core2d/src/plugin/Fog.mjs

Multiplatform 2D interaction engine

"use strict";

import { Sprite } from "../Sprite.mjs";

export class Fog extends Sprite {
  init() {
    this.scene.add(new FogLayer().setImageId("fogSprite0").setSpeedX(-1));

    this.scene.add(
      new FogLayer()
        .setImageId("fogSprite1")
        .setSpeedX(1)
        .setRight(this.scene.right)
    );
  }
}

class FogLayer extends Sprite {
  init() {
    this.setLayerIndex(2)
      .setHeight(this.scene.height)
      .setWidth(this.scene.width * 2);
  }

  update() {
    if (
      (this.speedX < 0 && this.right == this.scene.right) ||
      (this.speedX > 0 && this.left == this.scene.left)
    ) {
      const SIGNAL = this.speedX / Math.abs(this.speedX);
      this.x -= this.scene.width * SIGNAL;
    }
  }
}