add support for depth in barcode generations

- Introduced depth parameter to EncodeWithDepth function to allow generating barcodes with specified color depth.
- Updated Encode function to use EncodeWithDepth with a default depth of 16.

datamatrix/codelayout.go

@@ -11,13 +11,15 @@ type codeLayout struct {
 	matrix *utils.BitList
 	occupy *utils.BitList
 	size   *dmCodeSize
+	depth int
 }
 
-func newCodeLayout(size *dmCodeSize) *codeLayout {
+func newCodeLayout(size *dmCodeSize, depth int) *codeLayout {
 	result := new(codeLayout)
 	result.matrix = utils.NewBitList(size.MatrixColumns() * size.MatrixRows())
 	result.occupy = utils.NewBitList(size.MatrixColumns() * size.MatrixRows())
 	result.size = size
+	result.depth = depth
 	return result
 }
 
@@ -159,7 +161,7 @@ func (l *codeLayout) SetValues(data []byte) {
 }
 
 func (l *codeLayout) Merge() *datamatrixCode {
-	result := newDataMatrixCode(l.size)
+	result := newDataMatrixCodeWithDepth(l.size, l.depth)
 
 	//dotted horizontal lines
 	for r := 0; r < l.size.Rows; r += (l.size.RegionRows() + 2) {

datamatrix/datamatrixcode.go

@@ -12,10 +12,15 @@ type datamatrixCode struct {
 	*utils.BitList
 	*dmCodeSize
 	content string
+	depth   int
+}
+
+func newDataMatrixCodeWithDepth(size *dmCodeSize, depth int) *datamatrixCode {
+	return &datamatrixCode{utils.NewBitList(size.Rows * size.Columns), size, "", depth}
 }
 
 func newDataMatrixCode(size *dmCodeSize) *datamatrixCode {
-	return &datamatrixCode{utils.NewBitList(size.Rows * size.Columns), size, ""}
+	return &datamatrixCode{utils.NewBitList(size.Rows * size.Columns), size, "", 16}
 }
 
 func (c *datamatrixCode) Content() string {
@@ -27,7 +32,7 @@ func (c *datamatrixCode) Metadata() barcode.Metadata {
 }
 
 func (c *datamatrixCode) ColorModel() color.Model {
-	return color.Gray16Model
+	return utils.ColorModel(c.depth)
 }
 
 func (c *datamatrixCode) Bounds() image.Rectangle {
@@ -36,9 +41,9 @@ func (c *datamatrixCode) Bounds() image.Rectangle {
 
 func (c *datamatrixCode) At(x, y int) color.Color {
 	if c.get(x, y) {
-		return color.Black
+		return utils.BlackColor(c.depth)
 	}
-	return color.White
+	return utils.WhiteColor(c.depth)
 }
 
 func (c *datamatrixCode) get(x, y int) bool {

datamatrix/encoder.go

@@ -8,7 +8,7 @@ import (
 )
 
 // Encode returns a Datamatrix barcode for the given content
-func Encode(content string) (barcode.Barcode, error) {
+func EncodeWithDepth(content string, depth int) (barcode.Barcode, error) {
 	data := encodeText(content)
 
 	var size *dmCodeSize
@@ -23,7 +23,7 @@ func Encode(content string) (barcode.Barcode, error) {
 	}
 	data = addPadding(data, size.DataCodewords())
 	data = ec.calcECC(data, size)
-	code := render(data, size)
+	code := render(data, size, depth)
 	if code != nil {
 		code.content = content
 		return code, nil
@@ -31,8 +31,13 @@ func Encode(content string) (barcode.Barcode, error) {
 	return nil, errors.New("unable to render barcode")
 }
 
-func render(data []byte, size *dmCodeSize) *datamatrixCode {
-	cl := newCodeLayout(size)
+// Encode returns a Datamatrix barcode for the given content
+func Encode(content string) (barcode.Barcode, error) {
+	return EncodeWithDepth(content, 16)
+}
+
+func render(data []byte, size *dmCodeSize, depth int) *datamatrixCode {
+	cl := newCodeLayout(size, depth)
 
 	cl.SetValues(data)