random beziers example

bezier.go

@@ -17,7 +17,7 @@ func CubicBezier(x0, y0, x1, y1, x2, y2, x3, y3 float64) []Point {
 	l := (math.Hypot(x1-x0, y1-y0) +
 		math.Hypot(x2-x1, y2-y1) +
 		math.Hypot(x3-x2, y3-y2))
-	n := int((l + 0.5))
+	n := int(l + 0.5)
 	if n < 4 {
 		n = 4
 	}

examples/beziers.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"math/rand"
+
+	"github.com/fogleman/gg"
+)
+
+func random() float64 {
+	return rand.Float64()*2 - 1
+}
+
+func point() (x, y float64) {
+	return random(), random()
+}
+
+func randomQuadratic(dc *gg.Context) {
+	x0, y0 := point()
+	x1, y1 := point()
+	x2, y2 := point()
+	dc.MoveTo(x0, y0)
+	dc.QuadraticTo(x1, y1, x2, y2)
+}
+
+func randomCubic(dc *gg.Context) {
+	x0, y0 := point()
+	x1, y1 := point()
+	x2, y2 := point()
+	x3, y3 := point()
+	dc.MoveTo(x0, y0)
+	dc.CubicTo(x1, y1, x2, y2, x3, y3)
+}
+
+func main() {
+	const (
+		S = 256
+		W = 8
+		H = 8
+	)
+	dc := gg.NewContext(S*W, S*H)
+	dc.SetRGB(1, 1, 1)
+	dc.Clear()
+	for j := 0; j < H; j++ {
+		for i := 0; i < W; i++ {
+			x := float64(i)*S + S/2
+			y := float64(j)*S + S/2
+			dc.Push()
+			dc.Translate(x, y)
+			dc.Scale(S/2, S/2)
+			randomCubic(dc)
+			// randomQuadratic(dc)
+			dc.Pop()
+		}
+	}
+	dc.SetRGBA(0, 0, 0, 0.1)
+	dc.FillPreserve()
+	dc.SetRGB(0, 0, 0)
+	dc.SetLineWidth(16)
+	dc.StrokePreserve()
+	dc.SavePNG("out.png")
+}