stars example

examples/stars.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"math"
+	"math/rand"
+
+	"github.com/fogleman/gg"
+)
+
+type Point struct {
+	X, Y float64
+}
+
+func Polygon(n int) []Point {
+	result := make([]Point, n)
+	for i := 0; i < n; i++ {
+		a := float64(i)*2*math.Pi/float64(n) - math.Pi/2
+		result[i] = Point{math.Cos(a), math.Sin(a)}
+	}
+	return result
+}
+
+func main() {
+	const W = 1200
+	const H = 120
+	const S = 100
+	dc := gg.NewContext(W, H)
+	dc.SetHexColor("#FFFFFF")
+	dc.Clear()
+	n := 5
+	points := Polygon(n)
+	for x := S / 2; x < W; x += S {
+		dc.Push()
+		s := rand.Float64()*S/4 + S/4
+		dc.Translate(float64(x), H/2)
+		dc.Rotate(rand.Float64() * 2 * math.Pi)
+		dc.Scale(s, s)
+		for i := 0; i < n+1; i++ {
+			index := (i * 2) % n
+			p := points[index]
+			dc.LineTo(p.X, p.Y)
+		}
+		dc.SetLineWidth(10)
+		dc.SetHexColor("#FFCC00")
+		dc.StrokePreserve()
+		dc.SetHexColor("#FFE43A")
+		dc.Fill()
+		dc.Pop()
+	}
+	dc.SavePNG("out.png")
+}