Example #1
0
func main() {
	const (
		w = 400
		h = 400
	)
	r := raster.NewRasterizer(w, h)
	r.UseNonZeroWinding = true

	cjs := []struct {
		c raster.Capper
		j raster.Joiner
	}{
		{raster.RoundCapper, raster.RoundJoiner},
		{raster.ButtCapper, raster.BevelJoiner},
		{raster.SquareCapper, raster.BevelJoiner},
	}

	for i, cj := range cjs {
		var path raster.Path
		path.Start(fixed.P(30+100*i, 30+120*i))
		path.Add1(fixed.P(180+100*i, 80+120*i))
		path.Add1(fixed.P(50+100*i, 130+120*i))
		raster.Stroke(r, path, fixed.I(20), cj.c, cj.j)
	}

	rgba := image.NewRGBA(image.Rect(0, 0, w, h))
	draw.Draw(rgba, rgba.Bounds(), image.Black, image.Point{}, draw.Src)
	p := raster.NewRGBAPainter(rgba)
	p.SetColor(color.RGBA{0x7f, 0x7f, 0x7f, 0xff})
	r.Rasterize(p)

	white := color.RGBA{0xff, 0xff, 0xff, 0xff}
	for i := range cjs {
		rgba.SetRGBA(30+100*i, 30+120*i, white)
		rgba.SetRGBA(180+100*i, 80+120*i, white)
		rgba.SetRGBA(50+100*i, 130+120*i, white)
	}

	// Save that RGBA image to disk.
	outFile, err := os.Create("out.png")
	if err != nil {
		log.Println(err)
		os.Exit(1)
	}
	defer outFile.Close()
	b := bufio.NewWriter(outFile)
	err = png.Encode(b, rgba)
	if err != nil {
		log.Println(err)
		os.Exit(1)
	}
	err = b.Flush()
	if err != nil {
		log.Println(err)
		os.Exit(1)
	}
	fmt.Println("Wrote out.png OK.")
}
Example #2
0
File: graph.go Project: rsc/tmp
func plotPath(f func(*big.Rat) *big.Rat, fminx, fminy, fmaxx, fmaxy *big.Rat, r fixed.Rectangle26_6) raster.Path {
	px := r.Min.X
	var path raster.Path
	for ; px <= r.Max.X; px += 1 << 6 {
		fx := new(big.Rat).Add(fminx, new(big.Rat).Mul(new(big.Rat).Sub(fmaxx, fminx), new(big.Rat).Quo(big.NewRat(int64(px-r.Min.X), 1<<6), big.NewRat(int64(r.Max.X-r.Min.X), 1<<6))))
		fy := f(fx)
		fdy := new(big.Rat).Mul(new(big.Rat).Sub(fy, fminy), new(big.Rat).Quo(big.NewRat(int64(r.Max.Y-r.Min.Y), 1), new(big.Rat).Sub(fmaxy, fminy)))
		dy, _ := fdy.Float64()
		py := r.Min.Y + fixed.Int26_6(dy+0.5)
		if len(path) == 0 {
			path.Start(fixed.Point26_6{px, py})
		} else {
			path.Add1(fixed.Point26_6{px, py})
		}
	}
	return path
}
Example #3
0
func (s *Sparkline) Draw(dst draw.Image) {
	if len(s.data) == 0 {
		return
	}

	min := s.data[0]
	max := s.data[0]
	for _, n := range s.data[1:] {
		if n < min {
			min = n
		}
		if n > max {
			max = n
		}
	}

	// try to be helpful when there's limited data
	if max < 1.0 {
		max = 1.0
	}
	if min > max-1.0 {
		min = max - 1.0
		if min < 0.0 {
			min = 0.0
		}
	}

	bounds := dst.Bounds()
	dx, dy := bounds.Dx(), bounds.Dy()

	tmp := image.NewRGBA(image.Rectangle{Max: image.Point{X: dx, Y: dy}})
	p := raster.NewRGBAPainter(tmp)

	r := raster.NewRasterizer(dx, dy)
	r.UseNonZeroWinding = true

	var q raster.Path
	q.Start(s.scale(0, s.data[0], min, max, dx, dy))
	for i, n := range s.data[1:] {
		pt := s.scale(i+1, n, min, max, dx, dy)
		q.Add1(pt)
	}
	const strokeWidth = fixed.Int26_6(5 << 6)
	r.AddStroke(q, strokeWidth, raster.RoundCapper, raster.RoundJoiner)
	p.SetColor(s.fg)
	r.Rasterize(p)

	r.Clear()
	q.Clear()
	headPt := s.scale(len(s.data)-1, s.data[len(s.data)-1], min, max, dx, dy)
	q.Start(headPt)
	// miniscule nudge so something actually is output
	q.Add1(headPt.Add(fixed.Point26_6{X: 1, Y: 1}))
	const headWidth = fixed.Int26_6(8 << 6)
	r.AddStroke(q, headWidth, raster.RoundCapper, raster.RoundJoiner)
	// TODO really decide between uint64 vs float32 vs uint32 etc
	//	value := uint64((s.data[len(s.data)-1] - min) / max * float32(^uint64(0)))
	value := uint64(s.data[len(s.data)-1])
	headColor := PickColor(s.thresholds, value)
	p.SetColor(headColor)
	r.Rasterize(p)
	draw.Draw(dst, bounds, tmp, image.ZP, draw.Over)
}
Example #4
0
File: graph.go Project: rsc/tmp
func Handler(w http.ResponseWriter, req *http.Request) {
	const size = 500
	c := image.NewRGBA(image.Rect(0, 0, size, size))
	white := &image.Uniform{C: color.White}
	draw.Draw(c, c.Bounds(), white, image.ZP, draw.Src)

	p := raster.NewRGBAPainter(c)
	p.SetColor(color.Black)
	r := raster.NewRasterizer(500, 500)
	r.UseNonZeroWinding = true
	var path raster.Path
	path.Start(nudge(fixed.P(50, 50)))
	path.Add1(nudge(fixed.P(50, 450)))
	path.Add1(nudge(fixed.P(450, 450)))
	r.AddStroke(path, fixed.I(2), raster.ButtCapper, raster.BevelJoiner)
	r.Rasterize(p)
	r.Clear()

	p.SetColor(color.Gray16{0x7FFF})
	path.Clear()
	r.Clear()
	path.Start(nudge(fixed.P(450, 450)))
	path.Add1(nudge(fixed.P(450, 50)))
	path.Add1(nudge(fixed.P(50, 50)))
	r.AddStroke(path, fixed.I(1), raster.ButtCapper, raster.BevelJoiner)
	r.Rasterize(p)

	p.SetColor(color.Gray16{0x7FFF})
	for x := 50; x <= 450; x += 50 {
		path.Clear()
		path.Start(nudge(fixed.P(x, 450)))
		path.Add1(nudge(fixed.P(x, 460)))
		r.AddStroke(path, fixed.I(1), raster.ButtCapper, raster.BevelJoiner)
	}
	for x := 50; x <= 450; x += 50 {
		path.Clear()
		path.Start(nudge(fixed.P(50, x)))
		path.Add1(nudge(fixed.P(40, x)))
		r.AddStroke(path, fixed.I(1), raster.ButtCapper, raster.BevelJoiner)
	}
	r.Rasterize(p)

	p.SetColor(color.RGBA{0x00, 0x00, 0xFF, 0xFF})
	r.Clear()
	path.Clear()
	path.Start(nudge(fixed.P(50, 450)))
	path.Add1(nudge(fixed.P(450, 50)))
	r.AddStroke(path, fixed.I(1), raster.ButtCapper, raster.BevelJoiner)
	r.Rasterize(p)

	p.SetColor(color.RGBA{0xCC, 0x00, 0x00, 0xFF})
	r.Clear()
	window := fixed.Rectangle26_6{fixed.P(50, 450), fixed.P(450, 50)}
	//	path = plotPath(ratSin, big.NewRat(0, 1), big.NewRat(-1, 1), big.NewRat(10, 1), big.NewRat(1, 1), window)

	//	path = plotPath(ratProb, big.NewRat(0, 1), big.NewRat(0, 1), big.NewRat(1, 1<<57), big.NewRat(1, 1<<57), window)

	var lo, hi *big.Rat
	var locap, hicap, scalecap string
	id, _ := strconv.Atoi(req.FormValue("x"))
	switch id {
	case 0:
		lo = big.NewRat(1<<53-1<<3, 1<<54)
		hi = big.NewRat(1<<53+1<<3, 1<<54)
		locap = "1/2 - 1/2^51"
		hicap = "1/2 + 1/2^51"
		scalecap = "1/2^53"
	case 1:
		lo = big.NewRat(1<<54-1<<4, 1<<54)
		hi = big.NewRat(1<<54, 1<<54)
		locap = "1 - 1/2^50"
		hicap = "1"
		scalecap = "1/2^53"
	case 2:
		lo = big.NewRat(0, 1<<54)
		hi = big.NewRat(1<<4, 1<<54)
		locap = "0"
		hicap = "1/2^50"
		scalecap = "1/2^53"
	case 3:
		lo = big.NewRat(0, 1<<54)
		hi = big.NewRat(1<<2, 1<<62)
		locap = "0"
		hicap = "1/2^59"
		scalecap = "1/2^63"
	}

	mode, _ := strconv.Atoi(req.FormValue("mode"))
	path = plotPath(ratProb(mode), lo, lo, hi, hi, window)
	r.AddStroke(path, fixed.I(1), raster.ButtCapper, raster.BevelJoiner)
	r.Rasterize(p)

	var modestr string
	switch mode {
	case 0:
		modestr = "original behavior (can return 1)"
	case 1:
		modestr = "new behavior (too much 0)"
	case 2:
		modestr = "retry loop"
	}

	data, err := ioutil.ReadFile("/tmp/luxisr.ttf")
	if err != nil {
		panic(err)
	}
	tfont, err := freetype.ParseFont(data)
	if err != nil {
		panic(err)
	}
	const pt = 10
	ft := freetype.NewContext()
	ft.SetDst(c)
	ft.SetDPI(100)
	ft.SetFont(tfont)
	ft.SetFontSize(float64(pt))
	ft.SetSrc(image.NewUniform(color.Black))

	ft.SetClip(image.Rect(0, 0, 0, 0))
	wid, err := ft.DrawString(locap, freetype.Pt(0, 0))
	if err != nil {
		panic(err)
	}
	pp := freetype.Pt(50, 480)
	pp.X -= wid.X / 2
	ft.SetClip(c.Bounds())
	ft.DrawString(locap, pp)

	ft.SetClip(image.Rect(0, 0, 0, 0))
	wid, err = ft.DrawString(hicap, freetype.Pt(0, 0))
	if err != nil {
		panic(err)
	}
	pp = freetype.Pt(450, 480)
	pp.X -= wid.X / 2
	ft.SetClip(c.Bounds())
	ft.DrawString(hicap, pp)

	r.Clear()
	p.SetColor(color.Black)
	path.Clear()
	const dy = 5
	path.Start(nudge(fixed.P(400, 400)))
	path.Add1(nudge(fixed.P(400, 400-dy)))
	path.Add1(nudge(fixed.P(400, 400+dy)))
	path.Add1(nudge(fixed.P(400, 400)))
	path.Add1(nudge(fixed.P(450, 400)))
	path.Add1(nudge(fixed.P(450, 400-dy)))
	path.Add1(nudge(fixed.P(450, 400+dy)))
	path.Add1(nudge(fixed.P(450, 400)))
	r.AddStroke(path, fixed.I(2), raster.ButtCapper, raster.BevelJoiner)
	r.Rasterize(p)

	ft.SetClip(image.Rect(0, 0, 0, 0))
	wid, err = ft.DrawString(scalecap, freetype.Pt(0, 0))
	if err != nil {
		panic(err)
	}
	pp = freetype.Pt(425, 420)
	pp.X -= wid.X / 2
	ft.SetClip(c.Bounds())
	ft.DrawString(scalecap, pp)

	ft.SetClip(image.Rect(0, 0, 0, 0))
	wid, err = ft.DrawString(modestr, freetype.Pt(0, 0))
	if err != nil {
		panic(err)
	}
	pp = freetype.Pt(250, 490)
	pp.X -= wid.X / 2
	ft.SetClip(c.Bounds())
	ft.DrawString(modestr, pp)

	w.Write(pngEncode(c))
}