code: function _scaleCanvas(ctx, params, transforms) {
  
  	// Scale both the x- and y- axis using the 'scale' property
  	if (params.scale !== 1) {
  		params.scaleX = params.scaleY = params.scale;
  	}
  
  	// Scale canvas using shape as center of rotation
  	ctx.translate(params.x, params.y);
  	ctx.scale(params.scaleX, params.scaleY);
  	ctx.translate(-params.x, -params.y);
  
  	// If transformation data was given
  	if (transforms) {
  		// Update transformation data
  		transforms.scaleX *= params.scaleX;
  		transforms.scaleY *= params.scaleY;
  	}
  }
docs: Scales canvas (internal)