How to do a simple character controller?

How do I make a simple character controller in SpriteKit?

• I'm making a game in sprite kit and in order to move my character I am applying an impulse but that is a problem because that moves him every 50 pixels or so. My question is, could someone please show me how to make a simple character controller so my character can move continuously until the user lets go from holding down the screen? My GameScene.swift file: import SpriteKit class GameScene: SKScene, SKPhysicsContactDelegate { let character = SKSpriteNode(texture: SKTexture(imageNamed: "character")) var move = false override func didMoveToView(view: SKView) { /* Setup your scene here */ //world self.physicsWorld.contactDelegate = self self.physicsBody = SKPhysicsBody(edgeLoopFromRect: self.frame) //character character.position = CGPointMake(self.frame.size.width * 0.6, self.frame.size.height * 0.6) character.setScale(0.2) character.physicsBody = SKPhysicsBody(rectangleOfSize: character.size) character.physicsBody?.dynamic = true character.physicsBody?.allowsRotation = false self.addChild(character) character.physicsBody?.affectedByGravity = true //platform 1 var platform = SKSpriteNode(texture: SKTexture(imageNamed: "platform")) platform.position = CGPointMake(self.frame.size.width * 0.6, CGRectGetMidY(self.frame)) platform.physicsBody = SKPhysicsBody(rectangleOfSize: platform.size) platform.physicsBody?.dynamic = false platform.setScale(0.25) platform.physicsBody?.friction = 1 platform.physicsBody?.restitution = 0 platform.physicsBody?.linearDamping = 0 self.addChild(platform) //platform 2 var platformTexture2 = SKTexture(imageNamed: "platform") var platform2 = SKSpriteNode(texture: platformTexture2) platform2.position = CGPointMake(self.frame.size.width * 0.4, self.frame.size.height * 0.3) platform2.physicsBody = SKPhysicsBody(rectangleOfSize: platform2.size) platform2.physicsBody?.dynamic = false platform2.setScale(0.25) platform2.physicsBody?.friction = 1 platform2.physicsBody?.restitution = 0 platform2.physicsBody?.linearDamping = 0 self.addChild(platform2) //platform main var platformTexture3 = SKTexture(imageNamed: "platform") var platform3 = SKSpriteNode(texture: platformTexture2) platform3.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMinY(self.frame) + platform3.size.height / 3) platform3.physicsBody = SKPhysicsBody(rectangleOfSize: platform3.size) platform3.physicsBody?.dynamic = false platform3.setScale(1) platform3.size.width = platform3.size.width * CGFloat(2.0) platform3.physicsBody?.friction = 1 platform3.physicsBody?.restitution = 0 platform3.physicsBody?.linearDamping = 0 self.addChild(platform3) } override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) { /* Called when a touch begins */ for touch: AnyObject in touches { let location = touch.locationInNode(self) if location.x < CGRectGetMidX(self.frame){ character.physicsBody?.applyImpulse(CGVector(dx: -50, dy: 0)) } else if location.x > CGRectGetMidX(self.frame){ character.physicsBody?.applyImpulse(CGVector(dx: 50, dy: 0)) } } func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) { character.physicsBody?.velocity = CGVector(dx: 0, dy: 0) } func update(currentTime: CFTimeInterval) { /* Called before each frame is rendered */ } }; }

• Answer:

  One way to accomplish this is to maintain a variable to keep track of the state of the touch events (left, right, or none). Here are the basic steps: In touchesBegan, set touch state variable to left or right In update, apply impulse continuously while user is touching the screen In touchesEnded, reset the touch state variable Here's an example of how to implement this... Above GameScene class definition, add the following enum TouchState { case Left case Right case None } In GameScene, add the following variable var touchLocation:TouchState = .None In GameScene, add or replace the following methods override func update(currentTime: CFTimeInterval) { // Apply impulse to physics body while users is touching the screen switch (touchState) { case .Left: character.physicsBody?.applyImpulse(CGVector(dx: -1, dy: 0)) case .Right: character.physicsBody?.applyImpulse(CGVector(dx: 1, dy: 0)) case .None: break } } override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) { for touch:AnyObject in touches { let location = touch.locationInNode(self) if location.x < CGRectGetMidX(self.frame) { touchState = .Left } else if location.x > CGRectGetMidX(self.frame) { touchState = .Right } } } override func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) { // Update touch status touchState = .None } Here's the GameScene.swift... import SpriteKit enum TouchLocation { case Left case Right case None } class GameScene: SKScene, SKPhysicsContactDelegate { var character = SKSpriteNode(imageNamed: "character") var touchLocation:TouchLocation = .None override func didMoveToView(view: SKView) { /* Setup your scene here */ scaleMode = .ResizeFill //character character.position = CGPointMake(view.frame.size.width * 0.5, view.frame.size.height * 0.5) character.setScale(0.1) character.physicsBody = SKPhysicsBody(rectangleOfSize: character.size) character.physicsBody?.dynamic = true character.physicsBody?.allowsRotation = false self.addChild(character) character.physicsBody?.affectedByGravity = true //platform 1 var platform = SKSpriteNode(texture: SKTexture(imageNamed: "platform")) platform.position = CGPointMake(view.frame.size.width * 0.6, CGRectGetMidY(view.frame)) platform.physicsBody = SKPhysicsBody(rectangleOfSize: platform.size) platform.physicsBody?.dynamic = false platform.setScale(0.25) platform.physicsBody?.friction = 1 platform.physicsBody?.restitution = 0 platform.physicsBody?.linearDamping = 0 self.addChild(platform) //platform 2 var platformTexture2 = SKTexture(imageNamed: "platform") var platform2 = SKSpriteNode(texture: platformTexture2) platform2.position = CGPointMake(view.frame.size.width * 0.4, view.frame.size.height * 0.3) platform2.physicsBody = SKPhysicsBody(rectangleOfSize: platform2.size) platform2.physicsBody?.dynamic = false platform2.setScale(0.25) platform2.physicsBody?.friction = 1 platform2.physicsBody?.restitution = 0 platform2.physicsBody?.linearDamping = 0 self.addChild(platform2) //platform main var platformTexture3 = SKTexture(imageNamed: "platform") var platform3 = SKSpriteNode(texture: platformTexture2) platform3.position = CGPointMake(CGRectGetMidX(view.frame), CGRectGetMinY(view.frame) + platform3.size.height / 3) platform3.physicsBody = SKPhysicsBody(rectangleOfSize: platform3.size) platform3.physicsBody?.dynamic = false platform3.setScale(1) platform3.size.width = platform3.size.width * CGFloat(2.0) platform3.physicsBody?.friction = 1 platform3.physicsBody?.restitution = 0 platform3.physicsBody?.linearDamping = 0 self.addChild(platform3) } override func update(currentTime: CFTimeInterval) { /* Called before each frame is rendered */ switch (touchLocation) { case .Left: character.physicsBody?.applyImpulse(CGVector(dx: -1, dy: 0)) case .Right: character.physicsBody?.applyImpulse(CGVector(dx: 1, dy: 0)) case .None: break } } override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) { for touch:AnyObject in touches { let location = touch.locationInNode(self) if location.x < CGRectGetMidX(self.frame) { touchLocation = .Left } else if location.x > CGRectGetMidX(self.frame) { touchLocation = .Right } } } override func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) { touchLocation = .None } }