            }
+        }
+    }
+
+    private void raiseAdaptiveInFlightLimit() {
+        while (true) {
+            int current = adaptiveInFlightLimit.get();
+            if (current >= threads) {
+                return;
+            }
+
+            int next = Math.min(threads, current + 1);
+            if (adaptiveInFlightLimit.compareAndSet(current, next)) {
+                logAdaptiveLimit("increase", next);
+                return;
+            }
+        }
+    }
+
+    private void logAdaptiveLimit(String mode, int value) {
+        long now = M.ms();
+        long last = lastAdaptiveLogAt.get();
+        if (now - last < 5000L) {
+            return;
+        }
+
+        if (lastAdaptiveLogAt.compareAndSet(last, now)) {
+            Iris.info("Async pregen adaptive limit " + mode + " -> " + value + " " + metricsSnapshot());
+        }
+    }
+
+    private int resolveNonFoliaConcurrencyCap() {
+        int worldGenThreads = Math.max(1, IrisSettings.get().getConcurrency().getWorldGenThreads());
+        int recommended = worldGenThreads * NON_FOLIA_CONCURRENCY_FACTOR;
+        int bounded = Math.max(8, Math.min(NON_FOLIA_MAX_CONCURRENCY, recommended));
+        return bounded;
+    }
+
     private String metricsSnapshot() {
         long stalledFor = Math.max(0L, M.ms() - lastProgressAt.get());
         return "world=" + world.getName()
                 + " permits=" + semaphore.availablePermits() + "/" + threads
+                + " adaptiveLimit=" + adaptiveInFlightLimit.get()
                 + " inFlight=" + inFlight.get()
                 + " submitted=" + submitted.get()
                 + " completed=" + completed.get()
@@ -149,6 +249,7 @@ public class AsyncPregenMethod implements PregeneratorMethod {
     private void markFinished(boolean success) {
         if (success) {
             completed.incrementAndGet();
+            onSuccess();
         } else {
             failed.incrementAndGet();
         }
@@ -177,8 +278,9 @@ public class AsyncPregenMethod implements PregeneratorMethod {
         Iris.info("Async pregen init: world=" + world.getName()
                 + ", mode=" + (J.isFolia() ? "folia" : "paper")
                 + ", threads=" + threads
+                + ", adaptiveLimit=" + adaptiveInFlightLimit.get()
                 + ", urgent=" + urgent
-                + ", timeout=" + CHUNK_LOAD_TIMEOUT_SECONDS + "s");
+                + ", timeout=" + timeoutSeconds + "s");
         unloadAndSaveAllChunks();
         increaseWorkerThreads();
     }
@@ -216,6 +318,14 @@ public class AsyncPregenMethod implements PregeneratorMethod {
         listener.onChunkGenerating(x, z);
         try {
             long waitStart = M.ms();
+            while (inFlight.get() >= adaptiveInFlightLimit.get()) {
+                long waited = Math.max(0L, M.ms() - waitStart);
+                logPermitWaitIfNeeded(x, z, waited);
+                if (!J.sleep(5)) {
+                    return;
+                }
+            }
+
             while (!semaphore.tryAcquire(5, TimeUnit.SECONDS)) {
                 logPermitWaitIfNeeded(x, z, Math.max(0L, M.ms() - waitStart));
             }
@@ -288,7 +398,7 @@ public class AsyncPregenMethod implements PregeneratorMethod {
         @Override
         public void generate(int x, int z, PregenListener listener) {
             if (!J.runRegion(world, x, z, () -> PaperLib.getChunkAtAsync(world, x, z, true, urgent)
-                    .orTimeout(CHUNK_LOAD_TIMEOUT_SECONDS, TimeUnit.SECONDS)
+                    .orTimeout(timeoutSeconds, TimeUnit.SECONDS)
                     .whenComplete((chunk, throwable) -> {
                         boolean success = false;
                         try {
@@ -328,15 +438,16 @@ public class AsyncPregenMethod implements PregeneratorMethod {
                 boolean success = false;
                 try {
                     Chunk i = PaperLib.getChunkAtAsync(world, x, z, true, urgent)
-                            .orTimeout(CHUNK_LOAD_TIMEOUT_SECONDS, TimeUnit.SECONDS)
+                            .orTimeout(timeoutSeconds, TimeUnit.SECONDS)
                             .exceptionally(e -> onChunkFutureFailure(x, z, e))
                             .get();
 
-                    listener.onChunkGenerated(x, z);
-                    listener.onChunkCleaned(x, z);
                     if (i == null) {
                         return;
                     }
+
+                    listener.onChunkGenerated(x, z);
+                    listener.onChunkCleaned(x, z);
                     lastUse.put(i, M.ms());
                     success = true;
                 } catch (InterruptedException ignored) {
@@ -361,16 +472,18 @@ public class AsyncPregenMethod implements PregeneratorMethod {
         @Override
         public void generate(int x, int z, PregenListener listener) {
             PaperLib.getChunkAtAsync(world, x, z, true, urgent)
-                    .orTimeout(CHUNK_LOAD_TIMEOUT_SECONDS, TimeUnit.SECONDS)
+                    .orTimeout(timeoutSeconds, TimeUnit.SECONDS)
                     .exceptionally(e -> onChunkFutureFailure(x, z, e))
                     .thenAccept(i -> {
                         boolean success = false;
                         try {
+                            if (i == null) {
+                                return;
+                            }
+
                             listener.onChunkGenerated(x, z);
                             listener.onChunkCleaned(x, z);
-                            if (i != null) {
                             lastUse.put(i, M.ms());
-                            }
                             success = true;
                         } finally {
                             markFinished(success);

core/src/main/java/art/arcane/iris/engine/framework/Engine.java

@@ -236,12 +236,17 @@ public interface Engine extends DataProvider, Fallible, LootProvider, BlockUpdat
 
     @BlockCoordinates
     default IrisBiome getCaveBiome(int x, int y, int z) {
+        return getCaveBiome(x, y, z, null);
+    }
+
+    @BlockCoordinates
+    default IrisBiome getCaveBiome(int x, int y, int z, IrisDimensionCarvingResolver.State state) {
         IrisBiome surfaceBiome = getSurfaceBiome(x, z);
         int worldY = y + getWorld().minHeight();
-        IrisDimensionCarvingEntry rootCarvingEntry = IrisDimensionCarvingResolver.resolveRootEntry(this, worldY);
+        IrisDimensionCarvingEntry rootCarvingEntry = IrisDimensionCarvingResolver.resolveRootEntry(this, worldY, state);
         if (rootCarvingEntry != null) {
-            IrisDimensionCarvingEntry resolvedCarvingEntry = IrisDimensionCarvingResolver.resolveFromRoot(this, rootCarvingEntry, x, z);
+            IrisDimensionCarvingEntry resolvedCarvingEntry = IrisDimensionCarvingResolver.resolveFromRoot(this, rootCarvingEntry, x, z, state);
-            IrisBiome resolvedCarvingBiome = IrisDimensionCarvingResolver.resolveEntryBiome(this, resolvedCarvingEntry);
+            IrisBiome resolvedCarvingBiome = IrisDimensionCarvingResolver.resolveEntryBiome(this, resolvedCarvingEntry, state);
             if (resolvedCarvingBiome != null) {
                 return resolvedCarvingBiome;
             }
@@ -321,9 +326,7 @@ public interface Engine extends DataProvider, Fallible, LootProvider, BlockUpdat
 
         var chunk = mantle.getChunk(c).use();
         try {
-            Semaphore semaphore = new Semaphore(1024);
+            Runnable tileTask = () -> {
-            chunk.raiseFlagUnchecked(MantleFlag.ETCHED, () -> {
-                chunk.raiseFlagUnchecked(MantleFlag.TILE, run(semaphore, c, () -> {
                 chunk.iterate(TileWrapper.class, (x, y, z, v) -> {
                     Block block = c.getBlock(x & 15, y + getWorld().minHeight(), z & 15);
                     if (!TileData.setTileState(block, v.getData())) {
@@ -334,14 +337,15 @@ public interface Engine extends DataProvider, Fallible, LootProvider, BlockUpdat
                         Iris.warn("Failed to set tile entity data at [%d %d %d | %s] for tile %s!", block.getX(), block.getY(), block.getZ(), blockType, tileType);
                     }
                 });
-                }, 0));
+            };
-                chunk.raiseFlagUnchecked(MantleFlag.CUSTOM, run(semaphore, c, () -> {
+
+            Runnable customTask = () -> {
                 chunk.iterate(Identifier.class, (x, y, z, v) -> {
                     Iris.service(ExternalDataSVC.class).processUpdate(this, c.getBlock(x & 15, y + getWorld().minHeight(), z & 15), v);
                 });
-                }, 0));
+            };
 
-                chunk.raiseFlagUnchecked(MantleFlag.UPDATE, run(semaphore, c, () -> {
+            Runnable updateTask = () -> {
                 PrecisionStopwatch p = PrecisionStopwatch.start();
                 int[][] grid = new int[16][16];
                 for (int x = 0; x < 16; x++) {
@@ -370,8 +374,9 @@ public interface Engine extends DataProvider, Fallible, LootProvider, BlockUpdat
 
                 for (int x = 0; x < 16; x++) {
                     for (int z = 0; z < 16; z++) {
-                            if (grid[x][z] == Integer.MIN_VALUE)
+                        if (grid[x][z] == Integer.MIN_VALUE) {
                             continue;
+                        }
                         update(x, grid[x][z], z, c, chunk, rng);
                     }
                 }
@@ -384,7 +389,22 @@ public interface Engine extends DataProvider, Fallible, LootProvider, BlockUpdat
                 });
                 chunk.deleteSlices(MatterUpdate.class);
                 getMetrics().getUpdates().put(p.getMilliseconds());
-                }, RNG.r.i(1, 20))); //Why is there a random delay here?
+            };
+
+            if (shouldRunChunkUpdateInline(c)) {
+                chunk.raiseFlagUnchecked(MantleFlag.ETCHED, () -> {
+                    chunk.raiseFlagUnchecked(MantleFlag.TILE, tileTask);
+                    chunk.raiseFlagUnchecked(MantleFlag.CUSTOM, customTask);
+                    chunk.raiseFlagUnchecked(MantleFlag.UPDATE, updateTask);
+                });
+                return;
+            }
+
+            Semaphore semaphore = new Semaphore(1024);
+            chunk.raiseFlagUnchecked(MantleFlag.ETCHED, () -> {
+                chunk.raiseFlagUnchecked(MantleFlag.TILE, run(semaphore, c, tileTask, 0));
+                chunk.raiseFlagUnchecked(MantleFlag.CUSTOM, run(semaphore, c, customTask, 0));
+                chunk.raiseFlagUnchecked(MantleFlag.UPDATE, run(semaphore, c, updateTask, RNG.r.i(1, 20)));
             });
 
             try {
@@ -398,6 +418,18 @@ public interface Engine extends DataProvider, Fallible, LootProvider, BlockUpdat
         }
     }
 
+    private static boolean shouldRunChunkUpdateInline(Chunk chunk) {
+        if (chunk == null) {
+            return false;
+        }
+
+        if (!J.isFolia()) {
+            return J.isPrimaryThread();
+        }
+
+        return J.isOwnedByCurrentRegion(chunk.getWorld(), chunk.getX(), chunk.getZ());
+    }
+
     private static Runnable run(Semaphore semaphore, Chunk contextChunk, Runnable runnable, int delay) {
         return () -> {
             try {
@@ -407,13 +439,23 @@ public interface Engine extends DataProvider, Fallible, LootProvider, BlockUpdat
             }
 
             int effectiveDelay = J.isFolia() ? 0 : delay;
-            J.runRegion(contextChunk.getWorld(), contextChunk.getX(), contextChunk.getZ(), () -> {
+            boolean scheduled = J.runRegion(contextChunk.getWorld(), contextChunk.getX(), contextChunk.getZ(), () -> {
                 try {
                     runnable.run();
                 } finally {
                     semaphore.release();
                 }
             }, effectiveDelay);
+
+            if (!scheduled) {
+                try {
+                    if (J.isPrimaryThread()) {
+                        runnable.run();
+                    }
+                } finally {
+                    semaphore.release();
+                }
+            }
         };
     }
 

core/src/main/java/art/arcane/iris/engine/framework/EngineMetrics.java

@@ -37,6 +37,8 @@ public class EngineMetrics {
     private final AtomicRollingSequence cave;
     private final AtomicRollingSequence ravine;
     private final AtomicRollingSequence deposit;
+    private final AtomicRollingSequence carveResolve;
+    private final AtomicRollingSequence carveApply;
 
     public EngineMetrics(int mem) {
         this.total = new AtomicRollingSequence(mem);
@@ -52,6 +54,8 @@ public class EngineMetrics {
         this.cave = new AtomicRollingSequence(mem);
         this.ravine = new AtomicRollingSequence(mem);
         this.deposit = new AtomicRollingSequence(mem);
+        this.carveResolve = new AtomicRollingSequence(mem);
+        this.carveApply = new AtomicRollingSequence(mem);
     }
 
     public KMap<String, Double> pull() {
@@ -69,6 +73,8 @@ public class EngineMetrics {
         v.put("cave", cave.getAverage());
         v.put("ravine", ravine.getAverage());
         v.put("deposit", deposit.getAverage());
+        v.put("carve.resolve", carveResolve.getAverage());
+        v.put("carve.apply", carveApply.getAverage());
 
         return v;
     }

core/src/main/java/art/arcane/iris/engine/mantle/components/IrisCaveCarver3D.java

@@ -28,6 +28,7 @@ import art.arcane.iris.util.project.noise.CNG;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.math.RNG;
 import art.arcane.volmlib.util.matter.MatterCavern;
+import art.arcane.volmlib.util.scheduling.PrecisionStopwatch;
 
 import java.util.Arrays;
 
@@ -35,6 +36,7 @@ public class IrisCaveCarver3D {
     private static final byte LIQUID_AIR = 0;
     private static final byte LIQUID_LAVA = 2;
     private static final byte LIQUID_FORCED_AIR = 3;
+    private static final ThreadLocal<Scratch> SCRATCH = ThreadLocal.withInitial(Scratch::new);
 
     private final Engine engine;
     private final IrisData data;
@@ -49,6 +51,11 @@ public class IrisCaveCarver3D {
     private final MatterCavern carveAir;
     private final MatterCavern carveLava;
     private final MatterCavern carveForcedAir;
+    private final double baseWeight;
+    private final double detailWeight;
+    private final double warpStrength;
+    private final boolean hasWarp;
+    private final boolean hasModules;
 
     public IrisCaveCarver3D(Engine engine, IrisCaveProfile profile) {
         this.engine = engine;
@@ -65,8 +72,12 @@ public class IrisCaveCarver3D {
         this.warpDensity = profile.getWarpStyle().create(baseRng.nextParallelRNG(770_713), data);
         this.surfaceBreakDensity = profile.getSurfaceBreakStyle().create(baseRng.nextParallelRNG(341_219), data);
         this.thresholdRng = baseRng.nextParallelRNG(489_112);
+        this.baseWeight = profile.getBaseWeight();
+        this.detailWeight = profile.getDetailWeight();
+        this.warpStrength = profile.getWarpStrength();
+        this.hasWarp = this.warpStrength > 0D;
 
-        double weight = Math.abs(profile.getBaseWeight()) + Math.abs(profile.getDetailWeight());
+        double weight = Math.abs(baseWeight) + Math.abs(detailWeight);
         int index = 0;
         for (IrisCaveFieldModule module : profile.getModules()) {
             CNG moduleDensity = module.getStyle().create(baseRng.nextParallelRNG(1_000_003L + (index * 65_537L)), data);
@@ -77,12 +88,16 @@ public class IrisCaveCarver3D {
         }
 
         normalization = weight <= 0 ? 1 : weight;
+        hasModules = !modules.isEmpty();
     }
 
     public int carve(MantleWriter writer, int chunkX, int chunkZ) {
-        double[] fullWeights = new double[256];
+        Scratch scratch = SCRATCH.get();
-        Arrays.fill(fullWeights, 1D);
+        if (!scratch.fullWeightsInitialized) {
-        return carve(writer, chunkX, chunkZ, fullWeights, 0D, 0D, null);
+            Arrays.fill(scratch.fullWeights, 1D);
+            scratch.fullWeightsInitialized = true;
+        }
+        return carve(writer, chunkX, chunkZ, scratch.fullWeights, 0D, 0D, null);
     }
 
     public int carve(
@@ -105,10 +120,15 @@ public class IrisCaveCarver3D {
             double thresholdPenalty,
             IrisRange worldYRange
     ) {
+        PrecisionStopwatch applyStopwatch = PrecisionStopwatch.start();
+        try {
+            Scratch scratch = SCRATCH.get();
             if (columnWeights == null || columnWeights.length < 256) {
-            double[] fullWeights = new double[256];
+                if (!scratch.fullWeightsInitialized) {
-            Arrays.fill(fullWeights, 1D);
+                    Arrays.fill(scratch.fullWeights, 1D);
-            columnWeights = fullWeights;
+                    scratch.fullWeightsInitialized = true;
+                }
+                columnWeights = scratch.fullWeights;
             }
 
             double resolvedMinWeight = Math.max(0D, Math.min(1D, minWeight));
@@ -137,11 +157,11 @@ public class IrisCaveCarver3D {
 
             int x0 = chunkX << 4;
             int z0 = chunkZ << 4;
-        int[] columnSurface = new int[256];
+            int[] columnSurface = scratch.columnSurface;
-        int[] columnMaxY = new int[256];
+            int[] columnMaxY = scratch.columnMaxY;
-        int[] surfaceBreakFloorY = new int[256];
+            int[] surfaceBreakFloorY = scratch.surfaceBreakFloorY;
-        boolean[] surfaceBreakColumn = new boolean[256];
+            boolean[] surfaceBreakColumn = scratch.surfaceBreakColumn;
-        double[] columnThreshold = new double[256];
+            double[] columnThreshold = scratch.columnThreshold;
 
             for (int lx = 0; lx < 16; lx++) {
                 int x = x0 + lx;
@@ -213,6 +233,9 @@ public class IrisCaveCarver3D {
             }
 
             return carved;
+        } finally {
+            engine.getMetrics().getCarveApply().put(applyStopwatch.getMilliseconds());
+        }
     }
 
     private int carvePass(
@@ -305,12 +328,16 @@ public class IrisCaveCarver3D {
     }
 
     private double sampleDensity(int x, int y, int z) {
+        if (!hasWarp && !hasModules) {
+            double density = signed(baseDensity.noise(x, y, z)) * baseWeight;
+            density += signed(detailDensity.noise(x, y, z)) * detailWeight;
+            return density / normalization;
+        }
+
         double warpedX = x;
         double warpedY = y;
         double warpedZ = z;
-        double warpStrength = profile.getWarpStrength();
+        if (hasWarp) {
-
-        if (warpStrength > 0) {
             double warpA = signed(warpDensity.noise(x, y, z));
             double warpB = signed(warpDensity.noise(x + 31.37D, y - 17.21D, z + 23.91D));
             double offsetX = warpA * warpStrength;
@@ -321,9 +348,10 @@ public class IrisCaveCarver3D {
             warpedZ += offsetZ;
         }
 
-        double density = signed(baseDensity.noise(warpedX, warpedY, warpedZ)) * profile.getBaseWeight();
+        double density = signed(baseDensity.noise(warpedX, warpedY, warpedZ)) * baseWeight;
-        density += signed(detailDensity.noise(warpedX, warpedY, warpedZ)) * profile.getDetailWeight();
+        density += signed(detailDensity.noise(warpedX, warpedY, warpedZ)) * detailWeight;
 
+        if (hasModules) {
             for (ModuleState module : modules) {
                 if (y < module.minY || y > module.maxY) {
                     continue;
@@ -336,6 +364,7 @@ public class IrisCaveCarver3D {
 
                 density += moduleDensity * module.weight;
             }
+        }
 
         return density / normalization;
     }
@@ -397,4 +426,14 @@ public class IrisCaveCarver3D {
             this.invert = module.isInvert();
         }
     }
+
+    private static final class Scratch {
+        private final int[] columnSurface = new int[256];
+        private final int[] columnMaxY = new int[256];
+        private final int[] surfaceBreakFloorY = new int[256];
+        private final boolean[] surfaceBreakColumn = new boolean[256];
+        private final double[] columnThreshold = new double[256];
+        private final double[] fullWeights = new double[256];
+        private boolean fullWeightsInitialized;
+    }
 }

core/src/main/java/art/arcane/iris/engine/mantle/components/MantleCarvingComponent.java

@@ -31,9 +31,9 @@ import art.arcane.iris.engine.object.IrisRange;
 import art.arcane.iris.util.project.context.ChunkContext;
 import art.arcane.volmlib.util.documentation.ChunkCoordinates;
 import art.arcane.volmlib.util.mantle.flag.ReservedFlag;
+import art.arcane.volmlib.util.scheduling.PrecisionStopwatch;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.Comparator;
 import java.util.IdentityHashMap;
 import java.util.List;
@@ -47,16 +47,37 @@ public class MantleCarvingComponent extends IrisMantleComponent {
     private static final int FIELD_SIZE = CHUNK_SIZE + (BLEND_RADIUS * 2);
     private static final double MIN_WEIGHT = 0.08D;
     private static final double THRESHOLD_PENALTY = 0.24D;
+    private static final int KERNEL_WIDTH = (BLEND_RADIUS * 2) + 1;
+    private static final int KERNEL_SIZE = KERNEL_WIDTH * KERNEL_WIDTH;
+    private static final int[] KERNEL_DX = new int[KERNEL_SIZE];
+    private static final int[] KERNEL_DZ = new int[KERNEL_SIZE];
+    private static final double[] KERNEL_WEIGHT = new double[KERNEL_SIZE];
 
     private final Map<IrisCaveProfile, IrisCaveCarver3D> profileCarvers = new IdentityHashMap<>();
 
+    static {
+        int kernelIndex = 0;
+        for (int offsetX = -BLEND_RADIUS; offsetX <= BLEND_RADIUS; offsetX++) {
+            for (int offsetZ = -BLEND_RADIUS; offsetZ <= BLEND_RADIUS; offsetZ++) {
+                KERNEL_DX[kernelIndex] = offsetX;
+                KERNEL_DZ[kernelIndex] = offsetZ;
+                int edgeDistance = Math.max(Math.abs(offsetX), Math.abs(offsetZ));
+                KERNEL_WEIGHT[kernelIndex] = (BLEND_RADIUS + 1D) - edgeDistance;
+                kernelIndex++;
+            }
+        }
+    }
+
     public MantleCarvingComponent(EngineMantle engineMantle) {
         super(engineMantle, ReservedFlag.CARVED, 0);
     }
 
     @Override
     public void generateLayer(MantleWriter writer, int x, int z, ChunkContext context) {
-        List<WeightedProfile> weightedProfiles = resolveWeightedProfiles(x, z);
+        IrisDimensionCarvingResolver.State resolverState = new IrisDimensionCarvingResolver.State();
+        PrecisionStopwatch resolveStopwatch = PrecisionStopwatch.start();
+        List<WeightedProfile> weightedProfiles = resolveWeightedProfiles(x, z, resolverState);
+        getEngineMantle().getEngine().getMetrics().getCarveResolve().put(resolveStopwatch.getMilliseconds());
         for (WeightedProfile weightedProfile : weightedProfiles) {
             carveProfile(weightedProfile, writer, x, z);
         }
@@ -68,17 +89,51 @@ public class MantleCarvingComponent extends IrisMantleComponent {
         carver.carve(writer, cx, cz, weightedProfile.columnWeights, MIN_WEIGHT, THRESHOLD_PENALTY, weightedProfile.worldYRange);
     }
 
-    private List<WeightedProfile> resolveWeightedProfiles(int chunkX, int chunkZ) {
+    private List<WeightedProfile> resolveWeightedProfiles(int chunkX, int chunkZ, IrisDimensionCarvingResolver.State resolverState) {
-        IrisCaveProfile[] profileField = buildProfileField(chunkX, chunkZ);
+        IrisCaveProfile[] profileField = buildProfileField(chunkX, chunkZ, resolverState);
         Map<IrisCaveProfile, double[]> profileWeights = new IdentityHashMap<>();
+        IrisCaveProfile[] columnProfiles = new IrisCaveProfile[KERNEL_SIZE];
+        double[] columnProfileWeights = new double[KERNEL_SIZE];
 
         for (int localX = 0; localX < CHUNK_SIZE; localX++) {
             for (int localZ = 0; localZ < CHUNK_SIZE; localZ++) {
+                int profileCount = 0;
                 int columnIndex = (localX << 4) | localZ;
-                Map<IrisCaveProfile, Double> columnInfluence = sampleColumnInfluence(profileField, localX, localZ);
+                int centerX = localX + BLEND_RADIUS;
-                for (Map.Entry<IrisCaveProfile, Double> entry : columnInfluence.entrySet()) {
+                int centerZ = localZ + BLEND_RADIUS;
-                    double[] weights = profileWeights.computeIfAbsent(entry.getKey(), key -> new double[CHUNK_AREA]);
+                double totalKernelWeight = 0D;
-                    weights[columnIndex] = entry.getValue();
+
+                for (int kernelIndex = 0; kernelIndex < KERNEL_SIZE; kernelIndex++) {
+                    int sampleX = centerX + KERNEL_DX[kernelIndex];
+                    int sampleZ = centerZ + KERNEL_DZ[kernelIndex];
+                    IrisCaveProfile profile = profileField[(sampleX * FIELD_SIZE) + sampleZ];
+                    if (!isProfileEnabled(profile)) {
+                        continue;
+                    }
+
+                    double kernelWeight = KERNEL_WEIGHT[kernelIndex];
+                    int existingIndex = findProfileIndex(columnProfiles, profileCount, profile);
+                    if (existingIndex >= 0) {
+                        columnProfileWeights[existingIndex] += kernelWeight;
+                    } else {
+                        columnProfiles[profileCount] = profile;
+                        columnProfileWeights[profileCount] = kernelWeight;
+                        profileCount++;
+                    }
+                    totalKernelWeight += kernelWeight;
+                }
+
+                if (totalKernelWeight <= 0D || profileCount == 0) {
+                    continue;
+                }
+
+                for (int profileIndex = 0; profileIndex < profileCount; profileIndex++) {
+                    IrisCaveProfile profile = columnProfiles[profileIndex];
+                    double normalizedWeight = columnProfileWeights[profileIndex] / totalKernelWeight;
+                    double[] weights = profileWeights.computeIfAbsent(profile, key -> new double[CHUNK_AREA]);
+                    weights[columnIndex] = normalizedWeight;
+                    columnProfiles[profileIndex] = null;
+                    columnProfileWeights[profileIndex] = 0D;
                 }
             }
         }
@@ -106,11 +161,11 @@ public class MantleCarvingComponent extends IrisMantleComponent {
         }
 
         weightedProfiles.sort(Comparator.comparingDouble(WeightedProfile::averageWeight));
-        weightedProfiles.addAll(0, resolveDimensionCarvingProfiles(chunkX, chunkZ));
+        weightedProfiles.addAll(0, resolveDimensionCarvingProfiles(chunkX, chunkZ, resolverState));
         return weightedProfiles;
     }
 
-    private List<WeightedProfile> resolveDimensionCarvingProfiles(int chunkX, int chunkZ) {
+    private List<WeightedProfile> resolveDimensionCarvingProfiles(int chunkX, int chunkZ, IrisDimensionCarvingResolver.State resolverState) {
         List<WeightedProfile> weightedProfiles = new ArrayList<>();
         List<IrisDimensionCarvingEntry> entries = getDimension().getCarving();
         if (entries == null || entries.isEmpty()) {
@@ -122,7 +177,7 @@ public class MantleCarvingComponent extends IrisMantleComponent {
                 continue;
             }
 
-            IrisBiome rootBiome = IrisDimensionCarvingResolver.resolveEntryBiome(getEngineMantle().getEngine(), entry);
+            IrisBiome rootBiome = IrisDimensionCarvingResolver.resolveEntryBiome(getEngineMantle().getEngine(), entry, resolverState);
             if (rootBiome == null) {
                 continue;
             }
@@ -134,8 +189,8 @@ public class MantleCarvingComponent extends IrisMantleComponent {
                     int worldX = (chunkX << 4) + localX;
                     int worldZ = (chunkZ << 4) + localZ;
                     int columnIndex = (localX << 4) | localZ;
-                    IrisDimensionCarvingEntry resolvedEntry = IrisDimensionCarvingResolver.resolveFromRoot(getEngineMantle().getEngine(), entry, worldX, worldZ);
+                    IrisDimensionCarvingEntry resolvedEntry = IrisDimensionCarvingResolver.resolveFromRoot(getEngineMantle().getEngine(), entry, worldX, worldZ, resolverState);
-                    IrisBiome resolvedBiome = IrisDimensionCarvingResolver.resolveEntryBiome(getEngineMantle().getEngine(), resolvedEntry);
+                    IrisBiome resolvedBiome = IrisDimensionCarvingResolver.resolveEntryBiome(getEngineMantle().getEngine(), resolvedEntry, resolverState);
                     if (resolvedBiome == null) {
                         continue;
                     }
@@ -160,40 +215,7 @@ public class MantleCarvingComponent extends IrisMantleComponent {
         return weightedProfiles;
     }
 
-    private Map<IrisCaveProfile, Double> sampleColumnInfluence(IrisCaveProfile[] profileField, int localX, int localZ) {
+    private IrisCaveProfile[] buildProfileField(int chunkX, int chunkZ, IrisDimensionCarvingResolver.State resolverState) {
-        Map<IrisCaveProfile, Double> profileBlend = new IdentityHashMap<>();
-        int centerX = localX + BLEND_RADIUS;
-        int centerZ = localZ + BLEND_RADIUS;
-        double totalKernelWeight = 0D;
-
-        for (int offsetX = -BLEND_RADIUS; offsetX <= BLEND_RADIUS; offsetX++) {
-            for (int offsetZ = -BLEND_RADIUS; offsetZ <= BLEND_RADIUS; offsetZ++) {
-                int sampleX = centerX + offsetX;
-                int sampleZ = centerZ + offsetZ;
-                IrisCaveProfile profile = profileField[(sampleX * FIELD_SIZE) + sampleZ];
-                if (!isProfileEnabled(profile)) {
-                    continue;
-                }
-
-                double kernelWeight = haloWeight(offsetX, offsetZ);
-                profileBlend.merge(profile, kernelWeight, Double::sum);
-                totalKernelWeight += kernelWeight;
-            }
-        }
-
-        if (totalKernelWeight <= 0D || profileBlend.isEmpty()) {
-            return Collections.emptyMap();
-        }
-
-        Map<IrisCaveProfile, Double> normalized = new IdentityHashMap<>();
-        for (Map.Entry<IrisCaveProfile, Double> entry : profileBlend.entrySet()) {
-            normalized.put(entry.getKey(), entry.getValue() / totalKernelWeight);
-        }
-
-        return normalized;
-    }
-
-    private IrisCaveProfile[] buildProfileField(int chunkX, int chunkZ) {
         IrisCaveProfile[] profileField = new IrisCaveProfile[FIELD_SIZE * FIELD_SIZE];
         int startX = (chunkX << 4) - BLEND_RADIUS;
         int startZ = (chunkZ << 4) - BLEND_RADIUS;
@@ -202,19 +224,24 @@ public class MantleCarvingComponent extends IrisMantleComponent {
             int worldX = startX + fieldX;
             for (int fieldZ = 0; fieldZ < FIELD_SIZE; fieldZ++) {
                 int worldZ = startZ + fieldZ;
-                profileField[(fieldX * FIELD_SIZE) + fieldZ] = resolveColumnProfile(worldX, worldZ);
+                profileField[(fieldX * FIELD_SIZE) + fieldZ] = resolveColumnProfile(worldX, worldZ, resolverState);
             }
         }
 
         return profileField;
     }
 
-    private double haloWeight(int offsetX, int offsetZ) {
+    private int findProfileIndex(IrisCaveProfile[] profiles, int size, IrisCaveProfile profile) {
-        int edgeDistance = Math.max(Math.abs(offsetX), Math.abs(offsetZ));
+        for (int index = 0; index < size; index++) {
-        return (BLEND_RADIUS + 1D) - edgeDistance;
+            if (profiles[index] == profile) {
+                return index;
+            }
         }
 
-    private IrisCaveProfile resolveColumnProfile(int worldX, int worldZ) {
+        return -1;
+    }
+
+    private IrisCaveProfile resolveColumnProfile(int worldX, int worldZ, IrisDimensionCarvingResolver.State resolverState) {
         IrisCaveProfile resolved = null;
         IrisCaveProfile dimensionProfile = getDimension().getCaveProfile();
         if (isProfileEnabled(dimensionProfile)) {
@@ -239,7 +266,7 @@ public class MantleCarvingComponent extends IrisMantleComponent {
 
         int surfaceY = getEngineMantle().getEngine().getHeight(worldX, worldZ, true);
         int sampleY = Math.max(1, surfaceY - 56);
-        IrisBiome caveBiome = getEngineMantle().getEngine().getCaveBiome(worldX, sampleY, worldZ);
+        IrisBiome caveBiome = getEngineMantle().getEngine().getCaveBiome(worldX, sampleY, worldZ, resolverState);
         if (caveBiome != null) {
             IrisCaveProfile caveProfile = caveBiome.getCaveProfile();
             if (isProfileEnabled(caveProfile)) {

core/src/main/java/art/arcane/iris/engine/modifier/IrisCarveModifier.java

@@ -19,17 +19,18 @@
 package art.arcane.iris.engine.modifier;
 
 import art.arcane.iris.engine.actuator.IrisDecorantActuator;
-import art.arcane.iris.engine.data.cache.Cache;
 import art.arcane.iris.engine.framework.Engine;
 import art.arcane.iris.engine.framework.EngineAssignedModifier;
-import art.arcane.iris.engine.object.*;
+import art.arcane.iris.engine.object.InferredType;
-import art.arcane.volmlib.util.collection.KList;
+import art.arcane.iris.engine.object.IrisBiome;
-import art.arcane.volmlib.util.collection.KMap;
+import art.arcane.iris.engine.object.IrisDecorationPart;
+import art.arcane.iris.engine.object.IrisDecorator;
+import art.arcane.iris.engine.object.IrisDimensionCarvingResolver;
 import art.arcane.iris.util.project.context.ChunkContext;
 import art.arcane.iris.util.common.data.B;
 import art.arcane.volmlib.util.documentation.ChunkCoordinates;
-import art.arcane.volmlib.util.function.Consumer4;
 import art.arcane.iris.util.project.hunk.Hunk;
+import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.mantle.runtime.Mantle;
 import art.arcane.volmlib.util.mantle.runtime.MantleChunk;
 import art.arcane.volmlib.util.math.M;
@@ -42,6 +43,8 @@ import lombok.Data;
 import org.bukkit.Material;
 import org.bukkit.block.data.BlockData;
 
+import java.util.Arrays;
+
 public class IrisCarveModifier extends EngineAssignedModifier<BlockData> {
     private final RNG rng;
     private final BlockData AIR = Material.CAVE_AIR.createBlockData();
@@ -60,44 +63,46 @@ public class IrisCarveModifier extends EngineAssignedModifier<BlockData> {
         PrecisionStopwatch p = PrecisionStopwatch.start();
         Mantle<Matter> mantle = getEngine().getMantle().getMantle();
         MantleChunk<Matter> mc = mantle.getChunk(x, z).use();
-        KMap<Long, KList<Integer>> positions = new KMap<>();
+        IrisDimensionCarvingResolver.State resolverState = new IrisDimensionCarvingResolver.State();
-        KMap<IrisPosition, MatterCavern> walls = new KMap<>();
+        int[][] columnHeights = new int[256][];
-        Consumer4<Integer, Integer, Integer, MatterCavern> iterator = (xx, yy, zz, c) -> {
+        int[] columnHeightSizes = new int[256];
+        PackedWallBuffer walls = new PackedWallBuffer(512);
+        try {
+            PrecisionStopwatch resolveStopwatch = PrecisionStopwatch.start();
+            mc.iterate(MatterCavern.class, (xx, yy, zz, c) -> {
                 if (c == null) {
                     return;
                 }
 
-            if (yy >= getEngine().getWorld().maxHeight() - getEngine().getWorld().minHeight() || yy <= 0) { // Yes, skip bedrock
+                if (yy >= getEngine().getWorld().maxHeight() - getEngine().getWorld().minHeight() || yy <= 0) {
                     return;
                 }
 
                 int rx = xx & 15;
                 int rz = zz & 15;
-
+                int columnIndex = (rx << 4) | rz;
                 BlockData current = output.get(rx, yy, rz);
 
                 if (B.isFluid(current)) {
                     return;
                 }
 
-            positions.computeIfAbsent(Cache.key(rx, rz), (k) -> new KList<>()).qadd(yy);
+                appendColumnHeight(columnHeights, columnHeightSizes, columnIndex, yy);
-
-            //todo: Fix chunk decoration not working on chunk's border
 
                 if (rz < 15 && mc.get(xx, yy, zz + 1, MatterCavern.class) == null) {
-                walls.put(new IrisPosition(rx, yy, rz + 1), c);
+                    walls.put(rx, yy, rz + 1, c);
                 }
 
                 if (rx < 15 && mc.get(xx + 1, yy, zz, MatterCavern.class) == null) {
-                walls.put(new IrisPosition(rx + 1, yy, rz), c);
+                    walls.put(rx + 1, yy, rz, c);
                 }
 
                 if (rz > 0 && mc.get(xx, yy, zz - 1, MatterCavern.class) == null) {
-                walls.put(new IrisPosition(rx, yy, rz - 1), c);
+                    walls.put(rx, yy, rz - 1, c);
                 }
 
                 if (rx > 0 && mc.get(xx - 1, yy, zz, MatterCavern.class) == null) {
-                walls.put(new IrisPosition(rx - 1, yy, rz), c);
+                    walls.put(rx - 1, yy, rz, c);
                 }
 
                 if (current.getMaterial().isAir()) {
@@ -110,74 +115,83 @@ public class IrisCarveModifier extends EngineAssignedModifier<BlockData> {
                     output.set(rx, yy, rz, LAVA);
                 } else if (c.getLiquid() == 3) {
                     output.set(rx, yy, rz, AIR);
-            } else {
+                } else if (getEngine().getDimension().getCaveLavaHeight() > yy) {
-                if (getEngine().getDimension().getCaveLavaHeight() > yy) {
                     output.set(rx, yy, rz, LAVA);
                 } else {
                     output.set(rx, yy, rz, AIR);
                 }
-            }
+            });
-        };
+            getEngine().getMetrics().getCarveResolve().put(resolveStopwatch.getMilliseconds());
 
-        mc.iterate(MatterCavern.class, iterator);
+            PrecisionStopwatch applyStopwatch = PrecisionStopwatch.start();
-
+            try {
-        walls.forEach((i, v) -> {
+                walls.forEach((rx, yy, rz, cavern) -> {
-            IrisBiome biome = v.getCustomBiome().isEmpty()
+                    int worldX = rx + (x << 4);
-                    ? getEngine().getCaveBiome(i.getX() + (x << 4), i.getY(), i.getZ() + (z << 4))
+                    int worldZ = rz + (z << 4);
-                    : getEngine().getData().getBiomeLoader().load(v.getCustomBiome());
+                    IrisBiome biome = cavern.getCustomBiome().isEmpty()
+                            ? getEngine().getCaveBiome(worldX, yy, worldZ, resolverState)
+                            : getEngine().getData().getBiomeLoader().load(cavern.getCustomBiome());
 
                     if (biome != null) {
                         biome.setInferredType(InferredType.CAVE);
-                BlockData d = biome.getWall().get(rng, i.getX() + (x << 4), i.getY(), i.getZ() + (z << 4), getData());
+                        BlockData data = biome.getWall().get(rng, worldX, yy, worldZ, getData());
 
-                if (d != null && B.isSolid(output.get(i.getX(), i.getY(), i.getZ())) && i.getY() <= context.getHeight().get(i.getX(), i.getZ())) {
+                        if (data != null && B.isSolid(output.get(rx, yy, rz)) && yy <= context.getHeight().get(rx, rz)) {
-                    output.set(i.getX(), i.getY(), i.getZ(), d);
+                            output.set(rx, yy, rz, data);
                         }
                     }
                 });
 
-        positions.forEach((k, v) -> {
+                for (int columnIndex = 0; columnIndex < 256; columnIndex++) {
-            if (v.isEmpty()) {
+                    int size = columnHeightSizes[columnIndex];
-                return;
+                    if (size <= 0) {
-            }
-
-            int rx = Cache.keyX(k);
-            int rz = Cache.keyZ(k);
-            v.sort(Integer::compare);
-            CaveZone zone = new CaveZone();
-            zone.setFloor(v.get(0));
-            int buf = v.get(0) - 1;
-
-            for (Integer i : v) {
-                if (i < 0 || i > getEngine().getHeight()) {
                         continue;
                     }
 
-                if (i == buf + 1) {
+                    int[] heights = columnHeights[columnIndex];
-                    buf = i;
+                    Arrays.sort(heights, 0, size);
+                    int rx = columnIndex >> 4;
+                    int rz = columnIndex & 15;
+                    CaveZone zone = new CaveZone();
+                    zone.setFloor(heights[0]);
+                    int buf = heights[0] - 1;
+
+                    for (int heightIndex = 0; heightIndex < size; heightIndex++) {
+                        int y = heights[heightIndex];
+                        if (y < 0 || y > getEngine().getHeight()) {
+                            continue;
+                        }
+
+                        if (y == buf + 1) {
+                            buf = y;
                             zone.ceiling = buf;
                         } else if (zone.isValid(getEngine())) {
-                    processZone(output, mc, mantle, zone, rx, rz, rx + (x << 4), rz + (z << 4));
+                            processZone(output, mc, mantle, zone, rx, rz, rx + (x << 4), rz + (z << 4), resolverState);
                             zone = new CaveZone();
-                    zone.setFloor(i);
+                            zone.setFloor(y);
-                    buf = i;
+                            buf = y;
+                        } else {
+                            zone = new CaveZone();
+                            zone.setFloor(y);
+                            buf = y;
                         }
                     }
 
                     if (zone.isValid(getEngine())) {
-                processZone(output, mc, mantle, zone, rx, rz, rx + (x << 4), rz + (z << 4));
+                        processZone(output, mc, mantle, zone, rx, rz, rx + (x << 4), rz + (z << 4), resolverState);
                     }
-        });
+                }
-
+            } finally {
-        getEngine().getMetrics().getDeposit().put(p.getMilliseconds());
+                getEngine().getMetrics().getCarveApply().put(applyStopwatch.getMilliseconds());
+            }
+        } finally {
+            getEngine().getMetrics().getCave().put(p.getMilliseconds());
             mc.release();
         }
+    }
 
-    private void processZone(Hunk<BlockData> output, MantleChunk<Matter> mc, Mantle<Matter> mantle, CaveZone zone, int rx, int rz, int xx, int zz) {
+    private void processZone(Hunk<BlockData> output, MantleChunk<Matter> mc, Mantle<Matter> mantle, CaveZone zone, int rx, int rz, int xx, int zz, IrisDimensionCarvingResolver.State resolverState) {
-        boolean decFloor = B.isSolid(output.getClosest(rx, zone.floor - 1, rz));
-        boolean decCeiling = B.isSolid(output.getClosest(rx, zone.ceiling + 1, rz));
         int center = (zone.floor + zone.ceiling) / 2;
-        int thickness = zone.airThickness();
         String customBiome = "";
 
         if (B.isDecorant(output.getClosest(rx, zone.ceiling + 1, rz))) {
@@ -207,7 +221,7 @@ public class IrisCarveModifier extends EngineAssignedModifier<BlockData> {
         }
 
         IrisBiome biome = customBiome.isEmpty()
-                ? getEngine().getCaveBiome(xx, center, zz)
+                ? getEngine().getCaveBiome(xx, center, zz, resolverState)
                 : getEngine().getData().getBiomeLoader().load(customBiome);
 
         if (biome == null) {
@@ -272,6 +286,151 @@ public class IrisCarveModifier extends EngineAssignedModifier<BlockData> {
         }
     }
 
+    private void appendColumnHeight(int[][] heights, int[] sizes, int columnIndex, int y) {
+        int[] column = heights[columnIndex];
+        int size = sizes[columnIndex];
+        if (column == null) {
+            column = new int[8];
+            heights[columnIndex] = column;
+        } else if (size >= column.length) {
+            int nextSize = column.length << 1;
+            column = Arrays.copyOf(column, nextSize);
+            heights[columnIndex] = column;
+        }
+
+        column[size] = y;
+        sizes[columnIndex] = size + 1;
+    }
+
+    private static final class PackedWallBuffer {
+        private static final int EMPTY_KEY = -1;
+        private static final double LOAD_FACTOR = 0.75D;
+
+        private int[] keys;
+        private MatterCavern[] values;
+        private int mask;
+        private int resizeAt;
+        private int size;
+
+        private PackedWallBuffer(int expectedSize) {
+            int capacity = 1;
+            int minimumCapacity = Math.max(8, expectedSize);
+            while (capacity < minimumCapacity) {
+                capacity <<= 1;
+            }
+
+            this.keys = new int[capacity];
+            Arrays.fill(this.keys, EMPTY_KEY);
+            this.values = new MatterCavern[capacity];
+            this.mask = capacity - 1;
+            this.resizeAt = Math.max(1, (int) (capacity * LOAD_FACTOR));
+        }
+
+        private void put(int x, int y, int z, MatterCavern value) {
+            int key = pack(x, y, z);
+            int index = mix(key) & mask;
+
+            while (true) {
+                int existingKey = keys[index];
+                if (existingKey == EMPTY_KEY) {
+                    keys[index] = key;
+                    values[index] = value;
+                    size++;
+                    if (size >= resizeAt) {
+                        resize();
+                    }
+                    return;
+                }
+
+                if (existingKey == key) {
+                    values[index] = value;
+                    return;
+                }
+
+                index = (index + 1) & mask;
+            }
+        }
+
+        private void forEach(PackedWallConsumer consumer) {
+            for (int index = 0; index < keys.length; index++) {
+                int key = keys[index];
+                if (key == EMPTY_KEY) {
+                    continue;
+                }
+
+                MatterCavern cavern = values[index];
+                if (cavern == null) {
+                    continue;
+                }
+
+                consumer.accept(unpackX(key), unpackY(key), unpackZ(key), cavern);
+            }
+        }
+
+        private void resize() {
+            int[] oldKeys = keys;
+            MatterCavern[] oldValues = values;
+            int nextCapacity = oldKeys.length << 1;
+            keys = new int[nextCapacity];
+            Arrays.fill(keys, EMPTY_KEY);
+            values = new MatterCavern[nextCapacity];
+            mask = nextCapacity - 1;
+            resizeAt = Math.max(1, (int) (nextCapacity * LOAD_FACTOR));
+            size = 0;
+
+            for (int index = 0; index < oldKeys.length; index++) {
+                int key = oldKeys[index];
+                if (key == EMPTY_KEY) {
+                    continue;
+                }
+
+                MatterCavern value = oldValues[index];
+                if (value == null) {
+                    continue;
+                }
+
+                reinsert(key, value);
+            }
+        }
+
+        private void reinsert(int key, MatterCavern value) {
+            int index = mix(key) & mask;
+            while (keys[index] != EMPTY_KEY) {
+                index = (index + 1) & mask;
+            }
+
+            keys[index] = key;
+            values[index] = value;
+            size++;
+        }
+
+        private int pack(int x, int y, int z) {
+            return (y << 8) | ((x & 15) << 4) | (z & 15);
+        }
+
+        private int unpackX(int key) {
+            return (key >> 4) & 15;
+        }
+
+        private int unpackY(int key) {
+            return key >> 8;
+        }
+
+        private int unpackZ(int key) {
+            return key & 15;
+        }
+
+        private int mix(int value) {
+            int mixed = value * 0x9E3779B9;
+            return mixed ^ (mixed >>> 16);
+        }
+    }
+
+    @FunctionalInterface
+    private interface PackedWallConsumer {
+        void accept(int x, int y, int z, MatterCavern cavern);
+    }
+
     @Data
     public static class CaveZone {
         private int ceiling = -1;

core/src/main/java/art/arcane/iris/engine/object/IrisDimensionCarvingResolver.java

@@ -4,6 +4,9 @@ import art.arcane.iris.engine.framework.Engine;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.iris.util.project.noise.CNG;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -16,30 +19,46 @@ public final class IrisDimensionCarvingResolver {
     }
 
     public static IrisDimensionCarvingEntry resolveRootEntry(Engine engine, int worldY) {
+        return resolveRootEntry(engine, worldY, new State());
+    }
+
+    public static IrisDimensionCarvingEntry resolveRootEntry(Engine engine, int worldY, State state) {
+        State resolvedState = state == null ? new State() : state;
+        if (resolvedState.rootEntriesByWorldY.containsKey(worldY)) {
+            return resolvedState.rootEntriesByWorldY.get(worldY);
+        }
+
         IrisDimension dimension = engine.getDimension();
         List<IrisDimensionCarvingEntry> entries = dimension.getCarving();
         if (entries == null || entries.isEmpty()) {
+            resolvedState.rootEntriesByWorldY.put(worldY, null);
             return null;
         }
 
         IrisDimensionCarvingEntry resolved = null;
         for (IrisDimensionCarvingEntry entry : entries) {
-            if (!isRootCandidate(engine, entry, worldY)) {
+            if (!isRootCandidate(engine, entry, worldY, resolvedState)) {
                 continue;
             }
 
             resolved = entry;
         }
 
+        resolvedState.rootEntriesByWorldY.put(worldY, resolved);
         return resolved;
     }
 
     public static IrisDimensionCarvingEntry resolveFromRoot(Engine engine, IrisDimensionCarvingEntry rootEntry, int worldX, int worldZ) {
+        return resolveFromRoot(engine, rootEntry, worldX, worldZ, new State());
+    }
+
+    public static IrisDimensionCarvingEntry resolveFromRoot(Engine engine, IrisDimensionCarvingEntry rootEntry, int worldX, int worldZ, State state) {
+        State resolvedState = state == null ? new State() : state;
         if (rootEntry == null) {
             return null;
         }
 
-        IrisBiome rootBiome = resolveEntryBiome(engine, rootEntry);
+        IrisBiome rootBiome = resolveEntryBiome(engine, rootEntry, resolvedState);
         if (rootBiome == null) {
             return null;
         }
@@ -49,11 +68,11 @@ public final class IrisDimensionCarvingResolver {
             return rootEntry;
         }
 
-        Map<String, IrisDimensionCarvingEntry> entryIndex = engine.getDimension().getCarvingEntryIndex();
+        Map<String, IrisDimensionCarvingEntry> entryIndex = resolveEntryIndex(engine, resolvedState);
         IrisDimensionCarvingEntry current = rootEntry;
         int depth = remainingDepth;
         while (depth > 0) {
-            IrisDimensionCarvingEntry selected = selectChild(engine, current, worldX, worldZ, entryIndex);
+            IrisDimensionCarvingEntry selected = selectChild(engine, current, worldX, worldZ, entryIndex, resolvedState);
             if (selected == null || selected == current) {
                 break;
             }
@@ -70,14 +89,28 @@ public final class IrisDimensionCarvingResolver {
     }
 
     public static IrisBiome resolveEntryBiome(Engine engine, IrisDimensionCarvingEntry entry) {
+        return resolveEntryBiome(engine, entry, null);
+    }
+
+    public static IrisBiome resolveEntryBiome(Engine engine, IrisDimensionCarvingEntry entry, State state) {
         if (entry == null) {
             return null;
         }
 
+        if (state == null) {
             return entry.getRealBiome(engine.getData());
         }
 
-    private static boolean isRootCandidate(Engine engine, IrisDimensionCarvingEntry entry, int worldY) {
+        if (state.biomeCache.containsKey(entry)) {
+            return state.biomeCache.get(entry);
+        }
+
+        IrisBiome biome = entry.getRealBiome(engine.getData());
+        state.biomeCache.put(entry, biome);
+        return biome;
+    }
+
+    private static boolean isRootCandidate(Engine engine, IrisDimensionCarvingEntry entry, int worldY, State state) {
         if (entry == null || !entry.isEnabled()) {
             return false;
         }
@@ -87,7 +120,7 @@ public final class IrisDimensionCarvingResolver {
             return false;
         }
 
-        return resolveEntryBiome(engine, entry) != null;
+        return resolveEntryBiome(engine, entry, state) != null;
     }
 
     private static IrisDimensionCarvingEntry selectChild(
@@ -95,19 +128,50 @@ public final class IrisDimensionCarvingResolver {
             IrisDimensionCarvingEntry parent,
             int worldX,
             int worldZ,
-            Map<String, IrisDimensionCarvingEntry> entryIndex
+            Map<String, IrisDimensionCarvingEntry> entryIndex,
+            State state
     ) {
         KList<String> children = parent.getChildren();
         if (children == null || children.isEmpty()) {
             return parent;
         }
 
-        IrisBiome parentBiome = resolveEntryBiome(engine, parent);
+        IrisBiome parentBiome = resolveEntryBiome(engine, parent, state);
         if (parentBiome == null) {
             return parent;
         }
 
-        KList<CarvingChoice> options = new KList<>();
+        ParentSelectionPlan selectionPlan = state.selectionPlans.get(parent);
+        if (selectionPlan == null) {
+            selectionPlan = buildSelectionPlan(engine, parent, parentBiome, entryIndex, state);
+            state.selectionPlans.put(parent, selectionPlan);
+        }
+
+        if (selectionPlan.parentOnly) {
+            return parent;
+        }
+
+        long seed = resolveChildSeed(engine, state);
+        CNG childGenerator = parent.getChildrenGenerator(seed, engine.getData());
+        int selectedIndex = childGenerator.fit(0, selectionPlan.maxIndex, worldX, worldZ);
+        CarvingChoice selected = selectionPlan.get(selectedIndex);
+        if (selected == null || selected.entry == null) {
+            return parent;
+        }
+
+        return selected.entry;
+    }
+
+    private static ParentSelectionPlan buildSelectionPlan(
+            Engine engine,
+            IrisDimensionCarvingEntry parent,
+            IrisBiome parentBiome,
+            Map<String, IrisDimensionCarvingEntry> entryIndex,
+            State state
+    ) {
+        List<CarvingChoice> options = new ArrayList<>();
+        KList<String> children = parent.getChildren();
+        if (children != null) {
             for (String childId : children) {
                 if (childId == null || childId.isBlank()) {
                     continue;
@@ -118,27 +182,52 @@ public final class IrisDimensionCarvingResolver {
                     continue;
                 }
 
-            IrisBiome childBiome = resolveEntryBiome(engine, child);
+                IrisBiome childBiome = resolveEntryBiome(engine, child, state);
                 if (childBiome == null) {
                     continue;
                 }
 
                 options.add(new CarvingChoice(child, rarity(childBiome)));
             }
+        }
 
         options.add(new CarvingChoice(parent, rarity(parentBiome)));
         if (options.size() <= 1) {
-            return parent;
+            return ParentSelectionPlan.parentOnly();
         }
 
-        long seed = engine.getSeedManager().getCarve() ^ CHILD_SEED_SALT;
+        CarvingChoice[] mappedChoices = buildRarityMappedChoices(options);
-        CNG childGenerator = parent.getChildrenGenerator(seed, engine.getData());
+        if (mappedChoices.length == 0) {
-        CarvingChoice selected = childGenerator.fitRarity(options, worldX, worldZ);
+            return ParentSelectionPlan.parentOnly();
-        if (selected == null || selected.entry == null) {
-            return parent;
         }
 
-        return selected.entry;
+        return new ParentSelectionPlan(mappedChoices);
+    }
+
+    private static CarvingChoice[] buildRarityMappedChoices(List<CarvingChoice> choices) {
+        int max = 1;
+        for (CarvingChoice choice : choices) {
+            if (choice.rarity > max) {
+                max = choice.rarity;
+            }
+        }
+
+        max++;
+        List<CarvingChoice> mapped = new ArrayList<>();
+        boolean flip = false;
+        for (CarvingChoice choice : choices) {
+            int count = max - choice.rarity;
+            for (int index = 0; index < count; index++) {
+                flip = !flip;
+                if (flip) {
+                    mapped.add(choice);
+                } else {
+                    mapped.add(0, choice);
+                }
+            }
+        }
+
+        return mapped.toArray(new CarvingChoice[0]);
     }
 
     private static int rarity(IrisBiome biome) {
@@ -158,6 +247,68 @@ public final class IrisDimensionCarvingResolver {
         return Math.min(depth, MAX_CHILD_DEPTH);
     }
 
+    private static Map<String, IrisDimensionCarvingEntry> resolveEntryIndex(Engine engine, State state) {
+        if (state.entryIndex == null) {
+            state.entryIndex = engine.getDimension().getCarvingEntryIndex();
+        }
+
+        return state.entryIndex;
+    }
+
+    private static long resolveChildSeed(Engine engine, State state) {
+        if (state.childSeed == null) {
+            state.childSeed = engine.getSeedManager().getCarve() ^ CHILD_SEED_SALT;
+        }
+
+        return state.childSeed;
+    }
+
+    public static final class State {
+        private final Map<Integer, IrisDimensionCarvingEntry> rootEntriesByWorldY = new HashMap<>();
+        private final Map<IrisDimensionCarvingEntry, ParentSelectionPlan> selectionPlans = new IdentityHashMap<>();
+        private final Map<IrisDimensionCarvingEntry, IrisBiome> biomeCache = new IdentityHashMap<>();
+        private Map<String, IrisDimensionCarvingEntry> entryIndex;
+        private Long childSeed;
+    }
+
+    private static final class ParentSelectionPlan {
+        private final CarvingChoice[] mappedChoices;
+        private final int maxIndex;
+        private final boolean parentOnly;
+
+        private ParentSelectionPlan(CarvingChoice[] mappedChoices) {
+            this.mappedChoices = mappedChoices;
+            this.maxIndex = mappedChoices.length - 1;
+            this.parentOnly = false;
+        }
+
+        private ParentSelectionPlan() {
+            this.mappedChoices = null;
+            this.maxIndex = -1;
+            this.parentOnly = true;
+        }
+
+        private static ParentSelectionPlan parentOnly() {
+            return new ParentSelectionPlan();
+        }
+
+        private CarvingChoice get(int index) {
+            if (mappedChoices == null || mappedChoices.length == 0) {
+                return null;
+            }
+
+            if (index < 0) {
+                return mappedChoices[0];
+            }
+
+            if (index >= mappedChoices.length) {
+                return mappedChoices[mappedChoices.length - 1];
+            }
+
+            return mappedChoices[index];
+        }
+    }
+
     private static final class CarvingChoice implements IRare {
         private final IrisDimensionCarvingEntry entry;
         private final int rarity;

core/src/test/java/art/arcane/iris/engine/object/IrisDimensionCarvingResolverParityTest.java

@@ -0,0 +1,319 @@
+package art.arcane.iris.engine.object;
+
+import art.arcane.iris.core.loader.IrisData;
+import art.arcane.iris.core.loader.ResourceLoader;
+import art.arcane.iris.engine.framework.Engine;
+import art.arcane.iris.engine.framework.SeedManager;
+import art.arcane.iris.util.project.noise.CNG;
+import art.arcane.volmlib.util.collection.KList;
+import org.bukkit.Bukkit;
+import org.bukkit.Material;
+import org.bukkit.Server;
+import org.bukkit.block.data.BlockData;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Logger;
+
+import static org.junit.Assert.assertSame;
+import static org.mockito.Answers.CALLS_REAL_METHODS;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+
+public class IrisDimensionCarvingResolverParityTest {
+    private static final int MAX_CHILD_DEPTH = 32;
+    private static final long CHILD_SEED_SALT = 0x9E3779B97F4A7C15L;
+
+    @BeforeClass
+    public static void setupBukkit() {
+        if (Bukkit.getServer() != null) {
+            return;
+        }
+
+        Server server = mock(Server.class);
+        BlockData emptyBlockData = mock(BlockData.class);
+        doReturn(Logger.getLogger("IrisTest")).when(server).getLogger();
+        doReturn("IrisTestServer").when(server).getName();
+        doReturn("1.0").when(server).getVersion();
+        doReturn("1.0").when(server).getBukkitVersion();
+        doReturn(emptyBlockData).when(server).createBlockData(any(Material.class));
+        doReturn(emptyBlockData).when(server).createBlockData(anyString());
+        Bukkit.setServer(server);
+    }
+
+    @Test
+    public void resolverStatefulOverloadsMatchLegacyResolverAcrossSampleGrid() {
+        Fixture fixture = createFixture();
+        IrisDimensionCarvingResolver.State state = new IrisDimensionCarvingResolver.State();
+
+        for (int worldY = -64; worldY <= 320; worldY += 11) {
+            IrisDimensionCarvingEntry legacyRoot = legacyResolveRootEntry(fixture.engine, worldY);
+            IrisDimensionCarvingEntry statefulRoot = IrisDimensionCarvingResolver.resolveRootEntry(fixture.engine, worldY, state);
+            assertSame("root mismatch at worldY=" + worldY, legacyRoot, statefulRoot);
+
+            for (int worldX = -192; worldX <= 192; worldX += 31) {
+                for (int worldZ = -192; worldZ <= 192; worldZ += 37) {
+                    IrisDimensionCarvingEntry legacyResolved = legacyResolveFromRoot(fixture.engine, legacyRoot, worldX, worldZ);
+                    IrisDimensionCarvingEntry statefulResolved = IrisDimensionCarvingResolver.resolveFromRoot(fixture.engine, statefulRoot, worldX, worldZ, state);
+                    assertSame("entry mismatch at worldY=" + worldY + " worldX=" + worldX + " worldZ=" + worldZ, legacyResolved, statefulResolved);
+                }
+            }
+        }
+    }
+
+    @Test
+    public void caveBiomeStateOverloadMatchesDefaultOverloadAcrossSampleGrid() {
+        Fixture fixture = createFixture();
+        IrisDimensionCarvingResolver.State state = new IrisDimensionCarvingResolver.State();
+
+        for (int y = 1; y <= 300; y += 17) {
+            for (int x = -160; x <= 160; x += 23) {
+                for (int z = -160; z <= 160; z += 29) {
+                    IrisBiome defaultBiome = fixture.engine.getCaveBiome(x, y, z);
+                    IrisBiome stateBiome = fixture.engine.getCaveBiome(x, y, z, state);
+                    assertSame("cave biome mismatch at x=" + x + " y=" + y + " z=" + z, defaultBiome, stateBiome);
+                }
+            }
+        }
+    }
+
+    private Fixture createFixture() {
+        IrisBiome rootLowBiome = mock(IrisBiome.class);
+        IrisBiome rootHighBiome = mock(IrisBiome.class);
+        IrisBiome childABiome = mock(IrisBiome.class);
+        IrisBiome childBBiome = mock(IrisBiome.class);
+        IrisBiome childCBiome = mock(IrisBiome.class);
+        IrisBiome fallbackBiome = mock(IrisBiome.class);
+        IrisBiome surfaceBiome = mock(IrisBiome.class);
+
+        doReturn(6).when(rootLowBiome).getRarity();
+        doReturn(4).when(rootHighBiome).getRarity();
+        doReturn(2).when(childABiome).getRarity();
+        doReturn(5).when(childBBiome).getRarity();
+        doReturn(1).when(childCBiome).getRarity();
+        doReturn(0).when(fallbackBiome).getCaveMinDepthBelowSurface();
+
+        @SuppressWarnings("unchecked")
+        ResourceLoader<IrisBiome> biomeLoader = mock(ResourceLoader.class);
+        doReturn(rootLowBiome).when(biomeLoader).load("root-low");
+        doReturn(rootHighBiome).when(biomeLoader).load("root-high");
+        doReturn(childABiome).when(biomeLoader).load("child-a");
+        doReturn(childBBiome).when(biomeLoader).load("child-b");
+        doReturn(childCBiome).when(biomeLoader).load("child-c");
+
+        IrisData data = mock(IrisData.class);
+        doReturn(biomeLoader).when(data).getBiomeLoader();
+
+        IrisDimensionCarvingEntry rootLow = buildEntry("root-low", "root-low", new IrisRange(-64, 120), 4, List.of("child-a", "child-b"));
+        IrisDimensionCarvingEntry rootHigh = buildEntry("root-high", "root-high", new IrisRange(121, 320), 3, List.of("child-b", "child-c"));
+        IrisDimensionCarvingEntry childA = buildEntry("child-a", "child-a", new IrisRange(-2048, -1024), 3, List.of("child-b"));
+        IrisDimensionCarvingEntry childB = buildEntry("child-b", "child-b", new IrisRange(-2048, -1024), 2, List.of("child-c", "child-a"));
+        IrisDimensionCarvingEntry childC = buildEntry("child-c", "child-c", new IrisRange(-2048, -1024), 1, List.of());
+
+        KList<IrisDimensionCarvingEntry> carvingEntries = new KList<>();
+        carvingEntries.add(rootLow);
+        carvingEntries.add(rootHigh);
+        carvingEntries.add(childA);
+        carvingEntries.add(childB);
+        carvingEntries.add(childC);
+
+        Map<String, IrisDimensionCarvingEntry> index = new HashMap<>();
+        index.put(rootLow.getId(), rootLow);
+        index.put(rootHigh.getId(), rootHigh);
+        index.put(childA.getId(), childA);
+        index.put(childB.getId(), childB);
+        index.put(childC.getId(), childC);
+
+        IrisDimension dimension = mock(IrisDimension.class);
+        doReturn(carvingEntries).when(dimension).getCarving();
+        doReturn(index).when(dimension).getCarvingEntryIndex();
+
+        Engine engine = mock(Engine.class, CALLS_REAL_METHODS);
+        doReturn(dimension).when(engine).getDimension();
+        doReturn(data).when(engine).getData();
+        doReturn(new SeedManager(913_531_771L)).when(engine).getSeedManager();
+        doReturn(IrisWorld.builder().minHeight(-64).maxHeight(320).build()).when(engine).getWorld();
+        doReturn(surfaceBiome).when(engine).getSurfaceBiome(anyInt(), anyInt());
+        doReturn(fallbackBiome).when(engine).getCaveBiome(anyInt(), anyInt());
+
+        return new Fixture(engine);
+    }
+
+    private IrisDimensionCarvingEntry buildEntry(String id, String biome, IrisRange worldRange, int depth, List<String> children) {
+        IrisDimensionCarvingEntry entry = new IrisDimensionCarvingEntry();
+        entry.setId(id);
+        entry.setEnabled(true);
+        entry.setBiome(biome);
+        entry.setWorldYRange(worldRange);
+        entry.setChildRecursionDepth(depth);
+        entry.setChildren(new KList<>(children));
+        return entry;
+    }
+
+    private IrisDimensionCarvingEntry legacyResolveRootEntry(Engine engine, int worldY) {
+        IrisDimension dimension = engine.getDimension();
+        List<IrisDimensionCarvingEntry> entries = dimension.getCarving();
+        if (entries == null || entries.isEmpty()) {
+            return null;
+        }
+
+        IrisDimensionCarvingEntry resolved = null;
+        for (IrisDimensionCarvingEntry entry : entries) {
+            if (!legacyIsRootCandidate(engine, entry, worldY)) {
+                continue;
+            }
+
+            resolved = entry;
+        }
+
+        return resolved;
+    }
+
+    private IrisDimensionCarvingEntry legacyResolveFromRoot(Engine engine, IrisDimensionCarvingEntry rootEntry, int worldX, int worldZ) {
+        if (rootEntry == null) {
+            return null;
+        }
+
+        IrisBiome rootBiome = legacyResolveEntryBiome(engine, rootEntry);
+        if (rootBiome == null) {
+            return null;
+        }
+
+        int remainingDepth = clampDepth(rootEntry.getChildRecursionDepth());
+        if (remainingDepth <= 0) {
+            return rootEntry;
+        }
+
+        Map<String, IrisDimensionCarvingEntry> entryIndex = engine.getDimension().getCarvingEntryIndex();
+        IrisDimensionCarvingEntry current = rootEntry;
+        int depth = remainingDepth;
+        while (depth > 0) {
+            IrisDimensionCarvingEntry selected = legacySelectChild(engine, current, worldX, worldZ, entryIndex);
+            if (selected == null || selected == current) {
+                break;
+            }
+
+            depth--;
+            int childDepthLimit = clampDepth(selected.getChildRecursionDepth());
+            if (childDepthLimit < depth) {
+                depth = childDepthLimit;
+            }
+            current = selected;
+        }
+
+        return current;
+    }
+
+    private IrisBiome legacyResolveEntryBiome(Engine engine, IrisDimensionCarvingEntry entry) {
+        if (entry == null) {
+            return null;
+        }
+
+        return entry.getRealBiome(engine.getData());
+    }
+
+    private boolean legacyIsRootCandidate(Engine engine, IrisDimensionCarvingEntry entry, int worldY) {
+        if (entry == null || !entry.isEnabled()) {
+            return false;
+        }
+
+        IrisRange worldYRange = entry.getWorldYRange();
+        if (worldYRange != null && !worldYRange.contains(worldY)) {
+            return false;
+        }
+
+        return legacyResolveEntryBiome(engine, entry) != null;
+    }
+
+    private IrisDimensionCarvingEntry legacySelectChild(
+            Engine engine,
+            IrisDimensionCarvingEntry parent,
+            int worldX,
+            int worldZ,
+            Map<String, IrisDimensionCarvingEntry> entryIndex
+    ) {
+        KList<String> children = parent.getChildren();
+        if (children == null || children.isEmpty()) {
+            return parent;
+        }
+
+        IrisBiome parentBiome = legacyResolveEntryBiome(engine, parent);
+        if (parentBiome == null) {
+            return parent;
+        }
+
+        KList<LegacyCarvingChoice> options = new KList<>();
+        for (String childId : children) {
+            if (childId == null || childId.isBlank()) {
+                continue;
+            }
+
+            IrisDimensionCarvingEntry child = entryIndex.get(childId.trim());
+            if (child == null || !child.isEnabled()) {
+                continue;
+            }
+
+            IrisBiome childBiome = legacyResolveEntryBiome(engine, child);
+            if (childBiome == null) {
+                continue;
+            }
+
+            options.add(new LegacyCarvingChoice(child, rarity(childBiome)));
+        }
+
+        options.add(new LegacyCarvingChoice(parent, rarity(parentBiome)));
+        if (options.size() <= 1) {
+            return parent;
+        }
+
+        long seed = engine.getSeedManager().getCarve() ^ CHILD_SEED_SALT;
+        CNG childGenerator = parent.getChildrenGenerator(seed, engine.getData());
+        LegacyCarvingChoice selected = childGenerator.fitRarity(options, worldX, worldZ);
+        if (selected == null || selected.entry == null) {
+            return parent;
+        }
+
+        return selected.entry;
+    }
+
+    private int rarity(IrisBiome biome) {
+        if (biome == null) {
+            return 1;
+        }
+
+        int rarity = biome.getRarity();
+        return Math.max(rarity, 1);
+    }
+
+    private int clampDepth(int depth) {
+        if (depth <= 0) {
+            return 0;
+        }
+
+        return Math.min(depth, MAX_CHILD_DEPTH);
+    }
+
+    private record Fixture(Engine engine) {
+    }
+
+    private static final class LegacyCarvingChoice implements IRare {
+        private final IrisDimensionCarvingEntry entry;
+        private final int rarity;
+
+        private LegacyCarvingChoice(IrisDimensionCarvingEntry entry, int rarity) {
+            this.entry = entry;
+            this.rarity = rarity;
+        }
+
+        @Override
+        public int getRarity() {
+            return rarity;
+        }
+    }
+}