Revert "- reworked fog uniforms to move the global fog mode setting to the viewpoint buffer."

This reverts commit 8b26b6dd1e.

This was causing problems with light mode 2 because some edge cases were no longer handled properly.

src/gl/data/gl_viewpointbuffer.cpp

@@ -144,7 +144,6 @@ void GLViewpointBuffer::Set2D(int width, int height)
 		HWViewpointUniforms matrices;
 		matrices.SetDefaults();
 		matrices.mProjectionMatrix.ortho(0, width, height, 0, -1.0f, 1.0f);
-		matrices.mFogEnabled = 3;
 		matrices.CalcDependencies();
 		Map();
 		memcpy(mBufferPointer, &matrices, sizeof(matrices));

src/gl/renderer/gl_renderstate.cpp

@@ -119,7 +119,7 @@ bool FRenderState::ApplyShader()
 	static uint64_t firstFrame = 0;
 	// if firstFrame is not yet initialized, initialize it to current time
 	// if we're going to overflow a float (after ~4.6 hours, or 24 bits), re-init to regain precision
-	if ((firstFrame == 0) || (screen->FrameTime - firstFrame >= 1 << 24) || level.ShaderStartTime >= firstFrame)
+	if ((firstFrame == 0) || (screen->FrameTime - firstFrame >= 1<<24) || level.ShaderStartTime >= firstFrame)
 		firstFrame = screen->FrameTime;
 
 	static const float nulvec[] = { 0.f, 0.f, 0.f, 0.f };
@@ -133,15 +133,31 @@ bool FRenderState::ApplyShader()
 		activeShader->Bind();
 	}
 
+	int fogset = 0;
+
+	if (mFogEnabled)
+	{
+		if (mFogEnabled == 2)
+		{
+			fogset = -3;	// 2D rendering with 'foggy' overlay.
+		}
+		else if ((mFogColor & 0xffffff) == 0)
+		{
+			fogset = gl_fogmode;
+		}
+		else
+		{
+			fogset = -gl_fogmode;
+		}
+	}
+
 	glVertexAttrib4fv(VATTR_COLOR, mColor.vec);
 	glVertexAttrib4fv(VATTR_NORMAL, mNormal.vec);
 
 	activeShader->muDesaturation.Set(mDesaturation / 255.f);
+	activeShader->muFogEnabled.Set(fogset);
 	activeShader->muTextureMode.Set(mTextureMode == TM_MODULATE && mTempTM == TM_OPAQUE ? TM_OPAQUE : mTextureMode);
-	float fds = mLightParms[2];
-	if (!mFogEnabled) mLightParms[2] = 0;
 	activeShader->muLightParms.Set(mLightParms);
-	mLightParms[2] = fds;
 	activeShader->muFogColor.Set(mFogColor);
 	activeShader->muObjectColor.Set(mObjectColor);
 	activeShader->muObjectColor2.Set(mObjectColor2);

src/gl/scene/gl_scene.cpp

@@ -375,7 +375,6 @@ void FDrawInfo::DrawEndScene2D(sector_t * viewsector)
 	HWViewpointUniforms vp = VPUniforms;
 	vp.mViewMatrix.loadIdentity();
 	vp.mProjectionMatrix = vrmode->GetHUDSpriteProjection();
-	vp.mFogEnabled = 0;
 	GLRenderer->mViewpoints->SetViewpoint(&vp);
 	glDisable(GL_DEPTH_TEST);
 	glDisable(GL_MULTISAMPLE);

src/gl/shaders/gl_shader.cpp

@@ -68,8 +68,6 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 			int uViewHeight;		// Software fuzz scaling
 			float uClipHeight;
 			float uClipHeightDirection;
-			int uFogEnabled;
-
 		};
 	)";
 	
@@ -100,6 +98,7 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 	i_data += "#define uFogDensity uLightAttr.b\n";
 	i_data += "#define uLightFactor uLightAttr.g\n";
 	i_data += "#define uLightDist uLightAttr.r\n";
+	i_data += "uniform int uFogEnabled;\n";
 
 	// dynamic lights
 	i_data += "uniform int uLightIndex;\n";
@@ -331,6 +330,7 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 
 
 	muDesaturation.Init(hShader, "uDesaturationFactor");
+	muFogEnabled.Init(hShader, "uFogEnabled");
 	muTextureMode.Init(hShader, "uTextureMode");
 	muLightParms.Init(hShader, "uLightAttr");
 	muClipSplit.Init(hShader, "uClipSplit");

src/gl/shaders/gl_shader.h

@@ -242,6 +242,7 @@ class FShader
 	FName mName;
 
 	FBufferedUniform1f muDesaturation;
+	FBufferedUniform1i muFogEnabled;
 	FBufferedUniform1i muTextureMode;
 	FBufferedUniform4f muLightParms;
 	FBufferedUniform2f muClipSplit;

src/hwrenderer/scene/hw_drawinfo.cpp

@@ -280,6 +280,5 @@ void HWViewpointUniforms::SetDefaults()
 	mGlobVis = (float)R_GetGlobVis(r_viewwindow, r_visibility) / 32.f;
 	mPalLightLevels = static_cast<int>(gl_bandedswlight) | (static_cast<int>(gl_fogmode) << 8);
 	mClipLine.X = -10000000.0f;
-	mFogEnabled = gl_fogmode;
 
 }

src/hwrenderer/scene/hw_viewpointuniforms.h

@@ -16,7 +16,6 @@ struct HWViewpointUniforms
 	int mViewHeight = 0;
 	float mClipHeight = 0.f;
 	float mClipHeightDirection = 0.f;
-	int mFogEnabled = 0;
 
 	void CalcDependencies()
 	{