Fix fog and transparent surfaces with MSAA

Author: VReaperV

src/engine/renderer/GLUtils.h

@@ -78,6 +78,8 @@ struct GLConfig
 	int max3DTextureSize;
 	int maxCubeMapTextureSize;
 	int maxTextureUnits;
+	int maxColorTextureSamples;
+	int maxDepthTextureSamples;
 
 	char shadingLanguageVersionString[MAX_STRING_CHARS];
 	int  shadingLanguageVersion;
@@ -153,6 +155,7 @@ struct GLConfig
 	bool reflectionMappingAvailable;
 	bool reflectionMapping;
 	bool bloom;
+	int  MSAA; // 0 == disabled, otherwise used as sample count
 	bool ssao;
 	bool motionBlur;
 };

src/engine/renderer/tr_backend.cpp

@@ -1623,7 +1623,7 @@ void RB_RenderSSAO()
 
 	RB_PrepareForSamplingDepthMap();
 
-	TransitionMSAAToMain( GL_DEPTH_BUFFER_BIT );
+	TransitionMSAAToMain( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
 
 	GL_State( GLS_DEPTHTEST_DISABLE | GLS_SRCBLEND_DST_COLOR | GLS_DSTBLEND_ZERO );
 	GL_Cull( cullType_t::CT_TWO_SIDED );
@@ -1656,6 +1656,8 @@ void RB_RenderSSAO()
 
 	Tess_InstantScreenSpaceQuad();
 
+	TransitionMainToMSAA( GL_COLOR_BUFFER_BIT );
+
 	GL_CheckErrors();
 }