我们如何在不重新创建SKShapeNode的情况下更改其半径?在头文件中,只有一个使用circleOfRadius语法的初始化器。
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
}
}
基本上,你可以使用特定的 TimeInterval
作为持续时间启动 scaleTo
或 scaleBy
的 SKAction
,无论如何,我已将 Grimxn 类翻译到最新的 Swift 版本,以防你因其他原因而需要使用它:
class SizeableCircle: SKShapeNode {
var radius: Double {
didSet {
self.path = SizeableCircle.path(radius: self.radius)
}
}
init(radius: Double, position: CGPoint) {
self.radius = radius
super.init()
self.path = SizeableCircle.path(radius: self.radius)
self.position = position
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
class func path(radius: Double) -> CGMutablePath {
let path: CGMutablePath = CGMutablePath()
path.addArc(center: CGPoint.zero, radius: CGFloat(radius), startAngle: 0.0, endAngle: CGFloat(2.0*Double.pi), clockwise: false)
return path
}
}