Sprite Kit set Min. and Max. for Jump - ios

Question

I want to move a SKSpriteNode on the Y-Axis. The SKSpriteNode called Player has no Velocity.The Player can only jump if a Platform is in contact.
Everytime the Screen is touched, I want to give the Player an impulse with a minimum impulse or a maximum impulse
If the Screen is tapped shortly, the Minimum impulse should be e.g. y = 50.
If the Screen is hold, that means the finger is on the Screen long, the Maximum should be e.g. y = 100.
But the Player should be also able to jump between the Minimum and Maximum height, if for e.g. the Screen is not long but also not shortly pressed, the Player should only get an impulse of y = 70.
If the Screen is hold, the Player should jump to his max height, fall down, and if it is in contact with the Platform again, it should jump, because you still hold the Screen.
I have already tried this with the suggested answer in this Thread:StackOverFlow
But this does not give the Minimum jump, also no Press jump.
For clarity: The impulse should not be after the tap is done, but while it is tapped. The longer you hold, the longer the jump is.
import SpriteKit
import GameKit
struct Constants {
static let minimumJumpForce:CGFloat = 40.0
static let maximumJumpForce:CGFloat = 60.0
static let characterSideSpeed:CGFloat = 18.0
}
class GameScene: SKScene, SKPhysicsContactDelegate {
var Player: SKSpriteNode!
var Platform0: SKSpriteNode!
var World: SKNode!
var Camera: SKNode!
var force: CGFloat = 40.0
var pressed = false
var isCharacterOnGround = false
.....
func SpawnPlatforms() {
Platform0 = SKSpriteNode (color: SKColor.greenColor(), size: CGSize(width: self.frame.size.width , height: 25))
Platform0.position = CGPoint(x: self.frame.size.width / 2, y: -36)
Platform0.zPosition = 1
Platform0.physicsBody = SKPhysicsBody(rectangleOfSize:Platform0.size)
Platform0.physicsBody?.dynamic = false
Platform0.physicsBody?.allowsRotation = false
Platform0.physicsBody?.restitution = 0
Platform0.physicsBody?.usesPreciseCollisionDetection = true
Platform0.physicsBody?.categoryBitMask = Platform0Category
Platform0.physicsBody?.collisionBitMask = PlayerCategory
Platform0.physicsBody?.contactTestBitMask = PlayerCategory
World.addChild(Platform0)
}
func SpawnPlayer(){
Player = SKSpriteNode (imageNamed: "Image.png")
Player.size = CGSize(width: 64, height: 64)
Player.position = CGPoint(x: self.frame.size.width / 2, y: 0)
Player.zPosition = 2
Player.physicsBody = SKPhysicsBody(rectangleOfSize:CGSize(width: 35, height: 50))
Player.physicsBody?.dynamic = true
Player.physicsBody?.allowsRotation = false
Player.physicsBody?.restitution = 0.1
Player.physicsBody?.usesPreciseCollisionDetection = true
Player.physicsBody?.categoryBitMask = PlayerCategory
Player.physicsBody?.collisionBitMask = Platform0Category
Player.physicsBody?.contactTestBitMask = Platform0Category | Platform1Category | Platform2Category | Platform3Category | Platform4Category | Platform5Category
World.addChild(Player)
}
func jump(force : CGFloat){
if(self.isCharacterOnGround){
self.Player.physicsBody?.applyImpulse(CGVectorMake(0, force))
self.isCharacterOnGround = false
}
}
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
/* Called when a touch begins */
for touch in (touches as! Set<UITouch>) {
let location = touch.locationInNode(self)
self.pressed = true
let timerAction = SKAction.waitForDuration(0.0)
let update = SKAction.runBlock({
if(self.force < Constants.maximumJumpForce){
self.force += 2.0
}else{
self.jump(Constants.maximumJumpForce)
self.force = Constants.maximumJumpForce
}
})
let sequence = SKAction.sequence([timerAction, update])
let repeat = SKAction.repeatActionForever(sequence)
self.runAction(repeat, withKey:"repeatAction")
}
}
override func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) {
for touch in (touches as! Set<UITouch>) {
let location = touch.locationInNode(self)
self.removeActionForKey("repeatAction")
self.jump(self.force)
self.force = Constants.minimumJumpForce
self.pressed = false
}
}
func didBeginContact(contact: SKPhysicsContact) {
//this gets called automatically when two objects begin contact with each other
let contactMask = contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask
switch(contactMask) {
case PlayerCategory | Platform0Category:
//either the contactMask was the bro type or the ground type
println("Contact Made0")
Green = true
self.isCharacterOnGround = true
default:
return
}
}

Answer 1

Here is an working example on how to make something like:
long pressed jump based on duration of press
short (one tap jump)
restrict character to jump while in the air
keep character jumping while finger is on screen
Code (Swift 4.x)
import SpriteKit
struct Constants {
static let minimumJumpForce:CGFloat = 15.0
static let maximumJumpForce:CGFloat = 30.0
static let characterSideSpeed:CGFloat = 18.0
}
class GameScene: SKScene,SKPhysicsContactDelegate
{
let CharacterCategory : UInt32 = 0x1 << 1
let PlatformCategory : UInt32 = 0x1 << 2
let WallCategory : UInt32 = 0x1 << 3
var force: CGFloat = 16.0 //Initial force
var pressed = false
var isCharacterOnGround = false // Use this to prevent jumping while in the air
let character = SKSpriteNode(color: .green, size: CGSize(width: 30, height:30))
let debugLabel = SKLabelNode(fontNamed: "Geneva")
override func didMove(to view: SKView)
{
//Setup contact delegate so we can use didBeginContact and didEndContact methods
physicsWorld.contactDelegate = self
physicsWorld.speed = 0.5
//Setup borders so character can't escape from us :-)
self.physicsBody = SKPhysicsBody(edgeLoopFrom: self.frame)
self.physicsBody?.categoryBitMask = WallCategory
self.physicsBody?.collisionBitMask = CharacterCategory
//Setup character
character.position = CGPoint(x: 150, y: 150)
character.physicsBody = SKPhysicsBody(rectangleOf: character.size)
character.physicsBody?.categoryBitMask = CharacterCategory
character.physicsBody?.contactTestBitMask = PlatformCategory
character.physicsBody?.collisionBitMask = PlatformCategory | WallCategory
character.physicsBody?.allowsRotation = false
character.physicsBody?.isDynamic = true
character.physicsBody?.restitution = 0.1
self.addChild(character)
generatePlatforms()
debugLabel.text = " DEBUG: "
debugLabel.fontColor = .white
debugLabel.fontSize = 12.0
debugLabel.position = CGPoint(x: frame.midX, y: frame.midY+100)
self.addChild(debugLabel)
}
func generatePlatforms(){
for i in 1...4
{
let position = CGPoint(x: frame.midX, y: CGFloat(i)*140.0 - 100)
let platform = createPlatformAtPosition(position: position)
self.addChild(platform)
}
}
func createPlatformAtPosition(position : CGPoint)->SKSpriteNode{
let platform = SKSpriteNode(color: .green, size: CGSize(width: frame.size.width, height:20))
platform.position = position
platform.physicsBody = SKPhysicsBody(
edgeFrom: CGPoint(x: -platform.size.width/2.0, y:platform.size.height/2.0),
to:CGPoint(x: platform.size.width/2.0, y: platform.size.height/2.0))
platform.physicsBody?.categoryBitMask = PlatformCategory
platform.physicsBody?.contactTestBitMask = CharacterCategory
platform.physicsBody?.collisionBitMask = CharacterCategory
platform.physicsBody?.allowsRotation = false
platform.name = "platform"
platform.physicsBody?.isDynamic = false
platform.physicsBody?.restitution = 0.0
return platform
}
func jump(force : CGFloat){
if(self.isCharacterOnGround){
self.character.physicsBody?.applyImpulse(CGVector(dx: 0, dy: force))
self.character.physicsBody?.collisionBitMask = WallCategory
self.isCharacterOnGround = false
}
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
self.pressed = true
let timerAction = SKAction.wait(forDuration: 0.05)
let update = SKAction.run({
if(self.force < Constants.maximumJumpForce){
self.force += 2.0
}else{
self.jump(force: Constants.maximumJumpForce)
self.force = Constants.maximumJumpForce
}
})
let sequence = SKAction.sequence([timerAction, update])
let repeat_seq = SKAction.repeatForever(sequence)
self.run(repeat_seq, withKey:"repeatAction")
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
self.removeAction(forKey: "repeatAction")
self.jump(force: self.force)
self.force = Constants.minimumJumpForce
self.pressed = false
}
override func update(_ currentTime: TimeInterval) {
debugLabel.text = "DEBUG: onTheGround : \(isCharacterOnGround), force \(force)"
if(character.position.x <= character.size.width/2.0 + 5.0 && character.physicsBody!.velocity.dx < 0.0 ){
character.physicsBody?.applyForce(CGVector(dx: Constants.characterSideSpeed, dy: 0.0))
}else if((character.position.x >= self.frame.size.width - character.size.width/2.0 - 5.0) && character.physicsBody!.velocity.dx >= 0.0){
character.physicsBody?.applyForce(CGVector(dx: -Constants.characterSideSpeed, dy: 0.0))
}else if(character.physicsBody!.velocity.dx > 0.0){
character.physicsBody!.applyForce(CGVector(dx: Constants.characterSideSpeed, dy: 0.0))
}else{
character.physicsBody!.applyForce(CGVector(dx: -Constants.characterSideSpeed, dy: 0.0))
}
}
func didBegin(_ contact: SKPhysicsContact) {
var firstBody, secondBody: SKPhysicsBody
if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
firstBody = contact.bodyA
secondBody = contact.bodyB
} else {
firstBody = contact.bodyB
secondBody = contact.bodyA
}
if ((firstBody.categoryBitMask & CharacterCategory) != 0 &&
(secondBody.categoryBitMask & PlatformCategory != 0)) {
let platform = secondBody.node! as! SKSpriteNode
// platform.color = UIColor.redColor()
let platformSurfaceYPos = platform.position.y + platform.size.height/2.0
let player = contact.bodyB.node! as! SKSpriteNode
let playerLegsYPos = player.position.y - player.size.height/2.0
if((platformSurfaceYPos <= playerLegsYPos)){
character.physicsBody?.collisionBitMask = PlatformCategory | WallCategory
self.isCharacterOnGround = true
if(self.pressed){
let characterDx = character.physicsBody?.velocity.dx
character.physicsBody?.velocity = CGVector(dx: characterDx!, dy: 0.0)
self.jump(force: Constants.maximumJumpForce)
}
}
}
}
func didEnd(_ contact: SKPhysicsContact) {
var firstBody, secondBody: SKPhysicsBody
if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
firstBody = contact.bodyA
secondBody = contact.bodyB
} else {
firstBody = contact.bodyB
secondBody = contact.bodyA
}
if ((firstBody.categoryBitMask & CharacterCategory) != 0 &&
(secondBody.categoryBitMask & PlatformCategory != 0)) {
let platform = secondBody.node as! SKSpriteNode
let platformSurfaceYPos = platform.position.y + platform.size.height/2.0
let player = contact.bodyB.node as! SKSpriteNode
let playerLegsYPos = player.position.y - player.size.height/2.0
if((platformSurfaceYPos <= playerLegsYPos) && ((character.physicsBody?.velocity.dy)! > CGFloat(0.0))){
character.physicsBody?.collisionBitMask = WallCategory
self.isCharacterOnGround = false
}
}
}
}
Note that this is simple example, and in real application you will probably have to handle states like isOnTheGround in a different way. Right now, to determine if character is on the ground you just set isOnTheGround = true when character make a contact with platform, and set it to false in didEndContact...But there are situations when character can be in contact with platform while in the air (eg. side contact)...
EDIT:
I changed the code to let the player jump while pressed. Here is the result:
Important:
Actual platform implementation and contact handling is up to you and this is not tested. The only purpose of this example is to show you how to jump while pressed. Currently, physicsWorld.speed is set to 0.5 to make animation slower because its easier to debug like that, but you can change this to default value (1.0).
So, as you can see from the image, while player is on the first platform some small jumps are presented (by simple tapping, or short pressing). Then (player is still on first platform) long press has been made, and player has jumped on second platform. After that, another long press is done, but this time without releasing, and player starts jumping from one platform to another using maximum force.
This needs a lot of tweaking and proper platform & contact detection, but it can give you an idea about how to implement jumping you asked about.