Explosions.js

/*Stores all explosions*/
function Explosions() {
  this.explosions = new Array();
}

/*Adds an Explosion
 * @param {Point} position The initial x / y position of the explosion
 * @param {Number} initialRadius How big the explosion is when it first fires
 * @param {Number} fullSizeRadius how big is the full size radius?
 * @param {Integer} growthFrames How many frames does it take the explosion to grow?
 * @param {Number} initialAlpha The initial transparency of the explosion (0.0 clear, 1.0 opaque)
 * @param {Number} fullSizeAlpha What alpha should the explosion be when full?( 0.0-1.0)
 * @param {Number} fadeFrames   How many frames should the explosion last before fading?
 * @param {Number} finalAlpha What alpha should the explosion be before it fades (0.0-1.0)
 * @param {Integer} targetFrame What frame should we be before starting the animation?
 */
Explosions.prototype.add = function (
  position,
  color,
  initialRadius,
  fullSizeRadius,
  growthFrames,
  initialAlpha,
  fullSizeAlpha,
  fadeFrames,
  finalAlpha,
  targetFrame
) {
  var explosion = new Explosion(
    position,
    color,
    initialRadius,
    fullSizeRadius,
    growthFrames,
    initialAlpha,
    fullSizeAlpha,
    fadeFrames,
    finalAlpha,
    targetFrame
  );
  this.explosions.push(explosion);
};

/*Remove an Explosions
 *@param {Integer} index, The element to remove
 */
Explosions.prototype.remove = function (index) {
  this.explosions.splice(index, 1);
};

/*Remove all Explosions
 */
Explosions.prototype.removeAll = function () {
  for (var i = this.explosions.length - 1; i >= 0; i--) {
    this.remove(i);
  }
};

/*Draws all explosions, deletes all explosions that have reached the end of their life
 * @param {Canvas Drawing Context} ctx
 */
Explosions.prototype.drawAll = function (ctx, frame) {
  ctx.clearRect(0, 0, Background.WIDTH, Background.HEIGHT);
  for (var i = this.explosions.length - 1; i >= 0; i--) {
    if (this.explosions[i].draw(ctx)) {
      this.remove(i);
    }
  }
};