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Save some tape

master
Přemysl Janouch 1 year ago
parent
commit
e605078d89
Signed by: Přemysl Janouch <p@janouch.name> GPG Key ID: A0420B94F92B9493
1 changed files with 64 additions and 2 deletions
  1. +64
    -2
      label-exp/main.go

+ 64
- 2
label-exp/main.go View File

@@ -49,6 +49,28 @@ func (s *scaler) At(x, y int) color.Color {
return s.image.At(x/s.scale, y/s.scale)
}

// leftRotate is a 90 degree rotating image.Image wrapper.
type leftRotate struct {
image image.Image
}

// ColorModel implements image.Image.
func (lr *leftRotate) ColorModel() color.Model {
return lr.image.ColorModel()
}

// Bounds implements image.Image.
func (lr *leftRotate) Bounds() image.Rectangle {
r := lr.image.Bounds()
// Min is inclusive, Max is exclusive.
return image.Rect(r.Min.Y, -(r.Max.X - 1), r.Max.Y, -(r.Min.X - 1))
}

// At implements image.Image.
func (lr *leftRotate) At(x, y int) color.Color {
return lr.image.At(-y, x)
}

// -----------------------------------------------------------------------------

func decodeBitfieldErrors(b byte, errors [8]string) []string {
@@ -289,11 +311,10 @@ func printLabel(src image.Image) error {

var font *bdf.Font

// TODO: By rotating the label we can make it smaller, as an alternate mode.
func genLabel(text string, width int) image.Image {
// Create a scaled bitmap of the QR code.
qrImg, _ := qr.Encode(text, qr.H, qr.Auto)
qrImg, _ = barcode.Scale(qrImg, 306, 306)
qrImg, _ = barcode.Scale(qrImg, width, width)
qrRect := qrImg.Bounds()

// Create a scaled bitmap of the text label.
@@ -321,6 +342,45 @@ func genLabel(text string, width int) image.Image {
return combinedImg
}

func genLabelForHeight(text string, height int) image.Image {
// Create a scaled bitmap of the text label.
textRect, _ := font.BoundString(text)
textImg := image.NewRGBA(textRect)
draw.Draw(textImg, textRect, image.White, image.ZP, draw.Src)
font.DrawString(textImg, image.ZP, text)

// TODO: Make it possible to choose scale, or use some heuristic.
scaledTextImg := scaler{image: textImg, scale: 3}
//scaledTextImg := scaler{image: textImg, scale: 3}
scaledTextRect := scaledTextImg.Bounds()

remains := height - scaledTextRect.Dy() - 20

width := scaledTextRect.Dx()
if remains > width {
width = remains
}

// Create a scaled bitmap of the QR code.
qrImg, _ := qr.Encode(text, qr.H, qr.Auto)
qrImg, _ = barcode.Scale(qrImg, remains, remains)
qrRect := qrImg.Bounds()

// Combine.
combinedRect := image.Rect(0, 0, width, height)
combinedImg := image.NewRGBA(combinedRect)
draw.Draw(combinedImg, combinedRect, image.White, image.ZP, draw.Src)
draw.Draw(combinedImg,
combinedRect.Add(image.Point{X: (width - qrRect.Dx()) / 2, Y: 0}),
qrImg, image.ZP, draw.Src)

target := image.Rect(
(width-scaledTextRect.Dx())/2, qrRect.Dy()+20,
combinedRect.Max.X, combinedRect.Max.Y)
draw.Draw(combinedImg, target, &scaledTextImg, scaledTextRect.Min, draw.Src)
return combinedImg
}

var tmpl = template.Must(template.New("form").Parse(`
<!DOCTYPE html>
<html><body>
@@ -361,7 +421,9 @@ func handle(w http.ResponseWriter, r *http.Request) {
params.Width = 306 // Default to 29mm tape.
}

// TODO: Possibly just remove the for-width mode.
label := genLabel(params.Text, params.Width)
label = &leftRotate{image: genLabelForHeight(params.Text, params.Width)}
if r.FormValue("print") != "" {
if err := printLabel(label); err != nil {
log.Println("print error:", err)

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