Tranformations - Core Animation

Chapter review from Nick Lockwood's Core Animation book at Tumblr's iOS Book Club

Transcript

1. TRANSFORMATIONS IOS BOOK CLUB JASDEV SINGH
2. AFFINE TRANSFORMATIONS > Rotation > CGAffineTransformMakeRotation(_:) > Scaling > CGAffineTransformMakeScale(_:_:) > Translations > CGAffineTransformMakeTranslation(_:_:)
3. UIView transform PROPERTY Really just a wrapper on the underlying CALayer feature, affineTransform.
4. COMPOSING TRANSFORMATIONS Core Graphics provides functions that take existing transformations and applies another on top of it. > CGAffineTransformRotate(_:_:) > CGAffineTransformScale(_:_:_:) > CGAffineTransformTranslate(_:_:_:) > CGAffineTransformConcat(_:_:)
5. SAMPLE TRANSFORMATION > 50% scale > Rotate 30 degrees > Vertical translation by 200 points public func +(lhs: CGAffineTransform, rhs: CGAffineTransform) -> CGAffineTransform { return CGAffineTransformConcat(lhs, rhs) }
6. import UIKit class ViewController: UIViewController { let view1 = UIView() override func viewDidLoad() { super.viewDidLoad() view1.backgroundColor = .greenColor() view1.frame = CGRect(origin: view.center, size: CGSize(width: 150, height: 150)) view.addSubview(view1) let transform = CGAffineTransformIdentity + CGAffineTransformMakeScale(0.5, 0.5) + CGAffineTransformMakeRotation(CGFloat(M_PI) / 180 * 30) + CGAffineTransformMakeTranslation(0, 200) view1.layer.setAffineTransform(transform) } }
8. ARTISANAL TRANSFORMATIONS If you need to to make custom affine transformations that aren't built into Core Graphics, you can directly set values on the transformation matrix:
9. 3D TRANSFORMS The transform property on CALayer is of type CATransform3D. > CATransform3DMakeRotation(_:_:_:_:) > CATransform3DMakeScale(_:_:_:) > CATransform3DMakeTranslation(_:_:_:)
10. Perspective Projections By default, Core Animation uses isometric projections, which preserves parallel lines in 3D space. To give our 3D transformations a sense of depth, we have to add a perspective transform .
11. By default, . To apply perspective, set to , where is the distance between the imaginary camera and the screen, in points. usually works well.
12. sublayerTransform PROPERTY A CATranmsform3D property on CALayer that allows you to apply a transform to all sublayers!
13. doubleSided PROPERTY