From 09ccf5403eb0a0d85fa119c612b9070fe8807818 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Mon, 10 Jun 2019 10:50:14 -0700
Subject: [PATCH] GBA Video: Fix GL mode 0 y wrapping

---
 src/gba/renderers/gl.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/gba/renderers/gl.c b/src/gba/renderers/gl.c
index 72ddd1d8c..a54e0b028 100644
--- a/src/gba/renderers/gl.c
+++ b/src/gba/renderers/gl.c
@@ -146,8 +146,12 @@ static const char* const _renderMode0 =
 	"		coord.y -= coord.y % mosaic.y;\n"
 	"	}\n"
 	"	coord += (ivec2(0x3FF, 0x3FF000) & offset[int(texCoord.y)]) >> ivec2(0, 12);\n"
+	"	ivec2 wrap = ivec2(255, 511);\n"
 	"	if (size == 3) {\n"
 	"		coord.y += (coord.y & 256) << 1;\n"
+	"		wrap.y = 1023;\n"
+	"	} else if (size == 0) {\n"
+	"		wrap.y = 255;\n"
 	"	}\n"
 	"	if (size != 2) {\n"
 	"		coord.y &= ~256;\n"
@@ -155,7 +159,7 @@ static const char* const _renderMode0 =
 	"	if ((size & 1) == 1) {\n"
 	"		coord.y += coord.x & 256;\n"
 	"	}\n"
-	"	coord &= ivec2(255, 1023);\n"
+	"	coord &= wrap;\n"
 	"	int mapAddress = screenBase + (coord.x >> 3) + (coord.y >> 3) * 32;\n"
 	"	vec4 map = texelFetch(vram, ivec2(mapAddress & 255, mapAddress >> 8), 0);\n"
 	"	int tileFlags = int(map.g * 15.9);\n"