繪製移動正弦波抗鋸齒

Question

我要繪製在一個清晰和消除鋸齒方式可變頻率和可變幅度的移動正弦波。這怎麼可能？

Answer 1

好，我實現正弦波入的UIView的drawRect方法如下：

float x=75; 
float yc=50; 
float w=0; 
    while (w<=rect.frame.size.width) { 
    CGPathMoveToPoint(path, nil, w,y/2); 
    CGPathAddQuadCurveToPoint(path, nil, w+x/4, -yc,w+ x/2, y/2); 
    CGPathMoveToPoint(path, nil, w+x/2,y/2); 
    CGPathAddQuadCurveToPoint(path, nil, w+3*x/4, y+yc, w+x, y/2); 
    CGContextAddPath(context, path); 
    CGContextDrawPath(context, kCGPathStroke); 
    w+=x; 
    } 

在此，x是每個正弦波的寬度，而y是所述框架的高度。這將繪製數量的正弦波以適應整個UIViewFrame。它會產生清脆的正弦波，並且yc是控制手柄。嘗試一下，你可能會喜歡它。

如果寬度ie。 x與框架的寬度相似，則會產生單個正弦波。完整的正弦波的

數=（幀的寬度）/（「x」的每個正弦波的寬度）

Answer 2

製成的GeneratorOfOne的版本更完整，並迅速版本。這一個也用選定的顏色填充波浪的底部：

class WaveView: UIView { 

    private var maskPath: UIBezierPath! 
    @IBInspectable var fillColor: UIColor = UIColor.blueColor() 
    @IBInspectable var cycles: CGFloat = 7 

    override func drawRect(rect: CGRect) { 

     var w: CGFloat = 0    // Starting position 
     let width = rect.width 
     let y: CGFloat = rect.height 
     let yc: CGFloat = rect.height/2 
     let x = width/cycles 

     let context = UIGraphicsGetCurrentContext(); 
     CGContextSetFillColorWithColor(context, UIColor.greenColor().CGColor); 
     let path = CGPathCreateMutable(); 

     CGPathMoveToPoint(path, nil, 0, 0) 

     while (w<=rect.width) { 
      CGPathMoveToPoint(path, nil, w,y/2); 
      CGPathAddQuadCurveToPoint(path, nil, w+x/4, -yc, (w+x/2), y/2); 
      CGPathMoveToPoint(path, nil, w+x/2,y/2); 
      CGPathAddQuadCurveToPoint(path, nil, w+3*x/4, y+yc, w+x, y/2); 
      w+=x; 
     } 

     CGPathAddLineToPoint(path, nil, rect.width, rect.height) 
     CGPathAddLineToPoint(path, nil, 0, rect.height) 
     CGPathAddLineToPoint(path, nil, 0, y/2); 
     CGPathCloseSubpath(path) 

     maskPath = UIBezierPath(CGPath: path) 
     maskPath.lineCapStyle = CGLineCap.Square 
     maskPath.lineJoinStyle = CGLineJoin.Miter 

     CGContextAddPath(context, path); 
     CGContextSetFillColorWithColor(context, fillColor.CGColor) 
     CGContextFillPath(context) 
    } 

}