How to get absolute position of point inside CALayer

Question

how can I obtain the absolute position of a CGPoint inside a CALayer. I need this for exact pixel drawing

Edit: Absolute to the screen

Answer 1

Hit test the superlayers recursively, until you arrive at the root layer:

CGPoint originalPoint = // wherever from you obtain your original point
CALayer *layer = self;
CGPoint point = originalPoint;
while (layer.superlayer)
{
    point = [layer convertPoint:point toLayer:layer.superlayer];
    layer = layer.superlayer;
}

// here `point' will contain the exact position