From 097bbee2676eb99c96b3ae49d1eedb0c0b2c2a04 Mon Sep 17 00:00:00 2001
From: alyosha-tas <alexei.f.k@gmail.com>
Date: Wed, 7 Dec 2016 21:47:04 -0500
Subject: [PATCH] Fix Lightgun reading an undefined pixel color

---
 BizHawk.Emulation.Cores/Consoles/Nintendo/NES/PPU.cs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/PPU.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/PPU.cs
index 16c986736f..74e0406d60 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/PPU.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/PPU.cs
@@ -119,7 +119,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 						goto loopout;
 
 					short s = xbuf[j * 256 + i];
-					sum += _currentLuma[s];
+					
+					if ((s & 0x8000)==0)
+						sum += _currentLuma[s];
 				}
 			}
 			loopout: