CGPath 获取上面的 CGPoints

[imzyf]

https://stackoverflow.com/questions/12992462/how-to-get-the-cgpoints-of-a-cgpath

extension CGPath {

    func forEach( body: @convention(block) (CGPathElement) -> Void) {
        typealias Body = @convention(block) (CGPathElement) -> Void
        let callback: @convention(c) (UnsafeMutableRawPointer, UnsafePointer<CGPathElement>) -> Void = { (info, element) in
            let body = unsafeBitCast(info, to: Body.self)
            body(element.pointee)
        }
        print(MemoryLayout.size(ofValue: body))
        let unsafeBody = unsafeBitCast(body, to: UnsafeMutableRawPointer.self)
        self.apply(info: unsafeBody, function: unsafeBitCast(callback, to: CGPathApplierFunction.self))
    }

    func getPathElementsPoints() -> [CGPoint] {
        var arrayPoints : [CGPoint]! = [CGPoint]()
        self.forEach { element in
            switch (element.type) {
            case CGPathElementType.moveToPoint:
                arrayPoints.append(element.points[0])
            case .addLineToPoint:
                arrayPoints.append(element.points[0])
            case .addQuadCurveToPoint:
                arrayPoints.append(element.points[0])
                arrayPoints.append(element.points[1])
            case .addCurveToPoint:
                arrayPoints.append(element.points[0])
                arrayPoints.append(element.points[1])
                arrayPoints.append(element.points[2])
            default: break
            }
        }
        return arrayPoints
    }

    func getPathElementsPointsAndTypes() -> ([CGPoint],[CGPathElementType]) {
        var arrayPoints : [CGPoint]! = [CGPoint]()
        var arrayTypes : [CGPathElementType]! = [CGPathElementType]()
        self.forEach { element in
            switch (element.type) {
            case CGPathElementType.moveToPoint:
                arrayPoints.append(element.points[0])
                arrayTypes.append(element.type)
            case .addLineToPoint:
                arrayPoints.append(element.points[0])
                arrayTypes.append(element.type)
            case .addQuadCurveToPoint:
                arrayPoints.append(element.points[0])
                arrayPoints.append(element.points[1])
                arrayTypes.append(element.type)
                arrayTypes.append(element.type)
            case .addCurveToPoint:
                arrayPoints.append(element.points[0])
                arrayPoints.append(element.points[1])
                arrayPoints.append(element.points[2])
                arrayTypes.append(element.type)
                arrayTypes.append(element.type)
                arrayTypes.append(element.type)
            default: break
            }
        }
        return (arrayPoints,arrayTypes)
    }
}