Instance Method

CGLContextObj

Returns the destination CGL context to use for OpenGL rendering from within the execution method.

Required.

Declaration

- (CGLContextObj)CGLContextObj;

Return Value

The destination CGL context.

Discussion

To send commands to the OpenGL context:

  • Use CGL macros instead of changing the current OpenGL context.

  • Save and restore all OpenGL states except those defines by GL_CURRENT_BIT (vertex position, color, texture, and so on)

The following code shows how you’d use the method CGLContextObj:

// Set up using CGL macros.
#import <OpenGL/CGLMacro.h>
 
- (BOOL) execute:(id<QCPlugInContext>)context
              atTime:(NSTimeInterval)time
             withArguments:(NSDictionary *)arguments
{
    // Set the CGL context to a local variable.
    CGLContextObj cgl_ctx = [context CGLContextObj];
    if(cgl_ctx == NULL)
    return NO;
 
    // Save and set OpenGL states.
    // Put your OpenGL code here.
    // Restore the OpenGL states.
    return YES;
}

You can retrieve the corresponding OpenGL pixel format by calling the function CGLGetPixelFormat.