我怎么能做同样的事情，这个目标-c代码适用于iPhone而不是Mac？
EAGLContext *k_context = [[[EAGLContext alloc]
initWithAPI:kEAGLRenderingAPIOpenGLES1
sharegroup:[[[[CCDirector sharedDirector] openGLView] context] sharegroup]] autorelease];
[EAGLContext setCurrentContext:k_context];