CoreAnimation 核心动画二 锚点

锚点： anchorPoint     以锚点为中心 执行动画 （与 渔夫固定船的点时一致的）

anchorPoint 默认是 0.5，0.5  （注意： 锚点 是一个比例）

anchorPoint 在左上角的时候 为 0，0

anchorPoint 在右上角的时候 为 1，0

anchorPoint 在左下角的时候 为 0，1

anchorPoint 在右下角的时候 为 1，1

 1 #import "ViewController.h"
 2
 3 @interface ViewController ()
 4 {
 5     CALayer *APLayer;
 6     CALayer *ship;
 7 }
 8 @end
 9
10 @implementation ViewController
11
12 - (void)viewDidLoad {
13     [super viewDidLoad];
14     self.view.backgroundColor = [UIColor whiteColor];
15     UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.view.frame];
16     imageView.image = [UIImage imageNamed:@"网格.jpg"];
17     [self.view addSubview:imageView];
18
19     [self addShipLayer];
20
21 }
22
23 - (void)addShipLayer {
24
25     ship = [[CALayer alloc] init];
26     ship.backgroundColor = [UIColor brownColor].CGColor;
27     ship.bounds = CGRectMake(0, 0, 100, 100);
28     ship.position = self.view.center;
29 //    透明度 设置
30     ship.opacity = 0.5;
31     [self.view.layer addSublayer:ship];
32
33     NSLog(@"锚点y:%f\n锚点x:%f", ship.anchorPoint.y, ship.anchorPoint.x);
34
35
36     APLayer = [[CALayer alloc] init];
37     APLayer.bounds = CGRectMake(0, 0, 5, 5);
38 //    通过ship的尺寸  设置 APLayer 的中心点
39 //   position.x = ship的宽*锚点的X     position.y = ship的高*锚点的Y
40     CGFloat x = CGRectGetWidth(ship.bounds)*(ship.anchorPoint.x);
41     CGFloat y = CGRectGetHeight(ship.bounds)*(ship.anchorPoint.y);
42     APLayer.position = CGPointMake(x, y);
43     APLayer.backgroundColor = [UIColor cyanColor].CGColor;
44     [ship addSublayer:APLayer];
45 }
46
47 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
48     UITouch *touch = [touches anyObject];
49     CGPoint touchPoint = [touch locationInView:self.view];
50
51 //    通过点击屏幕的x点/屏幕的宽度 得到点击的点 与屏幕一个比例
52     CGFloat x = touchPoint.x/CGRectGetWidth([UIScreen mainScreen].bounds);
53 //    通过点击屏幕的y点/屏幕的高度 得到点击的点 与屏幕一个比例
54     CGFloat y = touchPoint.y/CGRectGetHeight([UIScreen mainScreen].bounds);
55 //    改变ship 的锚点
56     ship.anchorPoint = CGPointMake(x, y);
57
58
59     CGFloat cx = CGRectGetWidth(ship.bounds)*ship.anchorPoint.x;
60     CGFloat cy = CGRectGetHeight(ship.bounds)*ship.anchorPoint.y;
61     APLayer.position = CGPointMake(cx, cy);
62     NSLog(@"锚点y:%f\n锚点x:%f", ship.anchorPoint.y, ship.anchorPoint.x);
63 //    角度值经计算转化为幅度值。要把角度值转化为弧度制，可以使用一个简单的公式Mπ/180
64     ship.transform = CATransform3DMakeRotation (90*M_PI/180, 0, 0, 1);
65
66 }
67
68 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
69     ship.transform = CATransform3DIdentity;
70 }
71
72 - (void)didReceiveMemoryWarning {
73     [super didReceiveMemoryWarning];
74     // Dispose of any resources that can be recreated.
75 }
76
77 @end