iOS OpenGL Game, two GLKViews / GLKViewControllers

Question

i try to set up an Xcode project based on the template "OpenGL Game". That example has a StoryBoard with one GLKViewController and one GLKView.

I'd like to have:

• one GLKView filling half the screen
• one GLKView filling part of the other half
• different things drawn in the two GLKViews

The problem: - I can't seem to put two GLKViews onto a screen when using a StoryBoard - I can't get GLKViews to work when using a NIB file

I wonder if any of the two ways is possible and what would be the best way to proceed.

Even when setting up just one GLKView and GLKViewController in a NIB file it seems that neither the method update: is called nor the glkView:drawInRect: of the GLKViewController.

How can i best place two GLKViews into an iPad app onto the same screen?

EDIT: Sorry for being imprecise.

Basically what i want to do:

• I want to write an App that uses one screen
• in one half of the screen i want one View in which i draw OpenGL
• in one quarter i want another View in which i draw different OpenGL
• in the rest there should be some buttons

I use Xcode 4.2 for iOS 5.1 for iPad

First approach, use a StoryBoard:

• i can only place one large GLKView in which i draw OpenGL, no independent other GLKView
• the example OpenGL code in that GLKView (using the GLKViewController) works fine though.

Second approach, delete the StoryBoard and create a NIB file:

• i can place one GLKView into a Window, a GLKViewController-subclass next to it and link it to the GtkView, but there is nothing drawn in it
• i can place a second GLKView into the window, a different GLKViewController-subclass next to it but there isn't anything drawn in both GLKView.
• i used the GLKView / GLKViewController example that worked fine in a StoryBoard.

Any way would be fine with me, at the moment none works.

Thanks for any hints, Torsten.

SOLVED: I use a NIB file now and i added a PRECONFIGURED combination of GLKViewController / GLKView. Just placing a UIView and a UIViewController and then changing their type does not work.

Answer 1

I ran into this same issue recently, but with only 2 GLKViews instead of 3.

I ended up doing it all programmatically, since the storyboard method didn't seem to be robust enough for this.

What I did was create a "master" GLKViewController that would house all of my other GLKViews/GLKViewControllers.

I then add child subclassed GLKViewControllers with their subsequent views.

The tricky part that I found was that I needed to add the ViewControllers as a child as well as add their views as a child to the "master" view.

    GLKViewController master = [[GLKViewController alloc] initWithNibName:nil bundle:nil];

    GLKView *masterView = (GLKView *)master.view;
    masterView.context = context;

    master.view = masterView;

    /* I created a constructor with a parameter to identify dimensions and position for rendering  */
    GLKViewController *child1 = [[SubclassGLKViewController alloc] initWithNibName:nil bundle:nil];

    GLKView *child1View = (GLKView *)child1.view;
    child1View.context = context;

    child1.view = child1View;

    GLKViewController *child2 = [[SubclassGLKViewController alloc] initWithNibName:nil bundle:nil];

    GLKView *child2View = (GLKView *)child2.view;
    child2View.context = context;

    child2.view = child2View;    

    /*It seems all three of these steps are needed*/
    [master addChildViewController:child1];
    [child1 didMoveToParentViewController:master];

    [master.view addSubview:child1View];

Another thing I had to do was implement viewDidAppear in my GLKViewController subclass.

-(void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];

    if(some condition is met)
      change frame size to something
    else 
      change frame size to something else

    self.view.frame = frame;
}

Hope this helps.