Nested GLKView and GLKViewController

Question

I'm new to OpenGL ES and I'm experimenting with GLKit. My goal is to develop a very simple app just to get a good feel of OpenGL.

I started with Apple's sample code (OpenGL ES game) and I implemented basic gesture controls: panning, zooming, rotating (trackball algorithm).

Now that this is done, I wanted to play with the different projection matrices and I started to design a user interface to do just that:

http://tof.canardpc.com/view/7e0fc0da-9c63-489c-a1f1-eb6475dd3809.jpg

The only problem is that it doesn't work when the top view in a GLKViewController isn't a GLKView.

Is it possible to have a GLKView as a subview and still retain the cool features of GLKViewController?

Thank you.

Answer 1

Instead of the openGLView that is not used (and just takes up memory), you can use the main view dimensions:

_openGLViewController.view.frame = self.view.frame; // instead of _openGLView.frame

Answer 2

Ok so I found the answer.

The "OpenGL View Controller" in the picture must be a normal UIViewController. Subclass this view controller and in the viewDidLoad, create programmatically your OpenGL View Controller:

- (void)viewDidLoad
{
    [super viewDidLoad];

    _openGLViewController = [[FZIOpenGLViewController alloc] initWithNibName:@"FZIOpenGLView" bundle:nil];

    _openGLViewController.view.frame = _openGLView.frame;

    [self.view addSubview:_openGLViewController.view];

}

In this code, _openGLView is an IBOutlet representing "GLKit View" in the picture. It's basically just there to get the right dimensions.

_openGLViewController is your GLKViewController subclass that handles everything OpenGL. The .xib file FZIOpenGLView.xib is just a GLKView with the appropriate File Owner (FZIOpenGLViewController).

It works:

result http://tof.canardpc.com/view/e06a0d8b-0d58-4cc9-965c-00e6ddefd519.jpg