renderer: rewrite the GLSL extension enablement

- trust GLimp_InitExtensions and deduplicate the code - unify the way to tell an extension is available
DaemonEngine · Jun 8, 2024 · 289c75e · 289c75e
1 parent 5cf0f16
commit 289c75e
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Showing 8 changed files with 41 additions and 38 deletions.
diff --git a/src/engine/renderer/gl_shader.cpp b/src/engine/renderer/gl_shader.cpp
@@ -374,21 +374,18 @@ static std::string BuildDeformSteps( deformStage_t *deforms, int numDeforms )
 	return steps;
 }
 
+static void addExtension( std::string &str, bool available, int minGlslVersion, const std::string &name ) {
+	if ( !available )
+	{
+		return;
+	}
 
-static void addExtension( std::string &str, int enabled, int minGlslVersion,
-			  int supported, const char *name ) {
-	if( !enabled ) {
-		// extension disabled by user
-	} else if( glConfig2.shadingLanguageVersion >= minGlslVersion ) {
-		// the extension is available in the core language
-		str += Str::Format( "#define HAVE_%s 1\n", name );
-	} else if( supported ) {
-		// extension has to be explicitly enabled
+	if( glConfig2.shadingLanguageVersion < minGlslVersion )
+	{
 		str += Str::Format( "#extension GL_%s : require\n", name );
-		str += Str::Format( "#define HAVE_%s 1\n", name );
-	} else {
-		// extension is not supported
 	}
+
+	str += Str::Format( "#define HAVE_%s 1\n", name );
 }
 
 static void AddConst( std::string& str, const std::string& name, int value )
@@ -413,14 +410,25 @@ static std::string GenVersionDeclaration() {
 				       glConfig2.shadingLanguageVersion >= 150 ? (glConfig2.glCoreProfile ? "core" : "compatibility") : "");
 
 	// add supported GLSL extensions
-	addExtension( str, glConfig2.textureGatherAvailable, 400,
-		      GLEW_ARB_texture_gather, "ARB_texture_gather" );
-	addExtension( str, r_ext_gpu_shader4->integer, 130,
-		      GLEW_EXT_gpu_shader4, "EXT_gpu_shader4" );
-	addExtension( str, r_arb_gpu_shader5->integer, 400,
-		      GLEW_ARB_gpu_shader5, "ARB_gpu_shader5" );
-	addExtension( str, r_arb_uniform_buffer_object->integer, 140,
-		      GLEW_ARB_uniform_buffer_object, "ARB_uniform_buffer_object" );
+	struct extension_t {
+		bool available;
+		int minGlslVersion;
+		std::string name;
+	};
+
+	const std::vector<extension_t> extensions = {
+		{ glConfig2.gpuShader4Available, 130, "EXT_gpu_shader4" },
+		{ glConfig2.gpuShader5Available, 400, "ARB_gpu_shader5" },
+		{ glConfig2.textureGatherAvailable, 400, "ARB_texture_gather" },
+		{ glConfig2.textureIntegerAvailable, 0, "EXT_texture_integer" },
+		{ glConfig2.textureRGAvailable, 0, "ARB_texture_rg" },
+		{ glConfig2.uniformBufferObjectAvailable, 140, "ARB_uniform_buffer_object" },
+	};
+
+	for ( const auto& extension : extensions )
+	{
+		addExtension( str, extension.available, extension.minGlslVersion, extension.name );
+	}
 
 	return str;
 }
@@ -749,15 +757,6 @@ std::string     GLShaderManager::BuildGPUShaderText( Str::StringRef mainShaderNa
 	std::string env;
 	env.reserve( 1024 ); // Might help, just an estimate.
 
-	if ( glConfig2.textureRGAvailable )
-		AddDefine( env, "TEXTURE_RG", 1 );
-
-	if ( glConfig2.uniformBufferObjectAvailable )
-		AddDefine( env, "UNIFORM_BUFFER_OBJECT", 1 );
-
-	if ( glConfig2.textureIntegerAvailable )
-		AddDefine( env, "TEXTURE_INTEGER", 1 );
-
 	AddDefine( env, "r_AmbientScale", r_ambientScale->value );
 	AddDefine( env, "r_SpecularScale", r_specularScale->value );
 	AddDefine( env, "r_zNear", r_znear->value );

diff --git a/src/engine/renderer/glsl_source/computeLight_fp.glsl b/src/engine/renderer/glsl_source/computeLight_fp.glsl
@@ -35,7 +35,7 @@ uniform samplerCube u_EnvironmentMap1;
 uniform float u_EnvironmentInterpolation;
 #endif // USE_REFLECTIVE_SPECULAR
 
-#ifdef HAVE_ARB_uniform_buffer_object
+#if defined(HAVE_ARB_uniform_buffer_object)
 struct light {
   vec4  center_radius;
   vec4  color_type;
@@ -146,7 +146,7 @@ void computeDeluxeLight( vec3 lightDir, vec3 normal, vec3 viewDir, vec3 lightCol
 #endif // !USE_PHYSICAL_MAPPING
 }
 
-#if defined(TEXTURE_INTEGER) && defined(r_highPrecisionRendering)
+#if defined(HAVE_EXT_texture_integer) && defined(r_highPrecisionRendering)
 const int lightsPerLayer = 16;
 uniform usampler3D u_LightTiles;
 #define idxs_t uvec4
@@ -158,7 +158,7 @@ int nextIdx( inout idxs_t idxs ) {
   idxs = idxs >> 2;
   return int( tmp.x + tmp.y + tmp.z + tmp.w );
 }
-#else // !TEXTURE INTEGER
+#else // !HAVE_EXT_texture_integer
 const int lightsPerLayer = 4;
 uniform sampler3D u_LightTiles;
 #define idxs_t vec4
@@ -171,7 +171,7 @@ int nextIdx( inout idxs_t idxs ) {
   tmp -= 4.0 * idxs;
   return int( dot( tmp, vec4( 64.0, 16.0, 4.0, 1.0 ) ) );
 }
-#endif // TEXTURE_INTEGER
+#endif // HAVE_EXT_texture_integer
 
 const int numLayers = MAX_REF_LIGHTS / 256;
 

diff --git a/src/engine/renderer/glsl_source/debugShadowMap_fp.glsl b/src/engine/renderer/glsl_source/debugShadowMap_fp.glsl
@@ -23,7 +23,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 /* debugShadowMap_fp.glsl */
 
 /* swizzle one- and two-component textures to RG */
-#ifdef TEXTURE_RG
+#ifdef HAVE_ARB_texture_rg
 #  define SWIZ1 r
 #  define SWIZ2 rg
 #else

diff --git a/src/engine/renderer/glsl_source/forwardLighting_fp.glsl b/src/engine/renderer/glsl_source/forwardLighting_fp.glsl
@@ -23,7 +23,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 /* forwardLighting_fp.glsl */
 
 /* swizzle one- and two-component textures to RG */
-#ifdef TEXTURE_RG
+#ifdef HAVE_ARB_texture_rg
 #  define SWIZ1 r
 #  define SWIZ2 rg
 #else

diff --git a/src/engine/renderer/glsl_source/lighttile_fp.glsl b/src/engine/renderer/glsl_source/lighttile_fp.glsl
@@ -46,7 +46,7 @@ struct light {
   float angle;
 };
 
-#ifdef HAVE_ARB_uniform_buffer_object
+#if defined(HAVE_ARB_uniform_buffer_object)
 layout(std140) uniform u_Lights {
   vec4 lightvec[ MAX_REF_LIGHTS * 3 ];
 };
@@ -88,7 +88,7 @@ uniform vec3 u_zFar;
 
 const int numLayers = MAX_REF_LIGHTS / 256;
 
-#if defined(TEXTURE_INTEGER) && defined(r_highPrecisionRendering)
+#if defined(HAVE_EXT_texture_integer) && defined(r_highPrecisionRendering)
 #define idxs_t uvec4
 #define idx_initializer uvec4(3)
 DECLARE_OUTPUT(uvec4)

diff --git a/src/engine/renderer/glsl_source/shadowFill_fp.glsl b/src/engine/renderer/glsl_source/shadowFill_fp.glsl
@@ -33,7 +33,7 @@ IN(smooth) vec4		var_Color;
 
 DECLARE_OUTPUT(vec4)
 
-#ifdef TEXTURE_RG
+#ifdef HAVE_ARB_texture_rg
 #  define SWIZ1 r
 #  define SWIZ2 rg
 #else

diff --git a/src/engine/renderer/tr_public.h b/src/engine/renderer/tr_public.h
@@ -85,6 +85,7 @@ struct glconfig2_t
 	bool textureIntegerAvailable;
 	bool textureRGAvailable;
 	bool gpuShader4Available;
+	bool gpuShader5Available;
 	bool textureGatherAvailable;
 	int      maxDrawBuffers;
 

diff --git a/src/engine/sys/sdl_glimp.cpp b/src/engine/sys/sdl_glimp.cpp
@@ -1788,6 +1788,9 @@ static void GLimp_InitExtensions()
 	// made required in OpenGL 3.0
 	glConfig2.gpuShader4Available = LOAD_EXTENSION_WITH_TEST( ExtFlag_CORE, EXT_gpu_shader4, r_ext_gpu_shader4->value );
 
+	// made required in OpenGL 4.0
+	glConfig2.gpuShader5Available = LOAD_EXTENSION_WITH_TEST( ExtFlag_NONE, ARB_gpu_shader5, r_arb_gpu_shader5->value );
+
 	// made required in OpenGL 3.0
 	// GL_EXT_texture_integer can be used in shaders only if GL_EXT_gpu_shader4 is also available
 	glConfig2.textureIntegerAvailable = LOAD_EXTENSION_WITH_TEST( ExtFlag_CORE, EXT_texture_integer, r_ext_texture_integer->value )