更改SKShapeNode的半径

Question

如何在不重新创建的情况下更改SKShapeNode的半径？在头文件中,只有一个带有circleOfRadius语法的初始化器.

Answer 1

如果使用路径创建SKShapeNode,则可以稍后更改路径.试试这个:

class GameScene: SKScene {
    override func mouseDown(theEvent: NSEvent) {
        let location = theEvent.locationInNode(self)
        let node = self.nodeAtPoint(location)
        if let circle = node as? SizeableCircle { // clicking on an existing circle
            circle.radius = Double(arc4random_uniform(100))
        } else { // clicking on empty space
            self.addChild(SizeableCircle(radius: 100.0, position: location))
        }
    }
}

class SizeableCircle: SKShapeNode {

    var radius: Double {
        didSet {
            self.path = SizeableCircle.path(self.radius)
        }
    }

    init(radius: Double, position: CGPoint) {
        self.radius = radius

        super.init()

        self.path = SizeableCircle.path(self.radius)
        self.position = position
    }

    class func path(radius: Double) -> CGMutablePathRef {
        var path: CGMutablePathRef = CGPathCreateMutable()
        CGPathAddArc(path, nil, 0.0, 0.0, radius, 0.0, 2.0 * M_PI, true)
        return path
    }

}

这与缩放之间的区别在于,除非您制作它们,否则您设置的任何其他内容(例如行宽,文本子节点等)都不会更改.