Moved the majority of GLX code into opengl module.

src/x11_opengl.c

@@ -30,15 +30,565 @@
 
 #include "internal.h"
 
+#include <stdlib.h>
+
 
 // This is the only glXGetProcAddress variant not declared by glxext.h
 void (*glXGetProcAddressEXT(const GLubyte* procName))();
 
 
+//========================================================================
+// Initialize GLX-specific extensions
+//========================================================================
+
+static void initGLXExtensions(_GLFWwindow* window)
+{
+    if (_glfwPlatformExtensionSupported("GLX_EXT_swap_control"))
+    {
+        window->GLX.SwapIntervalEXT = (PFNGLXSWAPINTERVALEXTPROC)
+            _glfwPlatformGetProcAddress("glXSwapIntervalEXT");
+
+        if (window->GLX.SwapIntervalEXT)
+            window->GLX.EXT_swap_control = GL_TRUE;
+    }
+
+    if (_glfwPlatformExtensionSupported("GLX_SGI_swap_control"))
+    {
+        window->GLX.SwapIntervalSGI = (PFNGLXSWAPINTERVALSGIPROC)
+            _glfwPlatformGetProcAddress("glXSwapIntervalSGI");
+
+        if (window->GLX.SwapIntervalSGI)
+            window->GLX.SGI_swap_control = GL_TRUE;
+    }
+
+    if (_glfwPlatformExtensionSupported("GLX_SGIX_fbconfig"))
+    {
+        window->GLX.GetFBConfigAttribSGIX = (PFNGLXGETFBCONFIGATTRIBSGIXPROC)
+            _glfwPlatformGetProcAddress("glXGetFBConfigAttribSGIX");
+        window->GLX.ChooseFBConfigSGIX = (PFNGLXCHOOSEFBCONFIGSGIXPROC)
+            _glfwPlatformGetProcAddress("glXChooseFBConfigSGIX");
+        window->GLX.CreateContextWithConfigSGIX = (PFNGLXCREATECONTEXTWITHCONFIGSGIXPROC)
+            _glfwPlatformGetProcAddress("glXCreateContextWithConfigSGIX");
+        window->GLX.GetVisualFromFBConfigSGIX = (PFNGLXGETVISUALFROMFBCONFIGSGIXPROC)
+            _glfwPlatformGetProcAddress("glXGetVisualFromFBConfigSGIX");
+
+        if (window->GLX.GetFBConfigAttribSGIX &&
+            window->GLX.ChooseFBConfigSGIX &&
+            window->GLX.CreateContextWithConfigSGIX &&
+            window->GLX.GetVisualFromFBConfigSGIX)
+        {
+            window->GLX.SGIX_fbconfig = GL_TRUE;
+        }
+    }
+
+    if (_glfwPlatformExtensionSupported("GLX_ARB_multisample"))
+        window->GLX.ARB_multisample = GL_TRUE;
+
+    if (_glfwPlatformExtensionSupported("GLX_ARB_create_context"))
+    {
+        window->GLX.CreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)
+            _glfwPlatformGetProcAddress("glXCreateContextAttribsARB");
+
+        if (window->GLX.CreateContextAttribsARB)
+            window->GLX.ARB_create_context = GL_TRUE;
+    }
+
+    if (_glfwPlatformExtensionSupported("GLX_ARB_create_context_robustness"))
+        window->GLX.ARB_create_context_robustness = GL_TRUE;
+
+    if (_glfwPlatformExtensionSupported("GLX_ARB_create_context_profile"))
+        window->GLX.ARB_create_context_profile = GL_TRUE;
+
+    if (_glfwPlatformExtensionSupported("GLX_EXT_create_context_es2_profile"))
+        window->GLX.EXT_create_context_es2_profile = GL_TRUE;
+}
+
+
+//========================================================================
+// Returns the specified attribute of the specified GLXFBConfig
+// NOTE: Do not call this unless we have found GLX 1.3+ or GLX_SGIX_fbconfig
+//========================================================================
+
+static int getFBConfigAttrib(_GLFWwindow* window, GLXFBConfig fbconfig, int attrib)
+{
+    int value;
+
+    if (window->GLX.SGIX_fbconfig)
+    {
+        window->GLX.GetFBConfigAttribSGIX(_glfwLibrary.X11.display,
+                                          fbconfig, attrib, &value);
+    }
+    else
+        glXGetFBConfigAttrib(_glfwLibrary.X11.display, fbconfig, attrib, &value);
+
+    return value;
+}
+
+
+//========================================================================
+// Return a list of available and usable framebuffer configs
+//========================================================================
+
+static _GLFWfbconfig* getFBConfigs(_GLFWwindow* window, unsigned int* found)
+{
+    GLXFBConfig* fbconfigs;
+    _GLFWfbconfig* result;
+    int i, count = 0;
+
+    *found = 0;
+
+    if (_glfwLibrary.GLX.majorVersion == 1 && _glfwLibrary.GLX.minorVersion < 3)
+    {
+        if (!window->GLX.SGIX_fbconfig)
+        {
+            _glfwSetError(GLFW_OPENGL_UNAVAILABLE,
+                          "X11/GLX: GLXFBConfig support not found");
+            return NULL;
+        }
+    }
+
+    if (window->GLX.SGIX_fbconfig)
+    {
+        fbconfigs = window->GLX.ChooseFBConfigSGIX(_glfwLibrary.X11.display,
+                                                   _glfwLibrary.X11.screen,
+                                                   NULL,
+                                                   &count);
+        if (!count)
+        {
+            _glfwSetError(GLFW_OPENGL_UNAVAILABLE,
+                          "X11/GLX: No GLXFBConfigs returned");
+            return NULL;
+        }
+    }
+    else
+    {
+        fbconfigs = glXGetFBConfigs(_glfwLibrary.X11.display,
+                                    _glfwLibrary.X11.screen,
+                                    &count);
+        if (!count)
+        {
+            _glfwSetError(GLFW_OPENGL_UNAVAILABLE,
+                          "X11/GLX: No GLXFBConfigs returned");
+            return NULL;
+        }
+    }
+
+    result = (_GLFWfbconfig*) malloc(sizeof(_GLFWfbconfig) * count);
+    if (!result)
+    {
+        _glfwSetError(GLFW_OUT_OF_MEMORY,
+                      "X11/GLX: Failed to allocate _GLFWfbconfig array");
+        return NULL;
+    }
+
+    for (i = 0;  i < count;  i++)
+    {
+        if (!getFBConfigAttrib(window, fbconfigs[i], GLX_DOUBLEBUFFER) ||
+            !getFBConfigAttrib(window, fbconfigs[i], GLX_VISUAL_ID))
+        {
+            // Only consider double-buffered GLXFBConfigs with associated visuals
+            continue;
+        }
+
+        if (!(getFBConfigAttrib(window,
+                                fbconfigs[i],
+                                GLX_RENDER_TYPE) & GLX_RGBA_BIT))
+        {
+            // Only consider RGBA GLXFBConfigs
+            continue;
+        }
+
+        if (!(getFBConfigAttrib(window, fbconfigs[i], GLX_DRAWABLE_TYPE) & GLX_WINDOW_BIT))
+        {
+            // Only consider window GLXFBConfigs
+            continue;
+        }
+
+        result[*found].redBits = getFBConfigAttrib(window, fbconfigs[i], GLX_RED_SIZE);
+        result[*found].greenBits = getFBConfigAttrib(window, fbconfigs[i], GLX_GREEN_SIZE);
+        result[*found].blueBits = getFBConfigAttrib(window, fbconfigs[i], GLX_BLUE_SIZE);
+
+        result[*found].alphaBits = getFBConfigAttrib(window, fbconfigs[i], GLX_ALPHA_SIZE);
+        result[*found].depthBits = getFBConfigAttrib(window, fbconfigs[i], GLX_DEPTH_SIZE);
+        result[*found].stencilBits = getFBConfigAttrib(window, fbconfigs[i], GLX_STENCIL_SIZE);
+
+        result[*found].accumRedBits = getFBConfigAttrib(window, fbconfigs[i], GLX_ACCUM_RED_SIZE);
+        result[*found].accumGreenBits = getFBConfigAttrib(window, fbconfigs[i], GLX_ACCUM_GREEN_SIZE);
+        result[*found].accumBlueBits = getFBConfigAttrib(window, fbconfigs[i], GLX_ACCUM_BLUE_SIZE);
+        result[*found].accumAlphaBits = getFBConfigAttrib(window, fbconfigs[i], GLX_ACCUM_ALPHA_SIZE);
+
+        result[*found].auxBuffers = getFBConfigAttrib(window, fbconfigs[i], GLX_AUX_BUFFERS);
+        result[*found].stereo = getFBConfigAttrib(window, fbconfigs[i], GLX_STEREO);
+
+        if (window->GLX.ARB_multisample)
+            result[*found].samples = getFBConfigAttrib(window, fbconfigs[i], GLX_SAMPLES);
+        else
+            result[*found].samples = 0;
+
+        result[*found].platformID = (GLFWintptr) getFBConfigAttrib(window, fbconfigs[i], GLX_FBCONFIG_ID);
+
+        (*found)++;
+    }
+
+    XFree(fbconfigs);
+
+    return result;
+}
+
+
+//========================================================================
+// Error handler for BadMatch errors when requesting context with
+// unavailable OpenGL versions using the GLX_ARB_create_context extension
+//========================================================================
+
+static int errorHandler(Display *display, XErrorEvent* event)
+{
+    return 0;
+}
+
+
+//========================================================================
+// Read back framebuffer parameters from the context
+//========================================================================
+
+static void refreshContextParams(_GLFWwindow* window, GLXFBConfigID fbconfigID)
+{
+    int dummy;
+    GLXFBConfig* fbconfig;
+
+    int attribs[] = { GLX_FBCONFIG_ID, fbconfigID, None };
+
+    if (window->GLX.SGIX_fbconfig)
+    {
+        fbconfig = window->GLX.ChooseFBConfigSGIX(_glfwLibrary.X11.display,
+                                                  _glfwLibrary.X11.screen,
+                                                  attribs,
+                                                  &dummy);
+    }
+    else
+    {
+        fbconfig = glXChooseFBConfig(_glfwLibrary.X11.display,
+                                     _glfwLibrary.X11.screen,
+                                     attribs,
+                                     &dummy);
+    }
+
+    if (fbconfig == NULL)
+    {
+        // This should never ever happen
+        // TODO: Flag this as an error and propagate up
+        _glfwSetError(GLFW_PLATFORM_ERROR, "X11/GLX: Cannot find known "
+                                           "GLXFBConfig by ID. This cannot "
+                                           "happen. Have a nice day.\n");
+        abort();
+    }
+
+    // There is no clear definition of an "accelerated" context on X11/GLX, and
+    // true sounds better than false, so we hardcode true here
+    window->accelerated = GL_TRUE;
+
+    window->redBits = getFBConfigAttrib(window, *fbconfig, GLX_RED_SIZE);
+    window->greenBits = getFBConfigAttrib(window, *fbconfig, GLX_GREEN_SIZE);
+    window->blueBits = getFBConfigAttrib(window, *fbconfig, GLX_BLUE_SIZE);
+
+    window->alphaBits = getFBConfigAttrib(window, *fbconfig, GLX_ALPHA_SIZE);
+    window->depthBits = getFBConfigAttrib(window, *fbconfig, GLX_DEPTH_SIZE);
+    window->stencilBits = getFBConfigAttrib(window, *fbconfig, GLX_STENCIL_SIZE);
+
+    window->accumRedBits = getFBConfigAttrib(window, *fbconfig, GLX_ACCUM_RED_SIZE);
+    window->accumGreenBits = getFBConfigAttrib(window, *fbconfig, GLX_ACCUM_GREEN_SIZE);
+    window->accumBlueBits = getFBConfigAttrib(window, *fbconfig, GLX_ACCUM_BLUE_SIZE);
+    window->accumAlphaBits = getFBConfigAttrib(window, *fbconfig, GLX_ACCUM_ALPHA_SIZE);
+
+    window->auxBuffers = getFBConfigAttrib(window, *fbconfig, GLX_AUX_BUFFERS);
+    window->stereo = getFBConfigAttrib(window, *fbconfig, GLX_STEREO) ? GL_TRUE : GL_FALSE;
+
+    // Get FSAA buffer sample count
+    if (window->GLX.ARB_multisample)
+        window->samples = getFBConfigAttrib(window, *fbconfig, GLX_SAMPLES);
+    else
+        window->samples = 0;
+
+    XFree(fbconfig);
+}
+
+
+//========================================================================
+// Create the actual OpenGL context
+//========================================================================
+
+#define setGLXattrib(attribs, index, attribName, attribValue) \
+    attribs[index++] = attribName; \
+    attribs[index++] = attribValue;
+
+static int createContext(_GLFWwindow* window,
+                         const _GLFWwndconfig* wndconfig,
+                         GLXFBConfigID fbconfigID)
+{
+    int attribs[40];
+    int dummy, index;
+    GLXFBConfig* fbconfig;
+    GLXContext share = NULL;
+
+    if (wndconfig->share)
+        share = wndconfig->share->GLX.context;
+
+    // Retrieve the previously selected GLXFBConfig
+    {
+        index = 0;
+
+        setGLXattrib(attribs, index, GLX_FBCONFIG_ID, (int) fbconfigID);
+        setGLXattrib(attribs, index, None, None);
+
+        if (window->GLX.SGIX_fbconfig)
+        {
+            fbconfig = window->GLX.ChooseFBConfigSGIX(_glfwLibrary.X11.display,
+                                                      _glfwLibrary.X11.screen,
+                                                      attribs,
+                                                      &dummy);
+        }
+        else
+        {
+            fbconfig = glXChooseFBConfig(_glfwLibrary.X11.display,
+                                         _glfwLibrary.X11.screen,
+                                         attribs,
+                                         &dummy);
+        }
+
+        if (fbconfig == NULL)
+        {
+            _glfwSetError(GLFW_PLATFORM_ERROR,
+                          "X11/GLX: Failed to retrieve the selected GLXFBConfig");
+            return GL_FALSE;
+        }
+    }
+
+    // Retrieve the corresponding visual
+    if (window->GLX.SGIX_fbconfig)
+    {
+        window->GLX.visual = window->GLX.GetVisualFromFBConfigSGIX(_glfwLibrary.X11.display,
+                                                                   *fbconfig);
+    }
+    else
+    {
+        window->GLX.visual = glXGetVisualFromFBConfig(_glfwLibrary.X11.display,
+                                                      *fbconfig);
+    }
+
+    if (window->GLX.visual == NULL)
+    {
+        XFree(fbconfig);
+
+        _glfwSetError(GLFW_PLATFORM_ERROR,
+                      "X11/GLX: Failed to retrieve visual for GLXFBConfig");
+        return GL_FALSE;
+    }
+
+    if (window->GLX.ARB_create_context)
+    {
+        index = 0;
+
+        if (wndconfig->glMajor != 1 || wndconfig->glMinor != 0)
+        {
+            // Request an explicitly versioned context
+
+            setGLXattrib(attribs, index, GLX_CONTEXT_MAJOR_VERSION_ARB, wndconfig->glMajor);
+            setGLXattrib(attribs, index, GLX_CONTEXT_MINOR_VERSION_ARB, wndconfig->glMinor);
+        }
+
+        if (wndconfig->glForward || wndconfig->glDebug || wndconfig->glRobustness)
+        {
+            int flags = 0;
+
+            if (wndconfig->glForward)
+                flags |= GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
+
+            if (wndconfig->glDebug)
+                flags |= GLX_CONTEXT_DEBUG_BIT_ARB;
+
+            if (wndconfig->glRobustness)
+                flags |= GLX_CONTEXT_ROBUST_ACCESS_BIT_ARB;
+
+            setGLXattrib(attribs, index, GLX_CONTEXT_FLAGS_ARB, flags);
+        }
+
+        if (wndconfig->glProfile)
+        {
+            int flags = 0;
+
+            if (!window->GLX.ARB_create_context_profile)
+            {
+                _glfwSetError(GLFW_VERSION_UNAVAILABLE,
+                              "X11/GLX: An OpenGL profile requested but "
+                              "GLX_ARB_create_context_profile is unavailable");
+                return GL_FALSE;
+            }
+
+            if (wndconfig->glProfile == GLFW_OPENGL_ES2_PROFILE &&
+                !window->GLX.EXT_create_context_es2_profile)
+            {
+                _glfwSetError(GLFW_VERSION_UNAVAILABLE,
+                              "X11/GLX: OpenGL ES 2.x profile requested but "
+                              "GLX_EXT_create_context_es2_profile is unavailable");
+                return GL_FALSE;
+            }
+
+            if (wndconfig->glProfile == GLFW_OPENGL_CORE_PROFILE)
+                flags = GLX_CONTEXT_CORE_PROFILE_BIT_ARB;
+            else if (wndconfig->glProfile == GLFW_OPENGL_COMPAT_PROFILE)
+                flags = GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB;
+            else if (wndconfig->glProfile == GLFW_OPENGL_ES2_PROFILE)
+                flags = GLX_CONTEXT_ES2_PROFILE_BIT_EXT;
+
+            setGLXattrib(attribs, index, GLX_CONTEXT_PROFILE_MASK_ARB, flags);
+        }
+
+        if (wndconfig->glRobustness)
+        {
+            int strategy;
+
+            if (!window->GLX.ARB_create_context_robustness)
+            {
+                _glfwSetError(GLFW_VERSION_UNAVAILABLE,
+                              "X11/GLX: An OpenGL robustness strategy was "
+                              "requested but GLX_ARB_create_context_robustness "
+                              "is unavailable");
+                return GL_FALSE;
+            }
+
+            if (wndconfig->glRobustness == GLFW_OPENGL_NO_RESET_NOTIFICATION)
+                strategy = GLX_NO_RESET_NOTIFICATION_ARB;
+            else if (wndconfig->glRobustness == GLFW_OPENGL_LOSE_CONTEXT_ON_RESET)
+                strategy = GLX_LOSE_CONTEXT_ON_RESET_ARB;
+
+            setGLXattrib(attribs,
+                         index,
+                         GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB,
+                         strategy);
+        }
+
+        setGLXattrib(attribs, index, None, None);
+
+        // This is the only place we set an Xlib error handler, and we only do
+        // it because glXCreateContextAttribsARB generates a BadMatch error if
+        // the requested OpenGL version is unavailable (instead of a civilized
+        // response like returning NULL)
+        XSetErrorHandler(errorHandler);
+
+        window->GLX.context =
+            window->GLX.CreateContextAttribsARB(_glfwLibrary.X11.display,
+                                                *fbconfig,
+                                                share,
+                                                True,
+                                                attribs);
+
+        // We are done, so unset the error handler again (see above)
+        XSetErrorHandler(NULL);
+    }
+    else
+    {
+        if (window->GLX.SGIX_fbconfig)
+        {
+            window->GLX.context =
+                window->GLX.CreateContextWithConfigSGIX(_glfwLibrary.X11.display,
+                                                        *fbconfig,
+                                                        GLX_RGBA_TYPE,
+                                                        share,
+                                                        True);
+        }
+        else
+        {
+            window->GLX.context = glXCreateNewContext(_glfwLibrary.X11.display,
+                                                      *fbconfig,
+                                                      GLX_RGBA_TYPE,
+                                                      share,
+                                                      True);
+        }
+    }
+
+    XFree(fbconfig);
+
+    if (window->GLX.context == NULL)
+    {
+        // TODO: Handle all the various error codes here
+
+        _glfwSetError(GLFW_PLATFORM_ERROR,
+                      "X11/GLX: Failed to create OpenGL context");
+        return GL_FALSE;
+    }
+
+    refreshContextParams(window, fbconfigID);
+
+    return GL_TRUE;
+}
+
+#undef setGLXattrib
+
+
 //////////////////////////////////////////////////////////////////////////
 //////                       GLFW internal API                      //////
 //////////////////////////////////////////////////////////////////////////
 
+//========================================================================
+// Prepare for creation of the OpenGL context
+//========================================================================
+
+int _glfwCreateContext(_GLFWwindow* window,
+                       const _GLFWwndconfig* wndconfig,
+                       const _GLFWfbconfig* fbconfig)
+{
+    _GLFWfbconfig closest;
+
+    initGLXExtensions(window);
+
+    // Choose the best available fbconfig
+    {
+        unsigned int fbcount;
+        _GLFWfbconfig* fbconfigs;
+        const _GLFWfbconfig* result;
+
+        fbconfigs = getFBConfigs(window, &fbcount);
+        if (!fbconfigs)
+        {
+            _glfwSetError(GLFW_PLATFORM_ERROR,
+                          "X11/GLX: No usable GLXFBConfigs found");
+            return GL_FALSE;
+        }
+
+        result = _glfwChooseFBConfig(fbconfig, fbconfigs, fbcount);
+        if (!result)
+        {
+            _glfwSetError(GLFW_PLATFORM_ERROR,
+                          "X11/GLX: No GLXFBConfig matched the criteria");
+
+            free(fbconfigs);
+            return GL_FALSE;
+        }
+
+        closest = *result;
+        free(fbconfigs);
+    }
+
+    return createContext(window, wndconfig, closest.platformID);
+}
+
+
+//========================================================================
+// Destroy the OpenGL context
+//========================================================================
+
+void _glfwDestroyContext(_GLFWwindow* window)
+{
+    if (window->GLX.context)
+    {
+        // Release and destroy the context
+        glXMakeCurrent(_glfwLibrary.X11.display, None, NULL);
+        glXDestroyContext(_glfwLibrary.X11.display, window->GLX.context);
+        window->GLX.context = NULL;
+    }
+}
+
+
 //========================================================================
 // Make the OpenGL context associated with the specified window current
 //========================================================================

src/x11_platform.h

@@ -113,7 +113,6 @@ typedef intptr_t GLFWintptr;
 //------------------------------------------------------------------------
 typedef struct _GLFWcontextGLX
 {
-    GLXFBConfigID fbconfigID;        // ID of selected GLXFBConfig
     GLXContext    context;           // OpenGL rendering context
     XVisualInfo*  visual;            // Visual for selected GLXFBConfig
 
@@ -283,6 +282,12 @@ GLFWGLOBAL struct {
 // Time
 void _glfwInitTimer(void);
 
+// OpenGL support
+int _glfwCreateContext(_GLFWwindow* window,
+                       const _GLFWwndconfig* wndconfig,
+                       const _GLFWfbconfig* fbconfig);
+void _glfwDestroyContext(_GLFWwindow* window);
+
 // Fullscreen support
 int  _glfwGetClosestVideoMode(int* width, int* height, int* rate);
 void _glfwSetVideoModeMODE(int mode, int rate);

src/x11_window.c

@@ -43,17 +43,6 @@
 #define Button6            6
 #define Button7            7
 
-//========================================================================
-// Error handler for BadMatch errors when requesting context with
-// unavailable OpenGL versions using the GLX_ARB_create_context extension
-//========================================================================
-
-static int errorHandler(Display *display, XErrorEvent* event)
-{
-    return 0;
-}
-
-
 //========================================================================
 // Checks whether the event is a MapNotify for the specified window
 //========================================================================
@@ -98,417 +87,6 @@ static int translateChar(XKeyEvent* event)
 }
 
 
-//========================================================================
-// Returns the specified attribute of the specified GLXFBConfig
-// NOTE: Do not call this unless we have found GLX 1.3+ or GLX_SGIX_fbconfig
-//========================================================================
-
-static int getFBConfigAttrib(_GLFWwindow* window, GLXFBConfig fbconfig, int attrib)
-{
-    int value;
-
-    if (window->GLX.SGIX_fbconfig)
-    {
-        window->GLX.GetFBConfigAttribSGIX(_glfwLibrary.X11.display,
-                                          fbconfig, attrib, &value);
-    }
-    else
-        glXGetFBConfigAttrib(_glfwLibrary.X11.display, fbconfig, attrib, &value);
-
-    return value;
-}
-
-
-//========================================================================
-// Return a list of available and usable framebuffer configs
-//========================================================================
-
-static _GLFWfbconfig* getFBConfigs(_GLFWwindow* window, unsigned int* found)
-{
-    GLXFBConfig* fbconfigs;
-    _GLFWfbconfig* result;
-    int i, count = 0;
-
-    *found = 0;
-
-    if (_glfwLibrary.GLX.majorVersion == 1 && _glfwLibrary.GLX.minorVersion < 3)
-    {
-        if (!window->GLX.SGIX_fbconfig)
-        {
-            _glfwSetError(GLFW_OPENGL_UNAVAILABLE,
-                          "X11/GLX: GLXFBConfig support not found");
-            return NULL;
-        }
-    }
-
-    if (window->GLX.SGIX_fbconfig)
-    {
-        fbconfigs = window->GLX.ChooseFBConfigSGIX(_glfwLibrary.X11.display,
-                                                   _glfwLibrary.X11.screen,
-                                                   NULL,
-                                                   &count);
-        if (!count)
-        {
-            _glfwSetError(GLFW_OPENGL_UNAVAILABLE,
-                          "X11/GLX: No GLXFBConfigs returned");
-            return NULL;
-        }
-    }
-    else
-    {
-        fbconfigs = glXGetFBConfigs(_glfwLibrary.X11.display,
-                                    _glfwLibrary.X11.screen,
-                                    &count);
-        if (!count)
-        {
-            _glfwSetError(GLFW_OPENGL_UNAVAILABLE,
-                          "X11/GLX: No GLXFBConfigs returned");
-            return NULL;
-        }
-    }
-
-    result = (_GLFWfbconfig*) malloc(sizeof(_GLFWfbconfig) * count);
-    if (!result)
-    {
-        _glfwSetError(GLFW_OUT_OF_MEMORY,
-                      "X11/GLX: Failed to allocate _GLFWfbconfig array");
-        return NULL;
-    }
-
-    for (i = 0;  i < count;  i++)
-    {
-        if (!getFBConfigAttrib(window, fbconfigs[i], GLX_DOUBLEBUFFER) ||
-            !getFBConfigAttrib(window, fbconfigs[i], GLX_VISUAL_ID))
-        {
-            // Only consider double-buffered GLXFBConfigs with associated visuals
-            continue;
-        }
-
-        if (!(getFBConfigAttrib(window,
-                                fbconfigs[i],
-                                GLX_RENDER_TYPE) & GLX_RGBA_BIT))
-        {
-            // Only consider RGBA GLXFBConfigs
-            continue;
-        }
-
-        if (!(getFBConfigAttrib(window, fbconfigs[i], GLX_DRAWABLE_TYPE) & GLX_WINDOW_BIT))
-        {
-            // Only consider window GLXFBConfigs
-            continue;
-        }
-
-        result[*found].redBits = getFBConfigAttrib(window, fbconfigs[i], GLX_RED_SIZE);
-        result[*found].greenBits = getFBConfigAttrib(window, fbconfigs[i], GLX_GREEN_SIZE);
-        result[*found].blueBits = getFBConfigAttrib(window, fbconfigs[i], GLX_BLUE_SIZE);
-
-        result[*found].alphaBits = getFBConfigAttrib(window, fbconfigs[i], GLX_ALPHA_SIZE);
-        result[*found].depthBits = getFBConfigAttrib(window, fbconfigs[i], GLX_DEPTH_SIZE);
-        result[*found].stencilBits = getFBConfigAttrib(window, fbconfigs[i], GLX_STENCIL_SIZE);
-
-        result[*found].accumRedBits = getFBConfigAttrib(window, fbconfigs[i], GLX_ACCUM_RED_SIZE);
-        result[*found].accumGreenBits = getFBConfigAttrib(window, fbconfigs[i], GLX_ACCUM_GREEN_SIZE);
-        result[*found].accumBlueBits = getFBConfigAttrib(window, fbconfigs[i], GLX_ACCUM_BLUE_SIZE);
-        result[*found].accumAlphaBits = getFBConfigAttrib(window, fbconfigs[i], GLX_ACCUM_ALPHA_SIZE);
-
-        result[*found].auxBuffers = getFBConfigAttrib(window, fbconfigs[i], GLX_AUX_BUFFERS);
-        result[*found].stereo = getFBConfigAttrib(window, fbconfigs[i], GLX_STEREO);
-
-        if (window->GLX.ARB_multisample)
-            result[*found].samples = getFBConfigAttrib(window, fbconfigs[i], GLX_SAMPLES);
-        else
-            result[*found].samples = 0;
-
-        result[*found].platformID = (GLFWintptr) getFBConfigAttrib(window, fbconfigs[i], GLX_FBCONFIG_ID);
-
-        (*found)++;
-    }
-
-    XFree(fbconfigs);
-
-    return result;
-}
-
-
-//========================================================================
-// Create the OpenGL context
-//========================================================================
-
-#define setGLXattrib(attribs, index, attribName, attribValue) \
-    attribs[index++] = attribName; \
-    attribs[index++] = attribValue;
-
-static int createContext(_GLFWwindow* window,
-                         const _GLFWwndconfig* wndconfig,
-                         GLXFBConfigID fbconfigID)
-{
-    int attribs[40];
-    int dummy, index;
-    GLXFBConfig* fbconfig;
-    GLXContext share = NULL;
-
-    if (wndconfig->share)
-        share = wndconfig->share->GLX.context;
-
-    // Retrieve the previously selected GLXFBConfig
-    {
-        index = 0;
-
-        setGLXattrib(attribs, index, GLX_FBCONFIG_ID, (int) fbconfigID);
-        setGLXattrib(attribs, index, None, None);
-
-        if (window->GLX.SGIX_fbconfig)
-        {
-            fbconfig = window->GLX.ChooseFBConfigSGIX(_glfwLibrary.X11.display,
-                                                      _glfwLibrary.X11.screen,
-                                                      attribs,
-                                                      &dummy);
-        }
-        else
-        {
-            fbconfig = glXChooseFBConfig(_glfwLibrary.X11.display,
-                                         _glfwLibrary.X11.screen,
-                                         attribs,
-                                         &dummy);
-        }
-
-        if (fbconfig == NULL)
-        {
-            _glfwSetError(GLFW_PLATFORM_ERROR,
-                          "X11/GLX: Failed to retrieve the selected GLXFBConfig");
-            return GL_FALSE;
-        }
-    }
-
-    // Retrieve the corresponding visual
-    if (window->GLX.SGIX_fbconfig)
-    {
-        window->GLX.visual = window->GLX.GetVisualFromFBConfigSGIX(_glfwLibrary.X11.display,
-                                                                   *fbconfig);
-    }
-    else
-    {
-        window->GLX.visual = glXGetVisualFromFBConfig(_glfwLibrary.X11.display,
-                                                      *fbconfig);
-    }
-
-    if (window->GLX.visual == NULL)
-    {
-        XFree(fbconfig);
-
-        _glfwSetError(GLFW_PLATFORM_ERROR,
-                      "X11/GLX: Failed to retrieve visual for GLXFBConfig");
-        return GL_FALSE;
-    }
-
-    if (window->GLX.ARB_create_context)
-    {
-        index = 0;
-
-        if (wndconfig->glMajor != 1 || wndconfig->glMinor != 0)
-        {
-            // Request an explicitly versioned context
-
-            setGLXattrib(attribs, index, GLX_CONTEXT_MAJOR_VERSION_ARB, wndconfig->glMajor);
-            setGLXattrib(attribs, index, GLX_CONTEXT_MINOR_VERSION_ARB, wndconfig->glMinor);
-        }
-
-        if (wndconfig->glForward || wndconfig->glDebug || wndconfig->glRobustness)
-        {
-            int flags = 0;
-
-            if (wndconfig->glForward)
-                flags |= GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
-
-            if (wndconfig->glDebug)
-                flags |= GLX_CONTEXT_DEBUG_BIT_ARB;
-
-            if (wndconfig->glRobustness)
-                flags |= GLX_CONTEXT_ROBUST_ACCESS_BIT_ARB;
-
-            setGLXattrib(attribs, index, GLX_CONTEXT_FLAGS_ARB, flags);
-        }
-
-        if (wndconfig->glProfile)
-        {
-            int flags = 0;
-
-            if (!window->GLX.ARB_create_context_profile)
-            {
-                _glfwSetError(GLFW_VERSION_UNAVAILABLE,
-                              "X11/GLX: An OpenGL profile requested but "
-                              "GLX_ARB_create_context_profile is unavailable");
-                return GL_FALSE;
-            }
-
-            if (wndconfig->glProfile == GLFW_OPENGL_ES2_PROFILE &&
-                !window->GLX.EXT_create_context_es2_profile)
-            {
-                _glfwSetError(GLFW_VERSION_UNAVAILABLE,
-                              "X11/GLX: OpenGL ES 2.x profile requested but "
-                              "GLX_EXT_create_context_es2_profile is unavailable");
-                return GL_FALSE;
-            }
-
-            if (wndconfig->glProfile == GLFW_OPENGL_CORE_PROFILE)
-                flags = GLX_CONTEXT_CORE_PROFILE_BIT_ARB;
-            else if (wndconfig->glProfile == GLFW_OPENGL_COMPAT_PROFILE)
-                flags = GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB;
-            else if (wndconfig->glProfile == GLFW_OPENGL_ES2_PROFILE)
-                flags = GLX_CONTEXT_ES2_PROFILE_BIT_EXT;
-
-            setGLXattrib(attribs, index, GLX_CONTEXT_PROFILE_MASK_ARB, flags);
-        }
-
-        if (wndconfig->glRobustness)
-        {
-            int strategy;
-
-            if (!window->GLX.ARB_create_context_robustness)
-            {
-                _glfwSetError(GLFW_VERSION_UNAVAILABLE,
-                              "X11/GLX: An OpenGL robustness strategy was "
-                              "requested but GLX_ARB_create_context_robustness "
-                              "is unavailable");
-                return GL_FALSE;
-            }
-
-            if (wndconfig->glRobustness == GLFW_OPENGL_NO_RESET_NOTIFICATION)
-                strategy = GLX_NO_RESET_NOTIFICATION_ARB;
-            else if (wndconfig->glRobustness == GLFW_OPENGL_LOSE_CONTEXT_ON_RESET)
-                strategy = GLX_LOSE_CONTEXT_ON_RESET_ARB;
-
-            setGLXattrib(attribs,
-                         index,
-                         GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB,
-                         strategy);
-        }
-
-        setGLXattrib(attribs, index, None, None);
-
-        // This is the only place we set an Xlib error handler, and we only do
-        // it because glXCreateContextAttribsARB generates a BadMatch error if
-        // the requested OpenGL version is unavailable (instead of a civilized
-        // response like returning NULL)
-        XSetErrorHandler(errorHandler);
-
-        window->GLX.context =
-            window->GLX.CreateContextAttribsARB(_glfwLibrary.X11.display,
-                                                *fbconfig,
-                                                share,
-                                                True,
-                                                attribs);
-
-        // We are done, so unset the error handler again (see above)
-        XSetErrorHandler(NULL);
-    }
-    else
-    {
-        if (window->GLX.SGIX_fbconfig)
-        {
-            window->GLX.context =
-                window->GLX.CreateContextWithConfigSGIX(_glfwLibrary.X11.display,
-                                                        *fbconfig,
-                                                        GLX_RGBA_TYPE,
-                                                        share,
-                                                        True);
-        }
-        else
-        {
-            window->GLX.context = glXCreateNewContext(_glfwLibrary.X11.display,
-                                                      *fbconfig,
-                                                      GLX_RGBA_TYPE,
-                                                      share,
-                                                      True);
-        }
-    }
-
-    XFree(fbconfig);
-
-    if (window->GLX.context == NULL)
-    {
-        // TODO: Handle all the various error codes here
-
-        _glfwSetError(GLFW_PLATFORM_ERROR,
-                      "X11/GLX: Failed to create OpenGL context");
-        return GL_FALSE;
-    }
-
-    window->GLX.fbconfigID = fbconfigID;
-
-    return GL_TRUE;
-}
-
-#undef setGLXattrib
-
-
-//========================================================================
-// Initialize GLX-specific extensions
-//========================================================================
-
-static void initGLXExtensions(_GLFWwindow* window)
-{
-    if (_glfwPlatformExtensionSupported("GLX_EXT_swap_control"))
-    {
-        window->GLX.SwapIntervalEXT = (PFNGLXSWAPINTERVALEXTPROC)
-            _glfwPlatformGetProcAddress("glXSwapIntervalEXT");
-
-        if (window->GLX.SwapIntervalEXT)
-            window->GLX.EXT_swap_control = GL_TRUE;
-    }
-
-    if (_glfwPlatformExtensionSupported("GLX_SGI_swap_control"))
-    {
-        window->GLX.SwapIntervalSGI = (PFNGLXSWAPINTERVALSGIPROC)
-            _glfwPlatformGetProcAddress("glXSwapIntervalSGI");
-
-        if (window->GLX.SwapIntervalSGI)
-            window->GLX.SGI_swap_control = GL_TRUE;
-    }
-
-    if (_glfwPlatformExtensionSupported("GLX_SGIX_fbconfig"))
-    {
-        window->GLX.GetFBConfigAttribSGIX = (PFNGLXGETFBCONFIGATTRIBSGIXPROC)
-            _glfwPlatformGetProcAddress("glXGetFBConfigAttribSGIX");
-        window->GLX.ChooseFBConfigSGIX = (PFNGLXCHOOSEFBCONFIGSGIXPROC)
-            _glfwPlatformGetProcAddress("glXChooseFBConfigSGIX");
-        window->GLX.CreateContextWithConfigSGIX = (PFNGLXCREATECONTEXTWITHCONFIGSGIXPROC)
-            _glfwPlatformGetProcAddress("glXCreateContextWithConfigSGIX");
-        window->GLX.GetVisualFromFBConfigSGIX = (PFNGLXGETVISUALFROMFBCONFIGSGIXPROC)
-            _glfwPlatformGetProcAddress("glXGetVisualFromFBConfigSGIX");
-
-        if (window->GLX.GetFBConfigAttribSGIX &&
-            window->GLX.ChooseFBConfigSGIX &&
-            window->GLX.CreateContextWithConfigSGIX &&
-            window->GLX.GetVisualFromFBConfigSGIX)
-        {
-            window->GLX.SGIX_fbconfig = GL_TRUE;
-        }
-    }
-
-    if (_glfwPlatformExtensionSupported("GLX_ARB_multisample"))
-        window->GLX.ARB_multisample = GL_TRUE;
-
-    if (_glfwPlatformExtensionSupported("GLX_ARB_create_context"))
-    {
-        window->GLX.CreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)
-            _glfwPlatformGetProcAddress("glXCreateContextAttribsARB");
-
-        if (window->GLX.CreateContextAttribsARB)
-            window->GLX.ARB_create_context = GL_TRUE;
-    }
-
-    if (_glfwPlatformExtensionSupported("GLX_ARB_create_context_robustness"))
-        window->GLX.ARB_create_context_robustness = GL_TRUE;
-
-    if (_glfwPlatformExtensionSupported("GLX_ARB_create_context_profile"))
-        window->GLX.ARB_create_context_profile = GL_TRUE;
-
-    if (_glfwPlatformExtensionSupported("GLX_EXT_create_context_es2_profile"))
-        window->GLX.EXT_create_context_es2_profile = GL_TRUE;
-}
-
-
 //========================================================================
 // Create the X11 window (and its colormap)
 //========================================================================
@@ -1339,42 +917,10 @@ int _glfwPlatformOpenWindow(_GLFWwindow* window,
                             const _GLFWwndconfig* wndconfig,
                             const _GLFWfbconfig* fbconfig)
 {
-    _GLFWfbconfig closest;
-
     window->refreshRate = wndconfig->refreshRate;
     window->resizable   = wndconfig->resizable;
 
-    initGLXExtensions(window);
+    if (!_glfwCreateContext(window, wndconfig, fbconfig))
-
-    // Choose the best available fbconfig
-    {
-        unsigned int fbcount;
-        _GLFWfbconfig* fbconfigs;
-        const _GLFWfbconfig* result;
-
-        fbconfigs = getFBConfigs(window, &fbcount);
-        if (!fbconfigs)
-        {
-            _glfwSetError(GLFW_PLATFORM_ERROR,
-                          "X11/GLX: No usable GLXFBConfigs found");
-            return GL_FALSE;
-        }
-
-        result = _glfwChooseFBConfig(fbconfig, fbconfigs, fbcount);
-        if (!result)
-        {
-            _glfwSetError(GLFW_PLATFORM_ERROR,
-                          "X11/GLX: No GLXFBConfig matched the criteria");
-
-            free(fbconfigs);
-            return GL_FALSE;
-        }
-
-        closest = *result;
-        free(fbconfigs);
-    }
-
-    if (!createContext(window, wndconfig, (GLXFBConfigID) closest.platformID))
         return GL_FALSE;
 
     if (!createWindow(window, wndconfig))
@@ -1431,13 +977,7 @@ void _glfwPlatformCloseWindow(_GLFWwindow* window)
     if (window->mode == GLFW_FULLSCREEN)
         leaveFullscreenMode(window);
 
-    if (window->GLX.context)
+    _glfwDestroyContext(window);
-    {
-        // Release and destroy the context
-        glXMakeCurrent(_glfwLibrary.X11.display, None, NULL);
-        glXDestroyContext(_glfwLibrary.X11.display, window->GLX.context);
-        window->GLX.context = NULL;
-    }
 
     if (window->GLX.visual)
     {
@@ -1604,8 +1144,6 @@ void _glfwPlatformRestoreWindow(_GLFWwindow* window)
 
 void _glfwPlatformRefreshWindowParams(void)
 {
-    int dummy;
-    GLXFBConfig* fbconfig;
 #if defined(_GLFW_HAS_XRANDR)
     XRRScreenConfiguration* sc;
 #endif /*_GLFW_HAS_XRANDR*/
@@ -1616,58 +1154,6 @@ void _glfwPlatformRefreshWindowParams(void)
 #endif /*_GLFW_HAS_XF86VIDMODE*/
     _GLFWwindow* window = _glfwLibrary.currentWindow;
 
-    int attribs[] = { GLX_FBCONFIG_ID, window->GLX.fbconfigID, None };
-
-    if (window->GLX.SGIX_fbconfig)
-    {
-        fbconfig = window->GLX.ChooseFBConfigSGIX(_glfwLibrary.X11.display,
-                                                  _glfwLibrary.X11.screen,
-                                                  attribs,
-                                                  &dummy);
-    }
-    else
-    {
-        fbconfig = glXChooseFBConfig(_glfwLibrary.X11.display,
-                                     _glfwLibrary.X11.screen,
-                                     attribs,
-                                     &dummy);
-    }
-
-    if (fbconfig == NULL)
-    {
-        // This should never ever happen
-        // TODO: Flag this as an error and propagate up
-        fprintf(stderr, "Cannot find known GLXFBConfig by ID. "
-                        "This cannot happen. Have a nice day.\n");
-        abort();
-    }
-
-    // There is no clear definition of an "accelerated" context on X11/GLX, and
-    // true sounds better than false, so we hardcode true here
-    window->accelerated = GL_TRUE;
-
-    window->redBits = getFBConfigAttrib(window, *fbconfig, GLX_RED_SIZE);
-    window->greenBits = getFBConfigAttrib(window, *fbconfig, GLX_GREEN_SIZE);
-    window->blueBits = getFBConfigAttrib(window, *fbconfig, GLX_BLUE_SIZE);
-
-    window->alphaBits = getFBConfigAttrib(window, *fbconfig, GLX_ALPHA_SIZE);
-    window->depthBits = getFBConfigAttrib(window, *fbconfig, GLX_DEPTH_SIZE);
-    window->stencilBits = getFBConfigAttrib(window, *fbconfig, GLX_STENCIL_SIZE);
-
-    window->accumRedBits = getFBConfigAttrib(window, *fbconfig, GLX_ACCUM_RED_SIZE);
-    window->accumGreenBits = getFBConfigAttrib(window, *fbconfig, GLX_ACCUM_GREEN_SIZE);
-    window->accumBlueBits = getFBConfigAttrib(window, *fbconfig, GLX_ACCUM_BLUE_SIZE);
-    window->accumAlphaBits = getFBConfigAttrib(window, *fbconfig, GLX_ACCUM_ALPHA_SIZE);
-
-    window->auxBuffers = getFBConfigAttrib(window, *fbconfig, GLX_AUX_BUFFERS);
-    window->stereo = getFBConfigAttrib(window, *fbconfig, GLX_STEREO) ? GL_TRUE : GL_FALSE;
-
-    // Get FSAA buffer sample count
-    if (window->GLX.ARB_multisample)
-        window->samples = getFBConfigAttrib(window, *fbconfig, GLX_SAMPLES);
-    else
-        window->samples = 0;
-
     // Retrieve refresh rate if possible
     if (_glfwLibrary.X11.RandR.available)
     {
@@ -1694,8 +1180,6 @@ void _glfwPlatformRefreshWindowParams(void)
         // Zero means unknown according to the GLFW spec
         window->refreshRate = 0;
     }
-
-    XFree(fbconfig);
 }