https://www.jianshu.com/p/2316f0d9db65
1. Bezier curve
Software: PaintCode: direct drawing, an image producing software Bezier curve
Related concepts: UIBezierPath and CGPath
Method 1: - (void) moveToPoint: (CGPoint) point; // set the starting point of a Bezier curve; corresponds CGPath Method: CG_EXTERN void CGPathMoveToPoint (CGMutablePathRef __nullable path, const CGAffineTransform * __nullable m, CGFloat x, CGFloat y)
Method 2: - (void) addLineToPoint: (CGPoint) point; // linear Bezier curve end point; corresponds CGPath Method: CG_EXTERN void CGPathAddLineToPoint (CGMutablePathRef __nullable path, const CGAffineTransform * __nullable m, CGFloat x, CGFloat y)
Function: B (t) = (1-t) * P0 + t * P1; (0 ≤ t ≤1)
Method 3: - (void) addQuadCurveToPoint: (CGPoint) endPoint controlPoint: (CGPoint) controlPoint; // two yuan Bezier curve, and moveToPoint: (CGPoint) point; used together, point (P0 point) as the start point, endPoint (P2 point) the midpoint, controlPoint (P1 point) as a control point; corresponds CGPath method: CG_EXTERN void CGPathAddQuadCurveToPoint (CGMutablePathRef __nullable path, const CGAffineTransform * __ nullable m, CGFloat cpx, CGFloat cpy, CGFloat x, CGFloat y)
Function: B (t) = (1-t) * (1-t) * P0 + 2t * (1-t) * P1 + t * t * P2; (0 ≤ t ≤1)
Method 4: - (void) addCurveToPoint: (CGPoint) endPoint controlPoint1: (CGPoint) controlPoint1 controlPoint2: (CGPoint) controlPoint2; // three yuan Bezier curve, and the moveToPoint: (CGPoint) point; used together, point (P0 point) as a starting point, endPoint (P3 point) to the end point, controlPoint1 (P1 point) and controlPoint2 (P2 point) as a control point; corresponds CGPath method: CG_EXTERN void CGPathAddCurveToPoint (CGMutablePathRef __nullable path, const CGAffineTransform * __nullable m, CGFloat cp1x, CGFloat cp1y , CGFloat cp2x, CGFloat cp2y, CGFloat x, CGFloat y)
函数：B(t) = (1-t)*(1-t)*(1-t)*P0 + 3t*(1-t)(1-t)P1 + 3t*t*(1-t)P2 +t*t*t*P3;( 0 ≤ t ≤1 )
Method 5: - (void) addArcWithCenter: (CGPoint) center radius: (CGFloat) radius startAngle: (CGFloat) startAngle endAngle: (CGFloat) endAngle clockwise: (BOOL) clockwise; // draw a circle with a point arc, center: center radius: radius startAngle: starting angle clockwise: end angle clockwise: whether clockwise;
2. Bezier curve animation +
Steps: 1. Create a Bezier curve
2. Create CAShapeLayer create a layer, the layer is disposed in the path attribute a Bezier curve path, and set some properties of the layer
3. Create animation CABasicAnimation, and added to the layer CAShapeLayer created
Wherein: CABasicAnimation * checkAnimation = [CABasicAnimation animationWithKeyPath: @ "strokeEnd"]; keyPath: determining a start and end point of the animation by strokeStart and strokeEnd; CABasicAnimation in, fromValue and toValue area range determined start and end points are animations
3. Layer mask property application
Page interaction: - (void) animateTransition: (id) transitionContext; executed in the proxy method:
1.获取fromVC:ViewController * fromVC = (ViewController *)[transitionContext viewControllerForKey:UITransitionContextFromViewControllerKe
2.获取toVC：SecondViewController *toVC = (SecondViewController *)[transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
3.添加到containerView：UIView *contView = [transitionContext containerView];
[contView addSubview:toVC.view];
4. Set the mask is toVC CAShapeLayer, and add attributes for the animation path and CAShapeLayer;
5. At the end of the animation, the mask value is removed: - (void) animationDidStop: (CAAnimation *) anim finished: (BOOL) flag {[self.transitionContext viewControllerForKey: UITransitionContextToViewControllerKey] .view.layer.mask = nil;}
