From 248179a82c4272e907ffa11b1861adc8bb61b67f Mon Sep 17 00:00:00 2001
From: Hydrox <ikada@protonmail.ch>
Date: Wed, 10 Jun 2020 04:36:00 +0100
Subject: [PATCH] gpu: fix major visual glitches on linux (#11389)

Putting this if statement behind `localId < size` causes major visual
glitches with the Mesa graphics driver on AMD cards. We think this is a compiler bug as this change shouldn't be affecting anything.
---
 .../client/plugins/gpu/priority_render.glsl   | 41 +++++++++++--------
 1 file changed, 24 insertions(+), 17 deletions(-)

diff --git a/runelite-client/src/main/resources/net/runelite/client/plugins/gpu/priority_render.glsl b/runelite-client/src/main/resources/net/runelite/client/plugins/gpu/priority_render.glsl
index 8a3d4474d2..90af8d41f0 100644
--- a/runelite-client/src/main/resources/net/runelite/client/plugins/gpu/priority_render.glsl
+++ b/runelite-client/src/main/resources/net/runelite/client/plugins/gpu/priority_render.glsl
@@ -113,28 +113,35 @@ int count_prio_offset(int priority) {
 void get_face(uint localId, modelinfo minfo, int cameraYaw, int cameraPitch,
     out int prio, out int dis, out ivec4 o1, out ivec4 o2, out ivec4 o3) {
   int size = minfo.size;
+  int offset = minfo.offset;
+  int flags = minfo.flags;
+  uint ssboOffset;
+
+  if (localId < size) {
+    ssboOffset = localId;
+  } else {
+    ssboOffset = 0;
+  }
+
+  ivec4 thisA;
+  ivec4 thisB;
+  ivec4 thisC;
+
+  // Grab triangle vertices from the correct buffer
+  if (flags < 0) {
+    thisA = vb[offset + ssboOffset * 3];
+    thisB = vb[offset + ssboOffset * 3 + 1];
+    thisC = vb[offset + ssboOffset * 3 + 2];
+  } else {
+    thisA = tempvb[offset + ssboOffset * 3];
+    thisB = tempvb[offset + ssboOffset * 3 + 1];
+    thisC = tempvb[offset + ssboOffset * 3 + 2];
+  }
 
   if (localId < size) {
-    int offset = minfo.offset;
-    int flags = minfo.flags;
     int radius = (flags & 0x7fffffff) >> 12;
     int orientation = flags & 0x7ff;
 
-    ivec4 thisA;
-    ivec4 thisB;
-    ivec4 thisC;
-
-    // Grab triangle vertices from the correct buffer
-    if (flags < 0) {
-      thisA = vb[offset + localId * 3];
-      thisB = vb[offset + localId * 3 + 1];
-      thisC = vb[offset + localId * 3 + 2];
-    } else {
-      thisA = tempvb[offset + localId * 3];
-      thisB = tempvb[offset + localId * 3 + 1];
-      thisC = tempvb[offset + localId * 3 + 2];
-    }
-
     // rotate for model orientation
     ivec4 thisrvA = rotate(thisA, orientation);
     ivec4 thisrvB = rotate(thisB, orientation);