+#elif defined(__APPLE__)
+ // Prepend a '_' for the Unix C symbol mangling convention
+ char *symbolName = (char *) malloc(strlen(symbol) + 2);
+ strcpy(symbolName + 1, symbol);
+ symbolName[0] = '_';
+ NSSymbol nssymbol = NULL;
+ if (NSIsSymbolNameDefined(symbolName)) nssymbol = NSLookupAndBindSymbol(symbolName);
+ free(symbolName);
+ return nssymbol ? reinterpret_cast<QGLFunctionPointer>(NSAddressOfSymbol(nssymbol)) : reinterpret_cast<QGLFunctionPointer>(glInvalidFunction);