func buildMoon(theme gxui.Theme, center math.Point, radius float32) gxui.Image { c := 40 p := make(gxui.Polygon, c*2) for i := 0; i < c; i++ { frac := float32(i) / float32(c) α := math.Lerpf(math.Pi*1.2, math.Pi*-0.2, frac) p[i] = gxui.PolygonVertex{ Position: math.Point{ X: center.X + int(radius*math.Sinf(α)), Y: center.Y + int(radius*math.Cosf(α)), }, RoundedRadius: 0, } } for i := 0; i < c; i++ { frac := float32(i) / float32(c) α := math.Lerpf(math.Pi*-0.2, math.Pi*1.2, frac) r := math.Lerpf(radius, radius*0.5, math.Sinf(frac*math.Pi)) p[i+c] = gxui.PolygonVertex{ Position: math.Point{ X: center.X + int(r*math.Sinf(α)), Y: center.Y + int(r*math.Cosf(α)), }, RoundedRadius: 0, } } image := theme.CreateImage() image.SetPolygon(p, gxui.CreatePen(3, gxui.Gray80), gxui.CreateBrush(gxui.Gray40)) return image }
func buildStar(theme gxui.Theme, center math.Point, radius, rotation float32, points int) gxui.Image { p := make(gxui.Polygon, points*2) for i := 0; i < points*2; i++ { frac := float32(i) / float32(points*2) α := frac*math.TwoPi + rotation r := []float32{radius, radius / 2}[i&1] p[i] = gxui.PolygonVertex{ Position: math.Point{ X: center.X + int(r*math.Cosf(α)), Y: center.Y + int(r*math.Sinf(α)), }, RoundedRadius: []float32{0, 50}[i&1], } } image := theme.CreateImage() image.SetPolygon(p, gxui.CreatePen(3, gxui.Red), gxui.CreateBrush(gxui.Yellow)) return image }