text: SOSEngine.shapes.Circle = function(radius, x, y){
  	SOSEngine.shapes.Arc.call(this, radius, 0, 360, x, y);
  }
  SOSEngine.shapes.Circle.prototype = Object.create(SOSEngine.shapes.Arc.prototype);
  
  SOSEngine.shapes.FilledCircle = function(radius, x, y){
  	SOSEngine.Group.call(this);
  	this.init(radius, x, y);
  }
  SOSEngine.shapes.FilledCircle.prototype = Object.create(SOSEngine.Group.prototype);
  
  SOSEngine.shapes.FilledCircle.prototype.init = function(radius, x, y){
  	this.clear();
  	while (radius >= 0){	
  		this.add(new SOSEngine.shapes.Circle(radius--, x, y));
  	}
  }