HTML5 Game (Canvas) - UI Techniques?

Question

I\'m in the process of building a JavaScript / HTML5 game (using Canvas) for mobile (Android / iPhone/ WebOS) with PhoneGap. I\'m currently trying to design out how the UI a

Answer 1

You can do it a million ways. However you feel most comfortable and your engineers feel most confident.

If you're looking for inspiration or a code example, here's one way that I do it. I have a function that repeatedly draws a menu until a button is pressed. When the button is pressed, the game loads and the old menu click event listeners are removed and new game click event listeners are added. I also end the old draw loop of the menu and start a new game draw loop. Here's some selected snippets to give you the idea of how its done:

Game.prototype.loadMenu = function() {
  var game = this;
  var can = this.canvas;

  // now we can use the mouse for the menu
  can.addEventListener('click', game.menuClickEvent, false);
  can.addEventListener('touchstart', game.menuClickEvent, false);

  // draw menu
  this.loop = setInterval(function() { game.drawMenu() }, 30);
};

Game.prototype.drawMenu = function() {
  // ... draw the menu
}

Game.prototype.loadLevel = function(levelstring) {
  // unload menu
  var can = this.canvas;
  var game = this;
  can.removeEventListener('click', game.menuClickEvent, false);
  can.removeEventListener('touchstart', game.menuClickEvent, false);

  if (this.loop) clearInterval(this.loop);

  // ... other level init stuff


  // now we can press keys for the game
  //can.addEventListener('click', game.gameClickEvent, false);
  can.addEventListener('touchstart', game.gameClickEvent, false);
  can.addEventListener('keydown', game.gameKeyDownEvent, false);

  this.loop = setInterval(function() { game.tick() }, 30);
}

// called from tick()
Game.prototype.draw = function(advanceFrame) {
  // ...
}

This way I'm able to separate out game drawing and game events from menu drawing and menu events. It also gives me leeway to use game/animation elements in my menus should I want to make them look real pretty.

(I posted this at the twin gamedev discussion too)