Actor.js

// wrapper for "class" Actor
import {WebSystemObject} from './WebSystemObject';

export class Actor extends WebSystemObject {
  constructor(x, y) {
    super();
    // (x, y) = center of object
    // ATTENTION:
    // it represents the player position on the world(room), not the canvas position
    this.x = x;
    this.y = y;

    // move speed in pixels per second
    this.speed = 200;

    // render properties
    this.width = 50;
    this.height = 50;
  }

  update(step, worldWidth, worldHeight) {
    // parameter step is the time between frames ( in seconds )

    // check controls and move the player accordingly
    if (Game.controls.left) {
      this.x -= this.speed * step;
    }
    if (Game.controls.up) {
      this.y -= this.speed * step;
    }
    if (Game.controls.right) {
      this.x += this.speed * step;
    }
    if (Game.controls.down) {
      this.y += this.speed * step;
    }

    // don't let player leaves the world's boundary
    if (this.x - this.width / 2 < 0) {
      this.x = this.width / 2;
    }
    if (this.y - this.height / 2 < 0) {
      this.y = this.height / 2;
    }
    if (this.x + this.width / 2 > worldWidth) {
      this.x = worldWidth - this.width / 2;
    }
    if (this.y + this.height / 2 > worldHeight) {
      this.y = worldHeight - this.height / 2;
    }
  }

  draw(context, xView, yView) {
    // draw a simple rectangle shape as our player model
    context.save();
    context.fillStyle = 'black';
    // before draw we need to convert player world's position to canvas position
    context.fillRect((this.x - this.width / 2) - xView, (this.y - this.height / 2) - yView, this.width, this.height);
    context.restore();
  }

};

// Existen varios tipos de actores (implementar en z-order).
//  1._ Personajes.
//  2._ Decorados fijos.
//  3._ Decorados en movimiento (sprites).

//  4._ Cámaras.
//  5._ Sonidos (multicanal, real audio y MIDI).
//  6._ Interactividades.