Added support for EXT_framebuffer_sRGB.

Added sRGB extensions to standards conformance page.

docs/compat.dox

@@ -117,6 +117,11 @@ whether a context is flushed when it is released (made non-current).  Where this
 extension is unavailable, the `GLFW_CONTEXT_RELEASE_BEHAVIOR` hint will have no
 effect and the context will always be flushed when released.
 
+GLFW uses the `GLX_ARB_framebuffer_sRGB` and `GLX_EXT_framebuffer_sRGB`
+extensions to provide support for sRGB framebuffers.  Where both of these
+extensions are unavailable, the `GLFW_SRGB_CAPABLE` hint will have no effect.
+
+
 @section compat_wgl WGL extensions
 
 The WGL API is used to create OpenGL contexts on Microsoft Windows and other
@@ -154,6 +159,11 @@ whether a context is flushed when it is released (made non-current).  Where this
 extension is unavailable, the `GLFW_CONTEXT_RELEASE_BEHAVIOR` hint will have no
 effect and the context will always be flushed when released.
 
+GLFW uses the `WGL_ARB_framebuffer_sRGB` and `WGL_EXT_framebuffer_sRGB`
+extensions to provide support for sRGB framebuffers.  Where both of these
+extension are unavailable, the `GLFW_SRGB_CAPABLE` hint will have no effect.
+
+
 @section compat_osx OpenGL 3.2 and later on OS X
 
 Support for OpenGL 3.2 and above was introduced with OS X 10.7 and even then

docs/window.dox

@@ -206,6 +206,8 @@ Zero disables multisampling.  `GLFW_DONT_CARE` means the application has no
 preference.
 
 `GLFW_SRGB_CAPABLE` specifies whether the framebuffer should be sRGB capable.
+If supported, the created context will provide `GL_ARB_framebuffer_sRGB` or
+`GL_EXT_framebuffer_sRGB`.
 
 `GLFW_DOUBLEBUFFER` specifies whether the framebuffer should be double buffered.
 You nearly always want to use double buffering.  This is a hard constraint.

src/glx_context.c

@@ -117,7 +117,7 @@ static GLboolean chooseFBConfig(const _GLFWfbconfig* desired, GLXFBConfig* resul
         if (_glfw.glx.ARB_multisample)
             u->samples = getFBConfigAttrib(n, GLX_SAMPLES);
 
-        if (_glfw.glx.ARB_framebuffer_sRGB)
+        if (_glfw.glx.ARB_framebuffer_sRGB || _glfw.glx.EXT_framebuffer_sRGB)
             u->sRGB = getFBConfigAttrib(n, GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB);
 
         u->glx = n;
@@ -226,6 +226,9 @@ int _glfwInitContextAPI(void)
     if (_glfwPlatformExtensionSupported("GLX_ARB_framebuffer_sRGB"))
         _glfw.glx.ARB_framebuffer_sRGB = GL_TRUE;
 
+    if (_glfwPlatformExtensionSupported("GLX_EXT_framebuffer_sRGB"))
+        _glfw.glx.EXT_framebuffer_sRGB = GL_TRUE;
+
     if (_glfwPlatformExtensionSupported("GLX_ARB_create_context"))
     {
         _glfw.glx.CreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)

src/glx_context.h

@@ -81,6 +81,7 @@ typedef struct _GLFWlibraryGLX
     GLboolean       MESA_swap_control;
     GLboolean       ARB_multisample;
     GLboolean       ARB_framebuffer_sRGB;
+    GLboolean       EXT_framebuffer_sRGB;
     GLboolean       ARB_create_context;
     GLboolean       ARB_create_context_profile;
     GLboolean       ARB_create_context_robustness;

src/wgl_context.c

@@ -61,6 +61,8 @@ static void initWGLExtensions(_GLFWwindow* window)
         _glfwPlatformExtensionSupported("WGL_ARB_multisample");
     window->wgl.ARB_framebuffer_sRGB =
         _glfwPlatformExtensionSupported("WGL_ARB_framebuffer_sRGB");
+    window->wgl.EXT_framebuffer_sRGB =
+        _glfwPlatformExtensionSupported("WGL_EXT_framebuffer_sRGB");
     window->wgl.ARB_create_context =
         _glfwPlatformExtensionSupported("WGL_ARB_create_context");
     window->wgl.ARB_create_context_profile =
@@ -175,7 +177,8 @@ static GLboolean choosePixelFormat(_GLFWwindow* window,
             if (window->wgl.ARB_multisample)
                 u->samples = getPixelFormatAttrib(window, n, WGL_SAMPLES_ARB);
 
-            if (window->wgl.ARB_framebuffer_sRGB)
+            if (window->wgl.ARB_framebuffer_sRGB ||
+                window->wgl.EXT_framebuffer_sRGB)
             {
                 if (getPixelFormatAttrib(window, n, WGL_FRAMEBUFFER_SRGB_CAPABLE_ARB))
                     u->sRGB = GL_TRUE;
@@ -543,9 +546,13 @@ int _glfwAnalyzeContext(const _GLFWwindow* window,
     if (fbconfig->sRGB)
     {
         // sRGB is not a hard constraint, so do nothing if it's not supported
-        if (window->wgl.ARB_framebuffer_sRGB && window->wgl.ARB_pixel_format)
+        if ((window->wgl.ARB_framebuffer_sRGB ||
+             window->wgl.EXT_framebuffer_sRGB) &&
+            window->wgl.ARB_pixel_format)
+        {
             required = GL_TRUE;
         }
+    }
 
     if (required)
         return _GLFW_RECREATION_REQUIRED;

src/wgl_context.h

@@ -55,6 +55,7 @@ typedef struct _GLFWcontextWGL
     GLboolean                           EXT_swap_control;
     GLboolean                           ARB_multisample;
     GLboolean                           ARB_framebuffer_sRGB;
+    GLboolean                           EXT_framebuffer_sRGB;
     GLboolean                           ARB_pixel_format;
     GLboolean                           ARB_create_context;
     GLboolean                           ARB_create_context_profile;