Stabilized deposit overlap order

- Clumps prepare in parallel and place in dimension region biome order
- Placement evaluates host rules against preceding deposits
- Each clump uses independent deterministic random state
- Configured attempt counts are sampled once per chunk
- Block traversal reuses cursor coordinates
- Tests cover reversed worker completion and generation context cleanup

core/src/test/java/art/arcane/iris/engine/modifier/IrisDepositModifierContextTest.java

@@ -3,6 +3,9 @@ package art.arcane.iris.engine.modifier;
 import art.arcane.iris.engine.IrisEngine;
 import art.arcane.iris.engine.framework.Engine;
 import art.arcane.iris.engine.object.IrisDepositGenerator;
+import art.arcane.iris.engine.object.IrisDepositHeightDistribution;
+import art.arcane.iris.engine.object.IrisDepositPlacementScope;
+import art.arcane.iris.engine.object.IrisObject;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
@@ -16,6 +19,7 @@ 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.matter.Matter;
+import art.arcane.volmlib.util.math.RNG;
 import org.junit.Test;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
@@ -33,14 +37,12 @@ import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.ArgumentMatchers.eq;
-import static org.mockito.ArgumentMatchers.same;
+import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doReturn;
 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.when;
@@ -90,6 +92,26 @@ public class IrisDepositModifierContextTest {
         }
     }
 
+    @Test
+    public void failedClumpChanceDoesNotResampleTheConfiguredAttemptCount() {
+        Engine engine = mock(Engine.class, RETURNS_DEEP_STUBS);
+        IrisDepositGenerator generator = mock(IrisDepositGenerator.class);
+        when(generator.getSpawnChance()).thenReturn(1D);
+        when(generator.getMinPerChunk()).thenReturn(0);
+        when(generator.getMaxPerChunk()).thenReturn(4);
+        when(generator.getPerClumpSpawnChance()).thenReturn(0D);
+        RNG rng = mock(RNG.class);
+        when(rng.d()).thenReturn(0.5D);
+        when(rng.i(0, 5)).thenReturn(4, 0);
+        when(rng.nextParallelRNG(anyLong())).thenReturn(rng);
+
+        new IrisDepositModifier(engine).generate(generator, null, null, rng, 0, 0, false, null);
+
+        verify(generator, times(4)).getPerClumpSpawnChance();
+        verify(rng, times(1)).i(0, 5);
+        verify(generator, never()).getClump(any(), any(), any());
+    }
+
     private static final class Fixture implements AutoCloseable {
         private final ExecutorService executor = Executors.newSingleThreadExecutor();
         private final Engine engine;
@@ -138,16 +160,27 @@ public class IrisDepositModifierContextTest {
                     return null;
                 }).when(scope).close();
             }
-            modifier = spy(new IrisDepositModifier(engine));
-            doAnswer(invocation -> {
-                assertNotSame(caller, Thread.currentThread());
-                assertEquals(scoped, workerRuntime.get());
-                assertSame(engine, IrisContext.require().getEngine());
-                assertSame(context, IrisContext.require().getChunkContext());
-                assertEquals(71L, IrisContext.require().getGenerationSessionId());
-                completed.incrementAndGet();
-                return null;
-            }).when(modifier).generate(any(), same(chunk), any(), any(), eq(2), eq(-3), eq(false), same(context));
+            when(engine.getHeight()).thenReturn(16);
+            IrisObject clump = new IrisObject(1, 1, 1);
+            for (IrisDepositGenerator generator : new IrisDepositGenerator[]{dimensionDeposit, regionDeposit, biomeDeposit}) {
+                when(generator.getSpawnChance()).thenReturn(1D);
+                when(generator.getMinPerChunk()).thenReturn(1);
+                when(generator.getMaxPerChunk()).thenReturn(1);
+                when(generator.getPerClumpSpawnChance()).thenReturn(1D);
+                when(generator.getPlacementScope()).thenReturn(IrisDepositPlacementScope.FULL_HEIGHT);
+                when(generator.getHeightDistribution()).thenReturn(IrisDepositHeightDistribution.UNIFORM);
+                when(generator.matchesBiome(any(), any())).thenReturn(true);
+                doAnswer(invocation -> {
+                    assertNotSame(caller, Thread.currentThread());
+                    assertEquals(scoped, workerRuntime.get());
+                    assertSame(engine, IrisContext.require().getEngine());
+                    assertSame(context, IrisContext.require().getChunkContext());
+                    assertEquals(71L, IrisContext.require().getGenerationSessionId());
+                    completed.incrementAndGet();
+                    return clump;
+                }).when(generator).getClump(any(), any(), any());
+            }
+            modifier = new IrisDepositModifier(engine);
             doAnswer(invocation -> {
                 assertEquals(3, completed.get());
                 assertEquals(scoped ? 3 : 0, closedScopes.get());

core/src/test/java/art/arcane/iris/engine/modifier/IrisDepositModifierOrderingTest.java

@@ -0,0 +1,187 @@
+package art.arcane.iris.engine.modifier;
+
+import art.arcane.iris.engine.framework.Engine;
+import art.arcane.iris.engine.object.IrisDepositGenerator;
+import art.arcane.iris.engine.object.IrisDepositHeightDistribution;
+import art.arcane.iris.engine.object.IrisDepositPlacementScope;
+import art.arcane.iris.engine.object.IrisObject;
+import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.spi.PlatformBlockState;
+import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.util.common.math.IrisBlockVector;
+import art.arcane.iris.util.common.parallel.BurstExecutor;
+import art.arcane.iris.util.common.parallel.MultiBurst;
+import art.arcane.iris.util.project.context.ChunkContext;
+import art.arcane.iris.util.project.hunk.Hunk;
+import art.arcane.volmlib.util.collection.KList;
+import art.arcane.volmlib.util.mantle.runtime.MantleChunk;
+import art.arcane.volmlib.util.mantle.runtime.Mantle;
+import art.arcane.volmlib.util.matter.Matter;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class IrisDepositModifierOrderingTest {
+    @Before
+    public void bindPlatform() {
+        IrisPlatforms.unbind();
+        PlatformRegistries registries = mock(PlatformRegistries.class);
+        PlatformBlockState stone = state("stone");
+        when(registries.block(anyString())).thenReturn(stone);
+        when(registries.deepSlateOre(any(), any())).thenAnswer(invocation -> invocation.getArgument(1));
+        IrisPlatform platform = mock(IrisPlatform.class);
+        when(platform.registries()).thenReturn(registries);
+        IrisPlatforms.bind(platform);
+    }
+
+    @After
+    public void unbindPlatform() {
+        IrisPlatforms.unbind();
+    }
+
+    @Test
+    public void reverseWorkerCompletionKeepsDimensionRegionBiomePlacementOrder() throws Exception {
+        try (Fixture fixture = new Fixture(true)) {
+            fixture.generate();
+            assertEquals(List.of("biome", "region", "dimension"), fixture.completed);
+            fixture.assertBiomeWins();
+        }
+    }
+
+    @Test
+    public void inlinePreparationUsesTheSameOverlappingHostRules() throws Exception {
+        try (Fixture fixture = new Fixture(false)) {
+            fixture.generate();
+            assertEquals(List.of("dimension", "region", "biome"), fixture.completed);
+            fixture.assertBiomeWins();
+        }
+    }
+
+    private static PlatformBlockState state(String material) {
+        PlatformBlockState state = mock(PlatformBlockState.class);
+        when(state.key()).thenReturn("minecraft:" + material);
+        when(state.materialKey()).thenReturn("minecraft:" + material);
+        return state;
+    }
+
+    private static final class Fixture implements AutoCloseable {
+        private final ExecutorService executor = Executors.newFixedThreadPool(3);
+        private final List<String> completed = Collections.synchronizedList(new ArrayList<>());
+        private final CountDownLatch biomeReady = new CountDownLatch(1);
+        private final CountDownLatch regionReady = new CountDownLatch(1);
+        private final Engine engine = mock(Engine.class, RETURNS_DEEP_STUBS);
+        private final ChunkContext context = mock(ChunkContext.class, RETURNS_DEEP_STUBS);
+        private final PlatformBlockState stone = state("stone");
+        private final PlatformBlockState granite = state("granite");
+        private final PlatformBlockState diorite = state("diorite");
+        private final PlatformBlockState diamond = state("diamond_ore");
+        private final Hunk<PlatformBlockState> output = Hunk.newArrayHunk(16, 16, 16);
+        private final MantleChunk<Matter> chunk;
+        private final boolean parallel;
+
+        @SuppressWarnings("unchecked")
+        private Fixture(boolean parallel) {
+            this.parallel = parallel;
+            when(engine.getHeight()).thenReturn(16);
+            when(engine.getCaveBiome(anyInt(), anyInt(), anyInt(), any())).thenReturn(null);
+            when(engine.getDimension().getDepositVariants()).thenReturn(new KList<>());
+            when(context.getRegion().get(anyInt(), anyInt()).getDepositVariants()).thenReturn(new KList<>());
+            when(context.getGenerationSessionId()).thenReturn(11L);
+            chunk = mock(MantleChunk.class);
+            Mantle<Matter> mantle = engine.getMantle().getMantle();
+            doReturn(chunk).when(mantle).getChunk(0, 0);
+            when(chunk.use()).thenReturn(chunk);
+            MultiBurst pool = mock(MultiBurst.class);
+            BurstExecutor burst = new BurstExecutor(executor, 3);
+            burst.setMulticore(parallel);
+            when(engine.burst()).thenReturn(pool);
+            when(pool.burst(parallel)).thenReturn(burst);
+            IrisDepositGenerator dimensionDeposit = generator("dimension", stone, granite);
+            IrisDepositGenerator regionDeposit = generator("region", granite, diorite);
+            IrisDepositGenerator biomeDeposit = generator("biome", diorite, diamond);
+            when(engine.getDimension().getDeposits()).thenReturn(new KList<>(dimensionDeposit));
+            when(context.getRegion().get(7, 7).getDeposits()).thenReturn(new KList<>(regionDeposit));
+            when(context.getBiome().get(7, 7).getDeposits()).thenReturn(new KList<>(biomeDeposit));
+            for (int x = 0; x < 16; x++) {
+                for (int z = 0; z < 16; z++) {
+                    output.set(x, 4, z, stone);
+                }
+            }
+        }
+
+        private IrisDepositGenerator generator(String name, PlatformBlockState requiredHost, PlatformBlockState replacement) {
+            IrisDepositGenerator generator = mock(IrisDepositGenerator.class);
+            when(generator.getSpawnChance()).thenReturn(1D);
+            when(generator.getPerClumpSpawnChance()).thenReturn(1D);
+            when(generator.getMinPerChunk()).thenReturn(1);
+            when(generator.getMaxPerChunk()).thenReturn(1);
+            when(generator.getMinHeight()).thenReturn(4);
+            when(generator.getMaxHeight()).thenReturn(4);
+            when(generator.getPlacementScope()).thenReturn(IrisDepositPlacementScope.FULL_HEIGHT);
+            when(generator.getHeightDistribution()).thenReturn(IrisDepositHeightDistribution.UNIFORM);
+            when(generator.matchesBiome(any(), any())).thenReturn(true);
+            when(generator.canReplace(requiredHost)).thenReturn(true);
+            IrisObject clump = new IrisObject(33, 1, 33);
+            for (int x = -16; x <= 16; x++) {
+                for (int z = -16; z <= 16; z++) {
+                    clump.getBlocks().put(new IrisBlockVector(x, 0, z), replacement);
+                }
+            }
+            when(generator.getClump(any(), any(), any())).thenAnswer(invocation -> {
+                if (parallel && name.equals("dimension")) {
+                    assertTrue(regionReady.await(10, TimeUnit.SECONDS));
+                } else if (parallel && name.equals("region")) {
+                    assertTrue(biomeReady.await(10, TimeUnit.SECONDS));
+                }
+                completed.add(name);
+                if (name.equals("biome")) {
+                    biomeReady.countDown();
+                } else if (name.equals("region")) {
+                    regionReady.countDown();
+                }
+                return clump;
+            });
+            return generator;
+        }
+
+        private void generate() {
+            new IrisDepositModifier(engine).generateDeposits(output, 0, 0, parallel, context);
+            verify(chunk).release();
+        }
+
+        private void assertBiomeWins() {
+            for (int x = 0; x < 16; x++) {
+                for (int z = 0; z < 16; z++) {
+                    assertSame("Deposit collision at " + x + ",4," + z, diamond, output.get(x, 4, z));
+                }
+            }
+        }
+
+        @Override
+        public void close() throws Exception {
+            executor.shutdownNow();
+            assertTrue(executor.awaitTermination(10, TimeUnit.SECONDS));
+        }
+    }
+}