brigand / ActionEngine

a canvas game engine that makes sense

ActionEngine

Why?

Creating games on the canvas is difficult because there aren't any good, easy, quick, free game engines. Using a modular structure, ActionEngine attempts to build a library of common game actions gradually, by a variety of developers.

Making a Game

ActionScript depends on EaselJS, and can use SoundJS, but it doesn't need to be loaded in silent games.

Start by cloning this repository.

git clone {todo}
rm -rf .git # to discard repository information 

Now you may begin editing the game.html file. In the bottom, there's an object called prop. This is the structure for your game.

objects is an array of all objects in your scene. You can create objects in a variety of ways.

1. shape: Currently circle/oval/ellipse and square/rectangle are supported.

2. image: Any valid src property of an <img/> element. Or an image element it self. Most common is an image path relative to the html file.

Each object can have actions. Actions may be created inline, or you can choose from an ever-expanding set of pre-made actions. The simplest are in actions.movement.js. Here's an example actions object.

actions: {
    "w": actions.movement.up(7),
    "a": actions.movement.left(10),
    "d": actions.movement.right(10),
    "s": actions.movement.down(7)
}

Let's look at the actions.movement.left function (written in CoffeeScript). It takes a speed, and returns a function that will be called every time the action is triggered (in the above, that means each frame "a" is down).

Notice that the callback takes two options. The first is a reference to the game instance, so variables like score or health may be updated, or other objects may be interacted with. delta is the time in seconds since the last tick. this is the Shape/Bitmap object. You can change any properties EaselJS exposes, like x, y, rotation, scaleX, etc.

actions.movement =
  left: (speed) ->
    speed = arguments[0] or 20
    (game, delta) ->
      this.x -= speed * delta

More info will be added in time.