iOS 波浪效果的实现

iOS 波浪效果的实现

@interface ViewController ()

 

@property (strong, nonatomic) CADisplayLink *displayLink;

 

@property (strong, nonatomic) CAShapeLayer *shapeLayer;

 

@property (strong, nonatomic) UIBezierPath *path;

 

@property (strong, nonatomic) CAShapeLayer *shapeLayer2;

 

@property (strong, nonatomic) UIBezierPath *path2;

 

@end

 

@implementation ViewController

 

- (void)viewDidLoad {

    [super viewDidLoad];

    

    _shapeLayer = [CAShapeLayer layer];

    _shapeLayer.frame = CGRectMake(0, 100, 375, 150);

    [self.view.layer addSublayer:_shapeLayer];

    

    _shapeLayer2 = [CAShapeLayer layer];

    _shapeLayer2.frame = CGRectMake(0, 100, 375, 150);

    [self.view.layer addSublayer:_shapeLayer2];

 

    _shapeLayer.fillColor = [[UIColor yellowColor] colorWithAlphaComponent:0.3].CGColor;

    _shapeLayer2.fillColor = [[UIColor blueColor] colorWithAlphaComponent:0.3].CGColor;

    

    _displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(drawPath)];

    [_displayLink addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];

    

}

 

- (void)drawPath {

    

    static double i = 0;

    

    CGFloat A = 10.f;//A振幅

    CGFloat k = 0;//y轴偏移

    CGFloat ω = 0.03;//角速度ω变大，则波形在X轴上收缩（波形变紧密）；角速度ω变小，则波形在X轴上延展（波形变稀疏）。不等于0

    CGFloat φ = 0 + i;//初相，x=0时的相位；反映在坐标系上则为图像的左右移动。

    //y=Asin(ωx+φ)+k

    

    _path = [UIBezierPath bezierPath];

    _path2 = [UIBezierPath bezierPath];

    

    [_path moveToPoint:CGPointZero];

    [_path2 moveToPoint:CGPointZero];

    for (int i = 0; i < 376; i ++) {

        CGFloat x = i;

        CGFloat y = A * sin(ω*x+φ)+k;

        CGFloat y2 = A * cos(ω*x+φ)+k;

        [_path addLineToPoint:CGPointMake(x, y)];

        [_path2 addLineToPoint:CGPointMake(x, y2)];

    }

    [_path addLineToPoint:CGPointMake(375, -100)];

    [_path addLineToPoint:CGPointMake(0, -100)];

    _path.lineWidth = 1;

    

    _shapeLayer.path = _path.CGPath;

    

    [_path2 addLineToPoint:CGPointMake(375, -100)];

    [_path2 addLineToPoint:CGPointMake(0, -100)];

    _path2.lineWidth = 1;

    

    _shapeLayer2.path = _path2.CGPath;

    

    i += 0.1;

    if (i > M_PI * 2) {

        i = 0;//防止i越界

    }

}