OpenGL3: Add driver-dependent feature checks

source/Irrlicht/OpenGL/Driver.cpp

@@ -217,7 +217,7 @@ COpenGL3DriverBase::~COpenGL3DriverBase()
 	bool COpenGL3DriverBase::genericDriverInit(const core::dimension2d<u32>& screenSize, bool stencilBuffer)
 	{
 		initVersion();
-		initExtensions();
+		initFeatures();
 
 		// reset cache handler
 		delete CacheHandler;

source/Irrlicht/OpenGL/Driver.h

@@ -288,6 +288,8 @@ namespace video
 		void initVersion();
 		virtual OpenGLVersion getVersionFromOpenGL() const = 0;
 
+		virtual void initFeatures() = 0;
+
 		void chooseMaterial2D();
 
 		ITexture* createDeviceDependentTexture(const io::path& name, IImage* image) override;

source/Irrlicht/OpenGL/ExtensionHandler.cpp

@@ -15,52 +15,33 @@ namespace irr
 {
 namespace video
 {
-	void COpenGL3ExtensionHandler::initExtensions()
+	void COpenGL3ExtensionHandler::initExtensionsOld()
 	{
-		GLint major, minor;
+		auto extensions_string = reinterpret_cast<const char *>(glGetString(GL_EXTENSIONS));
-		glGetIntegerv(GL_MAJOR_VERSION, &major);
+		const char *pos = extensions_string;
-		glGetIntegerv(GL_MINOR_VERSION, &minor);
+		while (const char *next = strchr(pos, ' ')) {
-		Version = 100 * major + 10 * minor;
+			std::string name{pos, next};
+			addExtension(name.c_str());
+			pos = next + 1;
+		}
+		addExtension(pos);
+	}
 
+	void COpenGL3ExtensionHandler::initExtensionsNew()
+	{
 		GLint ext_count = 0;
 		GL.GetIntegerv(GL_NUM_EXTENSIONS, &ext_count);
-		for (int k = 0; k < ext_count; k++) {
+		for (int k = 0; k < ext_count; k++)
-			auto ext_name = (char *)GL.GetStringi(GL_EXTENSIONS, k);
+			addExtension(reinterpret_cast<const char *>(GL.GetStringi(GL_EXTENSIONS, k)));
+	}
+
+	void COpenGL3ExtensionHandler::addExtension(const char *name) {
 		for (size_t j=0; j<IRR_OGLES_Feature_Count; ++j) {
-				if (!strcmp(getFeatureString(j), ext_name)) {
+			if (!strcmp(getFeatureString(j), name)) {
 				FeatureAvailable[j] = true;
 				break;
 			}
 		}
 	}
-
-		GLint val=0;
-		glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &val);
-		Feature.MaxTextureUnits = static_cast<u8>(val);
-
-	#ifdef GL_EXT_texture_filter_anisotropic
-		if (FeatureAvailable[IRR_GL_EXT_texture_filter_anisotropic])
-		{
-			glGetIntegerv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &val);
-			MaxAnisotropy = static_cast<u8>(val);
-		}
-	#endif
-	#ifdef GL_MAX_ELEMENTS_INDICES
-		glGetIntegerv(GL_MAX_ELEMENTS_INDICES, &val);
-		MaxIndices=val;
-	#endif
-		glGetIntegerv(GL_MAX_TEXTURE_SIZE, &val);
-		MaxTextureSize=static_cast<u32>(val);
-	#ifdef GL_EXT_texture_lod_bias
-		if (FeatureAvailable[IRR_GL_EXT_texture_lod_bias])
-			glGetFloatv(GL_MAX_TEXTURE_LOD_BIAS_EXT, &MaxTextureLODBias);
-	#endif
-		glGetFloatv(GL_ALIASED_LINE_WIDTH_RANGE, DimAliasedLine);
-		glGetFloatv(GL_ALIASED_POINT_SIZE_RANGE, DimAliasedPoint);
-
-		Feature.MaxTextureUnits = core::min_(Feature.MaxTextureUnits, static_cast<u8>(MATERIAL_MAX_TEXTURES));
-		Feature.ColorAttachment = 1;
-	}
-
 } // end namespace video
 } // end namespace irr

source/Irrlicht/OpenGL/ExtensionHandler.h

@@ -24,7 +24,8 @@ namespace video
 	public:
 		COpenGL3ExtensionHandler() : COGLESCoreExtensionHandler() {}
 
-		void initExtensions();
+		void initExtensionsOld();
+		void initExtensionsNew();
 
 		bool queryFeature(video::E_VIDEO_DRIVER_FEATURE feature) const
 		{
@@ -80,6 +81,12 @@ namespace video
 			};
 		}
 
+		static GLint GetInteger(GLenum key) {
+			GLint val = 0;
+			glGetIntegerv(key, &val);
+			return val;
+		};
+
 		inline void irrGlActiveTexture(GLenum texture)
 		{
 			glActiveTexture(texture);
@@ -181,6 +188,9 @@ namespace video
 		inline void irrGlBlendEquationSeparateIndexed(GLuint buf, GLenum modeRGB, GLenum modeAlpha)
 		{
 		}
+
+	private:
+		void addExtension(const char *name);
 	};
 
 }

source/Irrlicht/OpenGL3/Driver.cpp

@@ -26,6 +26,33 @@ namespace video {
 		return {OpenGLSpec::Core, (u8)major, (u8)minor, 0};
 	}
 
+	void COpenGL3Driver::initFeatures() {
+		assert (Version.Spec == OpenGLSpec::Compat);
+		assert (Version.Major >= 3);
+		initExtensionsNew();
+
+		// COGLESCoreExtensionHandler::Feature
+		static_assert(MATERIAL_MAX_TEXTURES <= 16, "Only up to 16 textures are guaranteed");
+		Feature.BlendOperation = true;
+		Feature.ColorAttachment = GetInteger(GL_MAX_COLOR_ATTACHMENTS);
+		Feature.MaxTextureUnits = MATERIAL_MAX_TEXTURES;
+		Feature.MultipleRenderTarget = GetInteger(GL_MAX_DRAW_BUFFERS);
+
+		// COGLESCoreExtensionHandler
+		if (FeatureAvailable[IRR_GL_EXT_texture_filter_anisotropic])
+			MaxAnisotropy = GetInteger(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT);
+		MaxIndices = GetInteger(GL_MAX_ELEMENTS_INDICES);
+		MaxTextureSize = GetInteger(GL_MAX_TEXTURE_SIZE);
+		glGetFloatv(GL_MAX_TEXTURE_LOD_BIAS, &MaxTextureLODBias);
+		glGetFloatv(GL_ALIASED_LINE_WIDTH_RANGE, DimAliasedLine);
+		DimAliasedPoint[0] = 1.0f;
+		DimAliasedPoint[1] = 1.0f;
+
+		GLint val = 0;
+		glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_STENCIL, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &val);
+		StencilBuffer = val == GL_FRAMEBUFFER_DEFAULT;
+	}
+
 	IVideoDriver* createOpenGL3Driver(const SIrrlichtCreationParameters& params, io::IFileSystem* io, IContextManager* contextManager)
 	{
 		os::Printer::log("Using COpenGL3Driver", ELL_INFORMATION);

source/Irrlicht/OpenGL3/Driver.h

@@ -19,6 +19,7 @@ namespace video {
 
 	protected:
 		OpenGLVersion getVersionFromOpenGL() const override;
+		void initFeatures() override;
 	};
 
 }

source/Irrlicht/OpenGLES2/Driver.cpp

@@ -21,6 +21,41 @@ namespace video {
 		return {OpenGLSpec::ES, (u8)major, (u8)minor, 0};
 	}
 
+	void COpenGLES2Driver::initFeatures() {
+		assert (Version.Major >= 2);
+		if (Version.Major >= 3)
+			initExtensionsNew();
+		else
+			initExtensionsOld();
+
+		// COGLESCoreExtensionHandler::Feature
+		static_assert(MATERIAL_MAX_TEXTURES <= 8, "Only up to 8 textures are guaranteed");
+		Feature.BlendOperation = true;
+		Feature.ColorAttachment = 1;
+		if (Version.Major >= 3 || FeatureAvailable[IRR_GL_EXT_draw_buffers])
+			Feature.ColorAttachment = GetInteger(GL_MAX_COLOR_ATTACHMENTS);
+		Feature.MaxTextureUnits = MATERIAL_MAX_TEXTURES;
+		if (Version.Major >= 3 || FeatureAvailable[IRR_GL_EXT_draw_buffers])
+			Feature.MultipleRenderTarget = GetInteger(GL_MAX_DRAW_BUFFERS);
+
+		// COGLESCoreExtensionHandler
+		if (FeatureAvailable[IRR_GL_EXT_texture_filter_anisotropic])
+			MaxAnisotropy = GetInteger(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT);
+		if (Version.Major >= 3 || FeatureAvailable[IRR_GL_EXT_draw_range_elements])
+			MaxIndices = GetInteger(GL_MAX_ELEMENTS_INDICES);
+		MaxTextureSize = GetInteger(GL_MAX_TEXTURE_SIZE);
+		if (FeatureAvailable[IRR_GL_EXT_texture_lod_bias])
+			glGetFloatv(GL_MAX_TEXTURE_LOD_BIAS, &MaxTextureLODBias);
+		glGetFloatv(GL_ALIASED_LINE_WIDTH_RANGE, DimAliasedLine); // NOTE: this is not in the OpenGL ES 2.0 spec...
+		glGetFloatv(GL_ALIASED_POINT_SIZE_RANGE, DimAliasedPoint);
+
+		if (Version.Major >= 3 || FeatureAvailable[IRR_GL_ARB_framebuffer_object]) {
+			GLint val = 0;
+			glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_STENCIL, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &val);
+			StencilBuffer = val == GL_FRAMEBUFFER_DEFAULT;
+		}
+	}
+
 	IVideoDriver* createOGLES2Driver(const SIrrlichtCreationParameters& params, io::IFileSystem* io, IContextManager* contextManager)
 	{
 		os::Printer::log("Using COpenGLES2Driver", ELL_INFORMATION);

source/Irrlicht/OpenGLES2/Driver.h

@@ -19,6 +19,7 @@ namespace video {
 
 	protected:
 		OpenGLVersion getVersionFromOpenGL() const override;
+		void initFeatures() override;
 	};
 
 }