ios - 删除部分 CGPath

Question

如何删除路径的某些部分？我在屏幕上绘制了一条路径，现在假设我想删除 1/3:

我试过这样做(路径是我的原始路径，cPath是将被剪切的副本):

let sizePath = CGPathGetBoundingBox(path).size
UIGraphicsBeginImageContext(sizePath)
let context = UIGraphicsGetCurrentContext()
let cPath = CGPathCreateMutableCopy(path)
CGContextAddPath(context, cPath)
CGContextDrawPath(context, .Stroke)
let rect = CGRectMake(currentPosition.x, 0, sizePath.width, sizePath.height)
CGContextClipToRect(context, rect)
//How to Recive here this Clipped Path from context???

UIGraphicsEndImageContext()

但我不知道如何从我的上下文中接收这条路径...

Answer 1

您需要CGContextClipToRect之前您CGContextDrawPath。裁剪区域只影响后续绘制。