PaperMC/paper-server/patches/sources/net/minecraft/world/level/BlockGetter.java.patch

--- a/net/minecraft/world/level/BlockGetter.java
+++ b/net/minecraft/world/level/BlockGetter.java
@@ -12,6 +12,7 @@
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.util.Mth;
+import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
 import net.minecraft.world.level.block.state.BlockState;
@@ -31,11 +32,20 @@
     default <T extends BlockEntity> Optional<T> getBlockEntity(BlockPos pos, BlockEntityType<T> type) {
         BlockEntity tileentity = this.getBlockEntity(pos);
 
-        return tileentity != null && tileentity.getType() == type ? Optional.of(tileentity) : Optional.empty();
+        return tileentity != null && tileentity.getType() == type ? (Optional<T>) Optional.of(tileentity) : Optional.empty(); // CraftBukkit - decompile error
     }
 
     BlockState getBlockState(BlockPos pos);
+    // Paper start - if loaded util
+    @Nullable BlockState getBlockStateIfLoaded(BlockPos blockposition);
 
+    default @Nullable Block getBlockIfLoaded(BlockPos blockposition) {
+        BlockState type = this.getBlockStateIfLoaded(blockposition);
+        return type == null ? null : type.getBlock();
+    }
+    @Nullable FluidState getFluidIfLoaded(BlockPos blockposition);
+    // Paper end
+
     FluidState getFluidState(BlockPos pos);
 
     default int getLightEmission(BlockPos pos) {
@@ -59,10 +69,25 @@
         });
     }
 
-    default BlockHitResult clip(ClipContext context) {
-        return (BlockHitResult) BlockGetter.traverseBlocks(context.getFrom(), context.getTo(), context, (raytrace1, blockposition) -> {
-            BlockState iblockdata = this.getBlockState(blockposition);
-            FluidState fluid = this.getFluidState(blockposition);
+    // CraftBukkit start - moved block handling into separate method for use by Block#rayTrace
+    default BlockHitResult clip(ClipContext raytrace1, BlockPos blockposition) {
+        // Paper start - Add predicate for blocks when raytracing
+        return clip(raytrace1, blockposition, null);
+    }
+
+    default BlockHitResult clip(ClipContext raytrace1, BlockPos blockposition, java.util.function.Predicate<? super org.bukkit.block.Block> canCollide) {
+            // Paper end - Add predicate for blocks when raytracing
+            // Paper start - Prevent raytrace from loading chunks
+            BlockState iblockdata = this.getBlockStateIfLoaded(blockposition);
+            if (iblockdata == null) {
+                // copied the last function parameter (listed below)
+                Vec3 vec3d = raytrace1.getFrom().subtract(raytrace1.getTo());
+
+                return BlockHitResult.miss(raytrace1.getTo(), Direction.getApproximateNearest(vec3d.x, vec3d.y, vec3d.z), BlockPos.containing(raytrace1.getTo()));
+            }
+            // Paper end - Prevent raytrace from loading chunks
+            if (iblockdata.isAir() || (canCollide != null && this instanceof LevelAccessor levelAccessor && !canCollide.test(org.bukkit.craftbukkit.block.CraftBlock.at(levelAccessor, blockposition)))) return null; // Paper - Perf: optimise air cases & check canCollide predicate
+            FluidState fluid = iblockdata.getFluidState(); // Paper - Perf: don't need to go to world state again
             Vec3 vec3d = raytrace1.getFrom();
             Vec3 vec3d1 = raytrace1.getTo();
             VoxelShape voxelshape = raytrace1.getBlockShape(iblockdata, this, blockposition);
@@ -73,6 +98,18 @@
             double d1 = movingobjectpositionblock1 == null ? Double.MAX_VALUE : raytrace1.getFrom().distanceToSqr(movingobjectpositionblock1.getLocation());
 
             return d0 <= d1 ? movingobjectpositionblock : movingobjectpositionblock1;
+    }
+    // CraftBukkit end
+
+    default BlockHitResult clip(ClipContext context) {
+        // Paper start - Add predicate for blocks when raytracing
+        return clip(context, (java.util.function.Predicate<org.bukkit.block.Block>) null);
+    }
+
+    default BlockHitResult clip(ClipContext context, java.util.function.Predicate<? super org.bukkit.block.Block> canCollide) {
+        // Paper end - Add predicate for blocks when raytracing
+        return (BlockHitResult) BlockGetter.traverseBlocks(context.getFrom(), context.getTo(), context, (raytrace1, blockposition) -> {
+            return this.clip(raytrace1, blockposition, canCollide); // CraftBukkit - moved into separate method // Paper - Add predicate for blocks when raytracing
         }, (raytrace1) -> {
             Vec3 vec3d = raytrace1.getFrom().subtract(raytrace1.getTo());
 
@@ -145,7 +182,7 @@
                 double d13 = d10 * (i1 > 0 ? 1.0D - Mth.frac(d4) : Mth.frac(d4));
                 double d14 = d11 * (j1 > 0 ? 1.0D - Mth.frac(d5) : Mth.frac(d5));
 
-                Object object;
+                T object; // CraftBukkit - decompile error
 
                 do {
                     if (d12 > 1.0D && d13 > 1.0D && d14 > 1.0D) {