Esempio n. 1
0
// Encode encodes a string using the given version, level, and mask.
func Encode(w http.ResponseWriter, req *http.Request) {
	val := func(s string) int {
		v, _ := strconv.Atoi(req.FormValue(s))
		return v
	}

	l := coding.Level(val("l"))
	v := coding.Version(val("v"))
	enc := coding.String(req.FormValue("t"))
	m := coding.Mask(val("m"))

	p, err := coding.NewPlan(v, l, m)
	if err != nil {
		panic(err)
	}
	cc, err := p.Encode(enc)
	if err != nil {
		panic(err)
	}

	c := &qr.Code{Bitmap: cc.Bitmap, Size: cc.Size, Stride: cc.Stride, Scale: 8}
	w.Header().Set("Content-Type", "image/png")
	w.Header().Set("Cache-Control", "public, max-age=3600")
	w.Write(c.PNG())
}
Esempio n. 2
0
// Encode returns an encoding of text at the given error correction level.
func Encode(text string, level Level) (*Code, error) {
	// Pick data encoding, smallest first.
	// We could split the string and use different encodings
	// but that seems like overkill for now.
	var enc coding.Encoding
	switch {
	case coding.Num(text).Check() == nil:
		enc = coding.Num(text)
	case coding.Alpha(text).Check() == nil:
		enc = coding.Alpha(text)
	default:
		enc = coding.String(text)
	}

	// Pick size.
	l := coding.Level(level)
	var v coding.Version
	for v = coding.MinVersion; ; v++ {
		if v > coding.MaxVersion {
			return nil, errors.New("text too long to encode as QR")
		}
		if enc.Bits(v) <= v.DataBytes(l)*8 {
			break
		}
	}

	// Build and execute plan.
	p, err := coding.NewPlan(v, l, 0)
	if err != nil {
		return nil, err
	}
	cc, err := p.Encode(enc)
	if err != nil {
		return nil, err
	}

	// TODO: Pick appropriate mask.

	return &Code{cc.Bitmap, cc.Size, cc.Stride, 8}, nil
}
Esempio n. 3
0
func makeFrame(req *http.Request, font string, pt, vers, l, scale, dots int) image.Image {
	lev := coding.Level(l)
	p, err := coding.NewPlan(coding.Version(vers), lev, 0)
	if err != nil {
		panic(err)
	}

	nd := p.DataBytes / p.Blocks
	nc := p.CheckBytes / p.Blocks
	extra := p.DataBytes - nd*p.Blocks

	cap := fmt.Sprintf("QR v%d, %s", vers, lev)
	if dots > 0 {
		cap = fmt.Sprintf("QR v%d order, from bottom right", vers)
	}
	m := makeImage(req, cap, font, pt, len(p.Pixel), 0, scale, func(x, y int) uint32 {
		pix := p.Pixel[y][x]
		switch pix.Role() {
		case coding.Data:
			if dots > 0 {
				return 0xffffffff
			}
			off := int(pix.Offset() / 8)
			nd := nd
			var i int
			for i = 0; i < p.Blocks; i++ {
				if i == extra {
					nd++
				}
				if off < nd {
					break
				}
				off -= nd
			}
			return blockColors[i%len(blockColors)]
		case coding.Check:
			if dots > 0 {
				return 0xffffffff
			}
			i := (int(pix.Offset()/8) - p.DataBytes) / nc
			return dark(blockColors[i%len(blockColors)])
		}
		if pix&coding.Black != 0 {
			return 0x000000ff
		}
		return 0xffffffff
	})

	if dots > 0 {
		b := m.Bounds()
		for y := 0; y <= len(p.Pixel); y++ {
			for x := 0; x < b.Dx(); x++ {
				m.SetRGBA(x, y*scale-(y/len(p.Pixel)), color.RGBA{127, 127, 127, 255})
			}
		}
		for x := 0; x <= len(p.Pixel); x++ {
			for y := 0; y < b.Dx(); y++ {
				m.SetRGBA(x*scale-(x/len(p.Pixel)), y, color.RGBA{127, 127, 127, 255})
			}
		}
		order := make([]image.Point, (p.DataBytes+p.CheckBytes)*8+1)
		for y, row := range p.Pixel {
			for x, pix := range row {
				if r := pix.Role(); r != coding.Data && r != coding.Check {
					continue
				}
				//      draw.Draw(m, m.Bounds().Add(image.Pt(x*scale, y*scale)), dot, image.ZP, draw.Over)
				order[pix.Offset()] = image.Point{x*scale + scale/2, y*scale + scale/2}
			}
		}

		for mode := 0; mode < 2; mode++ {
			for i, p := range order {
				q := order[i+1]
				if q.X == 0 {
					break
				}
				line(m, p, q, mode)
			}
		}
	}
	return m
}