Add sprite in function in Phaser 3

Question

I am adding a sprite to my game like this:

enemy = this.physics.add.sprite(280, 32, 'enemy');

Now I'd like to add it from inside a function like this:

spawn(this.enemy);

function spawn(enemy) {
    enemy = this.physics.add.sprite(280, 32, 'enemy');
}

It doesn't work, I get the following error:

TypeError: this.physics is undefined

What do I have to write instead of this.physics?

score 3 · Accepted Answer · edited Oct 12 '19 at 23:23

3

You should, instead, use an arrow function like so:

First, within the function preload(), add the sprite:

this.load.spritesheet('enemy', 'assets/enemy.png', { frameWidth: 32, frameHeight: 48 });

Second, within the function create(), add the following code:

spawn = (enemyName) => {
    enemyPlayer = this.physics.add.sprite(400, 450, enemyName);
}

spawn('enemy');

As you can see, we're passing the sprite's name as a function's parameter. You can, now, reuse this function to "spawn" other sprites. For example, spawn('stars').

edited Oct 12 '19 at 23:23

halfer

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answered Sep 27 '19 at 20:33

Manuel Abascal

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doesnt explain why "this.physics" is undefined – mxmissile Jul 17 '20 at 00:56
1

Because `this` no longer refers to the same thing when it's within a function; the scope changes, so now the function's `this` doesn't have a `physics` definition. – James Skemp Sep 13 '20 at 15:31

Add sprite in function in Phaser 3

1 Answers1