code: function( options ){
  
              var self = this
                  ,el
                  ,isTransparent
                  ;
  
              if (typeof PIXI === 'undefined') {
                  throw "PIXI not present - cannot continue";
              }
  
              // call parent init
              parent.init.call(this, options);
  
              // further options
              this.options.defaults( defaults, true );
              this.options.onChange(function(){
                  self.options.offset = new Physics.vector( self.options.offset );
              });
              this.options( options, true );
  
              isTransparent = (!this.options.styles.color || this.options.styles.color === 'transparent');
              // Hook in PIXI stage here
              this.stage = new PIXI.Stage(this.options.styles.color);
  
              // Create empty meta object for use later
              this.meta = {};
  
              el = (this.el && this.el.nodeName === 'CANVAS') ? el : null;
              // add the renderer view element to the DOM according to its type
              this.renderer = new PIXI.autoDetectRenderer(this.options.width, this.options.height, {
                  view: el,
                  transparent: isTransparent,
                  resolution: window.devicePixelRatio || 1
              });
  
              if ( !el ){
                  this.el = this.el || document.body;
                  // add to passed in element
                  this.el.appendChild( this.renderer.view );
              }
  
              if ( this.options.autoResize ){
                  this.resize();
              } else {
                  this.resize( this.options.width, this.options.height );
              }
          }
docs: extended