draw2dimg/ftgc.go
func (gc *GraphicContext) Fill(paths ...*draw2d.Path) {
	paths = append(paths, gc.Current.Path)
	gc.fillRasterizer.UseNonZeroWinding = gc.Current.FillRule == draw2d.FillRuleWinding

	/**** first method ****/
	flattener := draw2dbase.Transformer{Tr: gc.Current.Tr, Flattener: FtLineBuilder{Adder: gc.fillRasterizer}}
	for _, p := range paths {
		draw2dbase.Flatten(p, flattener, gc.Current.Tr.GetScale())
	}

	gc.paint(gc.fillRasterizer, gc.Current.FillColor)
}
func (gc *GraphicContext) Fill(paths ...*draw2d.Path) {
	paths = append(paths, gc.Current.Path)
	gc.fillRasterizer.UseNonZeroWinding = gc.Current.FillRule == draw2d.FillRuleWinding

	/**** first method ****/
	flattener := draw2dbase.Transformer{Tr: gc.Current.Tr, Flattener: FtLineBuilder{Adder: gc.fillRasterizer}}
	for _, p := range paths {
		draw2dbase.Flatten(p, flattener, gc.Current.Tr.GetScale())
	}

	gc.paint(gc.fillRasterizer, gc.Current.FillColor)
}
// Fill fills the paths with the color specified by SetFillColor