Pro OpenGL ES for iOS

CHAPTER 1: Computer Graphics: From Then to Now (^17)
@implementation TwoCubesViewController
@synthesize context = _context;
@synthesize effect = _effect;

• (void)viewDidLoad
  {
  [super viewDidLoad];

self.context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2]; //4

if (!self.context) {
NSLog(@"Failed to create ES context");
}

GLKView view = (GLKView )self.view; //5
view.context = self.context;
view.drawableDepthFormat = GLKViewDrawableDepthFormat24; //6

[self setupGL];
}

• (void)viewDidUnload
  {
  [super viewDidUnload];

[self tearDownGL];

if ([EAGLContext currentContext] == self.context) {
[EAGLContext setCurrentContext:nil];
}
self.context = nil;
}

• (void)didReceiveMemoryWarning
  {
  [super didReceiveMemoryWarning];
  // Release any cached data, images, etc. that aren't in use.
  }


• 
  

  (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientatio
  n
  {
  // Return YES for supported orientations.
  if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
  return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
  } else {
  return YES;
  }
  }