GL: implement {ARB,EXT}_clip_control.

doc/changelog.dox

@@ -101,6 +101,9 @@ See also:
     matching @gl_extension{OES,texture_view} and @gl_extension{EXT,texture_view}
     extensions on GLES 3.1+, exposed as @ref GL::Texture::view() and similar
     APIs on other texture types
+-   Implemented the GL 4.5 @gl_extension{ARB,clip_control} extension and
+    matching @gl_extension{EXT,clip_control} extension on GLES, exposed as
+    @ref GL::Renderer::setClipControl(). See also [mosra/magnum#543](https://github.com/mosra/magnum/issues/543).
 -   Implemented @gl_extension{EXT,texture_norm16} and
     @webgl_extension{EXT,texture_norm16} ES and WebGL extensions, making
     normalized 16-bit texture and renderbuffer formats available on all

doc/opengl-mapping.dox

@@ -106,7 +106,7 @@ OpenGL function                         | Matching API
 @fn_gl{ClearTexImage}                   | |
 @fn_gl{ClearTexSubImage}                | |
 @fn_gl{ClientWaitSync}                  | |
-@fn_gl{ClipControl}                     | |
+@fn_gl{ClipControl}                     | @ref GL::Renderer::setClipControl()
 @fn_gl{ColorMask}, \n `glColorMaski()`  | @ref GL::Renderer::setColorMask()
 @fn_gl{CompileShader}                   | @ref GL::Shader::compile()
 @fn_gl{CompressedTexImage1D}, \n @fn_gl{CompressedTexImage2D}, \n @fn_gl{CompressedTexImage3D} | @ref GL::Texture::setCompressedImage(), \n @ref GL::TextureArray::setCompressedImage(), \n @ref GL::CubeMapTexture::setCompressedImage(), \n @ref GL::CubeMapTextureArray::setCompressedImage(), \n @ref GL::RectangleTexture::setCompressedImage()

doc/opengl-support.dox

@@ -243,7 +243,7 @@ Extension                                   | Status
 ------------------------------------------- | ------
 GLSL 4.50                                   | done
 @gl_extension{ARB,ES3_1_compatibility}      | done
-@gl_extension{ARB,clip_control}             | |
+@gl_extension{ARB,clip_control}             | done
 @gl_extension{ARB,conditional_render_inverted} | done
 @gl_extension{ARB,cull_distance}            | done
 @gl_extension{ARB,derivative_control}       | done (shading language only)
@@ -482,6 +482,7 @@ Extension                                   | Status
 @gl_extension{EXT,texture_compression_rgtc} | done
 @gl_extension{EXT,texture_compression_bptc} | done
 @gl_extension{EXT,texture_compression_s3tc_srgb} | done
+@gl_extension{EXT,clip_control}             | done
 @gl_extension{EXT,depth_clamp}              | done
 @gl_extension{IMG,texture_compression_pvrtc} | done
 @gl_extension2{KHR,texture_compression_astc_hdr,KHR_texture_compression_astc_hdr} | done

src/Magnum/GL/Context.cpp

@@ -356,6 +356,7 @@ constexpr Extension ExtensionList[]{
     Extensions::APPLE::texture_format_BGRA8888{},
     Extensions::ARM::shader_framebuffer_fetch{},
     Extensions::ARM::shader_framebuffer_fetch_depth_stencil{},
+    Extensions::EXT::clip_control{},
     #ifndef MAGNUM_TARGET_GLES2
     Extensions::EXT::clip_cull_distance{},
     #endif

src/Magnum/GL/Extensions.h

@@ -479,9 +479,10 @@ namespace ANDROID {
     _extension( 70,EXT,texture_compression_bptc,    GLES300,    None) // #287
     #endif
     _extension( 71,EXT,texture_compression_s3tc_srgb, GLES200,  None) // #289
-    _extension( 72,EXT,depth_clamp,                 GLES200,    None) // #309
+    _extension( 72,EXT,clip_control,                GLES200,    None) // #290
+    _extension( 73,EXT,depth_clamp,                 GLES200,    None) // #309
 } namespace IMG {
-    _extension( 73,IMG,texture_compression_pvrtc,   GLES200,    None) // #54
+    _extension( 74,IMG,texture_compression_pvrtc,   GLES200,    None) // #54
 } namespace KHR {
     _extension( 80,KHR,texture_compression_astc_ldr,GLES200, GLES320) // #117
     _extension( 81,KHR,texture_compression_astc_hdr,GLES200,    None) // #117

src/Magnum/GL/Renderer.cpp

@@ -326,6 +326,16 @@ void Renderer::depthRangefImplementationDefault(const Float near, const Float fa
 }
 #endif
 
+#ifndef MAGNUM_TARGET_WEBGL
+void Renderer::setClipControl(const ClipOrigin origin, const ClipDepth depth) {
+    #ifndef MAGNUM_TARGET_GLES
+    glClipControl(GLenum(origin), GLenum(depth));
+    #else
+    glClipControlEXT(GLenum(origin), GLenum(depth));
+    #endif
+}
+#endif
+
 void Renderer::setColorMask(const GLboolean allowRed, const GLboolean allowGreen, const GLboolean allowBlue, const GLboolean allowAlpha) {
     glColorMask(allowRed, allowGreen, allowBlue, allowAlpha);
 }

src/Magnum/GL/Renderer.h

@@ -1187,7 +1187,61 @@ class MAGNUM_GL_EXPORT Renderer {
          * @}
          */
 
-        /** @{ @name Depth testing */
+        /** @{ @name Depth testing and clip control */
+
+        #ifndef MAGNUM_TARGET_WEBGL
+        /**
+         * @brief Clip origin
+         * @m_since_latest
+         *
+         * @see @ref setClipControl()
+         * @m_enum_values_as_keywords
+         * @requires_gl45 Extension @gl_extension{ARB,clip_control}
+         * @requires_es_extension Extension @gl_extension{EXT,clip_control}
+         * @requires_gles Clip control is not available in WebGL.
+         */
+        enum class ClipOrigin: GLenum {
+            /** Lower left */
+            #ifndef MAGNUM_TARGET_GLES
+            LowerLeft = GL_LOWER_LEFT,
+            #else
+            LowerLeft = GL_LOWER_LEFT_EXT,
+            #endif
+
+            /** Upper left */
+            #ifndef MAGNUM_TARGET_GLES
+            UpperLeft = GL_UPPER_LEFT,
+            #else
+            UpperLeft = GL_UPPER_LEFT_EXT,
+            #endif
+        };
+
+        /**
+         * @brief Clip depth
+         * @m_since_latest
+         *
+         * @see @ref setClipControl()
+         * @m_enum_values_as_keywords
+         * @requires_gl45 Extension @gl_extension{ARB,clip_control}
+         * @requires_es_extension Extension @gl_extension{EXT,clip_control}
+         * @requires_gles Clip control is not available in WebGL.
+         */
+        enum class ClipDepth: GLenum {
+            /** -1 to 1 */
+            #ifndef MAGNUM_TARGET_GLES
+            NegativeOneToOne = GL_NEGATIVE_ONE_TO_ONE,
+            #else
+            NegativeOneToOne = GL_NEGATIVE_ONE_TO_ONE_EXT,
+            #endif
+
+            /** 0 to 1 */
+            #ifndef MAGNUM_TARGET_GLES
+            ZeroToOne = GL_ZERO_TO_ONE,
+            #else
+            ZeroToOne = GL_ZERO_TO_ONE_EXT,
+            #endif
+        };
+        #endif
 
         /**
          * @brief Depth function
@@ -1236,6 +1290,21 @@ class MAGNUM_GL_EXPORT Renderer {
          */
         static void setDepthRange(Float near, Float far);
 
+        #ifndef MAGNUM_TARGET_WEBGL
+        /**
+         * @brief Set clipping behavior
+         * @m_since_latest
+         *
+         * Initial value is @ref ClipOrigin::LowerLeft and
+         * @ref ClipDepth::NegativeOneToOne.
+         * @see @fn_gl_keyword{ClipControl}
+         * @requires_gl45 Extension @gl_extension{ARB,clip_control}
+         * @requires_es_extension Extension @gl_extension{EXT,clip_control}
+         * @requires_gles Clip control is not available in WebGL.
+         */
+        static void setClipControl(ClipOrigin origin, ClipDepth depth);
+        #endif
+
         /* Since 1.8.17, the original short-hand group closing doesn't work
            anymore. FFS. */
         /**

src/Magnum/GL/Test/RendererGLTest.cpp

@@ -69,6 +69,9 @@ struct RendererGLTest: OpenGLTester {
     void drawBuffersBlend();
     #endif
     template<class T> void clearDepthDepthRange();
+    #ifndef MAGNUM_TARGET_WEBGL
+    void clipControl();
+    #endif
 
     private:
         PluginManager::Manager<Trade::AbstractImporter> _manager{"nonexistent"};
@@ -93,7 +96,11 @@ RendererGLTest::RendererGLTest() {
               #ifndef MAGNUM_TARGET_GLES
               &RendererGLTest::clearDepthDepthRange<Double>,
               #endif
-              &RendererGLTest::clearDepthDepthRange<Float>});
+              &RendererGLTest::clearDepthDepthRange<Float>,
+              #ifndef MAGNUM_TARGET_WEBGL
+              &RendererGLTest::clipControl
+              #endif
+              });
 
     /* Load the plugins directly from the build tree. Otherwise they're either
        static and already loaded or not present in the build tree */
@@ -314,6 +321,24 @@ template<class T> void RendererGLTest::clearDepthDepthRange() {
     MAGNUM_VERIFY_NO_GL_ERROR();
 }
 
+#ifndef MAGNUM_TARGET_WEBGL
+void RendererGLTest::clipControl() {
+    #ifndef MAGNUM_TARGET_GLES
+    if(!Context::current().isExtensionSupported<Extensions::ARB::clip_control>())
+        CORRADE_SKIP(Extensions::ARB::clip_control::string() << "is not supported.");
+    #else
+    if(!Context::current().isExtensionSupported<Extensions::EXT::clip_control>())
+        CORRADE_SKIP(Extensions::EXT::clip_control::string() << "is not supported.");
+    #endif
+
+    /* Just setting the default value to verify it doesn't crash or emit an
+       error */
+    Renderer::setClipControl(Renderer::ClipOrigin::LowerLeft, Renderer::ClipDepth::NegativeOneToOne);
+
+    MAGNUM_VERIFY_NO_GL_ERROR();
+}
+#endif
+
 }}}}
 
 CORRADE_TEST_MAIN(Magnum::GL::Test::RendererGLTest)

src/MagnumExternal/OpenGL/GLES2/extensions.txt

@@ -93,6 +93,7 @@ extension EXT_pvrtc_sRGB                        optional
 extension EXT_draw_elements_base_vertex         optional
 extension EXT_polygon_offset_clamp              optional
 extension EXT_texture_compression_s3tc_srgb     optional
+extension EXT_clip_control                      optional
 extension EXT_depth_clamp                       optional
 extension IMG_texture_compression_pvrtc         optional
 # extension KHR_texture_compression_astc_hdr    optional

src/MagnumExternal/OpenGL/GLES2/flextGL.h

@@ -1004,6 +1004,15 @@ typedef void (APIENTRY *GLDEBUGPROCKHR)(GLenum source,GLenum type,GLuint id,GLen
 #define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT 0x8C4E
 #define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT 0x8C4F
 
+/* GL_EXT_clip_control */
+
+#define GL_LOWER_LEFT_EXT 0x8CA1
+#define GL_UPPER_LEFT_EXT 0x8CA2
+#define GL_NEGATIVE_ONE_TO_ONE_EXT 0x935E
+#define GL_ZERO_TO_ONE_EXT 0x935F
+#define GL_CLIP_ORIGIN_EXT 0x935C
+#define GL_CLIP_DEPTH_MODE_EXT 0x935D
+
 /* GL_EXT_depth_clamp */
 
 #define GL_DEPTH_CLAMP_EXT 0x864F
@@ -1256,6 +1265,10 @@ struct FlextGL {
     void(APIENTRY *RenderbufferStorageMultisampleAPPLE)(GLenum, GLsizei, GLenum, GLsizei, GLsizei);
     void(APIENTRY *ResolveMultisampleFramebufferAPPLE)(void);
 
+    /* GL_EXT_clip_control */
+
+    void(APIENTRY *ClipControlEXT)(GLenum, GLenum);
+
     /* GL_EXT_debug_label */
 
     void(APIENTRY *GetObjectLabelEXT)(GLenum, GLuint, GLsizei, GLsizei *, GLchar *);
@@ -1510,6 +1523,10 @@ extern FLEXTGL_EXPORT FlextGL flextGL;
 #define glRenderbufferStorageMultisampleAPPLE flextGL.RenderbufferStorageMultisampleAPPLE
 #define glResolveMultisampleFramebufferAPPLE flextGL.ResolveMultisampleFramebufferAPPLE
 
+/* GL_EXT_clip_control */
+
+#define glClipControlEXT flextGL.ClipControlEXT
+
 /* GL_EXT_debug_label */
 
 #define glGetObjectLabelEXT flextGL.GetObjectLabelEXT

src/MagnumExternal/OpenGL/GLES2/flextGLPlatform.cpp

@@ -54,6 +54,9 @@ void flextGLInit(Magnum::GL::Context&) {
     flextGL.RenderbufferStorageMultisampleAPPLE = reinterpret_cast<void(APIENTRY*)(GLenum, GLsizei, GLenum, GLsizei, GLsizei)>(loader.load("glRenderbufferStorageMultisampleAPPLE"));
     flextGL.ResolveMultisampleFramebufferAPPLE = reinterpret_cast<void(APIENTRY*)(void)>(loader.load("glResolveMultisampleFramebufferAPPLE"));
 
+    /* GL_EXT_clip_control */
+    flextGL.ClipControlEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum)>(loader.load("glClipControlEXT"));
+
     /* GL_EXT_debug_label */
     flextGL.GetObjectLabelEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLuint, GLsizei, GLsizei *, GLchar *)>(loader.load("glGetObjectLabelEXT"));
     flextGL.LabelObjectEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLuint, GLsizei, const GLchar *)>(loader.load("glLabelObjectEXT"));

src/MagnumExternal/OpenGL/GLES2/flextGLPlatformIOS.cpp

@@ -36,6 +36,7 @@
 #undef glMultiDrawElementsInstancedANGLE
 #undef glRenderbufferStorageMultisampleAPPLE
 #undef glResolveMultisampleFramebufferAPPLE
+#undef glClipControlEXT
 #undef glGetObjectLabelEXT
 #undef glLabelObjectEXT
 #undef glInsertEventMarkerEXT
@@ -202,6 +203,11 @@ void flextGLInit(Magnum::GL::Context&) {
     flextGL.ResolveMultisampleFramebufferAPPLE = reinterpret_cast<void(APIENTRY*)(void)>(glResolveMultisampleFramebufferAPPLE);
     #endif
 
+    /* GL_EXT_clip_control */
+    #if GL_EXT_clip_control
+    flextGL.ClipControlEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum)>(glClipControlEXT);
+    #endif
+
     /* GL_EXT_debug_label */
     #if GL_EXT_debug_label
     flextGL.GetObjectLabelEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLuint, GLsizei, GLsizei *, GLchar *)>(glGetObjectLabelEXT);

src/MagnumExternal/OpenGL/GLES2/flextGLPlatformWindowsDesktop.cpp

@@ -153,6 +153,9 @@ void flextGLInit(Magnum::GL::Context&) {
     flextGL.VertexAttrib4fv = reinterpret_cast<void(APIENTRY*)(GLuint, const GLfloat *)>(loader.load("glVertexAttrib4fv"));
     flextGL.VertexAttribPointer = reinterpret_cast<void(APIENTRY*)(GLuint, GLint, GLenum, GLboolean, GLsizei, const void *)>(loader.load("glVertexAttribPointer"));
 
+    /* GL_EXT_clip_control */
+    flextGL.ClipControlEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum)>(loader.load("glClipControlEXT"));
+
     /* GL_EXT_debug_label */
     flextGL.GetObjectLabelEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLuint, GLsizei, GLsizei *, GLchar *)>(loader.load("glGetObjectLabelEXT"));
     flextGL.LabelObjectEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLuint, GLsizei, const GLchar *)>(loader.load("glLabelObjectEXT"));

src/MagnumExternal/OpenGL/GLES2/flextGLWindowsDesktop.h

@@ -1000,6 +1000,15 @@ typedef void (APIENTRY *GLDEBUGPROCKHR)(GLenum source,GLenum type,GLuint id,GLen
 #define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT 0x8C4E
 #define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT 0x8C4F
 
+/* GL_EXT_clip_control */
+
+#define GL_LOWER_LEFT_EXT 0x8CA1
+#define GL_UPPER_LEFT_EXT 0x8CA2
+#define GL_NEGATIVE_ONE_TO_ONE_EXT 0x935E
+#define GL_ZERO_TO_ONE_EXT 0x935F
+#define GL_CLIP_ORIGIN_EXT 0x935C
+#define GL_CLIP_DEPTH_MODE_EXT 0x935D
+
 /* GL_EXT_depth_clamp */
 
 #define GL_DEPTH_CLAMP_EXT 0x864F
@@ -1256,6 +1265,10 @@ struct FlextGL {
     void(APIENTRY *VertexAttrib4fv)(GLuint, const GLfloat *);
     void(APIENTRY *VertexAttribPointer)(GLuint, GLint, GLenum, GLboolean, GLsizei, const void *);
 
+    /* GL_EXT_clip_control */
+
+    void(APIENTRY *ClipControlEXT)(GLenum, GLenum);
+
     /* GL_EXT_debug_label */
 
     void(APIENTRY *GetObjectLabelEXT)(GLenum, GLuint, GLsizei, GLsizei *, GLchar *);
@@ -1610,6 +1623,10 @@ extern FLEXTGL_EXPORT FlextGL flextGL;
 #define glVertexAttrib4fv flextGL.VertexAttrib4fv
 #define glVertexAttribPointer flextGL.VertexAttribPointer
 
+/* GL_EXT_clip_control */
+
+#define glClipControlEXT flextGL.ClipControlEXT
+
 /* GL_EXT_debug_label */
 
 #define glGetObjectLabelEXT flextGL.GetObjectLabelEXT

src/MagnumExternal/OpenGL/GLES3/extensions.txt

@@ -69,6 +69,7 @@ extension EXT_clip_cull_distance                    optional
 extension EXT_texture_compression_rgtc              optional
 extension EXT_texture_compression_bptc              optional
 extension EXT_texture_compression_s3tc_srgb         optional
+extension EXT_clip_control                          optional
 extension EXT_depth_clamp                           optional
 extension IMG_texture_compression_pvrtc             optional
 # extension KHR_texture_compression_astc_hdr        optional

src/MagnumExternal/OpenGL/GLES3/flextGL.h

@@ -1629,6 +1629,15 @@ typedef void (APIENTRY *GLDEBUGPROCKHR)(GLenum source,GLenum type,GLuint id,GLen
 #define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT 0x8C4E
 #define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT 0x8C4F
 
+/* GL_EXT_clip_control */
+
+#define GL_LOWER_LEFT_EXT 0x8CA1
+#define GL_UPPER_LEFT_EXT 0x8CA2
+#define GL_NEGATIVE_ONE_TO_ONE_EXT 0x935E
+#define GL_ZERO_TO_ONE_EXT 0x935F
+#define GL_CLIP_ORIGIN_EXT 0x935C
+#define GL_CLIP_DEPTH_MODE_EXT 0x935D
+
 /* GL_EXT_depth_clamp */
 
 #define GL_DEPTH_CLAMP_EXT 0x864F
@@ -2101,6 +2110,10 @@ struct FlextGL {
     void(APIENTRY *TexParameterIuiv)(GLenum, GLenum, const GLuint *);
     void(APIENTRY *TexStorage3DMultisample)(GLenum, GLsizei, GLenum, GLsizei, GLsizei, GLsizei, GLboolean);
 
+    /* GL_EXT_clip_control */
+
+    void(APIENTRY *ClipControlEXT)(GLenum, GLenum);
+
     /* GL_EXT_copy_image */
 
     void(APIENTRY *CopyImageSubDataEXT)(GLuint, GLenum, GLint, GLint, GLint, GLint, GLuint, GLenum, GLint, GLint, GLint, GLint, GLsizei, GLsizei, GLsizei);
@@ -2452,6 +2465,10 @@ extern FLEXTGL_EXPORT FlextGL flextGL;
 #define glTexParameterIuiv flextGL.TexParameterIuiv
 #define glTexStorage3DMultisample flextGL.TexStorage3DMultisample
 
+/* GL_EXT_clip_control */
+
+#define glClipControlEXT flextGL.ClipControlEXT
+
 /* GL_EXT_copy_image */
 
 #define glCopyImageSubDataEXT flextGL.CopyImageSubDataEXT

src/MagnumExternal/OpenGL/GLES3/flextGLPlatform.cpp

@@ -161,6 +161,9 @@ void flextGLInit(Magnum::GL::Context&) {
     flextGL.TexParameterIuiv = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum, const GLuint *)>(loader.load("glTexParameterIuiv"));
     flextGL.TexStorage3DMultisample = reinterpret_cast<void(APIENTRY*)(GLenum, GLsizei, GLenum, GLsizei, GLsizei, GLsizei, GLboolean)>(loader.load("glTexStorage3DMultisample"));
 
+    /* GL_EXT_clip_control */
+    flextGL.ClipControlEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum)>(loader.load("glClipControlEXT"));
+
     /* GL_EXT_copy_image */
     flextGL.CopyImageSubDataEXT = reinterpret_cast<void(APIENTRY*)(GLuint, GLenum, GLint, GLint, GLint, GLint, GLuint, GLenum, GLint, GLint, GLint, GLint, GLsizei, GLsizei, GLsizei)>(loader.load("glCopyImageSubDataEXT"));
 

src/MagnumExternal/OpenGL/GLES3/flextGLPlatformIOS.cpp

@@ -33,6 +33,7 @@
 #undef glMultiDrawArraysInstancedANGLE
 #undef glMultiDrawElementsANGLE
 #undef glMultiDrawElementsInstancedANGLE
+#undef glClipControlEXT
 #undef glCopyImageSubDataEXT
 #undef glGetObjectLabelEXT
 #undef glLabelObjectEXT
@@ -184,6 +185,11 @@ void flextGLInit(Magnum::GL::Context&) {
     flextGL.MultiDrawElementsInstancedANGLE = reinterpret_cast<void(APIENTRY*)(GLenum, const GLsizei *, GLenum, const GLvoid *const*, const GLsizei*, GLsizei)>(glMultiDrawElementsInstancedANGLE);
     #endif
 
+    /* GL_EXT_clip_control */
+    #if GL_EXT_clip_control
+    flextGL.ClipControlEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum)>(glClipControlEXT);
+    #endif
+
     /* GL_EXT_copy_image */
     #if GL_EXT_copy_image
     flextGL.CopyImageSubDataEXT = reinterpret_cast<void(APIENTRY*)(GLuint, GLenum, GLint, GLint, GLint, GLint, GLuint, GLenum, GLint, GLint, GLint, GLint, GLsizei, GLsizei, GLsizei)>(glCopyImageSubDataEXT);

src/MagnumExternal/OpenGL/GLES3/flextGLPlatformWindowsDesktop.cpp

@@ -363,6 +363,9 @@ void flextGLInit(Magnum::GL::Context&) {
     flextGL.TexParameterIuiv = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum, const GLuint *)>(loader.load("glTexParameterIuiv"));
     flextGL.TexStorage3DMultisample = reinterpret_cast<void(APIENTRY*)(GLenum, GLsizei, GLenum, GLsizei, GLsizei, GLsizei, GLboolean)>(loader.load("glTexStorage3DMultisample"));
 
+    /* GL_EXT_clip_control */
+    flextGL.ClipControlEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum)>(loader.load("glClipControlEXT"));
+
     /* GL_EXT_copy_image */
     flextGL.CopyImageSubDataEXT = reinterpret_cast<void(APIENTRY*)(GLuint, GLenum, GLint, GLint, GLint, GLint, GLuint, GLenum, GLint, GLint, GLint, GLint, GLsizei, GLsizei, GLsizei)>(loader.load("glCopyImageSubDataEXT"));
 

src/MagnumExternal/OpenGL/GLES3/flextGLWindowsDesktop.h

@@ -1622,6 +1622,15 @@ typedef void (APIENTRY *GLDEBUGPROCKHR)(GLenum source,GLenum type,GLuint id,GLen
 #define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT 0x8C4E
 #define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT 0x8C4F
 
+/* GL_EXT_clip_control */
+
+#define GL_LOWER_LEFT_EXT 0x8CA1
+#define GL_UPPER_LEFT_EXT 0x8CA2
+#define GL_NEGATIVE_ONE_TO_ONE_EXT 0x935E
+#define GL_ZERO_TO_ONE_EXT 0x935F
+#define GL_CLIP_ORIGIN_EXT 0x935C
+#define GL_CLIP_DEPTH_MODE_EXT 0x935D
+
 /* GL_EXT_depth_clamp */
 
 #define GL_DEPTH_CLAMP_EXT 0x864F
@@ -2105,6 +2114,10 @@ struct FlextGL {
     void(APIENTRY *TexParameterIuiv)(GLenum, GLenum, const GLuint *);
     void(APIENTRY *TexStorage3DMultisample)(GLenum, GLsizei, GLenum, GLsizei, GLsizei, GLsizei, GLboolean);
 
+    /* GL_EXT_clip_control */
+
+    void(APIENTRY *ClipControlEXT)(GLenum, GLenum);
+
     /* GL_EXT_copy_image */
 
     void(APIENTRY *CopyImageSubDataEXT)(GLuint, GLenum, GLint, GLint, GLint, GLint, GLuint, GLenum, GLint, GLint, GLint, GLint, GLsizei, GLsizei, GLsizei);
@@ -2660,6 +2673,10 @@ extern FLEXTGL_EXPORT FlextGL flextGL;
 #define glTexParameterIuiv flextGL.TexParameterIuiv
 #define glTexStorage3DMultisample flextGL.TexStorage3DMultisample
 
+/* GL_EXT_clip_control */
+
+#define glClipControlEXT flextGL.ClipControlEXT
+
 /* GL_EXT_copy_image */
 
 #define glCopyImageSubDataEXT flextGL.CopyImageSubDataEXT