Added and fully implemented OES_standard_derivatives extension.

src/Context.cpp

@@ -251,6 +251,7 @@ const std::vector<Extension>& Extension::extensions(Version version) {
         _extension(GL,OES,vertex_half_float),
         _extension(GL,OES,packed_depth_stencil),
         _extension(GL,OES,depth_texture),
+        _extension(GL,OES,standard_derivatives),            // done
         _extension(GL,OES,vertex_array_object),
         _extension(GL,OES,required_internalformat)};
     #endif

src/Extensions.h

@@ -236,6 +236,7 @@ namespace GL {
         _extension(GL,OES,vertex_half_float,        GLES200, GLES300) // #38
         _extension(GL,OES,packed_depth_stencil,     GLES200, GLES300) // #43
         _extension(GL,OES,depth_texture,            GLES200, GLES300) // #44
+        _extension(GL,OES,standard_derivatives,     GLES200, GLES300) // #45
         _extension(GL,OES,vertex_array_object,      GLES200, GLES300) // #71
         _extension(GL,OES,required_internalformat,  GLES200, GLES300) // #?
     }

src/Renderer.cpp

@@ -46,6 +46,10 @@ void Renderer::setFeature(const Feature feature, const bool enabled) {
     enabled ? glEnable(GLenum(feature)) : glDisable(GLenum(feature));
 }
 
+void Renderer::setHint(const Hint target, const HintMode mode) {
+    glHint(GLenum(target), GLenum(mode));
+}
+
 void Renderer::setClearColor(const Color4<>& color) {
     glClearColor(color.r(), color.g(), color.b(), color.a());
 }

src/Renderer.h

@@ -192,6 +192,42 @@ class MAGNUM_EXPORT Renderer {
          */
         static void setFeature(Feature feature, bool enabled);
 
+        /**
+         * @brief Hint
+         *
+         * @see setHint()
+         */
+        enum class Hint: GLenum {
+            /**
+             * Accuracy of derivative calculation in fragment shader.
+             * @requires_gles30 %Extension @es_extension{OES,standard_derivatives}
+             */
+            #ifndef MAGNUM_TARGET_GLES2
+            FragmentShaderDerivative = GL_FRAGMENT_SHADER_DERIVATIVE_HINT
+            #else
+            FragmentShaderDerivative = GL_FRAGMENT_SHADER_DERIVATIVE_HINT_OES
+            #endif
+        };
+
+        /**
+         * @brief Hint mode
+         *
+         * @see setHint()
+         */
+        enum class HintMode: GLenum {
+            Fastest = GL_FASTEST,   /**< Most efficient option. */
+            Nicest = GL_NICEST,     /**< Most correct or highest quality option. */
+            DontCare = GL_DONT_CARE /**< No preference. */
+        };
+
+        /**
+         * @brief Set hint
+         *
+         * Initial value is @ref HintMode "HintMode::DontCare" for all targets.
+         * @see @fn_gl{Hint}
+         */
+        static void setHint(Hint target, HintMode mode);
+
         /*@}*/
 
         /** @{ @name Clearing values */