Added FORMAT_X32B32G32R32F as a renderable format

Added code to properly render to alphaless floating point formats.

Change-Id: I2e226fb787d8456f61a2946fb9c0d8a9dbb58243
Reviewed-on: https://swiftshader-review.googlesource.com/5128
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
diff --git a/src/Shader/PixelPipeline.cpp b/src/Shader/PixelPipeline.cpp
index 99f91e7..8adeed8 100644
--- a/src/Shader/PixelPipeline.cpp
+++ b/src/Shader/PixelPipeline.cpp
@@ -351,6 +351,7 @@
 			break;
 		case FORMAT_R32F:
 		case FORMAT_G32R32F:
+		case FORMAT_X32B32G32R32F:
 		case FORMAT_A32B32G32R32F:
 			convertSigned12(oC, current);
 			PixelRoutine::fogBlend(oC, fog);