(function (window) {
  
          function SpaceRock(size) {
                  this.initialize(size);
          }
  
          var p = SpaceRock.prototype = new createjs.Shape();
  
  // static properties:
          SpaceRock.LRG_ROCK = 40;
          SpaceRock.MED_ROCK = 20;
          SpaceRock.SML_ROCK = 10;
  
  // public properties:
  
          p.bounds;        //visual radial size
          p.hit;                //average radial disparity
          p.size;                //size value itself
          p.spin;                //spin ammount
          p.score;        //score value
  
          p.vX;                //velocity X
          p.vY;                //velocity Y
  
          p.active;        //is it active
  
  // constructor:
          p.Shape_initialize = p.initialize;        //unique to avoid overiding base class
  
          p.initialize = function (size) {
                  this.Shape_initialize(); // super call
  
                  this.activate(size);
          }
  
  // public methods:
  
          //handle drawing a spaceRock
          p.getShape = function (size) {
                  var angle = 0;
                  var radius = size;
  
                  this.size = size;
                  this.hit = size;
                  this.bounds = 0;
  
                  //setup
                  this.graphics.clear();
                  this.graphics.beginStroke("#FFFFFF");
                  this.graphics.moveTo(0, size);
  
                  //draw spaceRock
                  while (angle < (Math.PI * 2 - .5)) {
                          angle += .25 + (Math.random() * 100) / 500;
                          radius = size + (size / 2 * Math.random());
                          this.graphics.lineTo(Math.sin(angle) * radius, Math.cos(angle) * radius);
  
                          //track visual depiction for interaction
                          if (radius > this.bounds) {
                                  this.bounds = radius;
                          }        //furthest point
  
                          this.hit = (this.hit + radius) / 2;                                        //running average
                  }
  
                  this.graphics.closePath(); // draw the last line segment back to the start point.
                  this.hit *= 1.1; //pad a bit
          }
  
          //handle reinit for poolings sake
          p.activate = function (size) {
                  this.getShape(size);
  
                  //pick a random direction to move in and base the rotation off of speed
                  var angle = Math.random() * (Math.PI * 2);
                  this.vX = Math.sin(angle) * (5 - size / 10);
                  this.vY = Math.cos(angle) * (5 - size / 10);
                  this.spin = (Math.random() + 0.2 ) * this.vX;
  
                  //associate score with size
                  this.score = (5 - size / 10) * 100;
                  this.active = true;
          }
  
          //handle what a spaceRock does to itself every frame
          p.tick = function (event) {
                  this.rotation += this.spin;
                  this.x += this.vX;
                  this.y += this.vY;
          }
  
          //position the spaceRock so it floats on screen
          p.floatOnScreen = function (width, height) {
                  //base bias on real estate and pick a side or top/bottom
                  if (Math.random() * (width + height) > width) {
                          //side; ensure velocity pushes it on screen
                          if (this.vX > 0) {
                                  this.x = -2 * this.bounds;
                          } else {
                                  this.x = 2 * this.bounds + width;
                          }
                          //randomly position along other dimension
                          if (this.vY > 0) {
                                  this.y = Math.random() * height * 0.5;
                          } else {
                                  this.y = Math.random() * height * 0.5 + 0.5 * height;
                          }
                  } else {
                          //top/bottom; ensure velocity pushes it on screen
                          if (this.vY > 0) {
                                  this.y = -2 * this.bounds;
                          } else {
                                  this.y = 2 * this.bounds + height;
                          }
                          //randomly position along other dimension
                          if (this.vX > 0) {
                                  this.x = Math.random() * width * 0.5;
                          } else {
                                  this.x = Math.random() * width * 0.5 + 0.5 * width;
                          }
                  }
          }
  
          p.hitPoint = function (tX, tY) {
                  return this.hitRadius(tX, tY, 0);
          }
  
          p.hitRadius = function (tX, tY, tHit) {
                  //early returns speed it up
                  if (tX - tHit > this.x + this.hit) {
                          return;
                  }
                  if (tX + tHit < this.x - this.hit) {
                          return;
                  }
  
                  if (tY - tHit > this.y + this.hit) {
                          return;
                  }
  
                  if (tY + tHit < this.y - this.hit) {
                          return;
                  }
  
                  //now do the circle distance test
                  return this.hit + tHit > Math.sqrt(Math.pow(Math.abs(this.x - tX), 2) + Math.pow(Math.abs(this.y - tY), 2));
          }
  
          window.SpaceRock = SpaceRock;
  
  }(window));