func (gc *GraphicContext) ClearRect(x1, y1, x2, y2 int) {
	mask := gc.newMask(x1, y1, x2-x1, y2-y1)

	newGroup := &Group{
		Groups: gc.svg.Groups,
		Mask:   "url(#" + mask.Id + ")",
	}

	// replace groups with new masked group
	gc.svg.Groups = []*Group{newGroup}
}
func (gc *GraphicContext) ClearRect(x1, y1, x2, y2 int) {
	mask := gc.newMask(x1, y1, x2-x1, y2-y1)

	newGroup := &Group{
		Groups: gc.svg.Groups,
		Mask:   "url(#" + mask.Id + ")",
	}

	
	gc.svg.Groups = []*Group{newGroup}
}
func ( gc * GraphicContext ) ClearRect ( x1 , y1 , x2 , y2 int ) { mask := gc . newMask ( x1 , y1 , x2 - x1 , y2 - y1 ) newGroup := & Group { Groups : gc . svg . Groups , Mask : " " + mask . Id + " " , } // replace groups with new masked group gc . svg . Groups = [ ] * Group { newGroup } }
// ClearRect fills the specified rectangle with a default transparent color
ClearRect fills the specified rectangle with a default transparent color