feat: support for world-access driven heightmaps

hollow-cube · Mar 26, 2024 · 3a76ff8 · 3a76ff8
1 parent bcc7d3e
commit 3a76ff8
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Showing 9 changed files with 79 additions and 21 deletions.
diff --git a/src/main/java/net/hollowcube/polar/AnvilPolar.java b/src/main/java/net/hollowcube/polar/AnvilPolar.java
@@ -235,12 +235,9 @@ public class AnvilPolar {
                     if (blockEntity != null) blockEntities.add(blockEntity);
                 }
 
-                var heightmaps = new byte[PolarChunk.HEIGHTMAP_BYTE_SIZE][PolarChunk.HEIGHTMAPS.length];
+                var heightmaps = new int[PolarChunk.MAX_HEIGHTMAPS][];
                 chunkData.getCompound("Heightmaps");
                 //todo: heightmaps
-//                MOTION_BLOCKING MOTION_BLOCKING_NO_LEAVES
-//                OCEAN_FLOOR OCEAN_FLOOR_WG
-//                WORLD_SURFACE WORLD_SURFACE_WG
 
                 var userData = new byte[0];
 

diff --git a/src/main/java/net/hollowcube/polar/PaletteUtil.java b/src/main/java/net/hollowcube/polar/PaletteUtil.java
@@ -1,8 +1,15 @@
 package net.hollowcube.polar;
 
+import net.minestom.server.utils.validate.Check;
+
 final class PaletteUtil {
     private PaletteUtil() {}
 
+    public static int bitsToRepresent(int n) {
+        Check.argCondition(n < 1, "n must be greater than 0");
+        return Integer.SIZE - Integer.numberOfLeadingZeros(n);
+    }
+
     public static long[] pack(int[] ints, int bitsPerEntry) {
         int intsPerLong = (int) Math.floor(64d / bitsPerEntry);
         long[] longs = new long[(int) Math.ceil(ints.length / (double) intsPerLong)];

diff --git a/src/main/java/net/hollowcube/polar/PolarChunk.java b/src/main/java/net/hollowcube/polar/PolarChunk.java
@@ -1,6 +1,7 @@
 package net.hollowcube.polar;
 
 
+import net.minestom.server.instance.Chunk;
 import org.jetbrains.annotations.Nullable;
 import org.jglrxavpok.hephaistos.nbt.NBTCompound;
 
@@ -14,7 +15,7 @@ public record PolarChunk(
         int z,
         PolarSection[] sections,
         List<BlockEntity> blockEntities,
-        byte[][] heightmaps,
+        int[][] heightmaps,
         byte[] userData
 ) {
 
@@ -34,9 +35,10 @@ public record PolarChunk(
             HEIGHTMAP_WORLD_SURFACE,
             HEIGHTMAP_WORLD_SURFACE_WG,
     };
-    static final int HEIGHTMAP_BYTE_SIZE = 32;
+    static final int HEIGHTMAP_SIZE = Chunk.CHUNK_SIZE_X * Chunk.CHUNK_SIZE_Z;
+    static final int MAX_HEIGHTMAPS = 32;
 
-    public byte @Nullable [] heightmap(int type) {
+    public int @Nullable [] heightmap(int type) {
         return heightmaps[type];
     }
 

diff --git a/src/main/java/net/hollowcube/polar/PolarLoader.java b/src/main/java/net/hollowcube/polar/PolarLoader.java
@@ -154,6 +154,8 @@ public void loadInstance(@NotNull Instance instance) {
                 loadBlockEntity(blockEntity, chunk);
             }
 
+            worldAccess.loadHeightmaps(chunk, chunkData.heightmaps());
+
             var userData = chunkData.userData();
             if (userData.length > 0) {
                 worldAccess.loadChunkData(chunk, new NetworkBuffer(ByteBuffer.wrap(userData)));
@@ -286,7 +288,7 @@ private void updateChunkData(@NotNull Short2ObjectMap<String> blockCache, @NotNu
         var sections = new PolarSection[dimension.getHeight() / Chunk.CHUNK_SECTION_SIZE];
         assert sections.length == chunk.getSections().size(): "World height mismatch";
 
-        var heightmaps = new byte[32][PolarChunk.HEIGHTMAPS.length];
+        var heightmaps = new int[PolarChunk.MAX_HEIGHTMAPS][];
 
         var userData = new byte[0];
 
@@ -365,11 +367,9 @@ private void updateChunkData(@NotNull Short2ObjectMap<String> blockCache, @NotNu
                 );
             }
 
-            //todo heightmaps
-
-            if (worldAccess != null)
-                userData = NetworkBuffer.makeArray(b -> worldAccess.saveChunkData(chunk, b));
+            worldAccess.saveHeightmaps(chunk, heightmaps);
 
+            userData = NetworkBuffer.makeArray(b -> worldAccess.saveChunkData(chunk, b));
         }
 
         worldDataLock.writeLock().lock();

diff --git a/src/main/java/net/hollowcube/polar/PolarReader.java b/src/main/java/net/hollowcube/polar/PolarReader.java
@@ -1,6 +1,7 @@
 package net.hollowcube.polar;
 
 import com.github.luben.zstd.Zstd;
+import net.minestom.server.instance.Chunk;
 import net.minestom.server.network.NetworkBuffer;
 import net.minestom.server.utils.NamespaceID;
 import net.minestom.server.utils.chunk.ChunkUtils;
@@ -66,13 +67,16 @@ private PolarReader() {}
 
         var blockEntities = buffer.readCollection(b -> readBlockEntity(version, b), MAX_BLOCK_ENTITIES);
 
-        var heightmaps = new byte[PolarChunk.HEIGHTMAP_BYTE_SIZE][PolarChunk.HEIGHTMAPS.length];
+        var heightmaps = new int[PolarChunk.MAX_HEIGHTMAPS][];
         int heightmapMask = buffer.read(INT);
-        for (int i = 0; i < PolarChunk.HEIGHTMAPS.length; i++) {
-            if ((heightmapMask & PolarChunk.HEIGHTMAPS[i]) == 0)
+        for (int i = 0; i < PolarChunk.MAX_HEIGHTMAPS; i++) {
+            if ((heightmapMask & (1 << i)) == 0)
                 continue;
 
-            heightmaps[i] = buffer.readBytes(32);
+            var packed = buffer.read(LONG_ARRAY);
+            var bitsPerEntry = packed.length * 64 / PolarChunk.HEIGHTMAP_SIZE;
+            heightmaps[i] = new int[PolarChunk.HEIGHTMAP_SIZE];
+            PaletteUtil.unpack(heightmaps[i], packed, bitsPerEntry);
         }
 
         // Objects

diff --git a/src/main/java/net/hollowcube/polar/PolarWorldAccess.java b/src/main/java/net/hollowcube/polar/PolarWorldAccess.java
@@ -7,6 +7,7 @@
 import net.minestom.server.utils.NamespaceID;
 import net.minestom.server.world.biomes.Biome;
 import net.minestom.server.world.biomes.VanillaBiome;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -61,6 +62,12 @@ default void loadChunkData(@NotNull Chunk chunk, @Nullable NetworkBuffer userDat
      */
     default void saveChunkData(@NotNull Chunk chunk, @NotNull NetworkBuffer userData) {}
 
+    @ApiStatus.Experimental
+    default void loadHeightmaps(@NotNull Chunk chunk, int[][] heightmaps) {}
+
+    @ApiStatus.Experimental
+    default void saveHeightmaps(@NotNull Chunk chunk, int[][] heightmaps) {}
+
     /**
      * Called when a chunk is being loaded by a {@link PolarLoader} to convert biome ids back to instances.
      * <br/><br/>

diff --git a/src/main/java/net/hollowcube/polar/PolarWriter.java b/src/main/java/net/hollowcube/polar/PolarWriter.java
@@ -1,6 +1,7 @@
 package net.hollowcube.polar;
 
 import com.github.luben.zstd.Zstd;
+import net.minestom.server.instance.Chunk;
 import net.minestom.server.network.NetworkBuffer;
 import net.minestom.server.utils.chunk.ChunkUtils;
 import org.jetbrains.annotations.NotNull;
@@ -19,7 +20,7 @@ public static byte[] write(@NotNull PolarWorld world) {
         content.write(BYTE, world.minSection());
         content.write(BYTE, world.maxSection());
         content.write(BYTE_ARRAY, world.userData());
-        content.writeCollection(world.chunks(), PolarWriter::writeChunk);
+        content.writeCollection(world.chunks(), (b , c) -> writeChunk(b, c, world.maxSection() - world.minSection() + 1));
 
         // Create final buffer
         return NetworkBuffer.makeArray(buffer -> {
@@ -39,7 +40,7 @@ public static byte[] write(@NotNull PolarWorld world) {
         });
     }
 
-    private static void writeChunk(@NotNull NetworkBuffer buffer, @NotNull PolarChunk chunk) {
+    private static void writeChunk(@NotNull NetworkBuffer buffer, @NotNull PolarChunk chunk, int sectionCount) {
         buffer.write(VAR_INT, chunk.x());
         buffer.write(VAR_INT, chunk.z());
 
@@ -48,8 +49,21 @@ private static void writeChunk(@NotNull NetworkBuffer buffer, @NotNull PolarChun
         }
         buffer.writeCollection(chunk.blockEntities(), PolarWriter::writeBlockEntity);
 
-        //todo heightmaps
-        buffer.write(INT, PolarChunk.HEIGHTMAP_NONE);
+        {
+            int heightmapBits = 0;
+            for (int i = 0; i < PolarChunk.MAX_HEIGHTMAPS; i++) {
+                if (chunk.heightmap(i) != null)
+                    heightmapBits |= 1 << i;
+            }
+            buffer.write(INT, heightmapBits);
+
+            int bitsPerEntry = PaletteUtil.bitsToRepresent(sectionCount * Chunk.CHUNK_SECTION_SIZE);
+            for (int i = 0; i < PolarChunk.MAX_HEIGHTMAPS; i++) {
+                var heightmap = chunk.heightmap(i);
+                if (heightmap == null) continue;
+                buffer.write(LONG_ARRAY, PaletteUtil.pack(heightmap, bitsPerEntry));
+            }
+        }
 
         buffer.write(BYTE_ARRAY, chunk.userData());
     }

diff --git a/src/test/java/net/hollowcube/polar/TestPolarReader.java b/src/test/java/net/hollowcube/polar/TestPolarReader.java
@@ -2,6 +2,9 @@
 
 import org.junit.jupiter.api.Test;
 
+import java.util.Arrays;
+import java.util.List;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
@@ -26,4 +29,26 @@ void testNewerVersionFail() {
         assertEquals("Unsupported Polar version. Up to " + PolarWorld.LATEST_VERSION + " is supported, found 20560.", e.getMessage());
     }
 
+    @Test
+    void testHeightmapReadWrite() {
+        var world = new PolarWorld();
+        var emptySections = new PolarSection[24];
+        Arrays.fill(emptySections, new PolarSection());
+        var heightmaps = new int[PolarChunk.MAX_HEIGHTMAPS][];
+        heightmaps[0] = new int[PolarChunk.HEIGHTMAP_SIZE];
+        for (int i = 0; i < PolarChunk.HEIGHTMAP_SIZE; i++) {
+            heightmaps[0][i] = i;
+        }
+        world.updateChunkAt(0, 0, new PolarChunk(0, 0, emptySections, List.of(), heightmaps, new byte[0]));
+
+        var raw = PolarWriter.write(world);
+        var newWorld = PolarReader.read(raw);
+        var newChunk = newWorld.chunkAt(0, 0);
+        var newHeightmap = newChunk.heightmap(0);
+        for (int i = 0; i < PolarChunk.HEIGHTMAP_SIZE; i++) {
+            assertEquals(i, newHeightmap[i]);
+        }
+
+    }
+
 }
diff --git a/src/test/java/net/hollowcube/polar/TestUserDataWriteRead.java b/src/test/java/net/hollowcube/polar/TestUserDataWriteRead.java
@@ -25,7 +25,9 @@ void testWriteRead() {
 
         var emptySections = new PolarSection[24];
         Arrays.fill(emptySections, new PolarSection());
-        world.updateChunkAt(0, 0, new PolarChunk(0, 0, emptySections, List.of(), new byte[0][0], new byte[0]));
+
+        var heightmaps = new int[PolarChunk.MAX_HEIGHTMAPS][];
+        world.updateChunkAt(0, 0, new PolarChunk(0, 0, emptySections, List.of(), heightmaps, new byte[0]));
 
         var wa = new UpdateTimeWorldAccess();
         var loader = new PolarLoader(world).setWorldAccess(wa);