ctb: Fix bug where missing preview images would corrupt bottom lift height & speed

README.md

@@ -205,10 +205,3 @@ The command line tool is designed to be used in a 'pipeline' style, for example:
 
     Known resins: (from local user ChiTuBox config)
 
-        Profile                                  bottom 5 layers, 50; nominal 15
-        Voxelab Black for 0.05mm                 bottom 6 layers, 50; nominal 10
-        Voxelab Green for 0.05mm                 bottom 6 layers, 50; nominal 10
-        Voxelab Grey for 0.05mm                  bottom 6 layers, 50; nominal 8
-        Voxelab Red for 0.05mm                   bottom 6 layers, 50; nominal 10
-        Voxelab Transparent for 0.05mm           bottom 6 layers, 50; nominal 10
-        Voxelab White for 0.05mm                 bottom 6 layers, 50; nominal 9

cmd/uv3dp/info.go

@@ -37,7 +37,22 @@ func NewInfoCommand() (info *InfoCommand) {
 	return
 }
 
+func printExposure(mode string, exp *uv3dp.Exposure) {
+	fmt.Printf("%v:\n", mode)
+	fmt.Printf("  Exposure: %.2gs on, %.2gs off", exp.LightOnTime, exp.LightOffTime)
+	if exp.LightPWM != 255 {
+		fmt.Printf(", PWM %v", exp.LightPWM)
+	}
+	fmt.Printf("  Lift: %v mm, %v mm/min\n",
+		exp.LiftHeight, exp.LiftSpeed)
+	fmt.Printf("  Retract: %v mm, %v mm/min\n",
+		exp.RetractHeight, exp.RetractSpeed)
+}
+
 func (info *InfoCommand) Filter(input uv3dp.Printable) (output uv3dp.Printable, err error) {
+	exp := input.Exposure()
+	bot := input.Bottom()
+
 	if info.SizeSummary {
 		size := input.Size()
 		fmt.Printf("Layers: %v, %vx%v slices, %.2f x %.2f x %.2f mm bed required\n",
@@ -55,27 +70,8 @@ func (info *InfoCommand) Filter(input uv3dp.Printable) (output uv3dp.Printable,
 	}
 
 	if info.ExposureSummary {
-		exp := input.Exposure()
-		bot := input.Bottom()
-
-		fmt.Printf("Exposure: %.2gs on, %.2gs off",
-			exp.LightOnTime,
-			exp.LightOffTime)
-		if exp.LightPWM != 255 {
-			fmt.Printf(", PWM %v", exp.LightPWM)
-		}
-		fmt.Println()
-		fmt.Printf("Bottom: %.2gs on, %.2gs off",
-			bot.Exposure.LightOnTime,
-			bot.Exposure.LightOffTime)
-		if bot.Exposure.LightPWM != 255 {
-			fmt.Printf(", PWM %v", bot.Exposure.LightPWM)
-		}
-		fmt.Printf(" (%v layers)\n", bot.Count)
-		fmt.Printf("Lift: %v mm, %v mm/min\n",
-			exp.LiftHeight, exp.LiftSpeed)
-		fmt.Printf("Retract: %v mm, %v mm/min\n",
-			exp.RetractHeight, exp.RetractSpeed)
+		printExposure(fmt.Sprintf("Bottom (%v layers)", bot.Count), &bot.Exposure)
+		printExposure("Normal", &exp)
 
 		keys := input.MetadataKeys()
 

ctb/format.go

@@ -37,7 +37,7 @@ const (
 
 type ctbHeader struct {
 	Magic          uint32     // 00:
-	Version        uint32     // 04: Always '2'
+	Version        uint32     // 04: Always '3'
 	BedSizeMM      [3]float32 // 08:
 	_              [2]uint32  // 14:
 	HeightMM       float32    // 1c:
@@ -220,7 +220,6 @@ func (cf *Formatter) Encode(writer uv3dp.Writer, printable uv3dp.Printable) (err
 			return base
 		}
 
-		base += uint32(previewSize)
 		size := pic.Bounds().Size()
 		if size == image.Pt(0, 0) {
 			return base
@@ -232,6 +231,8 @@ func (cf *Formatter) Encode(writer uv3dp.Writer, printable uv3dp.Printable) (err
 			return base
 		}
 
+		base += uint32(previewSize)
+
 		rleHash[hash] = rleInfo{offset: base, rle: rle}
 		rleHashList = append(rleHashList, hash)
 
@@ -246,7 +247,14 @@ func (cf *Formatter) Encode(writer uv3dp.Writer, printable uv3dp.Printable) (err
 	previewHugeBase := headerBase + uint32(headerSize)
 
 	previewTinyBase := savePreview(previewHugeBase, &previewHuge, uv3dp.PreviewTypeHuge)
+	if previewTinyBase == previewHugeBase {
+		previewHugeBase = 0
+	}
+
 	paramBase := savePreview(previewTinyBase, &previewTiny, uv3dp.PreviewTypeTiny)
+	if paramBase == previewTinyBase {
+		previewTinyBase = 0
+	}
 
 	param := ctbParam{}
 	paramSize, _ := restruct.SizeOf(&param)
@@ -440,8 +448,13 @@ func (cf *Formatter) Encode(writer uv3dp.Writer, printable uv3dp.Printable) (err
 		fileData[base], _ = restruct.Pack(binary.LittleEndian, &layer)
 	}
 
-	fileData[int(previewHugeBase)], _ = restruct.Pack(binary.LittleEndian, &previewHuge)
-	fileData[int(previewTinyBase)], _ = restruct.Pack(binary.LittleEndian, &previewTiny)
+	if previewHugeBase > 0 {
+		fileData[int(previewHugeBase)], _ = restruct.Pack(binary.LittleEndian, &previewHuge)
+	}
+
+	if previewTinyBase > 0 {
+		fileData[int(previewTinyBase)], _ = restruct.Pack(binary.LittleEndian, &previewTiny)
+	}
 
 	for _, hash := range rleHashList {
 		info := rleHash[hash]
@@ -623,7 +636,7 @@ func (cf *Formatter) Decode(file uv3dp.Reader, filesize int64) (printable uv3dp.
 		var param ctbParam
 
 		addr := int(header.ParamOffset)
-		err = restruct.Unpack(data[addr:], binary.LittleEndian, &param)
+		err = restruct.Unpack(data[addr:addr+int(header.ParamSize)], binary.LittleEndian, &param)
 		if err != nil {
 			return
 		}