Tween and keyboard.is

[Kalahan]

I want to make a game where the player is only able to move between 5 positions along the  bottom of the canvas using the left and right cursor keys on the keyboard. 

 

So the player starts at the central position #2. If he presses the left cursor key he should move to position #1 and if pressing the right cursor key he should move to position #3. After the first move he should be able to move between position #1 and #3. 

 

I use the Tween.to method to move my sprite to the specific position (X and Y cordinates) whenever the appropiate key isDown.

 

This works the first time after loading the game. The sprite will move left to position #1 or right to position #3 properly. It will even move from position #3 to #1 and the other way around the way I expect it to. 

 

The problem is that after I change the position a third time the sprite moves back to it's original position. After a while back and forth multiple times. Even when I make sure to wait long enough between key presses to make sure the Tween is completed. 

 

I just don't understand why it's doing this. After a while it's happening so fast the player sprite is flickering betweens positions #1 and #3 constantly. 

 

var game = new Phaser.Game(350, 300, Phaser.AUTO, '', { preload: preload, create: create, update: update });

 

function preload() {

game.load.image('player', 'assets/player.png');

}

 

function create() {

 

game.physics.startSystem(Phaser.Physics.ARCADE);

 

position1X = 50

position2X = 150

position3X = 250

var game = new Phaser.Game(350, 300, Phaser.AUTO, '', { preload: preload, create: create, update: update });

 

function preload() {

game.load.image('player', 'assets/player.png');

}

 

function create() {

 

game.physics.startSystem(Phaser.Physics.ARCADE);

 

positionY = 250

position1X = 50

position2X = 150

position3X = 250

 

player = game.add.sprite(position2X, positionY, 'player');

playerTween = game.add.tween(player);

 

cursors = game.input.keyboard.createCursorKeys();

 

}

 

function update() {

 

if (cursors.left.isDown)

{

    playerTween.to({x: position1X, y: positionY}, 60);

    playerTween.start();

} else if (cursors.right.isDown)

{

    playerTween.to({x: position3X, y: positionY}, 60);

    playerTween.start(); 

}

 

}

 

player = game.add.sprite(position2X, positionY, 'player');

playerTween = game.add.tween(player);

 

cursors = game.input.keyboard.createCursorKeys();

 

}

 

function update() {

 

if (cursors.left.isDown)

{

    playerTween.to({x: position1X, y: positionY}, 60);

    playerTween.start();

} else if (cursors.right.isDown)

{

    playerTween.to({x: position3X, y: positionY}, 60);

    playerTween.start(); 

}

 

}

 

 

How can I fix this? Should I use tweens to move the player? Or should I use another method like sprite.moveToXY?

 

Thanks in advance! 

 

[rich]

The problem with using isDown inside the update loop is that almost certainly you're firing off a whole load of tweens. You need to add a check in there to ensure that another tween isn't create if one is already running (tween.isRunning will let you do this).