Contain a sprite node within the screen/view

Question

I have a sprite node which moves left to right with user touch. However currently it will exit the screen, I want to add a node either side so if the sprite node touches the node on either side it hugs it and remains there until user touch to make it travel the opposite direction.

This is what I thought of doing but it isn't working currently.

    let shipTexture = SKTexture(imageNamed: "ship.png")
    ship = SKSpriteNode(texture: shipTexture)
    ship.position = CGPoint(x: self.frame.midX, y: self.frame.midY)
    ship.zPosition = 3
    ship.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: 30, height: 100))
    ship.physicsBody!.isDynamic = true
    ship.physicsBody?.collisionBitMask = 0b1
    ship.physicsBody?.contactTestBitMask = 0b1
    ship.physicsBody!.collisionBitMask = 0b1
    ship.physicsBody?.affectedByGravity = false
    self.addChild(ship)



    let side = SKNode()
    side.position = CGPoint(x: self.frame.width / 2, y: self.frame.midY)

    side.physicsBody = SKPhysicsBody(edgeLoopFrom: CGRect(x: -240, y: -160, width: 480, height: 320))

    side.physicsBody!.isDynamic = false
    side.physicsBody?.collisionBitMask = 0b1
    side.physicsBody?.contactTestBitMask = 0b1
    side.physicsBody!.collisionBitMask = 0b1

    self.addChild(side)

    func didBegin(_ contact: SKPhysicsContact) {
        print("Collision")
    }
}

//var moveLeft = SKAction.moveBy(x: 800, y: 0, duration: 2)
//frame.size.width




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




    ship.removeAllActions()

    switch direction ?? .left {
    case .left:
        ship.run(SKAction.moveBy(x: -frame.size.width, y: 0, duration: 3))
    case .right:
        ship.run(SKAction.moveBy(x: frame.size.width, y: 0, duration: 3))
    }

    direction = direction == nil || direction == .right ? .left : .right
}

Answer 1

I got it. The reason is - you use action to move your node, but should use physics - force and impulse

Try this one:

import SpriteKit
import GameplayKit

var ship = SKSpriteNode()
var bg = SKSpriteNode()

class GameScene: SKScene, SKPhysicsContactDelegate {


    override func didMove(to view: SKView) {


        let bgTexture = SKTexture(imageNamed: "bg.png")
        let moveBGanimation = SKAction.move(by: CGVector(dx: 0, dy: -bgTexture.size().height), duration: 4)
        let shiftBGAnimation = SKAction.move(by: CGVector(dx: 0, dy: bgTexture.size().height), duration: 0)
        let moveBGForever = SKAction.repeatForever(SKAction.sequence([moveBGanimation, shiftBGAnimation]))

        var i: CGFloat = 0

        while i < 3 {

            bg = SKSpriteNode(texture: bgTexture)
            bg.position = CGPoint(x: self.frame.midX, y: bgTexture.size().height * i)
            bg.size.width = self.frame.width

            bg.run(moveBGForever)
            self.addChild(bg)

            i += 1

        }

        let shipTexture = SKTexture(imageNamed: "ship.png")
        ship = SKSpriteNode(texture: shipTexture)
        ship.position = CGPoint(x: self.frame.midX, y: self.frame.midY)
        ship.zPosition = 3
        ship.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: 30, height: 100))
        ship.physicsBody!.isDynamic = true
        ship.physicsBody?.collisionBitMask = 0b1
        ship.physicsBody?.contactTestBitMask = 0b1
        ship.physicsBody!.categoryBitMask = 0b1
        ship.physicsBody?.affectedByGravity = false
        self.addChild(ship)

        let side = SKNode()
        side.position = CGPoint(x: 0, y: 0)
        side.physicsBody = SKPhysicsBody(edgeLoopFrom: CGRect(x: -self.frame.width/2, y: -self.frame.height/2, width: self.frame.width, height: self.frame.height))

        side.physicsBody!.isDynamic = false
        side.physicsBody?.collisionBitMask = 0b1
        side.physicsBody?.contactTestBitMask = 0b1
        side.physicsBody!.categoryBitMask = 0b1

        self.addChild(side)

        self.physicsWorld.contactDelegate = self

        func didBegin(_ contact: SKPhysicsContact) {
            print("Collision")
        }

    }

    //var moveLeft = SKAction.moveBy(x: 800, y: 0, duration: 2)
    //frame.size.width

    enum Direction: Int {
        case left = 0
        case right
    }

    var direction: Direction?

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




        ship.removeAllActions()

        switch direction ?? .left {
        case .left:
            ship.physicsBody?.applyImpulse(CGVector(dx: -20, dy: 0))
            //ship.run(SKAction.moveBy(x: -frame.size.width, y: 0, duration: 3))
        case .right:
            ship.physicsBody?.applyImpulse(CGVector(dx: 20, dy: 0))
            //ship.run(SKAction.moveBy(x: frame.size.width, y: 0, duration: 3))
        }

        direction = direction == nil || direction == .right ? .left : .right
    }




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



    }

    override func update(_ currentTime: TimeInterval) {


    }
}