A little bit of fog-related cleanup

Document uniforms; use DotProduct function; use DECLARE_OUTPUT.

Author: slipher

src/engine/renderer/Material.cpp

@@ -1106,12 +1106,9 @@ void BindShaderFog( Material* material ) {
 	float eyeT;
 	vec4_t fogDepthVector;
 	if ( fog->hasSurface ) {
-		fogDepthVector[0] = fog->surface[0] * backEnd.orientation.axis[0][0] +
-			fog->surface[1] * backEnd.orientation.axis[0][1] + fog->surface[2] * backEnd.orientation.axis[0][2];
-		fogDepthVector[1] = fog->surface[0] * backEnd.orientation.axis[1][0] +
-			fog->surface[1] * backEnd.orientation.axis[1][1] + fog->surface[2] * backEnd.orientation.axis[1][2];
-		fogDepthVector[2] = fog->surface[0] * backEnd.orientation.axis[2][0] +
-			fog->surface[1] * backEnd.orientation.axis[2][1] + fog->surface[2] * backEnd.orientation.axis[2][2];
+		fogDepthVector[0] = DotProduct( fog->surface, backEnd.orientation.axis[ 0 ] );
+		fogDepthVector[1] = DotProduct( fog->surface, backEnd.orientation.axis[ 1 ] );
+		fogDepthVector[2] = DotProduct( fog->surface, backEnd.orientation.axis[ 2 ] );
 		fogDepthVector[3] = -fog->surface[3] + DotProduct( backEnd.orientation.origin, fog->surface );
 
 		eyeT = DotProduct( backEnd.orientation.viewOrigin, fogDepthVector ) + fogDepthVector[3];

src/engine/renderer/glsl_source/fogGlobal_fp.glsl

@@ -32,11 +32,7 @@ uniform colorPack u_Color;
 uniform vec4		u_FogDistanceVector;
 uniform mat4		u_UnprojectMatrix;
 
-#if __VERSION__ > 120
-out vec4 outputColor;
-#else
-#define outputColor gl_FragColor
-#endif
+DECLARE_OUTPUT(vec4)
 
 void	main()
 {
@@ -48,9 +44,8 @@ void	main()
 	vec4 P = u_UnprojectMatrix * vec4(gl_FragCoord.xy, depth, 1.0);
 	P.xyz /= P.w;
 
-	// calculate the length in fog (t is always 0 if eye is in fog)
+	// calculate the length in fog (t is always 1 if eye is in fog)
 	st.s = dot(P.xyz, u_FogDistanceVector.xyz) + u_FogDistanceVector.w;
-	// st.s = vertexDistanceToCamera;
 	st.t = 1.0;
 
 	vec4 color = texture2D(u_ColorMap, st);

src/engine/renderer/glsl_source/fogQuake3_fp.glsl

@@ -26,7 +26,6 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
 uniform sampler2D u_FogMap;
 
-IN(smooth) vec3		var_Position;
 IN(smooth) vec2		var_TexCoords;
 IN(smooth) vec4		var_Color;
 
@@ -41,8 +40,4 @@ void	main()
 	color *= var_Color;
 
 	outputColor = color;
-
-#if 0
-	outputColor = vec4(vec3(1.0, 0.0, 0.0), color.a);
-#endif
 }

src/engine/renderer/glsl_source/fogQuake3_vp.glsl

@@ -34,11 +34,14 @@ uniform colorPack u_ColorGlobal;
 uniform mat4		u_ModelMatrix;
 uniform mat4		u_ModelViewProjectionMatrix;
 
-uniform vec4		u_FogDistanceVector;
-uniform vec4		u_FogDepthVector;
+uniform vec4		u_FogDistanceVector; // view axis in model coordinates, scaled by fog density
+uniform vec4		u_FogDepthVector; // fog plane in model coordinates
 uniform float		u_FogEyeT;
 
 OUT(smooth) vec3	var_Position;
+
+// var_TexCoords.s is distance from viewer to vertex dotted with view axis
+// var_TexCoords.t is the fraction of the viewer-to-vertex ray which is inside fog
 OUT(smooth) vec2	var_TexCoords;
 OUT(smooth) vec4	var_Color;
 

src/engine/renderer/tr_shade.cpp

@@ -1613,12 +1613,9 @@ void Render_fog( shaderStage_t* pStage )
 	vec4_t fogDepthVector;
 	if ( fog->hasSurface )
 	{
-		fogDepthVector[ 0 ] = fog->surface[ 0 ] * backEnd.orientation.axis[ 0 ][ 0 ] +
-		                      fog->surface[ 1 ] * backEnd.orientation.axis[ 0 ][ 1 ] + fog->surface[ 2 ] * backEnd.orientation.axis[ 0 ][ 2 ];
-		fogDepthVector[ 1 ] = fog->surface[ 0 ] * backEnd.orientation.axis[ 1 ][ 0 ] +
-		                      fog->surface[ 1 ] * backEnd.orientation.axis[ 1 ][ 1 ] + fog->surface[ 2 ] * backEnd.orientation.axis[ 1 ][ 2 ];
-		fogDepthVector[ 2 ] = fog->surface[ 0 ] * backEnd.orientation.axis[ 2 ][ 0 ] +
-		                      fog->surface[ 1 ] * backEnd.orientation.axis[ 2 ][ 1 ] + fog->surface[ 2 ] * backEnd.orientation.axis[ 2 ][ 2 ];
+		fogDepthVector[ 0 ] = DotProduct( fog->surface, backEnd.orientation.axis[ 0 ] );
+		fogDepthVector[ 1 ] = DotProduct( fog->surface, backEnd.orientation.axis[ 1 ] );
+		fogDepthVector[ 2 ] = DotProduct( fog->surface, backEnd.orientation.axis[ 2 ] );
 		fogDepthVector[ 3 ] = -fog->surface[ 3 ] + DotProduct( backEnd.orientation.origin, fog->surface );
 
 		eyeT = DotProduct( backEnd.orientation.viewOrigin, fogDepthVector ) + fogDepthVector[ 3 ];