From 3280e3040056b2d0735b833b1e7e4d43fac3ec43 Mon Sep 17 00:00:00 2001
From: Peter Strath <168037f38@gmail.com>
Date: Fri, 25 Oct 2019 13:31:49 +0100
Subject: [PATCH] Prevent diagonal movement into blocks

Fixed in Craft pull request https://github.com/fogleman/Craft/pull/216
from usernamefreaks.

Bug report: https://github.com/fogleman/Craft/issues/209
---
 src/main.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/src/main.c b/src/main.c
index 02cc1edb2..4974dc209 100644
--- a/src/main.c
+++ b/src/main.c
@@ -734,6 +734,36 @@ int collide(int height, float *x, float *y, float *z) {
         if (pz > pad && is_obstacle(map_get(map, nx, ny - dy, nz + 1))) {
             *z = nz + pad;
         }
+
+        // check the 4 diagonally neighboring blocks for obstacle as well
+        if (px < -pad && pz > pad && is_obstacle(map_get(map, nx - 1, ny - dy, nz + 1))) {
+            if(ABS(px) < ABS(pz)) {
+                *x = nx - pad;
+            } else {
+                *z = nz + pad;
+            }
+        }
+        if (px > pad && pz > pad && is_obstacle(map_get(map, nx + 1, ny - dy, nz + 1))) {
+            if(ABS(px) < ABS(pz)) {
+                *x = nx + pad;
+            } else {
+                *z = nz + pad;
+            }
+        }
+        if (px < -pad && pz < -pad && is_obstacle(map_get(map, nx - 1, ny - dy, nz - 1))) {
+            if(ABS(px) < ABS(pz)) {
+                *x = nx - pad;
+            } else {
+                *z = nz - pad;
+            }
+        }
+        if (px > pad && pz < -pad && is_obstacle(map_get(map, nx + 1, ny - dy, nz - 1))) {
+            if(ABS(px) < ABS(pz)) {
+                *x = nx + pad;
+            } else {
+                *z = nz - pad;
+            }
+        }
     }
     return result;
 }