ios - 如何使用 spriteKit 快速绘制圆圈？

Question

刚开始用swift做ios开发，不知道怎么画圆。我只是想画一个圆圈，将它设置为一个变量并显示在屏幕上，这样我以后就可以将它用作主要播放器。任何人都可以告诉我如何执行此操作或为此提供代码吗？

我在网上找到这段代码:

var Circle = SKShapeNode(circleOfRadius: 40)
Circle.position = CGPointMake(500, 500)
Circle.name = "defaultCircle"
Circle.strokeColor = SKColor.blackColor()
Circle.glowWidth = 10.0
Circle.fillColor = SKColor.yellowColor()
Circle.physicsBody = SKPhysicsBody(circleOfRadius: 40)
Circle.physicsBody?.dynamic = true //.physicsBody?.dynamic = true
self.addChild(Circle)

但是当我把它放在 xcode 上并运行应用程序时，游戏场景中什么也没有出现。

Answer 1

如果你只想在某个时候画一个简单的圆圈，那就是这样的:

func oneLittleCircle(){

    var Circle = SKShapeNode(circleOfRadius: 100 ) // Size of Circle
    Circle.position = CGPointMake(frame.midX, frame.midY)  //Middle of Screen
    Circle.strokeColor = SKColor.blackColor()
    Circle.glowWidth = 1.0
    Circle.fillColor = SKColor.orangeColor()
    self.addChild(Circle)
}

下面的代码在用户触摸的地方画了一个圆圈。 您可以将默认的 iOS SpriteKit 项目“GameScene.swift”代码替换为以下代码。

//
// Draw Circle At Touch .swift
// Replace GameScene.swift in the Default SpriteKit Project, with this code.


import SpriteKit

class GameScene: SKScene {
override func didMoveToView(view: SKView) {
    /* Setup your scene here */
    scene?.backgroundColor = SKColor.whiteColor()  //background color to white

}

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
    /* Called when a touch begins */

    for touch: AnyObject in touches {
        let location = touch.locationInNode(self)
        makeCirlceInPosition(location)  // Call makeCircleInPostion, send touch location.
    }
}


//  Where the Magic Happens!
func makeCirlceInPosition(location: CGPoint){

    var Circle = SKShapeNode(circleOfRadius: 70 ) // Size of Circle = Radius setting.
    Circle.position = location  //touch location passed from touchesBegan.
    Circle.name = "defaultCircle"
    Circle.strokeColor = SKColor.blackColor()
    Circle.glowWidth = 1.0
    Circle.fillColor = SKColor.clearColor()
    self.addChild(Circle)
}
  override func update(currentTime: CFTimeInterval) {
    /* Called before each frame is rendered */
}}