Fix incorrect collision shape for hopper item suck

It shouldn't cost too much more to check the correct shape,
provided that it is cached and we use the overall AABB
to collect possible entities to check against.

The issues with the old check code is that it will use two
getEntitiesOfClass calls plus the addition of streams
_and_ the toAabbs() logic on VoxelShape. The new code
caches toAabbs, uses one getEntitiesOfClass call, and
does not use streams. Then compared to 1.12, we are
only performing two additional AABB checks per item.

1 files changed, 30 insertions, 11 deletions

diff --git a/patches/server/0949-Optimize-Hoppers.patch b/patches/server/0949-Optimize-Hoppers.patch
index 0290810efc..7b6b38c931 100644
--- a/patches/server/0949-Optimize-Hoppers.patch
+++ b/patches/server/0949-Optimize-Hoppers.patch
@@ -68,7 +68,7 @@ index 5bdad1866386908b9fef74d15862eb107fabe68f..370a25d2deb54f10a35ee24d9e7e92fb
          }
  
 diff --git a/src/main/java/net/minecraft/world/level/block/entity/HopperBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/HopperBlockEntity.java
-index 6907e647ef4d3f5c9c46edb4cf0905844dd1cea9..beb70310f2e9657fee89cb4b6a9885712b0116e6 100644
+index 6907e647ef4d3f5c9c46edb4cf0905844dd1cea9..a8a26a0a37a08b6bbeb5a1fde417d6f448d3c79f 100644
 --- a/src/main/java/net/minecraft/world/level/block/entity/HopperBlockEntity.java
 +++ b/src/main/java/net/minecraft/world/level/block/entity/HopperBlockEntity.java
 @@ -193,6 +193,201 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
@@ -509,20 +509,39 @@ index 6907e647ef4d3f5c9c46edb4cf0905844dd1cea9..beb70310f2e9657fee89cb4b6a988571
                  stack = leftover; // Paper
                  flag = true;
              } else if (HopperBlockEntity.canMergeItems(itemstack1, stack)) {
-@@ -517,18 +723,28 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
+@@ -516,19 +722,47 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
+         // CraftBukkit end
      }
  
++    // Paper start - optimize hopper item suck in
++    static final AABB HOPPER_ITEM_SUCK_OVERALL = Hopper.SUCK.bounds();
++    static final AABB[] HOPPER_ITEM_SUCK_INDIVIDUAL = Hopper.SUCK.toAabbs().toArray(new AABB[0]);
++    // Paper end - optimize hopper item suck in
++
      public static List<ItemEntity> getItemsAtAndAbove(Level world, Hopper hopper) {
 -        return (List) hopper.getSuckShape().toAabbs().stream().flatMap((axisalignedbb) -> {
 -            return world.getEntitiesOfClass(ItemEntity.class, axisalignedbb.move(hopper.getLevelX() - 0.5D, hopper.getLevelY() - 0.5D, hopper.getLevelZ() - 0.5D), EntitySelector.ENTITY_STILL_ALIVE).stream();
 -        }).collect(Collectors.toList());
-+        // Paper start - Optimize item suck in. remove streams, restore 1.12 checks. Seriously checking the bowl?!
-+        double x = hopper.getLevelX();
-+        double y = hopper.getLevelY();
-+        double z = hopper.getLevelZ();
-+        AABB bb = new AABB(x - 0.5D, y, z - 0.5D, x + 0.5D, y + 1.5D, z + 0.5D);
-+        return world.getEntitiesOfClass(ItemEntity.class, bb, Entity::isAlive);
-+        // Paper end
++        // Paper start - optimize hopper item suck in
++        // eliminate multiple getEntitiesOfClass() but maintain the voxelshape collision by moving
++        // the individual AABB checks into the predicate
++        final double shiftX = hopper.getLevelX() - 0.5D;
++        final double shiftY = hopper.getLevelY() - 0.5D;
++        final double shiftZ = hopper.getLevelZ() - 0.5D;
++        return world.getEntitiesOfClass(ItemEntity.class, HOPPER_ITEM_SUCK_OVERALL.move(shiftX, shiftY, shiftZ), (final Entity entity) -> {
++            if (!entity.isAlive()) { // EntitySelector.ENTITY_STILL_ALIVE
++                return false;
++            }
++
++            for (final AABB aabb : HOPPER_ITEM_SUCK_INDIVIDUAL) {
++                if (aabb.move(shiftX, shiftY, shiftZ).intersects(entity.getBoundingBox())) {
++                    return true;
++                }
++            }
++
++            return false;
++        });
++        // Paper end - optimize hopper item suck in
      }
  
      @Nullable
@@ -542,7 +561,7 @@ index 6907e647ef4d3f5c9c46edb4cf0905844dd1cea9..beb70310f2e9657fee89cb4b6a988571
          Object object = null;
          BlockPos blockposition = BlockPos.containing(x, y, z);
          if ( !world.spigotConfig.hopperCanLoadChunks && !world.hasChunkAt( blockposition ) ) return null; // Spigot
-@@ -548,7 +764,7 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
+@@ -548,7 +782,7 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
              }
          }
  
@@ -551,7 +570,7 @@ index 6907e647ef4d3f5c9c46edb4cf0905844dd1cea9..beb70310f2e9657fee89cb4b6a988571
              List<Entity> list = world.getEntities((Entity) null, new AABB(x - 0.5D, y - 0.5D, z - 0.5D, x + 0.5D, y + 0.5D, z + 0.5D), EntitySelector.CONTAINER_ENTITY_SELECTOR);
  
              if (!list.isEmpty()) {
-@@ -560,7 +776,7 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
+@@ -560,7 +794,7 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
      }
  
      private static boolean canMergeItems(ItemStack first, ItemStack second) {