SakuraMC/patches/server/0048-Fix-paper-world-border-collision.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samsuik <40902469+Samsuik@users.noreply.github.com>
Date: Wed, 29 Nov 2023 23:36:21 +0000
Subject: [PATCH] Fix paper world border collision


diff --git a/src/main/java/io/papermc/paper/util/CollisionUtil.java b/src/main/java/io/papermc/paper/util/CollisionUtil.java
index 310ad76abcb263fbb067270f522007457c62c81b..1edae701aa293ae61039119421ced42828b9a470 100644
--- a/src/main/java/io/papermc/paper/util/CollisionUtil.java
+++ b/src/main/java/io/papermc/paper/util/CollisionUtil.java
@@ -1555,27 +1555,19 @@ public final class CollisionUtil {
 
     public static boolean isAlmostCollidingOnBorder(final WorldBorder worldborder, final double boxMinX, final double boxMaxX,
                                                     final double boxMinZ, final double boxMaxZ) {
-        final double borderMinX = worldborder.getMinX(); // -X
-        final double borderMaxX = worldborder.getMaxX(); // +X
+        // Sakura start - this method always returned true
+        final double borderMinX = worldborder.getMinX() + COLLISION_EPSILON; // -X
+        final double borderMaxX = worldborder.getMaxX() - COLLISION_EPSILON; // +X
 
-        final double borderMinZ = worldborder.getMinZ(); // -Z
-        final double borderMaxZ = worldborder.getMaxZ(); // +Z
+        final double borderMinZ = worldborder.getMinZ() + COLLISION_EPSILON; // -Z
+        final double borderMaxZ = worldborder.getMaxZ() - COLLISION_EPSILON; // +Z
 
         return
-            // Not intersecting if we're smaller
-            !voxelShapeIntersect(
-                boxMinX + COLLISION_EPSILON, Double.NEGATIVE_INFINITY, boxMinZ + COLLISION_EPSILON,
-                boxMaxX - COLLISION_EPSILON, Double.POSITIVE_INFINITY, boxMaxZ - COLLISION_EPSILON,
-                borderMinX, Double.NEGATIVE_INFINITY, borderMinZ, borderMaxX, Double.POSITIVE_INFINITY, borderMaxZ
-            )
-            &&
-
-            // Are intersecting if we're larger
-            voxelShapeIntersect(
-                boxMinX - COLLISION_EPSILON, Double.NEGATIVE_INFINITY, boxMinZ - COLLISION_EPSILON,
-                boxMaxX + COLLISION_EPSILON, Double.POSITIVE_INFINITY, boxMaxZ + COLLISION_EPSILON,
-                borderMinX, Double.NEGATIVE_INFINITY, borderMinZ, borderMaxX, Double.POSITIVE_INFINITY, borderMaxZ
-            );
+            // within the border at present
+            !isCollidingWithBorderEdge(worldborder, boxMinX, boxMaxX, boxMinZ, boxMaxZ)
+            // outside the border if we are larger or the border is shrunk
+            && boxMinX < borderMinX || boxMaxX > borderMaxX || boxMinZ < borderMinZ || boxMaxZ > borderMaxZ;
+        // Sakura end
     }
 
     public static boolean isCollidingWithBorderEdge(final WorldBorder worldborder, final AABB boundingBox) {
@@ -1584,11 +1576,13 @@ public final class CollisionUtil {
 
     public static boolean isCollidingWithBorderEdge(final WorldBorder worldborder, final double boxMinX, final double boxMaxX,
                                                     final double boxMinZ, final double boxMaxZ) {
-        final double borderMinX = worldborder.getMinX() + COLLISION_EPSILON; // -X
-        final double borderMaxX = worldborder.getMaxX() - COLLISION_EPSILON; // +X
+        // Sakura start - compare against an enlarged border
+        final double borderMinX = worldborder.getMinX() - COLLISION_EPSILON; // -X
+        final double borderMaxX = worldborder.getMaxX() + COLLISION_EPSILON; // +X
 
-        final double borderMinZ = worldborder.getMinZ() + COLLISION_EPSILON; // -Z
-        final double borderMaxZ = worldborder.getMaxZ() - COLLISION_EPSILON; // +Z
+        final double borderMinZ = worldborder.getMinZ() - COLLISION_EPSILON; // -Z
+        final double borderMaxZ = worldborder.getMaxZ() + COLLISION_EPSILON; // +Z
+        // Sakura end
 
         return boxMinX < borderMinX || boxMaxX > borderMaxX || boxMinZ < borderMinZ || boxMaxZ > borderMaxZ;
     }