code: function _getCanvasData(canvas) {
  	var dataCache = caches.dataCache, data;
  	if (dataCache._canvas === canvas && dataCache._data) {
  
  		// Retrieve canvas data from cache if possible
  		data = dataCache._data;
  
  	} else {
  
  		// Retrieve canvas data from jQuery's internal data storage
  		data = $.data(canvas, 'jCanvas');
  		if (!data) {
  
  			// Create canvas data object if it does not already exist
  			data = {
  				// The associated canvas element
  				canvas: canvas,
  				// Layers array
  				layers: [],
  				// Layer maps
  				layer: {
  					names: {},
  					groups: {}
  				},
  				eventHooks: {},
  				// All layers that intersect with the event coordinates (regardless of visibility)
  				intersecting: [],
  				// The topmost layer whose area contains the event coordinates
  				lastIntersected: null,
  				cursor: $(canvas).css('cursor'),
  				// Properties for the current drag event
  				drag: {
  					layer: null,
  					dragging: false
  				},
  				// Data for the current event
  				event: {
  					type: null,
  					x: null,
  					y: null
  				},
  				// Events which already have been bound to the canvas
  				events: {},
  				// The canvas's current transformation state
  				transforms: _cloneTransforms(baseTransforms),
  				savedTransforms: [],
  				// Whether a layer is being animated or not
  				animating: false,
  				// The layer currently being animated
  				animated: null,
  				// The device pixel ratio
  				pixelRatio: 1,
  				// Whether pixel ratio transformations have been applied
  				scaled: false,
  				// Whether the canvas should be redrawn when a layer mousemove
  				// event triggers (either directly, or indirectly via dragging)
  				redrawOnMousemove: false
  			};
  			// Use jQuery to store canvas data
  			$.data(canvas, 'jCanvas', data);
  
  		}
  		// Cache canvas data for faster retrieval
  		dataCache._canvas = canvas;
  		dataCache._data = data;
  
  	}
  	return data;
  }
docs: /* Layer API Retrieved the stored jCanvas data for a canvas element