Re: CAOpenGLLayer

FROM : Stefan Hafeneger
DATE : Wed Apr 02 21:23:52 2008

Hi John,

I now setup the environment in copyCGLContextForPixelFormat. The 
folling code seemd to work fine. Do you see anything that would create 
a crash or is this okay? The code should work if the view moves from 
one screen to another, shouldn't it?

[CODE]
- (CGLPixelFormatObj)copyCGLPixelFormatForDisplayMask:(uint32_t)mask {
   CGLPixelFormatAttribute attributes[] =
   {
       kCGLPFADisplayMask, mask,
       kCGLPFAAccelerated,
       kCGLPFAColorSize, 24,
       kCGLPFAAlphaSize, 8,
       kCGLPFADepthSize, 16,
       kCGLPFANoRecovery,
       kCGLPFAMultisample,
       kCGLPFASupersample,
       kCGLPFASampleAlpha,
       0
   };
   CGLPixelFormatObj pixelFormatObj = NULL;
   GLint numPixelFormats = 0;
   CGLChoosePixelFormat(attributes, &pixelFormatObj, &numPixelFormats);
   if(pixelFormatObj == NULL)
       NSLog(@"Error: Could not choose pixel format!");
   return pixelFormatObj;
}

- (void)releaseCGLPixelFormat:(CGLPixelFormatObj)pixelFormat {
   CGLDestroyPixelFormat(pixelFormat);
}

- (CGLContextObj)copyCGLContextForPixelFormat:
(CGLPixelFormatObj)pixelFormat {
   CGLContextObj contextObj = NULL;
   CGLCreateContext(pixelFormat, NULL, &contextObj);
   if(contextObj == NULL)
       NSLog(@"Error: Could not create context!");
   
   CGLSetCurrentContext(contextObj);
   
   //
   // Setup OpenGL environment.
   //
   
   return contextObj;
}

- (void)releaseCGLContext:(CGLContextObj)glContext {
   
   //
   // Clean up OpenGL environment.
   //
   
   CGLDestroyContext(glContext);
}
[/CODE]

With best wishes, Stefan