Added print chunking to avoid gibberish.

Author: BigJk

frontend/src/js/ui/views/settings/index.jsx

@@ -161,6 +161,36 @@ export default () => {
 									oninput={binder.checkbox(store.data.settings.commands, 'cut')}
 								/>
 							</Form>
+							<div className='divider' />
+						</div>
+						<div className='w-50 mb2'>
+							<div className='f5 mb2 pt2'>Print Chunking</div>
+							<div className='lh-copy o-70'>
+								If you are using a old printer with a small print buffer you can tell Sales & Dungeons to split the printing into smaller chunks. This
+								might help in avoiding gibberish print-outs.
+							</div>
+							<Form horizontal={true}>
+								<Switch
+									label='Enable'
+									labelCol={4}
+									value={store.data.settings.commands.splitPrinting}
+									oninput={binder.checkbox(store.data.settings.commands, 'splitPrinting')}
+								/>
+								<Input
+									label='Split Height'
+									labelCol={4}
+									placeholder='Pixel height to split like 300'
+									value={store.data.settings.commands.splitHeight}
+									oninput={binder.inputNumber(store.data.settings.commands, 'splitHeight')}
+								/>
+								<Input
+									label='Split Delay'
+									labelCol={4}
+									placeholder='Delay after a print in milliseconds like 1000'
+									value={store.data.settings.commands.splitDelay}
+									oninput={binder.inputNumber(store.data.settings.commands, 'splitDelay')}
+								/>
+							</Form>
 						</div>
 					</div>
 				</div>

rpc/print.go

@@ -8,6 +8,7 @@ import (
 	"image"
 	"image/png"
 	"io/ioutil"
+	"math"
 	"math/rand"
 	"net"
 	"net/http"
@@ -147,33 +148,75 @@ func print(db database.Database, printer printing.PossiblePrinter, html string)
 	renderCache.SetDefault(tempId, finalHtml)
 
 	// Render the html to image
-	image, err := rendering.RenderURL(fmt.Sprintf("http://127.0.0.1:7123/api/html/%s", tempId), settings.PrinterWidth)
+	renderedImage, err := rendering.RenderURL(fmt.Sprintf("http://127.0.0.1:7123/api/html/%s", tempId), settings.PrinterWidth)
 	if err != nil {
 		return fmt.Errorf("html to image rendering failed: %w", err)
 	}
 
-	// Print
-	buf := &bytes.Buffer{}
+	imageRgb := renderedImage.(*image.RGBA)
+	height := imageRgb.Bounds().Max.Y
+	width := imageRgb.Bounds().Max.X
 
-	if settings.Commands.ExplicitInit {
-		epson.InitPrinter(buf)
-	}
+	var images []image.Image
+	if settings.Commands.SplitPrinting && height > settings.Commands.SplitHeight {
+		if settings.Commands.SplitHeight < 100 {
+			return fmt.Errorf("please use a split height of at least 100")
+		}
 
-	if settings.Commands.ForceStandardMode {
-		epson.SetStandardMode(buf)
-	}
+		chunks := int(math.Ceil(float64(height) / float64(settings.Commands.SplitHeight)))
 
-	buf.WriteString(strings.Repeat("\n", settings.Commands.LinesBefore))
-	epson.Image(buf, image)
-	buf.WriteString(strings.Repeat("\n", 5+settings.Commands.LinesAfter))
+		// Chunk the images
+		for i := 0; i < chunks; i++ {
+			y1 := i * settings.Commands.SplitHeight
+			y2 := y1 + settings.Commands.SplitHeight
+			if y2 > height {
+				y2 = height
+			}
 
-	if settings.Commands.Cut {
-		epson.CutPaper(buf)
+			images = append(images, imageRgb.SubImage(image.Rect(0, y1, width, y2)))
+		}
+	} else {
+		images = []image.Image{renderedImage}
 	}
 
-	err = selectedPrinter.Print(settings.PrinterEndpoint, image, buf.Bytes())
-	if err != nil {
-		return fmt.Errorf("printer wasn't able to print: %w", err)
+	// Print
+	for i, img := range images {
+		buf := &bytes.Buffer{}
+
+		// At the first chunk set modes and lines
+		if i == 0 {
+			if settings.Commands.ExplicitInit {
+				epson.InitPrinter(buf)
+			}
+
+			if settings.Commands.ForceStandardMode {
+				epson.SetStandardMode(buf)
+			}
+
+			buf.WriteString(strings.Repeat("\n", settings.Commands.LinesBefore))
+		}
+
+		epson.Image(buf, img)
+
+		// At the last chunk insert lines and cut
+		if i == len(images)-1 {
+			buf.WriteString(strings.Repeat("\n", 5+settings.Commands.LinesAfter))
+
+			if settings.Commands.Cut {
+				epson.CutPaper(buf)
+			}
+		}
+
+		// Print chunk
+		err = selectedPrinter.Print(settings.PrinterEndpoint, renderedImage, buf.Bytes())
+		if err != nil {
+			return fmt.Errorf("printer wasn't able to print: %w", err)
+		}
+
+		// Add delay to consecutive prints
+		if len(images) > 1 && settings.Commands.SplitDelay > 0 {
+			time.Sleep(time.Millisecond * time.Duration(settings.Commands.SplitDelay))
+		}
 	}
 
 	return nil

settings.go

@@ -11,6 +11,9 @@ type Settings struct {
 		ForceStandardMode bool `json:"forceStandardMode"`
 		LinesBefore       int  `json:"linesBefore"`
 		LinesAfter        int  `json:"linesAfter"`
+		SplitPrinting     bool `json:"splitPrinting"`
+		SplitHeight       int  `json:"splitHeight"`
+		SplitDelay        int  `json:"splitDelay"`
 	} `json:"commands"`
 	Stylesheets           []string `json:"stylesheets"`
 	SpellcheckerLanguages []string `json:"spellcheckerLanguages"`

thermalprinter/epson/epson.go

@@ -36,24 +36,26 @@ func LineBreak(buf io.Writer) {
 func Image(buf io.Writer, image image.Image) {
 	bb := image.Bounds()
 
-	width := bb.Max.X
+	height := bb.Max.Y - bb.Min.Y
+	realWidth := bb.Max.X - bb.Min.X
+	width := realWidth
 	if width%8 != 0 {
 		width += 8
 	}
 
 	xL := uint8(width % 2048 / 8)
 	xH := uint8(width / 2048)
-	yL := uint8(bb.Max.Y % 256)
-	yH := uint8(bb.Max.Y / 256)
+	yL := uint8(height % 256)
+	yH := uint8(height / 256)
 
 	_, _ = buf.Write([]byte{0x1d, 0x76, 0x30, 48, xL, xH, yL, yH})
 
 	var cb byte
 	var bindex byte
-	for y := 0; y < bb.Max.Y; y++ {
-		for x := 0; x < int(math.Ceil(float64(bb.Max.X)/8.0))*8; x++ {
-			if x < bb.Max.X {
-				r, g, b, a := image.At(x, y).RGBA()
+	for y := 0; y < height; y++ {
+		for x := 0; x < int(math.Ceil(float64(realWidth)/8.0))*8; x++ {
+			if x < realWidth {
+				r, g, b, a := image.At(bb.Min.X+x, bb.Min.Y+y).RGBA()
 				r, g, b, a = r>>8, g>>8, b>>8, a>>8
 
 				if a > 255/2 {