Cached more water rasters

- Stored raster tiers fluids and feature ids as per-chunk palettes
- Derived cave ceilings from terrain heights and water heads
- Raised the water raster cache from 1024 to 8192 chunks

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

@@ -56,7 +56,7 @@ import java.util.function.Predicate;
 import java.util.function.Supplier;
 
 public final class HydrologyRuntime {
-    private static final int RASTER_CAPACITY = 1024;
+    private static final int RASTER_CAPACITY = 8192;
     private static final int KEEP_SCOPES = 2;
     private static final int CHUNKS_PER_WINDOW = WindowKey.SIZE >> 4;
     public static final int MAX_PREGENERATION_REGIONS = 4096;

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

@@ -2,6 +2,8 @@ package art.arcane.iris.generation.hydrology.raster;
 
 import art.arcane.iris.generation.hydrology.water.HydrologyTier;
 
+import java.util.Arrays;
+
 public final class ChunkWaterRaster {
     public static final int MAX_SHORE_DISTANCE = 32;
     public static final ChunkWaterRaster PROVISIONAL = new ChunkWaterRaster(true);
@@ -13,10 +15,13 @@ public final class ChunkWaterRaster {
     private final int[] terrain;
     private final int[] head;
     private final byte[] role;
-    private final HydrologyTier[] tier;
-    private final long[] featureId;
-    private final String[] fluid;
-    private final int[] caveCeiling;
+    private final byte[] tier;
+    private final HydrologyTier[] tiers;
+    private final byte[] feature;
+    private final long[] features;
+    private final byte[] fluid;
+    private final String[] fluids;
+    private final boolean caveMask;
     private final byte[] shoreDistance;
 
     private ChunkWaterRaster(boolean provisional) {
@@ -25,26 +30,32 @@ public final class ChunkWaterRaster {
         this.head = null;
         this.role = null;
         this.tier = null;
-        this.featureId = null;
+        this.tiers = null;
+        this.feature = null;
+        this.features = null;
         this.fluid = null;
-        this.caveCeiling = null;
+        this.fluids = null;
+        this.caveMask = false;
         this.shoreDistance = null;
     }
 
-    ChunkWaterRaster(int[] terrain, int[] head, byte[] role, HydrologyTier[] tier, long[] featureId, String[] fluid, int[] caveCeiling,
-                     byte[] shoreDistance) {
-        if (terrain.length != COLUMNS || head.length != COLUMNS || role.length != COLUMNS || tier.length != COLUMNS
-                || featureId.length != COLUMNS || fluid.length != COLUMNS || caveCeiling.length != COLUMNS || shoreDistance.length != COLUMNS) {
+    ChunkWaterRaster(int[] terrain, int[] head, byte[] role, Palette<HydrologyTier> tiers, LongPalette features, Palette<String> fluids,
+                     boolean caveMask, byte[] shoreDistance) {
+        if (terrain.length != COLUMNS || head.length != COLUMNS || role.length != COLUMNS || tiers.indices.length != COLUMNS
+                || features.indices.length != COLUMNS || fluids.indices.length != COLUMNS || shoreDistance.length != COLUMNS) {
             throw new IllegalArgumentException("A chunk water raster needs " + COLUMNS + " entries per array");
         }
         this.provisional = false;
         this.terrain = terrain;
         this.head = head;
         this.role = role;
-        this.tier = tier;
-        this.featureId = featureId;
-        this.fluid = fluid;
-        this.caveCeiling = caveCeiling;
+        this.tier = tiers.indices;
+        this.tiers = tiers.values();
+        this.feature = features.indices;
+        this.features = features.values();
+        this.fluid = fluids.indices;
+        this.fluids = fluids.values();
+        this.caveMask = caveMask;
         this.shoreDistance = shoreDistance;
     }
 
@@ -68,22 +79,22 @@ public final class ChunkWaterRaster {
 
     public HydrologyTier tier(int lx, int lz) {
         int index = index(lx, lz);
-        return tier == null ? null : tier[index];
+        return tier == null ? null : tiers[tier[index] & 0xFF];
     }
 
     public long featureId(int lx, int lz) {
         int index = index(lx, lz);
-        return featureId == null ? 0L : featureId[index];
+        return feature == null ? 0L : features[feature[index] & 0xFF];
     }
 
     public String fluid(int lx, int lz) {
         int index = index(lx, lz);
-        return fluid == null ? null : fluid[index];
+        return fluid == null ? null : fluids[fluid[index] & 0xFF];
     }
 
     public int caveCeiling(int lx, int lz) {
         int index = index(lx, lz);
-        return caveCeiling == null ? Integer.MAX_VALUE : caveCeiling[index];
+        return caveMask && head[index] != Integer.MIN_VALUE ? terrain[index] - 1 : Integer.MAX_VALUE;
     }
 
     public int shoreDistance(int lx, int lz) {
@@ -105,4 +116,53 @@ public final class ChunkWaterRaster {
         }
         return lz << 4 | lx;
     }
+
+    static final class Palette<T> {
+        private final byte[] indices = new byte[COLUMNS];
+        private final T[] seen;
+        private int size;
+
+        Palette(T[] seen) {
+            if (seen.length != COLUMNS) {
+                throw new IllegalArgumentException("A raster palette needs room for " + COLUMNS + " values");
+            }
+            this.seen = seen;
+        }
+
+        void set(int column, T value) {
+            int found = 0;
+            while (found < size && seen[found] != value) {
+                found++;
+            }
+            if (found == size) {
+                seen[size++] = value;
+            }
+            indices[column] = (byte) found;
+        }
+
+        private T[] values() {
+            return Arrays.copyOf(seen, size);
+        }
+    }
+
+    static final class LongPalette {
+        private final byte[] indices = new byte[COLUMNS];
+        private final long[] seen = new long[COLUMNS];
+        private int size;
+
+        void set(int column, long value) {
+            int found = 0;
+            while (found < size && seen[found] != value) {
+                found++;
+            }
+            if (found == size) {
+                seen[size++] = value;
+            }
+            indices[column] = (byte) found;
+        }
+
+        private long[] values() {
+            return Arrays.copyOf(seen, size);
+        }
+    }
 }

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

@@ -385,34 +385,37 @@ final class RasterComposer {
 
     private ChunkWaterRaster pack() {
         int columns = ChunkWaterRaster.COLUMNS;
+        boolean affected = false;
+        for (int lz = 0; lz < CHUNK && !affected; lz++) {
+            for (int lx = 0; lx < CHUNK && !affected; lx++) {
+                int cell = (lz + 1) * GRID + lx + 1;
+                affected = role[cell] != WaterRole.NONE || terrain[cell] != natural[cell] || shore(cell) < ChunkWaterRaster.MAX_SHORE_DISTANCE;
+            }
+        }
+        if (!affected) {
+            return ChunkWaterRaster.EMPTY;
+        }
         int[] terrainOut = new int[columns];
         int[] headOut = new int[columns];
         byte[] roleOut = new byte[columns];
-        HydrologyTier[] tierOut = new HydrologyTier[columns];
-        long[] featureOut = new long[columns];
-        String[] fluidOut = new String[columns];
-        int[] caveOut = new int[columns];
+        ChunkWaterRaster.Palette<HydrologyTier> tierOut = new ChunkWaterRaster.Palette<>(new HydrologyTier[columns]);
+        ChunkWaterRaster.LongPalette featureOut = new ChunkWaterRaster.LongPalette();
+        ChunkWaterRaster.Palette<String> fluidOut = new ChunkWaterRaster.Palette<>(new String[columns]);
         byte[] shoreOut = new byte[columns];
-        boolean caveMask = settings.deformation().caveMask();
-        boolean affected = false;
         for (int lz = 0; lz < CHUNK; lz++) {
             for (int lx = 0; lx < CHUNK; lx++) {
                 int cell = (lz + 1) * GRID + lx + 1;
                 int index = lz << 4 | lx;
-                int shore = shore(cell);
                 terrainOut[index] = terrain[cell];
                 headOut[index] = head[cell];
                 roleOut[index] = (byte) role[cell].ordinal();
-                tierOut[index] = tier[cell];
-                featureOut[index] = feature[cell];
-                fluidOut[index] = fluid[cell];
-                caveOut[index] = caveMask && head[cell] != Integer.MIN_VALUE ? terrain[cell] - 1 : Integer.MAX_VALUE;
-                shoreOut[index] = (byte) shore;
-                affected |= role[cell] != WaterRole.NONE || terrain[cell] != natural[cell] || shore < ChunkWaterRaster.MAX_SHORE_DISTANCE;
+                tierOut.set(index, tier[cell]);
+                featureOut.set(index, feature[cell]);
+                fluidOut.set(index, fluid[cell]);
+                shoreOut[index] = (byte) shore(cell);
             }
         }
-        return affected ? new ChunkWaterRaster(terrainOut, headOut, roleOut, tierOut, featureOut, fluidOut, caveOut, shoreOut)
-                : ChunkWaterRaster.EMPTY;
+        return new ChunkWaterRaster(terrainOut, headOut, roleOut, tierOut, featureOut, fluidOut, settings.deformation().caveMask(), shoreOut);
     }
 
     private int shore(int cell) {