darwin: Use GLX instead of OpenGL.framework if it is the current context

Also makes a stab at similar support for Win32

anholt#63

Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>

src/dispatch_common.c

@@ -482,16 +482,20 @@ epoxy_glx_dlsym(const char *name)
 void *
 epoxy_gl_dlsym(const char *name)
 {
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__APPLE__)
+if (!epoxy_current_context_is_glx()) {
+# if defined(_WIN32)
     return do_dlsym(&api.gl_handle, "OPENGL32", name, true);
-#elif defined(__APPLE__)
+# elif defined(__APPLE__)
     return do_dlsym(&api.gl_handle,
                     "/System/Library/Frameworks/OpenGL.framework/Versions/Current/OpenGL",
                     name, true);
-#else
+# endif
+}
+#endif
+
     /* There's no library for desktop GL support independent of GLX. */
     return epoxy_glx_dlsym(name);
-#endif
 }
 
 void *
@@ -615,7 +619,7 @@ epoxy_get_bootstrap_proc_address(const char *name)
      */
 #if PLATFORM_HAS_GLX
     if (api.glx_handle && glXGetCurrentContext())
-        return epoxy_gl_dlsym(name);
+        return epoxy_glx_dlsym(name);
 #endif
 
     /* If epoxy hasn't loaded any API-specific library yet, try to
@@ -644,22 +648,17 @@ epoxy_get_bootstrap_proc_address(const char *name)
     }
 #endif /* PLATFORM_HAS_EGL */
 
-    /* Fall back to GLX */
+    /* Fall back to the platform default */
     return epoxy_gl_dlsym(name);
 }
 
 void *
 epoxy_get_proc_address(const char *name)
 {
-#ifdef _WIN32
-    return wglGetProcAddress(name);
-#elif defined(__APPLE__)
-    return epoxy_gl_dlsym(name);
-#else
 #if PLATFORM_HAS_GLX
     if (epoxy_current_context_is_glx()) {
         return glXGetProcAddressARB((const GLubyte *)name);
-    } else
+    }
 #endif /* PLATFORM_HAS_GLX */
 #if PLATFORM_HAS_EGL
     {
@@ -674,8 +673,12 @@ epoxy_get_proc_address(const char *name)
         }
     }
 #endif /* PLATFORM_HAS_EGL */
+#if defined(_WIN32)
+    return wglGetProcAddress(name);
+#elif defined(__APPLE__)
+    return epoxy_gl_dlsym(name);
+#endif
     errx(1, "Couldn't find current GLX or EGL context.\n");
-#endif /* _WIN32 | __APPLE__*/
 }
 
 WRAPPER_VISIBILITY (void)