// FillStyle demonstrates the difference between even odd and non zero winding rule.
func FillStyle(gc draw2d.GraphicContext, x, y, width, height float64) {
sx, sy := width/232, height/220
gc.SetLineWidth(width / 40)
draw2dkit.Rectangle(gc, x+sx*0, y+sy*12, x+sx*232, y+sy*70)
var wheel1, wheel2 draw2d.Path
wheel1.ArcTo(x+sx*52, y+sy*70, sx*40, sy*40, 0, 2*math.Pi)
wheel2.ArcTo(x+sx*180, y+sy*70, sx*40, sy*40, 0, -2*math.Pi)
gc.SetFillRule(draw2d.FillRuleEvenOdd)
gc.SetFillColor(color.NRGBA{0, 0xB2, 0, 0xFF})
gc.SetStrokeColor(image.Black)
gc.FillStroke(&wheel1, &wheel2)
draw2dkit.Rectangle(gc, x, y+sy*140, x+sx*232, y+sy*198)
wheel1.Clear()
wheel1.ArcTo(x+sx*52, y+sy*198, sx*40, sy*40, 0, 2*math.Pi)
wheel2.Clear()
wheel2.ArcTo(x+sx*180, y+sy*198, sx*40, sy*40, 0, -2*math.Pi)
gc.SetFillRule(draw2d.FillRuleWinding)
gc.SetFillColor(color.NRGBA{0, 0, 0xE5, 0xFF})
gc.FillStroke(&wheel1, &wheel2)
}
// Main draws vertically spaced lines and returns the filename.
// This should only be used during testing.
func Main(gc draw2d.GraphicContext, ext string) (string, error) {
gc.SetFillRule(draw2d.FillRuleWinding)
gc.Clear()
// Draw the line
for x := 5.0; x < 297; x += 10 {
Draw(gc, x, 0, x, 210)
}
gc.ClearRect(100, 75, 197, 135)
draw2dkit.Ellipse(gc, 148.5, 105, 35, 25)
gc.SetFillColor(color.RGBA{0xff, 0xff, 0x44, 0xff})
gc.FillStroke()
// Return the output filename
return samples.Output("line", ext), nil
}