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javascripttypescriptgame-developmentphaser-frameworktween

How to read position x of Shape Object when during tween


I have the Circle object that extends shape and am trying to get the value of x or position of the object in 2d plane. During animation (tween) the position does not update and remains static. How do i fix this ?

export class Circle extends Phaser.GameObjects.Shape {
    tween;
    constructor(scene:Phaser.Scene, x, y) {
        super(scene);
        let enemy = scene.add.circle(x, y, 20);
        enemy.setStrokeStyle(1, 0x05F9FB);
    
        this.tween = scene.tweens.add({
            targets: enemy,
            x: 560,
            y: 200,
            ease: 'Power1',
            duration: 3000,
            yoyo: true,
            repeat: -1
        });
    }
}

I have the below method in update method and it always returns original x value not the update one during tween.

update() {
    //Always returns  the orginal position of x and not the updated or current state of x
    console.log(enemy.x);
}

Solution

  • The enemy position x and y is not the position of the circle, that is used in the tween. An option is, to create a property, so that you can acess the position, from the property.

    Here small example, how the access could work:

    // Minor formating for stackoverflow
    document.body.style = "display: flex;flex-direction: column;";    
    
    class Circle extends Phaser.GameObjects.Shape {
        constructor(scene, x, y) {
            super(scene, x, y);
            this.circle = scene.add.circle(x, y, 20);           
            this.circle.setStrokeStyle(3, 0x05F9FB);
        
            this.tween = scene.tweens.add({
                targets: this.circle,
                x: 400,
                y: 120,
                duration: 3000,
                yoyo: true,
                repeat: 3
            });
        }
    }
    
    var config = {
        type: Phaser.AUTO,
        width: 536,
        height: 163,
        scene: {
            create,
            update
        }
    }; 
    
    function update(){
        this.info.setText(`x: ${this.enemy.circle.x.toFixed(0)}\ny: ${this.enemy.circle.y.toFixed(0)}  `);
    }
    
    function create () {
        this.enemy =  new Circle(this, 100, 100);
        this.info = this.add.text(20,20, '', 0xffffff);
    }
    
    var game = new Phaser.Game(config);
    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/phaser.js">
    </script>

    Update:

    Info: To keep the code cleaner using a getter( and setter) or method might be cleaner

    Like this

     class Circle extends Phaser.GameObjects.Shape {
         ...
         getPosition(){
             let { x, y } = this.circle;
             return { x, y };
         }
     }