LeavesMC/leaves-server/minecraft-patches/features/0134-Configurable-collision-behavior.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Fortern <blueten.ki@gmail.com>
Date: Thu, 24 Oct 2024 23:10:34 +0800
Subject: [PATCH] Configurable collision behavior


diff --git a/ca/spottedleaf/moonrise/patches/collisions/CollisionUtil.java b/ca/spottedleaf/moonrise/patches/collisions/CollisionUtil.java
index 01cd38bba2deb6cf65c82b4e4ec352a2998fd339..8eb8e1447043498c6a0db1b56e877a91cd5fc438 100644
--- a/ca/spottedleaf/moonrise/patches/collisions/CollisionUtil.java
+++ b/ca/spottedleaf/moonrise/patches/collisions/CollisionUtil.java
@@ -101,6 +101,14 @@ public final class CollisionUtil {
                (box1.minZ - box2.maxZ) < -COLLISION_EPSILON && (box1.maxZ - box2.minZ) > COLLISION_EPSILON;
     }
 
+    // Leaves start - Configurable collision behavior
+    public static boolean voxelShapeIntersectVanilla(final AABB box1, final AABB box2) {
+        return box1.minX < box2.maxX && box1.maxX > box2.minX &&
+               box1.minY < box2.maxY && box1.maxY > box2.minY &&
+               box1.minZ < box2.maxZ && box1.maxZ > box2.minZ;
+    }
+    // Leaves end - Configurable collision behavior
+
     // assume !isEmpty(target) && abs(source_move) >= COLLISION_EPSILON
     public static double collideX(final AABB target, final AABB source, final double source_move) {
         if ((source.minY - target.maxY) < -COLLISION_EPSILON && (source.maxY - target.minY) > COLLISION_EPSILON &&
@@ -2014,7 +2022,9 @@ public final class CollisionUtil {
                                     AABB singleAABB = ((CollisionVoxelShape)blockCollision).moonrise$getSingleAABBRepresentation();
                                     if (singleAABB != null) {
                                         singleAABB = singleAABB.move((double)blockX, (double)blockY, (double)blockZ);
-                                        if (!voxelShapeIntersect(aabb, singleAABB)) {
+                                        // Leaves start - Configurable collision behavior
+                                        if (shouldSkip(aabb, blockCollision, singleAABB)) {
+                                        // Leaves end - Configurable collision behavior
                                             continue;
                                         }
 
@@ -2067,6 +2077,17 @@ public final class CollisionUtil {
         return ret;
     }
 
+    // Leaves start - Configurable collision behavior
+    private static boolean shouldSkip(net.minecraft.world.phys.AABB aabb, net.minecraft.world.phys.shapes.VoxelShape blockCollision, net.minecraft.world.phys.AABB singleAABB) {
+        boolean isBlockShape = blockCollision == net.minecraft.world.phys.shapes.Shapes.block();
+        return switch (org.leavesmc.leaves.LeavesConfig.fix.collisionBehavior) {
+            case PAPER -> !voxelShapeIntersect(aabb, singleAABB);
+            case VANILLA -> !voxelShapeIntersectVanilla(aabb, singleAABB);
+            case BLOCK_SHAPE_VANILLA -> isBlockShape && !voxelShapeIntersectVanilla(aabb, singleAABB) || !isBlockShape && !voxelShapeIntersect(aabb, singleAABB);
+        };
+    }
+    // Leaves end - Configurable collision behavior
+
     public static boolean getEntityHardCollisions(final Level world, final Entity entity, AABB aabb,
                                                   final List<AABB> into, final int collisionFlags, final Predicate<Entity> predicate) {
         final boolean checkOnly = (collisionFlags & COLLISION_FLAG_CHECK_ONLY) != 0;