func clearRect(gc *GraphicContext, x1, y1, x2, y2 float64) {
	// save state
	f := gc.Current.FillColor
	x, y := gc.pdf.GetXY()
	// cover page with white rectangle
	gc.SetFillColor(white)
	draw2dkit.Rectangle(gc, x1, y1, x2, y2)
	gc.Fill()
	// restore state
	gc.SetFillColor(f)
	gc.pdf.MoveTo(x, y)
}
func clearRect(gc *GraphicContext, x1, y1, x2, y2 float64) {
	
	f := gc.Current.FillColor
	x, y := gc.pdf.GetXY()
	
	gc.SetFillColor(white)
	draw2dkit.Rectangle(gc, x1, y1, x2, y2)
	gc.Fill()
	
	gc.SetFillColor(f)
	gc.pdf.MoveTo(x, y)
}
func clearRect ( gc * GraphicContext , x1 , y1 , x2 , y2 float64 ) { // save state f := gc . Current . FillColor x , y := gc . pdf . GetXY ( ) // cover page with white rectangle gc . SetFillColor ( white ) draw2dkit . Rectangle ( gc , x1 , y1 , x2 , y2 ) gc . Fill ( ) // restore state gc . SetFillColor ( f ) gc . pdf . MoveTo ( x , y ) }
// clearRect draws a white rectangle
clearRect draws a white rectangle