水波纹动画

CAShapeLayer *shaper = [CAShapeLayer layer];

shaper.fillColor = [UIColor redColor].CGColor;

[self.view.layer addSublayer:shaper];

CADisplayLink *display = [CADisplayLink displayLinkWithTarget:self selector:@selector(currentWave)];

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

-(void)currentWave

{

    CGMutablePathRef path = CGPathCreateMutable();

    CGPathMoveToPoint(path, NULL, 0, 100);

    CGFloat y = 0.f;

    /*水波纹动画  根据余旋公式*/

   for (CGFloat x = 0.f; x<=12; x++) {

        y = 2*sin(0.01*(23*x+11*y));

       CGPathAddLineToPoint(path, NULL, x, y);

   }

   CGPathAddLineToPoint(path, NULL, y, y);

   CGPathAddLineToPoint(path, NULL, 0, 0);

   CGPathCloseSubpath(path);

}