Baked object placement

- Bake rotated block offsets, palette indexes, tiles and canopy bits per object and spin kernel
- Resolve decay, rotation, waterlog and air facts once per palette entry per placement
- Skip the destination read for waterloggable states that cannot become waterlogged
- Move SpinKernel to its own file

core/src/main/java/art/arcane/iris/structure/object/IrisObject.java

@@ -61,6 +61,7 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.Map;
 import java.util.Objects;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.function.BiConsumer;
@@ -144,6 +145,7 @@ public class IrisObject extends IrisRegistrant {
     protected transient AtomicCache<AxisAlignedBB> aabb = new AtomicCache<>();
     transient final AtomicCache<KList<IrisBlockVector>> surfaceSupportOffsets = new AtomicCache<>();
     transient final AtomicCache<FloatingObjectFootprint> floatingFootprint = new AtomicCache<>();
+    transient final ConcurrentHashMap<ObjectPlacementBake.Key, ObjectPlacementBake> placementBakes = new ConcurrentHashMap<>();
     @Getter
     @Setter
     private transient TreeGrounding treeGrounding;

core/src/main/java/art/arcane/iris/structure/object/ObjectPlacementBake.java

@@ -0,0 +1,259 @@
+package art.arcane.iris.structure.object;
+
+import art.arcane.iris.generation.block.TileData;
+import art.arcane.iris.generation.block.VectorMap;
+import art.arcane.iris.generation.decoration.tree.TreeGrounding;
+import art.arcane.iris.generation.geometry.IrisBlockVector;
+import art.arcane.volmlib.nativelib.terrain.NativeBlockState;
+import it.unimi.dsi.fastutil.ints.IntArrayList;
+
+import java.util.ArrayList;
+import java.util.IdentityHashMap;
+import java.util.List;
+import java.util.concurrent.ConcurrentHashMap;
+
+final class ObjectPlacementBake {
+    private static final int MAXIMUM_VARIANTS_PER_OBJECT = 32;
+
+    private final long blocksRevision;
+    private final long statesRevision;
+    private final TreeGrounding grounding;
+    private final int count;
+    private final int[] offsetX;
+    private final int[] offsetY;
+    private final int[] offsetZ;
+    private final int[] layerY;
+    private final short[] paletteIndexes;
+    private final NativeBlockState[] palette;
+    private final int[] tileBlocks;
+    private final TileData[] tileValues;
+    private final long[] canopy;
+    private final Key key;
+    private volatile double[] exact;
+
+    private ObjectPlacementBake(Key key, long blocksRevision, long statesRevision, TreeGrounding grounding, int count,
+                                int[] offsetX, int[] offsetY, int[] offsetZ, int[] layerY, short[] paletteIndexes,
+                                NativeBlockState[] palette, int[] tileBlocks, TileData[] tileValues, long[] canopy) {
+        this.key = key;
+        this.blocksRevision = blocksRevision;
+        this.statesRevision = statesRevision;
+        this.grounding = grounding;
+        this.count = count;
+        this.offsetX = offsetX;
+        this.offsetY = offsetY;
+        this.offsetZ = offsetZ;
+        this.layerY = layerY;
+        this.paletteIndexes = paletteIndexes;
+        this.palette = palette;
+        this.tileBlocks = tileBlocks;
+        this.tileValues = tileValues;
+        this.canopy = canopy;
+    }
+
+    static ObjectPlacementBake of(IrisObject object, SpinKernel spin, boolean ceilingHang, IrisBlockVector translateOffset) {
+        Key key = Key.of(spin, ceilingHang, translateOffset);
+        ConcurrentHashMap<Key, ObjectPlacementBake> variants = object.placementBakes;
+        ObjectPlacementBake cached = variants.get(key);
+        if (cached != null && cached.matches(object)) {
+            return cached;
+        }
+        ObjectPlacementBake built = bake(object, key, spin, ceilingHang, translateOffset);
+        if (built.matches(object)) {
+            if (variants.size() >= MAXIMUM_VARIANTS_PER_OBJECT) {
+                variants.clear();
+            }
+            variants.put(key, built);
+        }
+        return built;
+    }
+
+    private static ObjectPlacementBake bake(IrisObject object, Key key, SpinKernel spin, boolean ceilingHang,
+                                            IrisBlockVector translateOffset) {
+        object.readLock.lock();
+        try {
+            VectorMap<NativeBlockState> blocks = object.blocks;
+            VectorMap<TileData> states = object.states;
+            long blocksRevision = blocks.modificationRevision();
+            long statesRevision = states.modificationRevision();
+            TreeGrounding grounding = object.getTreeGrounding();
+            boolean hasStates = !states.isEmpty();
+            IntArrayList x = new IntArrayList();
+            IntArrayList y = new IntArrayList();
+            IntArrayList z = new IntArrayList();
+            IntArrayList layer = new IntArrayList();
+            IntArrayList indexes = new IntArrayList();
+            IntArrayList tileBlocks = new IntArrayList();
+            List<TileData> tileValues = new ArrayList<>();
+            List<NativeBlockState> palette = new ArrayList<>();
+            IdentityHashMap<NativeBlockState, Integer> paletteSlots = new IdentityHashMap<>();
+            IntArrayList canopyBlocks = new IntArrayList();
+            boolean layerDiffers = false;
+            IrisBlockVector rotated = new IrisBlockVector(0, 0, 0);
+            VectorMap<NativeBlockState>.Cursor cursor = blocks.cursor();
+            int index = 0;
+            while (cursor.next()) {
+                IrisBlockVector source = cursor.key();
+                NativeBlockState state = cursor.value();
+                if (state == null) {
+                    state = IrisObject.States.air();
+                }
+                transform(source, rotated, spin, ceilingHang, translateOffset);
+                int roundedY = (int) Math.round(rotated.getY());
+                int floorY = rotated.getBlockY();
+                x.add((int) Math.round(rotated.getX()));
+                y.add(roundedY);
+                z.add((int) Math.round(rotated.getZ()));
+                layer.add(floorY);
+                layerDiffers |= floorY != roundedY;
+                Integer slot = paletteSlots.get(state);
+                if (slot == null) {
+                    slot = palette.size();
+                    palette.add(state);
+                    paletteSlots.put(state, slot);
+                }
+                indexes.add(slot);
+                if (hasStates) {
+                    TileData tile = states.get(source);
+                    if (tile != null) {
+                        tileBlocks.add(index);
+                        tileValues.add(tile);
+                    }
+                }
+                if (grounding != null && grounding.isCanopy(source.getBlockX(), source.getBlockY(), source.getBlockZ())) {
+                    canopyBlocks.add(index);
+                }
+                index++;
+            }
+            if (palette.size() > Short.MAX_VALUE) {
+                throw new IllegalStateException("Object " + object.getLoadKey() + " has more than "
+                        + Short.MAX_VALUE + " distinct block states");
+            }
+            short[] paletteIndexes = new short[index];
+            for (int block = 0; block < index; block++) {
+                paletteIndexes[block] = (short) indexes.getInt(block);
+            }
+            long[] canopy = null;
+            if (!canopyBlocks.isEmpty()) {
+                canopy = new long[(index + 63) >>> 6];
+                for (int block : canopyBlocks) {
+                    canopy[block >>> 6] |= 1L << (block & 63);
+                }
+            }
+            return new ObjectPlacementBake(key, blocksRevision, statesRevision, grounding, index,
+                    x.toIntArray(), y.toIntArray(), z.toIntArray(), layerDiffers ? layer.toIntArray() : null,
+                    paletteIndexes, palette.toArray(new NativeBlockState[0]),
+                    tileBlocks.isEmpty() ? null : tileBlocks.toIntArray(),
+                    tileValues.isEmpty() ? null : tileValues.toArray(new TileData[0]), canopy);
+        } finally {
+            object.readLock.unlock();
+        }
+    }
+
+    private static void transform(IrisBlockVector source, IrisBlockVector target, SpinKernel spin, boolean ceilingHang,
+                                  IrisBlockVector translateOffset) {
+        target.setX(source.getX());
+        target.setY(source.getY());
+        target.setZ(source.getZ());
+        spin.rotate(target);
+        if (ceilingHang) {
+            target.setY(-target.getBlockY());
+        }
+        if (translateOffset != null) {
+            target.add(translateOffset);
+        }
+    }
+
+    boolean matches(IrisObject object) {
+        return object.blocks.modificationRevision() == blocksRevision
+                && object.states.modificationRevision() == statesRevision
+                && object.getTreeGrounding() == grounding;
+    }
+
+    int count() {
+        return count;
+    }
+
+    int offsetX(int index) {
+        return offsetX[index];
+    }
+
+    int offsetY(int index) {
+        return offsetY[index];
+    }
+
+    int offsetZ(int index) {
+        return offsetZ[index];
+    }
+
+    int layerY(int index) {
+        return layerY == null ? offsetY[index] : layerY[index];
+    }
+
+    int paletteIndex(int index) {
+        return paletteIndexes[index];
+    }
+
+    NativeBlockState[] palette() {
+        return palette;
+    }
+
+    int[] tileBlocks() {
+        return tileBlocks;
+    }
+
+    TileData[] tileValues() {
+        return tileValues;
+    }
+
+    boolean canopy(int index) {
+        return canopy != null && (canopy[index >>> 6] & (1L << (index & 63))) != 0L;
+    }
+
+    double[] exact(IrisObject object, SpinKernel spin) {
+        double[] resolved = exact;
+        if (resolved != null) {
+            return resolved;
+        }
+        object.readLock.lock();
+        try {
+            resolved = new double[count * 3];
+            IrisBlockVector rotated = new IrisBlockVector(0, 0, 0);
+            VectorMap<NativeBlockState>.Cursor cursor = object.blocks.cursor();
+            int index = 0;
+            while (cursor.next() && index < count) {
+                transform(cursor.key(), rotated, spin, key.ceilingHang(), key.translateOffset());
+                resolved[index * 3] = rotated.getX();
+                resolved[index * 3 + 1] = rotated.getY();
+                resolved[index * 3 + 2] = rotated.getZ();
+                index++;
+            }
+            if (index != count) {
+                throw new IllegalStateException("Object " + object.getLoadKey() + " changed while its placement bake was read");
+            }
+        } finally {
+            object.readLock.unlock();
+        }
+        exact = resolved;
+        return resolved;
+    }
+
+    record Key(boolean rotates, int xMode, int yMode, int zMode, long xCos, long xSin, long yCos, long ySin,
+               long zCos, long zSin, boolean ceilingHang, boolean translating, long translateX, long translateY,
+               long translateZ) {
+        static Key of(SpinKernel spin, boolean ceilingHang, IrisBlockVector translateOffset) {
+            boolean translating = translateOffset != null;
+            return new Key(spin.rotates, spin.xMode, spin.yMode, spin.zMode,
+                    Double.doubleToLongBits(spin.xCos), Double.doubleToLongBits(spin.xSin),
+                    Double.doubleToLongBits(spin.yCos), Double.doubleToLongBits(spin.ySin),
+                    Double.doubleToLongBits(spin.zCos), Double.doubleToLongBits(spin.zSin), ceilingHang, translating,
+                    translating ? Double.doubleToLongBits(translateOffset.getX()) : 0L,
+                    translating ? Double.doubleToLongBits(translateOffset.getY()) : 0L,
+                    translating ? Double.doubleToLongBits(translateOffset.getZ()) : 0L);
+        }
+
+        IrisBlockVector translateOffset() {
+            return translating ? new IrisBlockVector(Double.longBitsToDouble(translateX),
+                    Double.longBitsToDouble(translateY), Double.longBitsToDouble(translateZ)) : null;
+        }
+    }
+}

core/src/main/java/art/arcane/iris/structure/object/SpinKernel.java

@@ -0,0 +1,152 @@
+package art.arcane.iris.structure.object;
+
+import art.arcane.iris.generation.geometry.IrisBlockVector;
+
+/**
+ * Precomputed vector rotation for a single placement.
+ * <p>
+ * This mirrors {@link IrisObjectRotation#rotate(IrisBlockVector, int, int, int)} branch for branch, with two
+ * differences: it mutates the vector handed to it instead of cloning, and the per-axis angle plus its cosine
+ * and sine are resolved once instead of once per block. The angle is a pure function of the axis clamp and the
+ * spin, both fixed for the placement, and Math.cos/Math.sin are pure, so every produced double is identical to
+ * the value the per-call form would have produced.
+ */
+final class SpinKernel {
+    static final int MODE_NONE = 0;
+    static final int MODE_FLIP = 1;
+    static final int MODE_QUARTER = 2;
+    static final int MODE_THREE_QUARTER = 3;
+    static final int MODE_ANGLE = 4;
+
+    final boolean rotates;
+    final int xMode;
+    final int yMode;
+    final int zMode;
+    final double xCos;
+    final double xSin;
+    final double yCos;
+    final double ySin;
+    final double zCos;
+    final double zSin;
+
+    SpinKernel(IrisObjectRotation rotation, int spinx, int spiny, int spinz) {
+        rotates = rotation.canRotate();
+        xMode = rotation.canRotateX() ? modeOf(rotation.getXAxis()) : MODE_NONE;
+        zMode = rotation.canRotateZ() ? modeOf(rotation.getZAxis()) : MODE_NONE;
+        yMode = rotation.canRotateY() ? modeOf(rotation.getYAxis()) : MODE_NONE;
+
+        double xAngle = xMode == MODE_ANGLE ? rotation.getXRotation(spinx) : 0;
+        double zAngle = zMode == MODE_ANGLE ? rotation.getZRotation(spinz) : 0;
+        double yAngle = yMode == MODE_ANGLE ? rotation.getYRotation(spiny) : 0;
+        xCos = Math.cos(xAngle);
+        xSin = Math.sin(xAngle);
+        zCos = Math.cos(zAngle);
+        zSin = Math.sin(zAngle);
+        yCos = Math.cos(yAngle);
+        ySin = Math.sin(yAngle);
+    }
+
+    private static int modeOf(IrisAxisRotationClamp clamp) {
+        if (!clamp.isLocked()) {
+            return MODE_ANGLE;
+        }
+
+        if (Math.abs(clamp.getMax()) % 360D == 180D) {
+            return MODE_FLIP;
+        }
+
+        if (clamp.getMax() % 360D == 90D || clamp.getMax() % 360D == -270D) {
+            return MODE_QUARTER;
+        }
+
+        if (clamp.getMax() == -90D || clamp.getMax() % 360D == 270D) {
+            return MODE_THREE_QUARTER;
+        }
+
+        return MODE_ANGLE;
+    }
+
+    /**
+     * Rotates in place. Axis order (X, then Z, then Y) is load bearing.
+     */
+    void rotate(IrisBlockVector v) {
+        if (!rotates) {
+            return;
+        }
+
+        switch (xMode) {
+            case MODE_FLIP -> {
+                v.setZ(-v.getZ());
+                v.setY(-v.getY());
+            }
+            case MODE_QUARTER -> {
+                double z = v.getZ();
+                v.setZ(v.getY());
+                v.setY(-z);
+            }
+            case MODE_THREE_QUARTER -> {
+                double z = v.getZ();
+                v.setZ(-v.getY());
+                v.setY(z);
+            }
+            case MODE_ANGLE -> {
+                double y = xCos * v.getY() - xSin * v.getZ();
+                double z = xSin * v.getY() + xCos * v.getZ();
+                v.setY(y);
+                v.setZ(z);
+            }
+            default -> {
+            }
+        }
+
+        switch (zMode) {
+            case MODE_FLIP -> {
+                v.setY(-v.getY());
+                v.setX(-v.getX());
+            }
+            case MODE_QUARTER -> {
+                double y = v.getY();
+                v.setY(v.getX());
+                v.setX(-y);
+            }
+            case MODE_THREE_QUARTER -> {
+                double y = v.getY();
+                v.setY(-v.getX());
+                v.setX(y);
+            }
+            case MODE_ANGLE -> {
+                double x = zCos * v.getX() - zSin * v.getY();
+                double y = zSin * v.getX() + zCos * v.getY();
+                v.setX(x);
+                v.setY(y);
+            }
+            default -> {
+            }
+        }
+
+        switch (yMode) {
+            case MODE_FLIP -> {
+                v.setX(-v.getX());
+                v.setZ(-v.getZ());
+            }
+            case MODE_QUARTER -> {
+                double x = v.getX();
+                v.setX(v.getZ());
+                v.setZ(-x);
+            }
+            case MODE_THREE_QUARTER -> {
+                double x = v.getX();
+                v.setX(-v.getZ());
+                v.setZ(x);
+            }
+            case MODE_ANGLE -> {
+                double x = yCos * v.getX() + ySin * v.getZ();
+                double z = -ySin * v.getX() + yCos * v.getZ();
+                v.setX(x);
+                v.setZ(z);
+            }
+            default -> {
+            }
+        }
+    }
+}

core/src/test/java/art/arcane/iris/structure/object/IrisObjectPlacementRunnerRegressionTest.java

@@ -791,7 +791,7 @@ public class IrisObjectPlacementRunnerRegressionTest {
 
                     object.place(0, ANCHOR_Y, 0, placer, placement, new RNG(2L), data);
 
-                    assertEquals(1, placer.blockReads);
+                    assertEquals(enabled || authored ? 1 : 0, placer.blockReads);
                     assertEquals(1, placer.writes().size());
                     assertSame(submerged && (enabled || authored) ? wet : dry,
                             placer.writes().get(0).state());

core/src/test/java/art/arcane/iris/structure/object/ObjectPlacementBakeTest.java

@@ -0,0 +1,76 @@
+package art.arcane.iris.structure.object;
+
+import art.arcane.iris.generation.geometry.IrisBlockVector;
+import art.arcane.iris.testsupport.KeyedBlockState;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotSame;
+import static org.junit.Assert.assertSame;
+
+public class ObjectPlacementBakeTest {
+    @Test
+    public void spinsResolvingToTheSameKernelShareOneBake() {
+        IrisObject object = object();
+        IrisObjectRotation rotation = new IrisObjectRotation();
+
+        ObjectPlacementBake first = ObjectPlacementBake.of(object, new SpinKernel(rotation, 0, 10, 0), false, null);
+        ObjectPlacementBake second = ObjectPlacementBake.of(object, new SpinKernel(rotation, 3, 80, 9), false, null);
+        ObjectPlacementBake turned = ObjectPlacementBake.of(object, new SpinKernel(rotation, 0, 100, 0), false, null);
+
+        assertSame(first, second);
+        assertNotSame(first, turned);
+        assertEquals(3, first.count());
+    }
+
+    @Test
+    public void bakedOffsetsMatchTheKernelTransformInCursorOrder() {
+        IrisObject object = object();
+        IrisObjectRotation rotation = IrisObjectRotation.of(0D, 90D, 0D);
+        SpinKernel spin = new SpinKernel(rotation, 0, 0, 0);
+        IrisBlockVector translate = new IrisBlockVector(1.5D, -2D, 0.25D);
+
+        ObjectPlacementBake bake = ObjectPlacementBake.of(object, spin, true, translate);
+        double[] exact = bake.exact(object, spin);
+
+        int index = 0;
+        for (IrisBlockVector source : object.getBlocks().keys()) {
+            IrisBlockVector expected = source.clone();
+            spin.rotate(expected);
+            expected.setY(-expected.getBlockY());
+            expected.add(translate);
+            assertEquals((int) Math.round(expected.getX()), bake.offsetX(index));
+            assertEquals((int) Math.round(expected.getY()), bake.offsetY(index));
+            assertEquals((int) Math.round(expected.getZ()), bake.offsetZ(index));
+            assertEquals(expected.getBlockY(), bake.layerY(index));
+            assertEquals(expected.getX(), exact[index * 3], 0D);
+            assertEquals(expected.getY(), exact[index * 3 + 1], 0D);
+            assertEquals(expected.getZ(), exact[index * 3 + 2], 0D);
+            index++;
+        }
+        assertEquals(bake.count(), index);
+    }
+
+    @Test
+    public void editedObjectsRebake() {
+        IrisObject object = object();
+        SpinKernel spin = new SpinKernel(new IrisObjectRotation(), 0, 0, 0);
+        ObjectPlacementBake before = ObjectPlacementBake.of(object, spin, false, null);
+
+        object.getBlocks().put(new IrisBlockVector(1, 1, 1), new KeyedBlockState("minecraft:dirt"));
+        ObjectPlacementBake after = ObjectPlacementBake.of(object, spin, false, null);
+
+        assertNotSame(before, after);
+        assertEquals(4, after.count());
+        assertSame(after, ObjectPlacementBake.of(object, spin, false, null));
+    }
+
+    private static IrisObject object() {
+        IrisObject object = new IrisObject(5, 5, 5);
+        KeyedBlockState stone = new KeyedBlockState("minecraft:stone");
+        object.getBlocks().put(new IrisBlockVector(-2, 0, 1), stone);
+        object.getBlocks().put(new IrisBlockVector(0, -1, 2), stone);
+        object.getBlocks().put(new IrisBlockVector(2, 2, -2), new KeyedBlockState("minecraft:oak_log[axis=y]"));
+        return object;
+    }
+}