From ef5b033b3acf81f95e61ce418be19f5d32481b13 Mon Sep 17 00:00:00 2001
From: Hayden K <819028+mrneo240@users.noreply.github.com>
Date: Wed, 27 Mar 2019 19:19:30 -0400
Subject: [PATCH] fix texture twiddle

---
 GL/texture.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/GL/texture.c b/GL/texture.c
index 17f3455..3dddacb 100644
--- a/GL/texture.c
+++ b/GL/texture.c
@@ -938,14 +938,21 @@ void APIENTRY glTexImage2D(GLenum target, GLint level, GLint internalFormat,
 
         if(needsTwiddling) {
             assert(type == GL_UNSIGNED_BYTE);  // Anything else needs this loop adjusting
+            GLuint x, y, min, mask;
 
             min = MIN(w, h);
-            min2 = min * min;
             mask = min - 1;
 
-            for(y = 0; y < h; y++) {
+            uint8 * pixels;
+            uint16 * vtex;
+            pixels = (uint8 *) data;
+            vtex = (uint16*)targetData;
+
+            for(y = 0; y < h; y += 2) {
                 for(x = 0; x < w; x++) {
-                    targetData[TWIDOUT(x & mask, y & mask) + (x / min + y / min) * min2] = ((GLubyte*) data)[y * w + x];
+                    vtex[TWIDOUT((y & mask) / 2, x & mask) +
+                            (x / min + y / min)*min * min / 2] =
+                                pixels[y * w + x] | (pixels[(y + 1) * w + x] << 8);
                 }
             }
         } else {