Michael Job, Life and Blog

The default coordinate for Quartz 2D is: Lower - Left In iOS, UIView have changed the coordinate to Upper - Left. (The reason UIKit ret

- (void)Combine { CGContextRef Context = UIGraphicsGetCurrentContext();   CGContextSaveGState(Context); CGContextScaleCTM(Context, 1.0, -1.0); CGContextTranslateCTM(Context, 0, -self.fram