From 4009a37692d9b9e5fa42b97ce4c9ed67da282a09 Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Wed, 1 May 2013 00:55:30 -0700
Subject: [PATCH] Improve blending with two fixed colors.

It's not right, but it's less bad.  Maybe there's a better way?

Improves Popolocrois and Lunar (battle) blending issues.
---
 GPU/GLES/StateMapping.cpp | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/GPU/GLES/StateMapping.cpp b/GPU/GLES/StateMapping.cpp
index 5a0df2f9123b..c01da70082a5 100644
--- a/GPU/GLES/StateMapping.cpp
+++ b/GPU/GLES/StateMapping.cpp
@@ -178,8 +178,19 @@ void TransformDrawEngine::ApplyDrawState(int prim) {
 					didReportBlend = true;
 
 					DEBUG_LOG(HLE, "ERROR INVALID blendcolorstate: FixA=%06x FixB=%06x FuncA=%i FuncB=%i", gstate.getFixA(), gstate.getFixB(), gstate.getBlendFuncA(), gstate.getBlendFuncB());
-					glBlendFuncA = GL_ONE;
-					glBlendFuncB = GL_ONE;
+					// Let's approximate, at least.
+					int blendSumA = (fixA & 0xFF) + ((fixA >> 8) & 0xFF) +  ((fixA >> 16) & 0xFF);
+					int blendSumB = (fixB & 0xFF) + ((fixB >> 8) & 0xFF) +  ((fixB >> 16) & 0xFF);
+					if (blendSumA < 64 * 3 && blendSumB > 192 * 3) {
+						glBlendFuncA = GL_ZERO;
+						glBlendFuncB = GL_ONE;
+					} else if (blendSumA > 192 * 3 && blendSumB < 64 * 3) {
+						glBlendFuncA = GL_ONE;
+						glBlendFuncB = GL_ZERO;
+					} else {
+						glBlendFuncA = GL_ONE;
+						glBlendFuncB = GL_ONE;
+					}
 				}
 			}
 			// At this point, through all paths above, glBlendFuncA and glBlendFuncB will be set somehow.