Single-pass deposit clumps

- Place ellipsoid deposit clumps from the footprint cells instead of rebuilding the clump object
- Skip ore cave-biome lookups when no pack biome scales ore deposits
- Reject terrain-limited clumps before biome work when scaling cannot apply
- Compute the chunk terrain limit once per chunk
- Draw the exposure discard roll only when the discard chance is positive

core/src/test/java/art/arcane/iris/generation/decoration/IrisDepositTuningTest.java

@@ -16,6 +16,8 @@ import org.junit.Test;
 import org.mockito.MockedStatic;
 
 import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.List;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -258,6 +260,40 @@ public class IrisDepositTuningTest {
         assertNull(generator.sampleClumpFootprint(new RNG(1L), data));
     }
 
+    @Test
+    public void ellipsoidFootprintCellsMatchTheBuiltClumpInPlacementOrder() {
+        IrisData data = mock(IrisData.class);
+        IrisDepositGenerator generator = new IrisDepositGenerator();
+        for (String key : new String[]{"minecraft:iron_ore", "minecraft:gold_ore", "minecraft:copper_ore"}) {
+            IrisBlockData block = mock(IrisBlockData.class);
+            NativeBlockState state = mock(NativeBlockState.class);
+            when(block.getBlockData(data)).thenReturn(state);
+            when(state.key()).thenReturn(key);
+            generator.getPalette().add(block);
+        }
+        generator.setShape(IrisDepositShape.VANILLA_ELLIPSOID);
+        for (int size : new int[]{0, 1, 3, 4, 9, 17, 25, 64}) {
+            generator.setMinSize(size).setMaxSize(size);
+            for (long seed = 0; seed < 300; seed++) {
+                IrisObject clump = generator.getClump(null, new RNG(seed), data);
+                List<String> expected = new ArrayList<>();
+                VectorMap<NativeBlockState>.Cursor cursor = clump.getBlocks().cursor();
+                while (cursor.next()) {
+                    expected.add(cursor.key().getBlockX() + "," + cursor.key().getBlockY() + ","
+                            + cursor.key().getBlockZ() + "=" + cursor.value().key());
+                }
+                RNG sampled = new RNG(seed);
+                IrisDepositGenerator.ClumpCells cells = generator.sampleClumpFootprint(sampled, data).cells();
+                List<String> actual = new ArrayList<>();
+                for (int cell = 0; cell < cells.size(); cell++) {
+                    actual.add(cells.x(cell) + "," + cells.y(cell) + "," + cells.z(cell) + "="
+                            + cells.block(cell).key());
+                }
+                assertEquals("size " + size + " seed " + seed, expected, actual);
+            }
+        }
+    }
+
     @Test
     public void vanillaScatteredSizeIsAnUpperCandidateBound() {
         IrisData data = mock(IrisData.class);

core/src/test/java/art/arcane/iris/generation/stage/IrisDepositModifierParityTest.java

@@ -107,6 +107,18 @@ public class IrisDepositModifierParityTest {
         }
     }
 
+    @Test
+    public void unscaledPacksSkipOreCaveBiomeLookupsWithIdenticalOutput() {
+        for (long seed : new long[]{101L, -73L, 90181L}) {
+            AtomicInteger scannedLookups = new AtomicInteger();
+            AtomicInteger unscannedLookups = new AtomicInteger();
+            long[] scanned = generateConfigured(seed, false, true, true, scannedLookups, null, false);
+            long[] unscanned = generateConfigured(seed, false, true, false, unscannedLookups, null, false);
+            assertArrayEquals("seed=" + seed, unscanned, scanned);
+            assertTrue(scannedLookups.get() < unscannedLookups.get());
+        }
+    }
+
     @Test
     public void unmatchableSurfaceBiomeFiltersSkipClumpsWithoutChangingOutput() {
         long[] expected = {-681153659952315909L, 784L, 2118L, 53L, 67L, 10L};
@@ -126,9 +138,15 @@ public class IrisDepositModifierParityTest {
         return generateConfigured(seed, multicore, caveVariant, enumerablePack, caveBiomeLookups, null);
     }
 
-    @SuppressWarnings("unchecked")
     private long[] generateConfigured(long seed, boolean multicore, boolean caveVariant, boolean enumerablePack,
                                       AtomicInteger caveBiomeLookups, AtomicInteger unmatchableClumps) {
+        return generateConfigured(seed, multicore, caveVariant, enumerablePack, caveBiomeLookups, unmatchableClumps, true);
+    }
+
+    @SuppressWarnings("unchecked")
+    private long[] generateConfigured(long seed, boolean multicore, boolean caveVariant, boolean enumerablePack,
+                                      AtomicInteger caveBiomeLookups, AtomicInteger unmatchableClumps,
+                                      boolean oreScaling) {
         Engine engine = mock(Engine.class, withSettings().stubOnly().defaultAnswer(RETURNS_DEEP_STUBS));
         ChunkContext context = mock(ChunkContext.class, withSettings().stubOnly().defaultAnswer(RETURNS_DEEP_STUBS));
         IrisDimension dimension = new IrisDimension();
@@ -136,8 +154,10 @@ public class IrisDepositModifierParityTest {
         IrisBiome surface = new IrisBiome();
         IrisBiome cave = new IrisBiome();
         cave.setLoadKey("allowed");
-        cave.setOreDepositFrequencyMultiplier(0.65D);
-        cave.setOreDepositSizeMultiplier(1.5D);
+        if (oreScaling) {
+            cave.setOreDepositFrequencyMultiplier(0.65D);
+            cave.setOreDepositSizeMultiplier(1.5D);
+        }
         IrisBiome denied = new IrisBiome();
         denied.setLoadKey("denied");
         IrisDepositVariant variant = new IrisDepositVariant().setMinHeight(-64).setMaxHeight(64);