节点接近时开始动画

Question

我有两个带纹理的节点（SKSpriteNode），我试图在节点靠近另一个带有y轴（范围为100 - 0）的节点时创建一些动画，此时动画开始。 我正试图做一些像Cut The Rope这样的事情，当时糖果在Om-Nom附近并且他张开嘴来抓住糖果。 请帮我代码（ 对不起我的英文

Answer 1

你可以用很少的代码来实现这种计算：

class GameScene: SKScene {
    var sprite1 : SKSpriteNode!
    var sprite2 : SKSpriteNode!
    var range : CGFloat = 0.0
    override func didMoveToView(view: SKView) {
        self.range = randomCGFloat(0.0, max: 100.0)
        sprite1 = SKSpriteNode.init(color: SKColor.blueColor(), size: CGSizeMake(40,40))
        sprite2 = SKSpriteNode.init(color: SKColor.redColor(), size: CGSizeMake(40,40))
        addChild(sprite1)
        addChild(sprite2)
        // Try to generate 10 positions and check relative distance
        print("The range to check is :\(range)")
        for i in 0...9 {
            print("\(i)) time:")
            let isNear = checkDistanceBtwSprites()
            if isNear {
                // do whatever you want with your sprites
            }
        }
    }
    func checkDistanceBtwSprites()->Bool{
        sprite1.position = getRandomPosition(40, maxX: 40, minY: 0, maxY: 320)
        sprite2.position = getRandomPosition(40, maxX: 40, minY: 0, maxY: 320)
        let distance = getDistance((sprite1.position), p2: (sprite2.position))
        print("distance for sprite1 and sprite2 is : \(distance)")
        if distance <= self.range {
            print("# -> success: sprite1 is near sprite2")
            return true
        }
        return false
    }
    func getRandomPosition(minX: CGFloat, maxX: CGFloat, minY:CGFloat, maxY:CGFloat)->CGPoint {
        return CGPointMake(randomCGFloat(minX, max: maxX),randomCGFloat(minY, max: maxY))
    }
    func randomCGFloat(min: CGFloat, max: CGFloat)->CGFloat {
        return (CGFloat(arc4random()) / CGFloat(UINT32_MAX)) * (max - min) + min
    }
    func getDistance(p1:CGPoint,p2:CGPoint)->CGFloat {
        let xDist = (p2.x - p1.x)
        let yDist = (p2.y - p1.y)
        return CGFloat(sqrt((xDist * xDist) + (yDist * yDist)))
    }
}

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