问创建可以使用图像作为填充的绘图应用程序的最佳方式

EN

import UIKit
import SpriteKit

class DrawView: SKScene {

  override func didMoveToView(view: SKView) {
    scaleMode = .ResizeFill
    backgroundColor = UIColor.whiteColor()

    //creating a triangle and filling it with the color blue
    let path = CGPathCreateMutable()
    CGPathAddArc(path, nil, 160, 284, 0, 0, CGFloat(M_PI*2), true)
    CGPathAddLineToPoint(path, nill, 60, 184)
    CGPathAddLineToPoint(path, nill, 260, 184)
    CGPathAddLineToPoint(path, nill, 60, 284)

    let triangle = SKShapeNode()
    triangle.lineCap = .Round
    triangle.lineJoin = .Round
    triangle.fillColor = UIColor.blueColor()
    triangle.path = path
    addChild(triangle)

    //placing image into SKSpriteNode
    let image = SKSpriteNode(imageNamed: "yourImage")
    image.size = CGSizeMake(320, 568)
    image.position = CGPointMake(160, 284)

    //creating an SKCropNode
    let imageCrop = SKCropNode()
    imageCrop.position = CGPointMake(0, 0)
    imageCrop.addChild(image) //adding image to the SKCropNode
    imageCrop.maskNode = triangle //using the triangle created as a mask
    addChild(imageCrop)
  }
}

class ViewController: UIViewController {
  override func viewDidLoad() {

  //create spritekit scene
  let skView = SKView(frame: CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height))
  skView.center = CGPointMake(self.view.bounds.size.width/2, self.view.bounds.size.height/2)
  self.view.addSubview(skView)

  //add drawing view to the scene
  let drawView = DrawView()
  sKView.presentScene(drawView)
  }
}