Implement gl3_colorlight, when set to 0, render lights without color

like the (original) software renderer. defaults to 1, of course

src/client/refresh/gl3/gl3_main.c

@@ -93,6 +93,7 @@ cvar_t *r_clear;
 cvar_t *gl3_particle_size;
 cvar_t *gl3_particle_fade_factor;
 cvar_t *gl3_particle_square;
+cvar_t *gl3_colorlight;
 
 cvar_t *gl_lefthand;
 cvar_t *r_gunfov;
@@ -210,6 +211,8 @@ GL3_Register(void)
 	gl3_particle_size = ri.Cvar_Get("gl3_particle_size", "40", CVAR_ARCHIVE);
 	gl3_particle_fade_factor = ri.Cvar_Get("gl3_particle_fade_factor", "1.2", CVAR_ARCHIVE);
 	gl3_particle_square = ri.Cvar_Get("gl3_particle_square", "0", CVAR_ARCHIVE);
+	// if set to 0, lights (from lightmaps, dynamic lights and on models) are white instead of colored
+	gl3_colorlight = ri.Cvar_Get("gl3_colorlight", "1", CVAR_ARCHIVE);
 
 	//  0: use lots of calls to glBufferData()
 	//  1: reduce calls to glBufferData() with one big VBO (see GL3_BufferAndDraw3D())
@@ -1746,9 +1749,10 @@ GL3_BeginFrame(float camera_separation)
 		GL3_UpdateUBO3D();
 	}
 
-	if(gl3_particle_square->modified)
+	if(gl3_particle_square->modified || gl3_colorlight->modified)
 	{
 		gl3_particle_square->modified = false;
+		gl3_colorlight->modified = false;
 		GL3_RecreateShaders();
 	}
 

src/client/refresh/gl3/gl3_mesh.c

@@ -161,6 +161,12 @@ DrawAliasFrameLerp(dmdl_t *paliashdr, entity_t* entity, vec3_t shadelight)
 		GL3_UseProgram(gl3state.si3Dalias.shaderProgram);
 	}
 
+	if(gl3_colorlight->value == 0.0f)
+	{
+		float avg = 0.333333f * (shadelight[0]+shadelight[1]+shadelight[2]);
+		shadelight[0] = shadelight[1] = shadelight[2] = avg;
+	}
+
 	/* move should be the delta back to the previous frame * backlerp */
 	VectorSubtract(entity->oldorigin, entity->origin, delta);
 	AngleVectors(entity->angles, vectors[0], vectors[1], vectors[2]);

src/client/refresh/gl3/gl3_shaders.c

@@ -516,6 +516,96 @@ static const char* fragmentSrc3Dlm = MULTILINE_STRING(
 		}
 );
 
+static const char* fragmentSrc3DlmNoColor = MULTILINE_STRING(
+
+		// it gets attributes and uniforms from fragmentCommon3D
+
+		struct DynLight { // gl3UniDynLight in C
+			vec3 lightOrigin;
+			float _pad;
+			//vec3 lightColor;
+			//float lightIntensity;
+			vec4 lightColor; // .a is intensity; this way it also works on OSX...
+			// (otherwise lightIntensity always contained 1 there)
+		};
+
+		layout (std140) uniform uniLights
+		{
+			DynLight dynLights[32];
+			uint numDynLights;
+			uint _pad1; uint _pad2; uint _pad3; // FFS, AMD!
+		};
+
+		uniform sampler2D tex;
+
+		uniform sampler2D lightmap0;
+		uniform sampler2D lightmap1;
+		uniform sampler2D lightmap2;
+		uniform sampler2D lightmap3;
+
+		uniform vec4 lmScales[4];
+
+		in vec2 passLMcoord;
+		in vec3 passWorldCoord;
+		in vec3 passNormal;
+		flat in uint passLightFlags;
+
+		void main()
+		{
+			vec4 texel = texture(tex, passTexCoord);
+
+			// apply intensity
+			texel.rgb *= intensity;
+
+			// apply lightmap
+			vec4 lmTex = texture(lightmap0, passLMcoord) * lmScales[0];
+			lmTex     += texture(lightmap1, passLMcoord) * lmScales[1];
+			lmTex     += texture(lightmap2, passLMcoord) * lmScales[2];
+			lmTex     += texture(lightmap3, passLMcoord) * lmScales[3];
+
+			if(passLightFlags != 0u)
+			{
+				// TODO: or is hardcoding 32 better?
+				for(uint i=0u; i<numDynLights; ++i)
+				{
+					// I made the following up, it's probably not too cool..
+					// it basically checks if the light is on the right side of the surface
+					// and, if it is, sets intensity according to distance between light and pixel on surface
+
+					// dyn light number i does not affect this plane, just skip it
+					if((passLightFlags & (1u << i)) == 0u)  continue;
+
+					float intens = dynLights[i].lightColor.a;
+
+					vec3 lightToPos = dynLights[i].lightOrigin - passWorldCoord;
+					float distLightToPos = length(lightToPos);
+					float fact = max(0, intens - distLightToPos - 52);
+
+					// move the light source a bit further above the surface
+					// => helps if the lightsource is so close to the surface (e.g. grenades, rockets)
+					//    that the dot product below would return 0
+					// (light sources that are below the surface are filtered out by lightFlags)
+					lightToPos += passNormal*32.0;
+
+					// also factor in angle between light and point on surface
+					fact *= max(0, dot(passNormal, normalize(lightToPos)));
+
+
+					lmTex.rgb += dynLights[i].lightColor.rgb * fact * (1.0/256.0);
+				}
+			}
+
+			// turn lightcolor into grey for gl3_colorlight 0
+			lmTex.rgb = vec3(0.333 * (lmTex.r+lmTex.g+lmTex.b));
+
+			lmTex.rgb *= overbrightbits;
+			outColor = lmTex*texel;
+			outColor.rgb = pow(outColor.rgb, vec3(gamma)); // apply gamma correction to result
+
+			outColor.a = 1; // lightmaps aren't used with translucent surfaces
+		}
+);
+
 static const char* fragmentSrc3Dcolor = MULTILINE_STRING(
 
 		// it gets attributes and uniforms from fragmentCommon3D
@@ -1011,7 +1101,11 @@ static qboolean createShaders(void)
 		R_Printf(PRINT_ALL, "WARNING: Failed to create shader program for color-only 2D rendering!\n");
 		return false;
 	}
-	if(!initShader3D(&gl3state.si3Dlm, vertexSrc3Dlm, fragmentSrc3Dlm))
+
+	const char* lightmappedFrag = (gl3_colorlight->value == 0.0f)
+	                               ? fragmentSrc3DlmNoColor : fragmentSrc3Dlm;
+
+	if(!initShader3D(&gl3state.si3Dlm, vertexSrc3Dlm, lightmappedFrag))
 	{
 		R_Printf(PRINT_ALL, "WARNING: Failed to create shader program for textured 3D rendering with lightmap!\n");
 		return false;
@@ -1038,7 +1132,7 @@ static qboolean createShaders(void)
 		R_Printf(PRINT_ALL, "WARNING: Failed to create shader program for water rendering!\n");
 		return false;
 	}
-	if(!initShader3D(&gl3state.si3DlmFlow, vertexSrc3DlmFlow, fragmentSrc3Dlm))
+	if(!initShader3D(&gl3state.si3DlmFlow, vertexSrc3DlmFlow, lightmappedFrag))
 	{
 		R_Printf(PRINT_ALL, "WARNING: Failed to create shader program for scrolling textured 3D rendering with lightmap!\n");
 		return false;

src/client/refresh/gl3/header/local.h

@@ -515,6 +515,7 @@ extern cvar_t *r_lightlevel;
 extern cvar_t *gl3_overbrightbits;
 extern cvar_t *gl3_particle_fade_factor;
 extern cvar_t *gl3_particle_square;
+extern cvar_t *gl3_colorlight;
 
 extern cvar_t *r_modulate;
 extern cvar_t *gl_lightmap;