// 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)
draw2d.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
}