From 2bacf8071f4faade5d5b8db282c30faf8fed4f7e Mon Sep 17 00:00:00 2001
From: Henrik Rydgard <hrydgard@gmail.com>
Date: Sun, 3 Feb 2013 12:27:52 +0100
Subject: [PATCH] Fix RotateUV. Apparently the rules are reversed in through
 mode.

---
 GPU/GLES/TransformPipeline.cpp | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/GPU/GLES/TransformPipeline.cpp b/GPU/GLES/TransformPipeline.cpp
index cf763cc7a8..534455fd24 100644
--- a/GPU/GLES/TransformPipeline.cpp
+++ b/GPU/GLES/TransformPipeline.cpp
@@ -348,11 +348,24 @@ static void SwapUVs(TransformedVertex &a, TransformedVertex &b) {
 // 1   0       0   1        1   2          3   0
 
 // Used by Star Soldier and Ys vs Sora.
-static void RotateUVs(TransformedVertex v[4]) {
-	if (/* (v[0].x > v[2].x && v[0].y < v[2].y) || */  // This first check seems wrong..
-		  (v[0].x < v[2].x && v[0].y > v[2].y)) {
+static void RotateUV(TransformedVertex v[4]) {
+	float x1 = v[2].x;
+	float x2 = v[0].x;
+	float y1 = v[2].y;
+	float y2 = v[0].y;
+
+	if ((x1 < x2 && y1 < y2) || (x1 > x2 && y1 > y2))
+		SwapUVs(v[1], v[3]);
+}
+
+static void RotateUVThrough(TransformedVertex v[4]) {
+	float x1 = v[2].x;
+	float x2 = v[0].x;
+	float y1 = v[2].y;
+	float y2 = v[0].y;
+
+	if ((x1 < x2 && y1 > y2) || (x1 > x2 && y1 < y2))
 		SwapUVs(v[1], v[3]);
-	}
 }
 
 // This is the software transform pipeline, which is necessary for supporting RECT
@@ -620,7 +633,10 @@ void TransformDrawEngine::SoftwareTransformAndDraw(
 				trans[3].u = saved.u;
 
 				// That's the four corners. Now process UV rotation.
-				RotateUVs(trans);
+				if (throughmode)
+					RotateUVThrough(trans);
+				else
+					RotateUV(trans);
 
 				// bottom right
 				trans[4] = trans[0];