如何防止关闭贝塞尔路径
问题描述:
我想创建贝塞尔曲线,并为我的对象创建碰撞边界。如何防止关闭贝塞尔路径
let firstSurfacePoint = CGPoint(x: 30, y: 120)
let secondSurfacePoint = CGPoint(x: 20, y: 200)
let thirdSurfacePoint = CGPoint(x: 200, y: 300)
let center = CGPoint(x: 150, y: 120)
let radius: CGFloat = 120.00
let arcWidth: CGFloat = 20.00
let fourthSurfacePoint = CGPoint(x: 240, y: 300)
func createCollisionPath(collision: UICollisionBehavior) {
let line = UIBezierPath()
line.moveToPoint(firstSurfacePoint)
line.addCurveToPoint(thirdSurfacePoint, controlPoint1: secondSurfacePoint, controlPoint2: secondSurfacePoint)
line.addLineToPoint(fourthSurfacePoint)
let currentPath = CAShapeLayer()
currentPath.path = line.CGPath
currentPath.strokeColor = UIColor.blackColor().CGColor
currentPath.fillColor = UIColor.clearColor().CGColor
currentPath.lineWidth = 1
view.layer.addSublayer(currentPath)
collision.addBoundaryWithIdentifier("curve", forPath: line)
}
同样差的结果我得到的,如果让我选择addArcWithCente
line.moveToPoint(firstSurfacePoint)
line.addArcWithCenter(center, radius: radius, startAngle: CGFloat(M_PI), endAngle: CGFloat(M_PI/2), clockwise: false)
line.addLineToPoint(fourthSurfacePoint)
在这两个尝试收到一个奇怪的结果,这是至关重要的,因为我无法创建一个适当的碰撞。在第一次尝试中,我的对象经过路径,就好像它是从第一点到第三点的直线,以及第二次尝试我做错了什么?
答
currentPath.fillColor = nil
或
currentPath.fillColor = UIColor.clearColor().CGColor
http://*.com/q/40756457/2303865 –