Added support for previews

This commit is contained in:
Ignacio Rivero 2025-06-22 17:11:07 -03:00
parent 5c55474145
commit 7a6d24e2e4

124
main.go
View File

@ -52,6 +52,7 @@ var (
getQueryCount bool
ejectPaper uint
retractPaper uint
outputPath string
)
func init() {
@ -85,6 +86,9 @@ func init() {
flag.UintVar(&retractPaper, "retract", 0, "Retract paper by N lines")
flag.UintVar(&retractPaper, "R", 0, "Retract paper by N lines")
flag.StringVar(&outputPath, "o", "", "Output PNG preview instead of printing (specify output path)")
flag.StringVar(&outputPath, "output", "", "Output PNG preview instead of printing (specify output path)")
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "Usage: %s [options] <image_path or ->\n", os.Args[0])
fmt.Fprintln(os.Stderr, `
@ -373,9 +377,86 @@ func sendLineCommand(client ble.Client, printChr *ble.Characteristic, cmdId byte
return client.WriteCharacteristic(printChr, cmd, true)
}
func renderPreviewFrom1bpp(pixels []byte, width, height int) image.Image {
img := image.NewGray(image.Rect(0, 0, width, height))
for y := 0; y < height; y++ {
for x := 0; x < width; x++ {
idx := (y*width + x) / 8
bit := uint(x % 8)
if pixels[idx]&(1<<bit) != 0 {
img.SetGray(x, y, color.Gray{Y: 0})
} else {
img.SetGray(x, y, color.Gray{Y: 255})
}
}
}
return img
}
func renderPreviewFrom4bpp(pixels []byte, width, height int) image.Image {
img := image.NewGray(image.Rect(0, 0, width, height))
for y := 0; y < height; y++ {
for x := 0; x < width; x++ {
idx := (y*width + x) >> 1
shift := uint(((x & 1) ^ 1) << 2)
val := (pixels[idx] >> shift) & 0x0F
gray := 255 - val*17
img.SetGray(x, y, color.Gray{Y: gray})
}
}
return img
}
func main() {
flag.Parse()
var printMode PrintMode
switch mode {
case "1bpp":
printMode = Mode1bpp
case "4bpp":
printMode = Mode4bpp
default:
fmt.Println("Invalid mode. Use '1bpp' or '4bpp'.")
return
}
imagePath := flag.Arg(0)
var pixels []byte
var height int
img, err := decodeImage(imagePath)
if err != nil {
log.Fatalf("Image load error: %v", err)
}
img = padImageToMinLines(img, minLines)
switch printMode {
case Mode1bpp:
pixels, height, err = loadImageMonoFromImage(img, ditherType)
case Mode4bpp:
pixels, height, err = loadImage4BitFromImage(img)
}
if err != nil {
log.Fatalf("Image conversion error: %v", err)
}
if outputPath != "" {
var previewImg image.Image
switch printMode {
case Mode1bpp:
previewImg = renderPreviewFrom1bpp(pixels, linePixels, height)
case Mode4bpp:
previewImg = renderPreviewFrom4bpp(pixels, linePixels, height)
}
err = imaging.Save(previewImg, outputPath)
if err != nil {
log.Fatalf("Failed to save PNG preview: %v", err)
}
fmt.Printf("Preview PNG written to %s\n", outputPath)
return
}
ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
defer stop()
@ -442,17 +523,15 @@ func main() {
log.Fatalf("Missing required print characteristic")
}
if notifyChr != nil {
// 1) Make sure the CCCD has been discovered so Subscribe can succeed.
_, _ = client.DiscoverDescriptors(nil, notifyChr)
needNotifications := getStatus || getBattery || getVersion || getPrintType || getQueryCount || ejectPaper > 0 || retractPaper > 0
// 2) Now subscribe. This registers the notification handler **and**
// writes 0x01-00 to the CCCD for us.
if notifyChr != nil && needNotifications {
_, _ = client.DiscoverDescriptors(nil, notifyChr)
err = client.Subscribe(notifyChr, false, func(b []byte) {
parseNotification(b)
})
if err != nil {
log.Printf("Subscribe still failed: %v notifications will be ignored", err)
log.Printf("Subscribe failed: %v notifications will be ignored", err)
} else {
log.Println("Subscribed to printer notifications.")
}
@ -486,9 +565,10 @@ func main() {
}
if flag.NArg() < 1 {
return // no image to print, other commands may have run
} else if flag.NArg() >= 1 && needNotifications {
log.Fatalf("Refusing to print and query at the same time due to a firmware bug. Please run print and query commands separately.")
}
imagePath := flag.Arg(0)
i := intensity
if i < 0 {
i = 0
@ -498,36 +578,6 @@ func main() {
}
intensityByte := byte(i)
var printMode PrintMode
switch mode {
case "1bpp":
printMode = Mode1bpp
case "4bpp":
printMode = Mode4bpp
default:
fmt.Println("Invalid mode. Use '1bpp' or '4bpp'.")
return
}
img, err := decodeImage(imagePath)
if err != nil {
log.Fatalf("Image load error: %v", err)
}
img = padImageToMinLines(img, minLines)
var pixels []byte
var height int
switch printMode {
case Mode1bpp:
pixels, height, err = loadImageMonoFromImage(img, ditherType)
case Mode4bpp:
pixels, height, err = loadImage4BitFromImage(img)
}
if err != nil {
log.Fatalf("Image conversion error: %v", err)
}
if dataChr == nil {
log.Fatalf("Missing required data characteristic")
}