objektif-c - Apakah fungsi CGRectApplyAffineTransform dalam CoreGraphics lakukan?

Question

CGRect rect = CGRectMake(0, 0, 300, 200);
        
rect = CGRectApplyAffineTransform(rect,
                                          CGAffineTransformMakeScale(1, -1));
cgPath = CGPathCreateWithRect(rect, NULL);

Apakah maksud kod ini?