Question

我正在构建一个无限的侧滚动游戏，我需要绘制一条球可以移动的线。我实现该系列的原始系统是在触摸移动的SKSpriteNode中产生的。由于性能原因，这是不成功的。然后我尝试使用CGPath和SKShapeNode，但它的性能极差，并且没有想法。基本上，我需要在玩家滑动或绘制的地方创建一条路径，我需要一个物理主体来完全包围所绘制线条的笔划。为了节省性能，移除不在相机视野中的行程或路径点也是非常重要的。我的目标的说明如下。

Answer 1

以下是如何使其有效运作的示例。您可以研究如何在场景中打开和关闭它以获得更高的效率。

基本前提是您使用1 SKShapeNode绘制连续线。绘制完线后，将其转换为纹理以用作SKSpriteNode

//
//  GameScene.swift
//  physics
//
//  Created by Anthony Randazzo on 7/28/17.
//  Copyright © 2017 SychoGaming. All rights reserved.
//

import SpriteKit
import GameplayKit

class GameScene: SKScene {

    private var shape = SKShapeNode()
    private var path : CGMutablePath!

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

        let position =  touches.first!.positionOnScene
        path = CGMutablePath()
        path.move(to: CGPoint.zero)
        shape.path = path
        shape.position = position
        self.addChild(shape)
    }

    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        let position =  touches.first!.positionOnScene - shape.position
        path.addLine(to: position)
        shape.path = path
    }

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        let position =  touches.first!.positionOnScene - shape.position
        path.closeSubpath()
        shape.removeFromParent()
        autoreleasepool
        {

            let sprite = SKSpriteNode(texture: self.view?.texture(from: shape,crop:shape.frame))

            sprite.position = CGPoint(x:shape.frame.midX,y:shape.frame.midY)
            let physicsBody = SKPhysicsBody(polygonFrom: path)
            physicsBody.isDynamic = false
            sprite.physicsBody = physicsBody

            addChild(sprite)
        }
    }

    override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
        let position =  touches.first!.positionOnScene
    }


    override func update(_ currentTime: TimeInterval) {
    }
}

extension UITouch
{
    var positionOnScene : CGPoint
    {
        return self.location(in: (self.view as! SKView).scene!)
    }
}
extension CGPoint
{
    static public func -(lhs:CGPoint,rhs:CGPoint) -> CGPoint
    {
        return CGPoint(x: lhs.x - rhs.x, y: lhs.y - rhs.y)
    }
    static public func -= (lhs:inout CGPoint,rhs:CGPoint)
    {
        lhs = lhs - rhs
    }
}

创建具有物理和强大性能的用户创建的行的方法

1 个答案: