KineticJS dynamic scale

dynamic_scale.js

function _dynamicScale( params ) {
	gutter 		= 200;
	initialScale 	= params.zoom;
	initialWidth 	= jQuery('#canvasEditor').innerWidth();
	initialHeight 	= jQuery('#canvasEditor').innerHeight();
	width 		= initialWidth / initialHeight * ( jQuery(window.top).innerHeight() - gutter );
	height 		= jQuery(window.top).innerHeight() - gutter;
	xScale	 	= ( width / initialWidth ) * initialScale.x;
	yScale 		= ( height / initialHeight ) * initialScale.y;
	scale 		= { x: xScale, y: yScale };
	params.zoom 	= newScale;
	params.width 	= width;
	params.height 	= height;
	stage.scale( params.zoom );
	stage.size({
	   	width: params.width,
	   	height: params.height
	});
	jQuery('#canvasEditor').css({
		width: params.width,
		height: params.height
  	});
	stage.draw();
}