add GLKViewController to subview - GLKView context causes crash

glkit, glkview, objective-c, opengl-es-2.0

Solution

After a few hours of messing around I found that adding the viewController as a child works:

#import "mainViewController.h"

@implementation mainViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.view.layer.backgroundColor = [UIColor colorWithRed:242.0f/255.0f green:242.0f/255.0f blue:242.0f/255.0f alpha:1.0].CGColor;

    boxViewController* chart = [[boxViewController alloc] init];
    chart.view.layer.frame = CGRectMake(10, 50, self.view.frame.size.width-20, self.view.frame.size.height/3);
    chart.view.layer.borderColor = [UIColor blackColor].CGColor;
    chart.view.layer.borderWidth = 2.0f;
    [self addChildViewController:chart];
    [self.view addSubview:chart.view];


}

Problem

I have a pretty simple set up in mind, having a mainViewController that has a GLKViewController on top of it. The idea is having my GLKViewController in a box, that take sup 1/3 of the screen, on the mainViewController. This can be seen below: That white box is my own custom GLKViewController with the follow code: boxViewController.h ``` //boxViewController.h #import <UIKit/UIKit.h> #import <GLKit/GLKit.h> @interface boxViewController : GLKViewController @end ``` boxViewController.m ``` //boxViewController.m #import "boxViewController.m" @interface boxViewController () { } @property (strong, nonatomic) EAGLContext *context; @end @implementation boxViewController -(void)viewDidLoad { [super viewDidLoad]; self.context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2]; if (!self.context) { NSLog(@"Failed to create ES context"); } GLKView *view = (GLKView *)self.view; // view.context = self.context; view.drawableDepthFormat = GLKViewDrawableDepthFormat24; } @end ``` On my `mainViewController` in the `viewDidLoad` I simply call boxViewController like this: ``` boxViewController* box = [[boxChartViewController alloc] init]; box.view.layer.frame = CGRectMake(10, 50, self.view.frame.size.width-20, self.view.frame.size.height/3); [self.view addSubview:box.view]; ``` which works perfect. Notice that in my boxViewController.m I had `view.context = self.context` commented out. If you uncomment it, my application crashes without any error messaging (it breaks with a `EXC_BAD_ACCESS` in the `objc_msgSend` assembly code [line 8 to be specific]). What am I doing incorrectly that when I set the context the application crashes? From all the tutorials I noticed that they have the same set up, except not setting the controller on another controller. Though I don't understand why GLKViewController couldn't be framed on another controller, so I don't think that's the issue.

Original source