GL: Add "frameCounter" uniform

Add the current frame counter as a uniform variable to the shaders, so
people can use it to do time-based animation.

src/graphics/C4DrawGL.cpp

@@ -227,6 +227,7 @@ bool CStdGL::PrepareSpriteShader(C4Shader& shader, const char* name, int ssc, C4
 	uniformNames[C4SSU_MaterialShininess] = "materialShininess"; // unused
 	uniformNames[C4SSU_Bones] = "bones"; // unused
 	uniformNames[C4SSU_CullMode] = "cullMode"; // unused
+	uniformNames[C4SSU_FrameCounter] = "frameCounter";
 	uniformNames[C4SSU_Count] = NULL;
 
 	const char* attributeNames[C4SSA_Count + 1];

src/graphics/C4DrawGL.h

@@ -77,6 +77,8 @@ enum C4SS_Uniforms
 	C4SSU_Bones, // for meshes
 	C4SSU_CullMode, // for meshes
 
+	C4SSU_FrameCounter, // for custom shaders
+
 	C4SSU_Count
 };
 

src/graphics/C4DrawMeshGL.cpp

@@ -538,6 +538,9 @@ namespace
 			pFoW->getFoW()->Ambient.GetFragTransform(pFoW->getViewportRegion(), clipRect, outRect, ambientTransform);
 			call.SetUniformMatrix2x3fv(C4SSU_AmbientTransform, 1, ambientTransform);
 		}
+
+		// Current frame counter
+		call.SetUniform1i(C4SSU_FrameCounter, ::Game.FrameCounter);
 	}
 
 	bool ResolveAutoParameter(C4ShaderCall& call, StdMeshMaterialShaderParameter& parameter, StdMeshMaterialShaderParameter::Auto value, DWORD dwModClr, DWORD dwPlayerColor, DWORD dwBlitMode, const C4FoWRegion* pFoW, const C4Rect& clipRect)

src/lib/StdMeshMaterial.cpp

@@ -885,6 +885,7 @@ bool StdMeshMaterialProgram::CompileShader(StdMeshMaterialLoader& loader, C4Shad
 	uniformNames[C4SSU_MaterialShininess] = "materialShininess";
 	uniformNames[C4SSU_Bones] = "bones";
 	uniformNames[C4SSU_CullMode] = "cullMode";
+	uniformNames[C4SSU_FrameCounter] = "frameCounter";
 	for (unsigned int i = 0; i < ParameterNames.size(); ++i)
 		uniformNames[C4SSU_Count + i] = ParameterNames[i].getData();
 	uniformNames[C4SSU_Count + ParameterNames.size()] = NULL;