+#ifdef __APPLE__
+
+#include <CoreFoundation/CoreFoundation.h>
+
+void* macosxGetGLProcAddress(const char *func) {
+
+ /* We may want to cache the bundleRef at some point */
+ static CFBundleRef bundle = 0;
+
+ if (!bundle) {
+
+ CFURLRef bundleURL = CFURLCreateWithFileSystemPath (kCFAllocatorDefault,
+ CFSTR("/System/Library/Frameworks/OpenGL.framework"), kCFURLPOSIXPathStyle, true);
+
+ bundle = CFBundleCreate (kCFAllocatorDefault, bundleURL);
+ CFRelease (bundleURL);
+ }
+
+ if (!bundle)
+ return 0;
+
+ CFStringRef functionName = CFStringCreateWithCString
+ (kCFAllocatorDefault, func, kCFStringEncodingASCII);
+
+ void *function;
+
+ function = CFBundleGetFunctionPointerForName (bundle, functionName);
+
+ CFRelease (functionName);
+
+ return function;
+}
+
+#elif !defined( WIN32 )
+
+void *SGGetGLProcAddress(const char *func) {
+ static void *libHandle = NULL;
+ static void *(*glXGetProcAddressPtr)(const GLubyte*) = 0;
+ void *fptr = NULL;
+
+ /*
+ * Clear the error buffer
+ */
+ dlerror();
+
+ /*
+ * Since libGL must be linked to the binary we run on, this is the
+ * right handle. That 'current binary' handle also avoids conflicts which
+ * arise from linking with a different libGL at link time an than later
+ * use the standard libGL at runtime ...
+ */
+ if (libHandle == NULL) {
+ libHandle = dlopen(NULL, RTLD_LAZY);
+
+ if (!libHandle) {
+ const char *error = dlerror();
+ if (error) {
+ SG_LOG(SG_GENERAL, SG_INFO, error);
+ return 0;
+ }
+ }
+
+ void* symbol = dlsym(libHandle, "glXGetProcAddress");
+ if (!symbol)
+ symbol = dlsym(libHandle, "glXGetProcAddressARB");
+ glXGetProcAddressPtr = (void *(*)(const GLubyte*)) symbol;
+ }
+
+ // First try the glx api function for that
+ if (glXGetProcAddressPtr) {
+ fptr = glXGetProcAddressPtr((const GLubyte*)func);
+
+ } else if (libHandle != NULL) {
+ fptr = dlsym(libHandle, func);
+
+ const char *error = dlerror();
+ if (error)
+ SG_LOG(SG_GENERAL, SG_INFO, error);
+ }
+
+ return fptr;
+}
+
+#endif
+