Implement explosion optimisations

2 files changed, 439 insertions, 1 deletions

diff --git a/moonrise_update_1_21_2.txt b/moonrise_update_1_21_2.txt
index 2ff8731cdf..c889f78d91 100644
--- a/moonrise_update_1_21_2.txt
+++ b/moonrise_update_1_21_2.txt
@@ -17,7 +17,6 @@ todo:
 - implement chunk_system.SectionStorageMixin diff from reference
 - implement chunk_system.SerializableChunkDataMixin diff from reference
 - implement chunk_system.ServerLevelMixin diff from reference
-- implement collisions.ServerExplosionMixin diff from reference
 - implement starlight.LevelLightEngineMixin diff from reference
 - implement starlight.ThreadedLevelLightEngineMixin diff from reference
 - implement starlight.ChunkSerializerMixin diff from reference
diff --git a/patches/server/0826-Moonrise-optimisation-patches.patch b/patches/server/0826-Moonrise-optimisation-patches.patch
index 536918d0f3..936f34e740 100644
--- a/patches/server/0826-Moonrise-optimisation-patches.patch
+++ b/patches/server/0826-Moonrise-optimisation-patches.patch
@@ -30275,6 +30275,445 @@ index 5eb8982678110fabb82a93c5ec67c666b7fde017..ade435de0af4ee3566fa4a490df53cdd
      @Nullable
      ChunkAccess getChunk(int chunkX, int chunkZ, ChunkStatus leastStatus, boolean create);
  
+diff --git a/src/main/java/net/minecraft/world/level/ServerExplosion.java b/src/main/java/net/minecraft/world/level/ServerExplosion.java
+index 86656de31b1e33381eddd3ef210122118b31e620..c7fd8ce0dae838d91915a1c7a34152bed3ac7682 100644
+--- a/src/main/java/net/minecraft/world/level/ServerExplosion.java
++++ b/src/main/java/net/minecraft/world/level/ServerExplosion.java
+@@ -64,6 +64,249 @@ public class ServerExplosion implements Explosion {
+     public float yield;
+     // CraftBukkit end
+     public boolean excludeSourceFromDamage = true; // Paper - Allow explosions to damage source
++    // Paper start - collisions optimisations
++    private static final double[] CACHED_RAYS;
++    static {
++        final it.unimi.dsi.fastutil.doubles.DoubleArrayList rayCoords = new it.unimi.dsi.fastutil.doubles.DoubleArrayList();
++
++        for (int x = 0; x <= 15; ++x) {
++            for (int y = 0; y <= 15; ++y) {
++                for (int z = 0; z <= 15; ++z) {
++                    if ((x == 0 || x == 15) || (y == 0 || y == 15) || (z == 0 || z == 15)) {
++                        double xDir = (double)((float)x / 15.0F * 2.0F - 1.0F);
++                        double yDir = (double)((float)y / 15.0F * 2.0F - 1.0F);
++                        double zDir = (double)((float)z / 15.0F * 2.0F - 1.0F);
++
++                        double mag = Math.sqrt(
++                                xDir * xDir + yDir * yDir + zDir * zDir
++                        );
++
++                        rayCoords.add((xDir / mag) * (double)0.3F);
++                        rayCoords.add((yDir / mag) * (double)0.3F);
++                        rayCoords.add((zDir / mag) * (double)0.3F);
++                    }
++                }
++            }
++        }
++
++        CACHED_RAYS = rayCoords.toDoubleArray();
++    }
++
++    private static final int CHUNK_CACHE_SHIFT = 2;
++    private static final int CHUNK_CACHE_MASK = (1 << CHUNK_CACHE_SHIFT) - 1;
++    private static final int CHUNK_CACHE_WIDTH = 1 << CHUNK_CACHE_SHIFT;
++
++    private static final int BLOCK_EXPLOSION_CACHE_SHIFT = 3;
++    private static final int BLOCK_EXPLOSION_CACHE_MASK = (1 << BLOCK_EXPLOSION_CACHE_SHIFT) - 1;
++    private static final int BLOCK_EXPLOSION_CACHE_WIDTH = 1 << BLOCK_EXPLOSION_CACHE_SHIFT;
++
++    // resistance = (res + 0.3F) * 0.3F;
++    // so for resistance = 0, we need res = -0.3F
++    private static final Float ZERO_RESISTANCE = Float.valueOf(-0.3f);
++    private it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap<ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache> blockCache = null;
++    private long[] chunkPosCache = null;
++    private net.minecraft.world.level.chunk.LevelChunk[] chunkCache = null;
++    private ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache[] directMappedBlockCache;
++    private BlockPos.MutableBlockPos mutablePos;
++
++    private ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache getOrCacheExplosionBlock(final int x, final int y, final int z,
++                                                                                                    final long key, final boolean calculateResistance) {
++        ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache ret = this.blockCache.get(key);
++        if (ret != null) {
++            return ret;
++        }
++
++        BlockPos pos = new BlockPos(x, y, z);
++
++        if (!this.level.isInWorldBounds(pos)) {
++            ret = new ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache(key, pos, null, null, 0.0f, true);
++        } else {
++            net.minecraft.world.level.chunk.LevelChunk chunk;
++            long chunkKey = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(x >> 4, z >> 4);
++            int chunkCacheKey = ((x >> 4) & CHUNK_CACHE_MASK) | (((z >> 4) << CHUNK_CACHE_SHIFT) & (CHUNK_CACHE_MASK << CHUNK_CACHE_SHIFT));
++            if (this.chunkPosCache[chunkCacheKey] == chunkKey) {
++                chunk = this.chunkCache[chunkCacheKey];
++            } else {
++                this.chunkPosCache[chunkCacheKey] = chunkKey;
++                this.chunkCache[chunkCacheKey] = chunk = this.level.getChunk(x >> 4, z >> 4);
++            }
++
++            BlockState blockState = ((ca.spottedleaf.moonrise.patches.getblock.GetBlockChunk)chunk).moonrise$getBlock(x, y, z);
++            FluidState fluidState = blockState.getFluidState();
++
++            Optional<Float> resistance = !calculateResistance ? Optional.empty() : this.damageCalculator.getBlockExplosionResistance((Explosion)(Object)this, this.level, pos, blockState, fluidState);
++
++            ret = new ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache(
++                    key, pos, blockState, fluidState,
++                    (resistance.orElse(ZERO_RESISTANCE).floatValue() + 0.3f) * 0.3f,
++                    false
++            );
++        }
++
++        this.blockCache.put(key, ret);
++
++        return ret;
++    }
++
++    private boolean clipsAnything(final Vec3 from, final Vec3 to,
++                                  final ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.LazyEntityCollisionContext context,
++                                  final ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache[] blockCache,
++                                  final BlockPos.MutableBlockPos currPos) {
++        // assume that context.delegated = false
++        final double adjX = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON * (from.x - to.x);
++        final double adjY = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON * (from.y - to.y);
++        final double adjZ = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON * (from.z - to.z);
++
++        if (adjX == 0.0 && adjY == 0.0 && adjZ == 0.0) {
++            return false;
++        }
++
++        final double toXAdj = to.x - adjX;
++        final double toYAdj = to.y - adjY;
++        final double toZAdj = to.z - adjZ;
++        final double fromXAdj = from.x + adjX;
++        final double fromYAdj = from.y + adjY;
++        final double fromZAdj = from.z + adjZ;
++
++        int currX = Mth.floor(fromXAdj);
++        int currY = Mth.floor(fromYAdj);
++        int currZ = Mth.floor(fromZAdj);
++
++        final double diffX = toXAdj - fromXAdj;
++        final double diffY = toYAdj - fromYAdj;
++        final double diffZ = toZAdj - fromZAdj;
++
++        final double dxDouble = Math.signum(diffX);
++        final double dyDouble = Math.signum(diffY);
++        final double dzDouble = Math.signum(diffZ);
++
++        final int dx = (int)dxDouble;
++        final int dy = (int)dyDouble;
++        final int dz = (int)dzDouble;
++
++        final double normalizedDiffX = diffX == 0.0 ? Double.MAX_VALUE : dxDouble / diffX;
++        final double normalizedDiffY = diffY == 0.0 ? Double.MAX_VALUE : dyDouble / diffY;
++        final double normalizedDiffZ = diffZ == 0.0 ? Double.MAX_VALUE : dzDouble / diffZ;
++
++        double normalizedCurrX = normalizedDiffX * (diffX > 0.0 ? (1.0 - Mth.frac(fromXAdj)) : Mth.frac(fromXAdj));
++        double normalizedCurrY = normalizedDiffY * (diffY > 0.0 ? (1.0 - Mth.frac(fromYAdj)) : Mth.frac(fromYAdj));
++        double normalizedCurrZ = normalizedDiffZ * (diffZ > 0.0 ? (1.0 - Mth.frac(fromZAdj)) : Mth.frac(fromZAdj));
++
++        for (;;) {
++            currPos.set(currX, currY, currZ);
++
++            // ClipContext.Block.COLLIDER -> BlockBehaviour.BlockStateBase::getCollisionShape
++            // ClipContext.Fluid.NONE -> ignore fluids
++
++            // read block from cache
++            final long key = BlockPos.asLong(currX, currY, currZ);
++
++            final int cacheKey =
++                    (currX & BLOCK_EXPLOSION_CACHE_MASK) |
++                    (currY & BLOCK_EXPLOSION_CACHE_MASK) << (BLOCK_EXPLOSION_CACHE_SHIFT) |
++                    (currZ & BLOCK_EXPLOSION_CACHE_MASK) << (BLOCK_EXPLOSION_CACHE_SHIFT + BLOCK_EXPLOSION_CACHE_SHIFT);
++            ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache cachedBlock = blockCache[cacheKey];
++            if (cachedBlock == null || cachedBlock.key != key) {
++                blockCache[cacheKey] = cachedBlock = this.getOrCacheExplosionBlock(currX, currY, currZ, key, false);
++            }
++
++            final BlockState blockState = cachedBlock.blockState;
++            if (blockState != null && !((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)blockState).moonrise$emptyContextCollisionShape()) {
++                net.minecraft.world.phys.shapes.VoxelShape collision = cachedBlock.cachedCollisionShape;
++                if (collision == null) {
++                    collision = ((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)blockState).moonrise$getConstantContextCollisionShape();
++                    if (collision == null) {
++                        collision = blockState.getCollisionShape(this.level, currPos, context);
++                        if (!context.isDelegated()) {
++                            // if it was not delegated during this call, assume that for any future ones it will not be delegated
++                            // again, and cache the result
++                            cachedBlock.cachedCollisionShape = collision;
++                        }
++                    } else {
++                        cachedBlock.cachedCollisionShape = collision;
++                    }
++                }
++
++                if (!collision.isEmpty() && collision.clip(from, to, currPos) != null) {
++                    return true;
++                }
++            }
++
++            if (normalizedCurrX > 1.0 && normalizedCurrY > 1.0 && normalizedCurrZ > 1.0) {
++                return false;
++            }
++
++            // inc the smallest normalized coordinate
++
++            if (normalizedCurrX < normalizedCurrY) {
++                if (normalizedCurrX < normalizedCurrZ) {
++                    currX += dx;
++                    normalizedCurrX += normalizedDiffX;
++                } else {
++                    // x < y && x >= z <--> z < y && z <= x
++                    currZ += dz;
++                    normalizedCurrZ += normalizedDiffZ;
++                }
++            } else if (normalizedCurrY < normalizedCurrZ) {
++                // y <= x && y < z
++                currY += dy;
++                normalizedCurrY += normalizedDiffY;
++            } else {
++                // y <= x && z <= y <--> z <= y && z <= x
++                currZ += dz;
++                normalizedCurrZ += normalizedDiffZ;
++            }
++        }
++    }
++
++    private float getSeenFraction(final Vec3 source, final Entity target,
++                                   final ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache[] blockCache,
++                                   final BlockPos.MutableBlockPos blockPos) {
++        final AABB boundingBox = target.getBoundingBox();
++        final double diffX = boundingBox.maxX - boundingBox.minX;
++        final double diffY = boundingBox.maxY - boundingBox.minY;
++        final double diffZ = boundingBox.maxZ - boundingBox.minZ;
++
++        final double incX = 1.0 / (diffX * 2.0 + 1.0);
++        final double incY = 1.0 / (diffY * 2.0 + 1.0);
++        final double incZ = 1.0 / (diffZ * 2.0 + 1.0);
++
++        if (incX < 0.0 || incY < 0.0 || incZ < 0.0) {
++            return 0.0f;
++        }
++
++        final double offX = (1.0 - Math.floor(1.0 / incX) * incX) * 0.5 + boundingBox.minX;
++        final double offY = boundingBox.minY;
++        final double offZ = (1.0 - Math.floor(1.0 / incZ) * incZ) * 0.5 + boundingBox.minZ;
++
++        final ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.LazyEntityCollisionContext context = new ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.LazyEntityCollisionContext(target);
++
++        int totalRays = 0;
++        int missedRays = 0;
++
++        for (double dx = 0.0; dx <= 1.0; dx += incX) {
++            final double fromX = Math.fma(dx, diffX, offX);
++            for (double dy = 0.0; dy <= 1.0; dy += incY) {
++                final double fromY = Math.fma(dy, diffY, offY);
++                for (double dz = 0.0; dz <= 1.0; dz += incZ) {
++                    ++totalRays;
++
++                    final Vec3 from = new Vec3(
++                            fromX,
++                            fromY,
++                            Math.fma(dz, diffZ, offZ)
++                    );
++
++                    if (!this.clipsAnything(from, source, context, blockCache, blockPos)) {
++                        ++missedRays;
++                    }
++                }
++            }
++        }
++
++        return (float)missedRays / (float)totalRays;
++    }
++    // Paper end - collisions optimisations
+ 
+     public ServerExplosion(ServerLevel world, @Nullable Entity entity, @Nullable DamageSource damageSource, @Nullable ExplosionDamageCalculator behavior, Vec3 pos, float power, boolean createFire, Explosion.BlockInteraction destructionType) {
+         this.level = world;
+@@ -127,64 +370,91 @@ public class ServerExplosion implements Explosion {
+     }
+ 
+     private List<BlockPos> calculateExplodedPositions() {
+-        Set<BlockPos> set = new HashSet();
+-        boolean flag = true;
+-
+-        for (int i = 0; i < 16; ++i) {
+-            for (int j = 0; j < 16; ++j) {
+-                for (int k = 0; k < 16; ++k) {
+-                    if (i == 0 || i == 15 || j == 0 || j == 15 || k == 0 || k == 15) {
+-                        double d0 = (double) ((float) i / 15.0F * 2.0F - 1.0F);
+-                        double d1 = (double) ((float) j / 15.0F * 2.0F - 1.0F);
+-                        double d2 = (double) ((float) k / 15.0F * 2.0F - 1.0F);
+-                        double d3 = Math.sqrt(d0 * d0 + d1 * d1 + d2 * d2);
+-
+-                        d0 /= d3;
+-                        d1 /= d3;
+-                        d2 /= d3;
+-                        float f = this.radius * (0.7F + this.level.random.nextFloat() * 0.6F);
+-                        double d4 = this.center.x;
+-                        double d5 = this.center.y;
+-                        double d6 = this.center.z;
+-
+-                        for (float f1 = 0.3F; f > 0.0F; f -= 0.22500001F) {
+-                            BlockPos blockposition = BlockPos.containing(d4, d5, d6);
+-                            BlockState iblockdata = this.level.getBlockState(blockposition);
+-                            FluidState fluid = iblockdata.getFluidState(); // Paper - Perf: Optimize call to getFluid for explosions
+-
+-                            if (!this.level.isInWorldBounds(blockposition)) {
+-                                break;
+-                            }
++        // Paper start - collision optimisations
++        final ObjectArrayList<BlockPos> ret = new ObjectArrayList<>();
+ 
+-                            Optional<Float> optional = this.damageCalculator.getBlockExplosionResistance(this, this.level, blockposition, iblockdata, fluid);
++        final Vec3 center = this.center;
+ 
+-                            if (optional.isPresent()) {
+-                                f -= ((Float) optional.get() + 0.3F) * 0.3F;
+-                            }
++        final ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache[] blockCache = this.directMappedBlockCache;
+ 
+-                            if (f > 0.0F && this.damageCalculator.shouldBlockExplode(this, this.level, blockposition, iblockdata, f)) {
+-                                set.add(blockposition);
+-                                // Paper start - prevent headless pistons from forming
+-                                if (!io.papermc.paper.configuration.GlobalConfiguration.get().unsupportedSettings.allowHeadlessPistons && iblockdata.getBlock() == Blocks.MOVING_PISTON) {
+-                                    net.minecraft.world.level.block.entity.BlockEntity extension = this.level.getBlockEntity(blockposition);
+-                                    if (extension instanceof net.minecraft.world.level.block.piston.PistonMovingBlockEntity blockEntity && blockEntity.isSourcePiston()) {
+-                                        net.minecraft.core.Direction direction = iblockdata.getValue(net.minecraft.world.level.block.piston.PistonHeadBlock.FACING);
+-                                        set.add(blockposition.relative(direction.getOpposite()));
+-                                    }
+-                                }
+-                                // Paper end - prevent headless pistons from forming
+-                            }
++        // use initial cache value that is most likely to be used: the source position
++        final ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache initialCache;
++        {
++            final int blockX = Mth.floor(center.x);
++            final int blockY = Mth.floor(center.y);
++            final int blockZ = Mth.floor(center.z);
++
++            final long key = BlockPos.asLong(blockX, blockY, blockZ);
++
++            initialCache = this.getOrCacheExplosionBlock(blockX, blockY, blockZ, key, true);
++        }
+ 
+-                            d4 += d0 * 0.30000001192092896D;
+-                            d5 += d1 * 0.30000001192092896D;
+-                            d6 += d2 * 0.30000001192092896D;
++        // only ~1/3rd of the loop iterations in vanilla will result in a ray, as it is iterating the perimeter of
++        // a 16x16x16 cube
++        // we can cache the rays and their normals as well, so that we eliminate the excess iterations / checks and
++        // calculations in one go
++        // additional aggressive caching of block retrieval is very significant, as at low power (i.e tnt) most
++        // block retrievals are not unique
++        for (int ray = 0, len = CACHED_RAYS.length; ray < len;) {
++            ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache cachedBlock = initialCache;
++
++            double currX = center.x;
++            double currY = center.y;
++            double currZ = center.z;
++
++            final double incX = CACHED_RAYS[ray];
++            final double incY = CACHED_RAYS[ray + 1];
++            final double incZ = CACHED_RAYS[ray + 2];
++
++            ray += 3;
++
++            float power = this.radius * (0.7F + this.level.random.nextFloat() * 0.6F);
++
++            do {
++                final int blockX = Mth.floor(currX);
++                final int blockY = Mth.floor(currY);
++                final int blockZ = Mth.floor(currZ);
++
++                final long key = BlockPos.asLong(blockX, blockY, blockZ);
++
++                if (cachedBlock.key != key) {
++                    final int cacheKey =
++                        (blockX & BLOCK_EXPLOSION_CACHE_MASK) |
++                            (blockY & BLOCK_EXPLOSION_CACHE_MASK) << (BLOCK_EXPLOSION_CACHE_SHIFT) |
++                            (blockZ & BLOCK_EXPLOSION_CACHE_MASK) << (BLOCK_EXPLOSION_CACHE_SHIFT + BLOCK_EXPLOSION_CACHE_SHIFT);
++                    cachedBlock = blockCache[cacheKey];
++                    if (cachedBlock == null || cachedBlock.key != key) {
++                        blockCache[cacheKey] = cachedBlock = this.getOrCacheExplosionBlock(blockX, blockY, blockZ, key, true);
++                    }
++                }
++
++                if (cachedBlock.outOfWorld) {
++                    break;
++                }
++
++                power -= cachedBlock.resistance;
++
++                if (power > 0.0f && cachedBlock.shouldExplode == null) {
++                    // note: we expect shouldBlockExplode to be pure with respect to power, as Vanilla currently is.
++                    // basically, it is unused, which allows us to cache the result
++                    final boolean shouldExplode = this.damageCalculator.shouldBlockExplode((Explosion)(Object)this, this.level, cachedBlock.immutablePos, cachedBlock.blockState, power);
++                    cachedBlock.shouldExplode = shouldExplode ? Boolean.TRUE : Boolean.FALSE;
++                    if (shouldExplode) {
++                        if (this.fire || !cachedBlock.blockState.isAir()) {
++                            ret.add(cachedBlock.immutablePos);
+                         }
+                     }
+                 }
+-            }
++
++                power -= 0.22500001F;
++                currX += incX;
++                currY += incY;
++                currZ += incZ;
++            } while (power > 0.0f);
+         }
+ 
+-        return new ObjectArrayList(set);
++        return ret;
++        // Paper end - collision optimisations
+     }
+ 
+     private void hurtEntities() {
+@@ -390,6 +660,14 @@ public class ServerExplosion implements Explosion {
+             return;
+         }
+         // CraftBukkit end
++        // Paper start - collision optimisations
++        this.blockCache = new it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap<>();
++        this.chunkPosCache = new long[CHUNK_CACHE_WIDTH * CHUNK_CACHE_WIDTH];
++        java.util.Arrays.fill(this.chunkPosCache, ChunkPos.INVALID_CHUNK_POS);
++        this.chunkCache = new net.minecraft.world.level.chunk.LevelChunk[CHUNK_CACHE_WIDTH * CHUNK_CACHE_WIDTH];
++        this.directMappedBlockCache = new ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache[BLOCK_EXPLOSION_CACHE_WIDTH * BLOCK_EXPLOSION_CACHE_WIDTH * BLOCK_EXPLOSION_CACHE_WIDTH];
++        this.mutablePos = new BlockPos.MutableBlockPos();
++        // Paper end - collision optimisations
+         this.level.gameEvent(this.source, (Holder) GameEvent.EXPLODE, this.center);
+         List<BlockPos> list = this.calculateExplodedPositions();
+ 
+@@ -405,6 +683,13 @@ public class ServerExplosion implements Explosion {
+         if (this.fire) {
+             this.createFire(list);
+         }
++        // Paper start - collision optimisations
++        this.blockCache = null;
++        this.chunkPosCache = null;
++        this.chunkCache = null;
++        this.directMappedBlockCache = null;
++        this.mutablePos = null;
++        // Paper end - collision optimisations
+ 
+     }
+ 
+@@ -494,12 +779,12 @@ public class ServerExplosion implements Explosion {
+     // Paper start - Optimize explosions
+     private float getBlockDensity(Vec3 vec3d, Entity entity) {
+         if (!this.level.paperConfig().environment.optimizeExplosions) {
+-            return getSeenPercent(vec3d, entity);
++            return this.getSeenFraction(vec3d, entity, this.directMappedBlockCache, this.mutablePos); // Paper - collision optimisations
+         }
+         CacheKey key = new CacheKey(this, entity.getBoundingBox());
+         Float blockDensity = this.level.explosionDensityCache.get(key);
+         if (blockDensity == null) {
+-            blockDensity = getSeenPercent(vec3d, entity);
++            blockDensity = this.getSeenFraction(vec3d, entity, this.directMappedBlockCache, this.mutablePos); // Paper - collision optimisations
+             this.level.explosionDensityCache.put(key, blockDensity);
+         }
+ 
 diff --git a/src/main/java/net/minecraft/world/level/biome/Biome.java b/src/main/java/net/minecraft/world/level/biome/Biome.java
 index 8590de51b572c0f73d45aee60313d466e4671da5..b725eea9d3ca81d2ef7802f5d0346d924aa1f808 100644
 --- a/src/main/java/net/minecraft/world/level/biome/Biome.java