Move to new generation API

- Currently not working due to lack of biome-setting capability via BiomeProvider for flat worlds

Bukkit/src/main/java/com/plotsquared/bukkit/generator/BukkitPlotGenerator.java

@@ -29,28 +29,35 @@ import com.plotsquared.bukkit.queue.GenChunk;
 import com.plotsquared.bukkit.util.BukkitUtil;
 import com.plotsquared.bukkit.util.BukkitWorld;
 import com.plotsquared.core.PlotSquared;
+import com.plotsquared.core.generator.ClassicPlotWorld;
 import com.plotsquared.core.generator.GeneratorWrapper;
 import com.plotsquared.core.generator.IndependentPlotGenerator;
 import com.plotsquared.core.generator.SingleWorldGenerator;
 import com.plotsquared.core.location.ChunkWrapper;
+import com.plotsquared.core.location.UncheckedWorldLocation;
 import com.plotsquared.core.plot.PlotArea;
 import com.plotsquared.core.plot.world.PlotAreaManager;
 import com.plotsquared.core.queue.ZeroedDelegateScopedQueueCoordinator;
 import com.plotsquared.core.util.ChunkManager;
+import com.sk89q.worldedit.bukkit.BukkitAdapter;
 import com.sk89q.worldedit.math.BlockVector2;
+import org.bukkit.HeightMap;
 import org.bukkit.World;
 import org.bukkit.block.Biome;
+import org.bukkit.generator.BiomeProvider;
 import org.bukkit.generator.BlockPopulator;
 import org.bukkit.generator.ChunkGenerator;
+import org.bukkit.generator.WorldInfo;
 import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Random;
 import java.util.Set;
 
-public class BukkitPlotGenerator extends ChunkGenerator
-        implements GeneratorWrapper<ChunkGenerator> {
+public class BukkitPlotGenerator extends ChunkGenerator implements GeneratorWrapper<ChunkGenerator> {
 
     @SuppressWarnings("unused")
     public final boolean PAPER_ASYNC_SAFE = true;
@@ -60,9 +67,15 @@ public class BukkitPlotGenerator extends ChunkGenerator
     private final ChunkGenerator platformGenerator;
     private final boolean full;
     private final String levelName;
+    private final boolean useNewGenerationMethods;
+    private final BiomeProvider biomeProvider;
     private List<BlockPopulator> populators;
     private boolean loaded = false;
 
+    private PlotArea lastPlotArea;
+    private int lastChunkX = Integer.MIN_VALUE;
+    private int lastChunkZ = Integer.MIN_VALUE;
+
     public BukkitPlotGenerator(
             final @NonNull String name,
             final @NonNull IndependentPlotGenerator generator,
@@ -75,18 +88,23 @@ public class BukkitPlotGenerator extends ChunkGenerator
         this.populators = new ArrayList<>();
         this.populators.add(new BlockStatePopulator(this.plotGenerator, this.plotAreaManager));
         this.full = true;
+        this.useNewGenerationMethods = PlotSquared.platform().serverVersion()[1] >= 17;
+        this.biomeProvider = new BukkitPlotBiomeProvider();
     }
 
     public BukkitPlotGenerator(final String world, final ChunkGenerator cg, final @NonNull PlotAreaManager plotAreaManager) {
         if (cg instanceof BukkitPlotGenerator) {
-            throw new IllegalArgumentException("ChunkGenerator: " + cg.getClass().getName()
-                    + " is already a BukkitPlotGenerator!");
+            throw new IllegalArgumentException("ChunkGenerator: " + cg
+                    .getClass()
+                    .getName() + " is already a BukkitPlotGenerator!");
         }
         this.plotAreaManager = plotAreaManager;
         this.levelName = world;
         this.full = false;
         this.platformGenerator = cg;
         this.plotGenerator = new DelegatePlotGenerator(cg, world);
+        this.useNewGenerationMethods = PlotSquared.platform().serverVersion()[1] >= 17;
+        this.biomeProvider = null;
     }
 
     @Override
@@ -112,30 +130,7 @@ public class BukkitPlotGenerator extends ChunkGenerator
     @Override
     public @NonNull List<BlockPopulator> getDefaultPopulators(@NonNull World world) {
         try {
-            if (!this.loaded) {
-                String name = world.getName();
-                PlotSquared.get().loadWorld(name, this);
-                final Set<PlotArea> areas = this.plotAreaManager.getPlotAreasSet(name);
-                if (!areas.isEmpty()) {
-                    PlotArea area = areas.iterator().next();
-                    if (!area.isMobSpawning()) {
-                        if (!area.isSpawnEggs()) {
-                            world.setSpawnFlags(false, false);
-                        }
-                        world.setAmbientSpawnLimit(0);
-                        world.setAnimalSpawnLimit(0);
-                        world.setMonsterSpawnLimit(0);
-                        world.setWaterAnimalSpawnLimit(0);
-                    } else {
-                        world.setSpawnFlags(true, true);
-                        world.setAmbientSpawnLimit(-1);
-                        world.setAnimalSpawnLimit(-1);
-                        world.setMonsterSpawnLimit(-1);
-                        world.setWaterAnimalSpawnLimit(-1);
-                    }
-                }
-                this.loaded = true;
-            }
+            checkLoaded(world);
         } catch (Exception e) {
             e.printStackTrace();
         }
@@ -154,12 +149,138 @@ public class BukkitPlotGenerator extends ChunkGenerator
         return toAdd;
     }
 
-    @Override
-    public @NonNull ChunkData generateChunkData(
-            @NonNull World world, @NonNull Random random, int x, int z,
-            @NonNull BiomeGrid biome
-    ) {
+    // Extracted to synchronized method for thread-safety, preventing multiple internal world load calls
+    private synchronized void checkLoaded(World world) {
+        if (!this.loaded) {
+            String name = world.getName();
+            PlotSquared.get().loadWorld(name, this);
+            final Set<PlotArea> areas = this.plotAreaManager.getPlotAreasSet(name);
+            if (!areas.isEmpty()) {
+                PlotArea area = areas.iterator().next();
+                if (!area.isMobSpawning()) {
+                    if (!area.isSpawnEggs()) {
+                        world.setSpawnFlags(false, false);
+                    }
+                    setSpawnLimits(world, 0);
+                } else {
+                    world.setSpawnFlags(true, true);
+                    setSpawnLimits(world, -1);
+                }
+            }
+            this.loaded = true;
+        }
+    }
 
+    @SuppressWarnings("deprecation") // Kept for compatibility with <=1.17.1
+    private void setSpawnLimits(World world, int spawnLimit) {
+        world.setAmbientSpawnLimit(spawnLimit);
+        world.setAnimalSpawnLimit(spawnLimit);
+        world.setMonsterSpawnLimit(spawnLimit);
+        world.setWaterAnimalSpawnLimit(spawnLimit);
+    }
+
+    @Override
+    public void generateNoise(
+            @NotNull final WorldInfo worldInfo,
+            @NotNull final Random random,
+            final int chunkX,
+            final int chunkZ,
+            @NotNull final ChunkData chunkData
+    ) {
+        if (this.platformGenerator != this) {
+            this.platformGenerator.generateNoise(worldInfo, random, chunkX, chunkZ, chunkData);
+            return;
+        }
+        int minY = chunkData.getMinHeight();
+        int maxY = chunkData.getMaxHeight();
+        GenChunk result = new GenChunk(minY, maxY);
+        // Set the chunk location
+        result.setChunk(new ChunkWrapper(worldInfo.getName(), chunkX, chunkZ));
+        // Set the result data
+        result.setChunkData(chunkData);
+        result.result = null;
+
+        // Catch any exceptions (as exceptions usually thrown)
+        try {
+            generate(BlockVector2.at(chunkX, chunkZ), worldInfo.getName(), result, false);
+        } catch (Throwable e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Override
+    public void generateSurface(
+            @NotNull final WorldInfo worldInfo,
+            @NotNull final Random random,
+            final int chunkX,
+            final int chunkZ,
+            @NotNull final ChunkData chunkData
+    ) {
+        if (platformGenerator != this) {
+            platformGenerator.generateSurface(worldInfo, random, chunkX, chunkZ, chunkData);
+        }
+    }
+
+    @Override
+    public void generateBedrock(
+            @NotNull final WorldInfo worldInfo,
+            @NotNull final Random random,
+            final int chunkX,
+            final int chunkZ,
+            @NotNull final ChunkData chunkData
+    ) {
+        if (platformGenerator != this) {
+            platformGenerator.generateBedrock(worldInfo, random, chunkX, chunkZ, chunkData);
+        }
+    }
+
+    @Override
+    public void generateCaves(
+            @NotNull final WorldInfo worldInfo,
+            @NotNull final Random random,
+            final int chunkX,
+            final int chunkZ,
+            @NotNull final ChunkData chunkData
+    ) {
+        if (platformGenerator != this) {
+            platformGenerator.generateCaves(worldInfo, random, chunkX, chunkZ, chunkData);
+        }
+    }
+
+    @Override
+    public @Nullable BiomeProvider getDefaultBiomeProvider(@NotNull final WorldInfo worldInfo) {
+        if (platformGenerator != this) {
+            return platformGenerator.getDefaultBiomeProvider(worldInfo);
+        }
+        return biomeProvider;
+    }
+
+    @Override
+    public int getBaseHeight(
+            @NotNull final WorldInfo worldInfo,
+            @NotNull final Random random,
+            final int x,
+            final int z,
+            @NotNull final HeightMap heightMap
+    ) {
+        PlotArea area = getPlotArea(worldInfo.getName(), x, z);
+        if (area instanceof ClassicPlotWorld cpw) {
+            // Default to plot height being the heighest point before decoration (i.e. roads, walls etc.)
+            return cpw.PLOT_HEIGHT;
+        }
+        return super.getBaseHeight(worldInfo, random, x, z, heightMap);
+    }
+
+    @SuppressWarnings("deprecation") // The entire method is deprecated, but kept for compatibility with <=1.16.2
+    @Override
+    @Deprecated(since = "TODO")
+    public @NonNull ChunkData generateChunkData(
+            @NonNull World world, @NonNull Random random, int x, int z, @NonNull BiomeGrid biome
+    ) {
+        if (useNewGenerationMethods) {
+            // Return super as it will throw an exception caught by the server that will mean this method is no longer used.
+            return super.generateChunkData(world, random, x, z, biome);
+        }
         int minY = BukkitWorld.getMinWorldHeight(world);
         int maxY = BukkitWorld.getMaxWorldHeight(world);
         GenChunk result = new GenChunk(minY, maxY);
@@ -169,7 +290,6 @@ public class BukkitPlotGenerator extends ChunkGenerator
                     for (int chunkZ = 0; chunkZ < 16; chunkZ++) {
                         for (int y = minY; y < maxY; y++) {
                             biome.setBiome(chunkX, y, chunkZ, Biome.PLAINS);
-
                         }
                     }
                 }
@@ -189,7 +309,7 @@ public class BukkitPlotGenerator extends ChunkGenerator
             if (this.platformGenerator != this) {
                 return this.platformGenerator.generateChunkData(world, random, x, z, biome);
             } else {
-                generate(BlockVector2.at(x, z), world, result);
+                generate(BlockVector2.at(x, z), world.getName(), result, true);
             }
         } catch (Throwable e) {
             e.printStackTrace();
@@ -198,25 +318,14 @@ public class BukkitPlotGenerator extends ChunkGenerator
         return result.getChunkData();
     }
 
-    private void generate(BlockVector2 loc, World world, ZeroedDelegateScopedQueueCoordinator result) {
-        // Load if improperly loaded
-        if (!this.loaded) {
-            String name = world.getName();
-            PlotSquared.get().loadWorld(name, this);
-            this.loaded = true;
-        }
+    private void generate(BlockVector2 loc, String world, ZeroedDelegateScopedQueueCoordinator result, boolean biomes) {
         // Process the chunk
         if (ChunkManager.preProcessChunk(loc, result)) {
             return;
         }
-        PlotArea area = this.plotAreaManager.getPlotArea(world.getName(), null);
-        if (area == null && (area = this.plotAreaManager.getPlotArea(this.levelName, null)) == null) {
-            throw new IllegalStateException(
-                    "Cannot regenerate chunk that does not belong to a plot area." + " Location: " + loc
-                            + ", world: " + world);
-        }
+        PlotArea area = getPlotArea(world, loc.getX(), loc.getZ());
         try {
-            this.plotGenerator.generateChunk(result, area);
+            this.plotGenerator.generateChunk(result, area, biomes);
         } catch (Throwable e) {
             // Recover from generator error
             e.printStackTrace();
@@ -273,4 +382,59 @@ public class BukkitPlotGenerator extends ChunkGenerator
         return this.levelName;
     }
 
+    private synchronized PlotArea getPlotArea(String name, int chunkX, int chunkZ) {
+        // Load if improperly loaded
+        if (!this.loaded) {
+            PlotSquared.get().loadWorld(name, this);
+            // Do not set loaded to true as we want to ensure spawn limits are set when "loading" is actually able to be
+            // completed properly.
+        }
+        if (lastPlotArea != null && name.equals(this.levelName) && chunkX == lastChunkX && chunkZ == lastChunkZ) {
+            return lastPlotArea;
+        }
+        PlotArea area = UncheckedWorldLocation.at(name, chunkX << 4, 0, chunkZ << 4).getPlotArea();
+        if (area == null) {
+            throw new IllegalStateException(String.format("Cannot generate chunk that does not belong to a plot area. World: %s",
+                    name
+            ));
+        }
+        this.lastChunkX = chunkX;
+        this.lastChunkZ = chunkZ;
+        return this.lastPlotArea = area;
+    }
+
+    private PlotArea getPlotArea(String name) {
+        final Set<PlotArea> areas = this.plotAreaManager.getPlotAreasSet(name);
+        if (!areas.isEmpty()) {
+            return areas.iterator().next();
+        }
+        return null;
+    }
+
+    /**
+     * Biome provider should never need to be accessed outside of this class.
+     */
+    private final class BukkitPlotBiomeProvider extends BiomeProvider {
+
+        private static final List<Biome> BIOMES;
+
+        static {
+            ArrayList<Biome> biomes = new ArrayList<>(List.of(Biome.values()));
+            biomes.remove(Biome.CUSTOM);
+            BIOMES = List.copyOf(biomes);
+        }
+
+        @Override
+        public @NotNull Biome getBiome(@NotNull final WorldInfo worldInfo, final int x, final int y, final int z) {
+            PlotArea area = getPlotArea(worldInfo.getName(), x >> 4, z >> 4);
+            return BukkitAdapter.adapt(plotGenerator.getBiome(area, x, y, z));
+        }
+
+        @Override
+        public @NotNull List<Biome> getBiomes(@NotNull final WorldInfo worldInfo) {
+            return BIOMES; // Allow all biomes
+        }
+
+    }
+
 }

Bukkit/src/main/java/com/plotsquared/bukkit/generator/DelegatePlotGenerator.java

@@ -34,6 +34,7 @@ import com.plotsquared.core.plot.PlotId;
 import com.plotsquared.core.queue.ZeroedDelegateScopedQueueCoordinator;
 import com.plotsquared.core.util.MathMan;
 import com.sk89q.worldedit.bukkit.BukkitAdapter;
+import com.sk89q.worldedit.world.biome.BiomeType;
 import org.bukkit.World;
 import org.bukkit.block.Biome;
 import org.bukkit.generator.BlockPopulator;
@@ -56,6 +57,11 @@ final class DelegatePlotGenerator extends IndependentPlotGenerator {
     public void initialize(PlotArea area) {
     }
 
+    @Override
+    public BiomeType getBiome(final PlotArea settings, final int x, final int y, final int z) {
+        return null;
+    }
+
     @Override
     public String getName() {
         return this.chunkGenerator.getClass().getName();
@@ -67,7 +73,7 @@ final class DelegatePlotGenerator extends IndependentPlotGenerator {
     }
 
     @Override
-    public void generateChunk(final ZeroedDelegateScopedQueueCoordinator result, PlotArea settings) {
+    public void generateChunk(final ZeroedDelegateScopedQueueCoordinator result, PlotArea settings, boolean biomes) {
         World world = BukkitUtil.getWorld(this.world);
         Location min = result.getMin();
         int chunkX = min.getX() >> 4;