renderer: generic texture3D disablement

Author: illwieckz

src/engine/renderer/GLUtils.h

@@ -128,6 +128,7 @@ struct GLConfig
 	bool gpuShader4Available;
 	bool gpuShader5Available;
 	bool textureGatherAvailable;
+	bool texture3DAvailable;
 	bool mat3x2Available;
 	bool assumeSmoothstep;
 	bool incrementalShaderCompilation;

src/engine/renderer/gl_shader.cpp

@@ -516,6 +516,10 @@ R"(#if !defined(GENERATED_EXTENSIONS_HEADER)
 		addExtension( str, addedExtension.available, addedExtension.minGlslVersion, addedExtension.name );
 	}
 
+	if ( glConfig.texture3DAvailable ) {
+		str += "#define HAVE_texture3D 1\n";
+	}
+
 	str +=
 R"(#endif // GENERATED_EXTENSIONS_HEADER
 

src/engine/renderer/glsl_source/lightMapping_fp.glsl

@@ -46,10 +46,12 @@ IN(smooth) vec3		var_Binormal;
 IN(smooth) vec3		var_Normal;
 
 uniform sampler2D u_LightMap;
-uniform sampler3D u_LightGrid1;
-
 uniform sampler2D u_DeluxeMap;
-uniform sampler3D u_LightGrid2;
+
+#if defined(HAVE_texture3D)
+	uniform sampler3D u_LightGrid1;
+	uniform sampler3D u_LightGrid2;
+#endif
 
 #if defined(USE_LIGHT_MAPPING) || defined(USE_DELUXE_MAPPING)
 	IN(smooth) vec2 var_TexLight;
@@ -156,9 +158,15 @@ void main()
 		#endif
 		vec3 lightDir;
 		vec3 ambientColor, lightColor;
-		ReadLightGrid(texel1, texel2, lightFactor, lightDir, ambientColor, lightColor);
+		#if HAVE_texture3D
+			ReadLightGrid(texel1, texel2, lightFactor, lightDir, ambientColor, lightColor);
 
-		color.rgb = ambientColor * r_AmbientScale * diffuse.rgb;
+			color.rgb = ambientColor * r_AmbientScale * diffuse.rgb;
+		#else
+			ambientColor = vec3(1.0);
+			lightColor = vec3(1.0);
+			color.rgb = diffuse.rgb;
+		#endif
 	#endif
 
 	#if defined(USE_LIGHT_MAPPING) && defined(USE_DELUXE_MAPPING)

src/engine/renderer/glsl_source/liquid_fp.glsl

@@ -47,8 +47,11 @@ uniform float		u_FresnelBias;
 uniform mat4		u_ModelMatrix;
 uniform mat4		u_UnprojectMatrix;
 
-uniform sampler3D       u_LightGrid1;
-uniform sampler3D       u_LightGrid2;
+#if HAVE_texture3D
+	uniform sampler3D       u_LightGrid1;
+	uniform sampler3D       u_LightGrid2;
+#endif
+
 uniform vec3            u_LightGridOrigin;
 uniform vec3            u_LightGridScale;
 
@@ -146,8 +149,12 @@ void	main()
 	#endif
 
 	// compute light direction in world space
-	vec4 texel = texture3D(u_LightGrid2, lightGridPos);
-	vec3 lightDir = normalize(texel.xyz - (128.0 / 255.0));
+	#if HAVE_texture3D
+		vec4 texel = texture3D(u_LightGrid2, lightGridPos);
+		vec3 lightDir = normalize(texel.xyz - (128.0 / 255.0));
+	#else
+		vec3 lightDir = vec3(1.0);
+	#endif
 
 	vec4 diffuse = vec4(0.0, 0.0, 0.0, 1.0);
 

src/engine/renderer/tr_bsp.cpp

@@ -3470,7 +3470,7 @@ R_LoadLightGrid
 */
 void R_LoadLightGrid( lump_t *l )
 {
-	if ( glConfig.max3DTextureSize == 0 )
+	if ( !glConfig.texture3DAvailable )
 	{
 		Log::Warn( "Grid lighting disabled because of missing 3D texture support." );
 

src/engine/sys/sdl_glimp.cpp

@@ -61,6 +61,10 @@ static Cvar::Cvar<bool> r_incrementalShaderCompilation(
 	"r_incrementalShaderCompilation", "Build separate shader units then link them alltogether at the end",
 	Cvar::NONE, true );
 
+static Cvar::Cvar<bool> r_useTexture3D(
+	"r_useTexture3D", "Use texture3D image format and sampler3D GLSL keyword",
+	Cvar::CHEAT, true );
+
 static Cvar::Cvar<bool> r_useMat3x2(
 	"r_useMat3x2", "Use mat3x2 GLSL type",
 	Cvar::NONE, true );
@@ -2115,6 +2119,8 @@ static void GLimp_InitExtensions()
 
 	// Stubbed or broken drivers may report garbage.
 
+	glConfig.texture3DAvailable = r_useTexture3D.Get();
+
 	if ( glConfig.maxTextureUnits < 0 )
 	{
 		Log::Warn( "Bad GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS value: %d", glConfig.maxTextureUnits );
@@ -2139,8 +2145,27 @@ static void GLimp_InitExtensions()
 		glConfig.maxCubeMapTextureSize = 0;
 	}
 
+	if ( glConfig.max3DTextureSize > 0 )
+	{
+		glConfig.texture3DAvailable = true;
+	}
+	else
+	{
+		logger.Warn( "Missing 3D texture support because of null max size" );
+	}
+
 	logger.Notice( "...using up to %d texture size.", glConfig.maxTextureSize );
-	logger.Notice( "...using up to %d 3D texture size.", glConfig.max3DTextureSize );
+
+	if ( glConfig.texture3DAvailable )
+	{
+		logger.Notice( "...using up to %d 3D texture size.", glConfig.max3DTextureSize );
+	}
+	else
+	{
+		logger.Notice( "...not using 3D textures." );
+		glConfig.max3DTextureSize = 0;
+	}
+
 	logger.Notice( "...using up to %d cube map texture size.", glConfig.maxCubeMapTextureSize );
 	logger.Notice( "...using up to %d texture units.", glConfig.maxTextureUnits );
 
@@ -2755,7 +2780,7 @@ static void GLimp_EnableAvailableFeatures()
 			glConfig.realtimeLighting = false;
 		}
 
-		if ( glConfig.max3DTextureSize == 0 )
+		if ( !glConfig.texture3DAvailable )
 		{
 			Log::Warn( "Tiled dynamic light renderer disabled because of missing 3D texture support." );
 			glConfig.realtimeLighting = false;
@@ -2789,7 +2814,7 @@ static void GLimp_EnableAvailableFeatures()
 
 	if ( glConfig.colorGrading )
 	{
-		if ( glConfig.max3DTextureSize == 0 )
+		if ( !glConfig.texture3DAvailable )
 		{
 			Log::Warn( "Color grading disabled because of missing 3D texture support." );
 			glConfig.colorGrading = false;
@@ -2966,6 +2991,7 @@ bool GLimp_Init()
 	Cvar::Latch( workaround_glHardware_mthreads_disableTextureBarrier );
 
 	Cvar::Latch( r_incrementalShaderCompilation );
+	Cvar::Latch( r_useTexture3D );
 	Cvar::Latch( r_useMat3x2 );
 
 	/* Enable S3TC on Mesa even if libtxc-dxtn is not available