ujs/test/js/game.example.js

import { App } from './app.js';
import { Scene, SceneLayer } from './scene.js';
import { Rect, StrokeRect, Sprite } from './objects.js';

// init player
let Player = {
  x: 400 / 2 - 5,
  y: 400 / 2 - 5,
  rect: null,
};
Player.rect = new Rect(Player.x, Player.y, 10, 10, 'black');
Player.rect.ticker = () => {
  Player.rect.y = Player.y;
  Player.rect.x = Player.x;
};

// init scene layers
let layerBg = new SceneLayer('background', [
  new Rect(50, 50, 100, 100, 'red'),
  new StrokeRect(150, 150, 40, 40, 'green', 'blue', 1),
]);

let layerHud = new SceneLayer('hud', [
  new Sprite('compass.png', 15, 15),
  new Sprite('compass-arrow.png', 27, 21),
]);

let layerInstances = new SceneLayer('Instances', [Player.rect], { debug: true });

// init app
let app = new App(document.querySelector('canvas'), 400, 400);

// init scene
let firstScene = new Scene(app.canvas, app.context, 400, 400);
firstScene.addLayer(layerBg);
firstScene.addLayer(layerInstances);
firstScene.addLayer(layerHud);

app.scene = firstScene;

// add app view in document
window.addEventListener('DOMContentLoaded', () => {
  document.body.appendChild(app.view);
});

// player key press listener
document.addEventListener('keydown', (e) => {
  switch (e.code) {
    case 'ArrowUp':
      Player.y -= 1;
      break;
    case 'ArrowDown':
      Player.y += 1;
      break;
    case 'ArrowLeft':
      Player.x -= 1;
      break;
    case 'ArrowRight':
      Player.x += 1;
      break;
  }
});