Fix: unsafe cast to worldgenrandom

Fixes #959
klikli-dev · Jul 31, 2023 · e4be359 · e4be359
1 parent 27e515f
commit e4be359
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Showing 2 changed files with 20 additions and 9 deletions.
diff --git a/src/main/java/com/klikli_dev/occultism/common/level/cave/SphericalCaveSubFeature.java b/src/main/java/com/klikli_dev/occultism/common/level/cave/SphericalCaveSubFeature.java
@@ -23,6 +23,7 @@
 package com.klikli_dev.occultism.common.level.cave;
 
 import com.klikli_dev.occultism.common.level.multichunk.IMultiChunkSubFeature;
+import com.klikli_dev.occultism.common.level.multichunk.MultiChunkFeature;
 import com.klikli_dev.occultism.common.level.multichunk.MultiChunkFeatureConfig;
 import com.klikli_dev.occultism.registry.OccultismTags;
 import com.klikli_dev.occultism.util.Math3DUtil;
@@ -35,7 +36,6 @@
 import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.level.block.state.BlockState;
 import net.minecraft.world.level.chunk.ChunkGenerator;
-import net.minecraft.world.level.levelgen.WorldgenRandom;
 import net.minecraft.world.phys.AABB;
 
 import java.util.ArrayList;
@@ -88,9 +88,10 @@ public boolean place(WorldGenLevel reader, ChunkGenerator generator, RandomSourc
         sphericalCaves.add(rootPosition);
 
         ChunkPos rootChunk = new ChunkPos(rootPosition);
+
         //Seed with root chunk position
-        ((WorldgenRandom) rand)
-                .setLargeFeatureWithSalt(reader.getSeed(), rootChunk.x, rootChunk.z, config.featureSeedSalt);
+        var seed = MultiChunkFeature.getLargeFeatureWithSaltSeed(reader.getSeed(), rootChunk.x, rootChunk.z, config.featureSeedSalt);
+        rand.setSeed(seed);
 
         List<Sphere> spheres = new ArrayList<>();
         int radiusBase = this.radius + rand.nextInt(this.maxRandomRadiusOffset);

diff --git a/src/main/java/com/klikli_dev/occultism/common/level/multichunk/MultiChunkFeature.java b/src/main/java/com/klikli_dev/occultism/common/level/multichunk/MultiChunkFeature.java
@@ -26,10 +26,11 @@
 import com.mojang.serialization.Codec;
 import net.minecraft.core.BlockPos;
 import net.minecraft.server.level.ServerChunkCache;
+import net.minecraft.util.RandomSource;
 import net.minecraft.world.level.ChunkPos;
 import net.minecraft.world.level.WorldGenLevel;
 import net.minecraft.world.level.chunk.ChunkGenerator;
-import net.minecraft.world.level.levelgen.WorldgenRandom;
+import net.minecraft.world.level.levelgen.XoroshiroRandomSource;
 import net.minecraft.world.level.levelgen.feature.Feature;
 import net.minecraft.world.level.levelgen.feature.FeaturePlaceContext;
 
@@ -45,8 +46,11 @@ public MultiChunkFeature(Codec<MultiChunkFeatureConfig> codec, IMultiChunkSubFea
         this.subFeature = subFeature;
     }
 
+    public static long getLargeFeatureWithSaltSeed(long pLevelSeed, int pRegionX, int pRegionZ, int pSalt) {
+        return (long) pRegionX * 341873128712L + (long) pRegionZ * 132897987541L + pLevelSeed + (long) pSalt;
+    }
 
-    protected List<BlockPos> getRootPositions(WorldGenLevel reader, ChunkGenerator generator, WorldgenRandom random,
+    protected List<BlockPos> getRootPositions(WorldGenLevel reader, ChunkGenerator generator, RandomSource random,
                                               ChunkPos generatingChunk,
                                               MultiChunkFeatureConfig config) {
         ArrayList<BlockPos> result = new ArrayList<>(1);
@@ -56,8 +60,8 @@ protected List<BlockPos> getRootPositions(WorldGenLevel reader, ChunkGenerator g
                 ChunkPos currentChunk = new ChunkPos(generatingChunk.x + i, generatingChunk.z + j);
 
                 //Seed random for this chunk, this way we get the same result no matter how often this is called.
-                random.setLargeFeatureWithSalt(reader.getSeed(), currentChunk.x, currentChunk.z,
-                        config.featureSeedSalt);
+                var seed = getLargeFeatureWithSaltSeed(reader.getSeed(), currentChunk.x, currentChunk.z, config.featureSeedSalt);
+                random.setSeed(seed);
 
                 if (random.nextInt(config.chanceToGenerate) == 0) {
                     //this chunk contains a root, so we generate a random
@@ -80,15 +84,21 @@ public boolean place(FeaturePlaceContext<MultiChunkFeatureConfig> context) {
 
         if (context.level().getChunkSource() instanceof ServerChunkCache chunkSource) {
             ChunkPos generatingChunk = new ChunkPos(pos);
+
+            //we create our own random here so that subsequent features are not affected by our custom seed gen.
+            //we also hand that to our sub feature so that that also doesn't modify the seed of the world random.
+            var random = new XoroshiroRandomSource(context.random().nextLong());
+
             List<BlockPos> rootPositions =
-                    this.getRootPositions(context.level(), context.chunkGenerator(), (WorldgenRandom) context.random(), generatingChunk, context.config());
+                    this.getRootPositions(context.level(), context.chunkGenerator(), random, generatingChunk, context.config());
+
             //If no root position was found in range, we exit
             if (rootPositions.isEmpty()) {
                 return false;
             }
             boolean generatedAny = false;
             for (BlockPos rootPosition : rootPositions) {
-                if (this.subFeature.place(context.level(), context.chunkGenerator(), context.random(), rootPosition,
+                if (this.subFeature.place(context.level(), context.chunkGenerator(), random, rootPosition,
                         Math3DUtil.bounds(generatingChunk, context.chunkGenerator().getGenDepth()), context.config()))
                     generatedAny = true;
             }