简单的 Sprite Kit 项目显示碰撞接触触摸事件

这是一个简单的 Sprite-Kit GameScene.swift。创建一个新的空 SpriteKit 项目,并用此替换 GameScene.swift。然后构建并运行。

单击屏幕上的任何对象以使其移动。检查日志和注释,看看哪些碰撞,哪些碰撞。

//
//  GameScene.swift
//  bounceTest
//
//  Created by Stephen Ives on 05/04/2016.
//  Copyright (c) 2016 Stephen Ives. All rights reserved.
//

import SpriteKit

class GameScene: SKScene, SKPhysicsContactDelegate {
    
    let objectSize = 150
    let initialImpulse: UInt32 = 300  // Needs to be proportional to objectSize
    
    //Physics categories
    let purpleSquareCategory:   UInt32 = 1 << 0
    let redCircleCategory:      UInt32 = 1 << 1
    let blueSquareCategory:     UInt32 = 1 << 2
    let edgeCategory:           UInt32 = 1 << 31
    
    let purpleSquare = SKSpriteNode()
    let blueSquare = SKSpriteNode()
    let redCircle = SKSpriteNode()
    
    override func didMove(to view: SKView) {
        
        physicsWorld.gravity = CGVector(dx: 0, dy: 0)
        
        //Create an boundary else everything will fly off-screen
        let edge = frame.insetBy(dx: 0, dy: 0)
        physicsBody = SKPhysicsBody(edgeLoopFrom: edge)
        physicsBody?.isDynamic = false  //This won't move
        name = "Screen_edge"
        
        scene?.backgroundColor = SKColor.black
        
        //        Give our 3 objects their attributes
        
        blueSquare.color = SKColor.blue
        blueSquare.size = CGSize(width: objectSize, height: objectSize)
        blueSquare.name = "shape_blueSquare"
        blueSquare.position = CGPoint(x: size.width * -0.25, y: size.height * 0.2)
        
        let circleShape = SKShapeNode(circleOfRadius: CGFloat(objectSize))
        circleShape.fillColor = SKColor.red
        redCircle.texture = view.texture(from: circleShape)
        redCircle.size = CGSize(width: objectSize, height: objectSize)
        redCircle.name = "shape_redCircle"
        redCircle.position = CGPoint(x: size.width * 0.4, y: size.height * -0.4)
        
        purpleSquare.color = SKColor.purple
        purpleSquare.size = CGSize(width: objectSize, height: objectSize)
        purpleSquare.name = "shape_purpleSquare"
        purpleSquare.position = CGPoint(x: size.width * -0.35, y: size.height * 0.4)
        
        addChild(blueSquare)
        addChild(redCircle)
        addChild(purpleSquare)
        
        redCircle.physicsBody = SKPhysicsBody(circleOfRadius: redCircle.size.width/2)
        blueSquare.physicsBody = SKPhysicsBody(rectangleOf: blueSquare.frame.size)
        purpleSquare.physicsBody = SKPhysicsBody(rectangleOf: purpleSquare.frame.size)
        
        setUpCollisions()
        
        checkPhysics()
        
    }
    
    
    func setUpCollisions() {
        
        //Assign our category bit masks to our physics bodies
        purpleSquare.physicsBody?.categoryBitMask = purpleSquareCategory
        redCircle.physicsBody?.categoryBitMask = redCircleCategory
        blueSquare.physicsBody?.categoryBitMask = blueSquareCategory
        physicsBody?.categoryBitMask = edgeCategory  // This is the edge for the scene itself
        
        // Set up the collisions. By default, everything collides with everything.
        
        redCircle.physicsBody?.collisionBitMask &= ~purpleSquareCategory  // Circle doesn't collide with purple square
        purpleSquare.physicsBody?.collisionBitMask = 0   // purpleSquare collides with nothing
        //        purpleSquare.physicsBody?.collisionBitMask |= (redCircleCategory | blueSquareCategory)  // Add collisions with red circle and blue square
        purpleSquare.physicsBody?.collisionBitMask = (redCircleCategory)  // Add collisions with red circle
        blueSquare.physicsBody?.collisionBitMask = (redCircleCategory)  // Add collisions with red circle
        
        
        // Set up the contact notifications. By default, nothing contacts anything.
        redCircle.physicsBody?.contactTestBitMask |= purpleSquareCategory   // Notify when red circle and purple square contact
        blueSquare.physicsBody?.contactTestBitMask |= redCircleCategory     // Notify when blue square and red circle contact
        
        // Make sure everything collides with the screen edge and make everything really 'bouncy'
        enumerateChildNodes(withName: "//shape*") { node, _ in
            node.physicsBody?.collisionBitMask |= self.edgeCategory  //Add edgeCategory to the collision bit mask
            node.physicsBody?.restitution = 0.9 // Nice and bouncy...
            node.physicsBody?.linearDamping = 0.1 // Nice and bouncy...
        }
             
        //Lastly, set ourselves as the contact delegate
        physicsWorld.contactDelegate = self
    }
    
    func didBegin(_ contact: SKPhysicsContact) {
        let contactMask = contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask
        
        switch contactMask {
        case purpleSquareCategory | blueSquareCategory:
            print("Purple square and Blue square have touched")
        case redCircleCategory | blueSquareCategory:
            print("Red circle and Blue square have touched")
        case redCircleCategory | purpleSquareCategory:
            print("Red circle and purple Square have touched")
        default: print("Unknown contact detected")
        }
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        
        for touch in touches {
            let touchedNode = selectNodeForTouch(touch.location(in: self))
            
            if let node = touchedNode {
                node.physicsBody?.applyImpulse(CGVector(dx: CGFloat(arc4random_uniform(initialImpulse)) - CGFloat(initialImpulse/2), dy: CGFloat(arc4random_uniform(initialImpulse)) - CGFloat(initialImpulse/2)))
                node.physicsBody?.applyTorque(CGFloat(arc4random_uniform(20)) - CGFloat(10))
            }
            
        }
    }
    
    // Return the sprite where the user touched the screen
    func selectNodeForTouch(_ touchLocation: CGPoint) -> SKSpriteNode? {
        
        let touchedNode = self.atPoint(touchLocation)
        print("Touched node is \(touchedNode.name)")
        //        let touchedColor = getPixelColorAtPoint(touchLocation)
        //        print("Touched colour is \(touchedColor)")
        
        if touchedNode is SKSpriteNode {
            return (touchedNode as! SKSpriteNode)
        } else {
            return nil
        }
    }
    
    //MARK: - Analyse the collision/contact set up.
    func checkPhysics() {
        
        // Create an array of all the nodes with physicsBodies
        var physicsNodes = [SKNode]()
        
        //Get all physics bodies
        enumerateChildNodes(withName: "//.") { node, _ in
            if let _ = node.physicsBody {
                physicsNodes.append(node)
            } else {
                print("\(node.name) does not have a physics body so cannot collide or be involved in contacts.")
            }
        }
        
        //For each node, check it's category against every other node's collion and contctTest bit mask
        for node in physicsNodes {
            let category = node.physicsBody!.categoryBitMask
            // Identify the node by its category if the name is blank
            let name = node.name != nil ? node.name! : "Category \(category)"
            
            let collisionMask = node.physicsBody!.collisionBitMask
            let contactMask = node.physicsBody!.contactTestBitMask
            
            // If all bits of the collisonmask set, just say it collides with everything.
            if collisionMask == UInt32.max {
                print("\(name) collides with everything")
            }
            
            for otherNode in physicsNodes {
            if (node.physicsBody?.dynamic == false) {
                print("This node \(name) is not dynamic")
            }
                if (node != otherNode) && (node.physicsBody?.isDynamic == true) {
                    let otherCategory = otherNode.physicsBody!.categoryBitMask
                    // Identify the node by its category if the name is blank
                    let otherName = otherNode.name != nil ? otherNode.name! : "Category \(otherCategory)"
                    
                    // If the collisonmask and category match, they will collide
                    if ((collisionMask & otherCategory) != 0) && (collisionMask != UInt32.max) {
                        print("\(name) collides with \(otherName)")
                    }
                    // If the contactMAsk and category match, they will contact
                    if (contactMask & otherCategory) != 0 {print("\(name) notifies when contacting \(otherName)")}
                }
            }
        }
    }
}