cgaffinetransform
Convert coordinates between parent/child UIView after CGAffineTransform
UIView’s -convertPoint:toView: and -convertPoint:fromView: should work for you.
Find Frame Coordinates After UIView Transform is Applied (CGAffineTransform)
One thing to keep in mind is that the transform changes the coordinate system, so you will need to be able to convert between the parent ‘view’ and the child (transformed) view. Also, transforms preserve the center of the transformed object but not any of the other coordinates. So you need to calculate things in … Read more
Max/Min Scale of Pinch Zoom in UIPinchGestureRecognizer – iPhone iOS
Here is the solution that I figured out after using Anomie’s answer as a starting point. – (void)handlePinchGesture:(UIPinchGestureRecognizer *)gestureRecognizer { if([gestureRecognizer state] == UIGestureRecognizerStateBegan) { // Reset the last scale, necessary if there are multiple objects with different scales lastScale = [gestureRecognizer scale]; } if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) { … Read more
CGAffineTransform Reset
If you are trying to reset the transformation, so that the image appears as it did originally, you can simply set the transform back to the identity. self.imageView.transform = CGAffineTransformIdentity If you want to apply arbitrary transformations to the transformed image, the easiest thing to do would be to use the CGAffineTransform methods that take … Read more
One step affine transform for rotation around a point?
A rotation of angle a around the point (x,y) corresponds to the affine transformation: CGAffineTransform transform = CGAffineTransformMake(cos(a),sin(a),-sin(a),cos(a),x-x*cos(a)+y*sin(a),y-x*sin(a)-y*cos(a)); You may need to plug in -a instead of a depending on whether you want the rotation to be clockwise or counterclockwise. Also, you may need to plug in -y instead of y depending on whether or … Read more
How to apply multiple transforms in Swift
You can apply multiple transforms by stacking them on top of each other. var t = CGAffineTransform.identity t = t.translatedBy(x: 100, y: 300) t = t.rotated(by: CGFloat.pi / 4) t = t.scaledBy(x: -1, y: 2) // … add as many as you want, then apply it to to the view imageView.transform = t Or more … Read more