Change u_Color to uint

`u_Color` was a vec4 that was being set from a `Color` object, which only has 8-bit precision per colour, so using up 4 times more memory than that to transfer it was quite atrocious. Instead, pack it into a uint32_t, then use `unpackUnorm4x8()` to unpack in the shader.

Also adds a macro for unpacking for hardware that doesn't support `GL_ARB_gpu_shader5`.

src/engine/renderer/gl_shader.cpp

@@ -502,6 +502,10 @@ static std::string GenCompatHeader() {
 		str += "float smoothstep(float edge0, float edge1, float x) { float t = clamp((x - edge0) / (edge1 - edge0), 0.0, 1.0); return t * t * (3.0 - 2.0 * t); }\n";
 	}
 
+	if ( !glConfig2.gpuShader5Available ) {
+		str += "#define unpackUnorm4x8( value ) ( ( vec4( value, value >> 8, value >> 16, value >> 24 ) & 0xFF ) / 255.0f )\n";
+	}
+
 	return str;
 }
 

src/engine/renderer/gl_shader.h

@@ -3099,17 +3099,17 @@ class u_CloudHeight :
 };
 
 class u_Color :
-	GLUniform4f
+	GLUniform1ui
 {
 public:
 	u_Color( GLShader *shader ) :
-		GLUniform4f( shader, "u_Color" )
+		GLUniform1ui( shader, "u_Color" )
 	{
 	}
 
 	void SetUniform_Color( const Color::Color& color )
 	{
-		this->SetValue( color.ToArray() );
+		this->SetValue( packUnorm4x8( color.ToArray() ) );
 	}
 };
 

src/engine/renderer/glsl_source/fogGlobal_fp.glsl

@@ -26,7 +26,7 @@ uniform sampler2D	u_ColorMap; // fog texture
 uniform sampler2D	u_DepthMap;
 
 uniform vec4		u_FogDistanceVector;
-uniform vec4		u_Color;
+uniform uint u_Color;
 uniform mat4		u_UnprojectMatrix;
 
 #if __VERSION__ > 120
@@ -52,5 +52,5 @@ void	main()
 
 	vec4 color = texture2D(u_ColorMap, st);
 
-	outputColor = u_Color * color;
+	outputColor = unpackUnorm4x8( u_Color ) * color;
 }

src/engine/renderer/glsl_source/fogQuake3_vp.glsl

@@ -29,7 +29,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 uniform float		u_Time;
 
 uniform vec4		u_ColorModulate;
-uniform vec4		u_Color;
+uniform uint		u_Color;
 uniform mat4		u_ModelMatrix;
 uniform mat4		u_ModelViewProjectionMatrix;
 
@@ -58,7 +58,7 @@ void	main()
 
 	VertexFetch( position, LB, color, texCoord, lmCoord );
 
-	color = /* color * u_ColorModulate + */ u_Color;
+	color = /* color * u_ColorModulate + */ unpackUnorm4x8( u_Color );
 
 	DeformVertex( position,
 		      LB.normal,

src/engine/renderer/glsl_source/forwardLighting_vp.glsl

@@ -32,7 +32,7 @@ uniform mat4		u_ModelMatrix;
 uniform mat4		u_ModelViewProjectionMatrix;
 
 uniform vec4		u_ColorModulate;
-uniform vec4		u_Color;
+uniform uint		u_Color;
 
 uniform float		u_Time;
 
@@ -63,7 +63,7 @@ void	main()
 	VertexFetch( position, LB, color, texCoord, lmCoord);
 
 	// assign color
-        color = color * u_ColorModulate + u_Color;
+        color = color * u_ColorModulate + unpackUnorm4x8( u_Color );
 
 	DeformVertex( position,
 		      LB.normal,

src/engine/renderer/glsl_source/generic_vp.glsl

@@ -33,7 +33,7 @@ uniform vec3		u_ViewOrigin;
 uniform float		u_Time;
 
 uniform vec4		u_ColorModulate;
-uniform vec4		u_Color;
+uniform uint		u_Color;
 #if defined(USE_TCGEN_ENVIRONMENT)
 uniform mat4		u_ModelMatrix;
 #endif
@@ -63,7 +63,7 @@ void	main()
 	vec2 texCoord, lmCoord;
 
 	VertexFetch( position, LB, color, texCoord, lmCoord );
-	color = color * u_ColorModulate + u_Color;
+	color = color * u_ColorModulate + unpackUnorm4x8( u_Color );
 
 	DeformVertex( position,
 		      LB.normal,

src/engine/renderer/glsl_source/lightMapping_vp.glsl

@@ -46,7 +46,7 @@ uniform mat4		u_ModelViewProjectionMatrix;
 uniform float		u_Time;
 
 uniform vec4		u_ColorModulate;
-uniform vec4		u_Color;
+uniform uint		u_Color;
 
 OUT(smooth) vec3	var_Position;
 OUT(smooth) vec2	var_TexCoords;
@@ -73,7 +73,7 @@ void main()
 
 	VertexFetch(position, LB, color, texCoord, lmCoord);
 
-	color = color * u_ColorModulate + u_Color;
+	color = color * u_ColorModulate + unpackUnorm4x8( u_Color );
 
 	DeformVertex(position, LB.normal, texCoord, color, u_Time);
 

src/engine/renderer/glsl_source/shadowFill_vp.glsl

@@ -26,7 +26,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #insert vertexSkinning_vp
 #insert vertexAnimation_vp
 
-uniform vec4		u_Color;
+uniform uint		u_Color;
 
 uniform mat4		u_TextureMatrix;
 uniform mat4		u_ModelMatrix;
@@ -73,5 +73,5 @@ void	main()
 	var_TexCoords = (u_TextureMatrix * vec4(texCoord, 0.0, 1.0)).st;
 
 	// assign color
-	var_Color = u_Color;
+	var_Color = unpackUnorm4x8( u_Color );
 }

src/engine/renderer/tr_local.h

@@ -124,6 +124,13 @@ static inline void snorm16ToFloat( const i16vec4_t in, vec4_t out )
 	out[ 3 ] = snorm16ToFloat( in[ 3 ] );
 }
 
+static inline uint32_t packUnorm4x8( const vec4_t in ) {
+	return uint32_t( floatToUnorm8( in[0] ) )
+		| ( uint32_t( floatToUnorm8( in[1] ) ) << 8 )
+		| ( uint32_t( floatToUnorm8( in[2] ) ) << 16 )
+		| ( uint32_t( floatToUnorm8( in[3] ) ) << 24 );
+}
+
 static inline f16_t floatToHalf( float in ) {
 	static float scale = powf(2.0f, 15 - 127);