From 9d5ae2b336b5738cc010541b2d997b65f54b455a Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Sun, 22 Feb 2015 19:11:11 -0800
Subject: [PATCH] For 5551 buffers, force stencil mask to 1/0.

4444 it would also be ideal to spread the bits, but that gets a bit
complicated.  5650 probably doesn't matter.
---
 GPU/GLES/StateMapping.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/GPU/GLES/StateMapping.cpp b/GPU/GLES/StateMapping.cpp
index 3c1e4008b8..374c196abc 100644
--- a/GPU/GLES/StateMapping.cpp
+++ b/GPU/GLES/StateMapping.cpp
@@ -693,7 +693,12 @@ void TransformDrawEngine::ApplyDrawState(int prim) {
 			glstate.stencilOp.set(stencilOps[gstate.getStencilOpSFail()],  // stencil fail
 				stencilOps[gstate.getStencilOpZFail()],  // depth fail
 				stencilOps[gstate.getStencilOpZPass()]); // depth pass
-			glstate.stencilMask.set(~abits);
+
+			if (gstate.FrameBufFormat() == GE_FORMAT_5551) {
+				glstate.stencilMask.set(abits <= 0x7f ? 0xff : 0x00);
+			} else {
+				glstate.stencilMask.set(~abits);
+			}
 		} else {
 			glstate.stencilTest.disable();
 		}