Add support for aztec encoding

aztec/aztec_writer.go

@@ -0,0 +1,131 @@
+package aztec
+
+import (
+	"strconv"
+
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/encoding/ianaindex"
+
+	"github.com/makiuchi-d/gozxing"
+	"github.com/makiuchi-d/gozxing/aztec/encoder"
+)
+
+// AztecWriter Renders an Aztec code as a BitMatrix.
+type AztecWriter struct{}
+
+func NewAztecWriter() gozxing.Writer {
+	return &AztecWriter{}
+}
+
+func (this *AztecWriter) EncodeWithoutHint(
+	contents string, format gozxing.BarcodeFormat, width, height int) (*gozxing.BitMatrix, error) {
+	return this.Encode(contents, format, width, height, nil)
+}
+
+func (this *AztecWriter) Encode(contents string, format gozxing.BarcodeFormat,
+	width, height int, hints map[gozxing.EncodeHintType]interface{}) (*gozxing.BitMatrix, error) {
+
+	if len(contents) == 0 {
+		return nil, gozxing.NewWriterException("IllegalArgumentException: Found empty contents")
+	}
+
+	if format != gozxing.BarcodeFormat_AZTEC {
+		return nil, gozxing.NewWriterException(
+			"IllegalArgumentException: Can only encode AZTEC, but got %v", format)
+	}
+
+	if width < 0 || height < 0 {
+		return nil, gozxing.NewWriterException(
+			"IllegalArgumentException: Requested dimensions are too small: %vx%v", width, height)
+	}
+
+	var charset encoding.Encoding
+	eccPercent := encoder.DEFAULT_EC_PERCENT
+	layers := encoder.DEFAULT_AZTEC_LAYERS
+
+	if hints != nil {
+		if cs, ok := hints[gozxing.EncodeHintType_CHARACTER_SET]; ok {
+			if str, ok := cs.(string); ok {
+				enc, err := ianaindex.IANA.Encoding(str)
+				if err == nil {
+					charset = enc
+				}
+			} else if enc, ok := cs.(encoding.Encoding); ok {
+				charset = enc
+			}
+		}
+		if ec, ok := hints[gozxing.EncodeHintType_ERROR_CORRECTION]; ok {
+			if ecInt, ok := ec.(int); ok {
+				eccPercent = ecInt
+			} else if str, ok := ec.(string); ok {
+				ecInt, err := strconv.Atoi(str)
+				if err != nil {
+					return nil, gozxing.NewWriterException("EncodeHintType_ERROR_CORRECTION = \"%v\": %w", ec, err)
+				}
+				eccPercent = ecInt
+			} else {
+				return nil, gozxing.NewWriterException(
+					"IllegalArgumentException: EncodeHintType_ERROR_CORRECTION %v", ec)
+			}
+		}
+		if l, ok := hints[gozxing.EncodeHintType_AZTEC_LAYERS]; ok {
+			if layersInt, ok := l.(int); ok {
+				layers = layersInt
+			} else if str, ok := l.(string); ok {
+				layersInt, err := strconv.Atoi(str)
+				if err != nil {
+					return nil, gozxing.NewWriterException("EncodeHintType_AZTEC_LAYERS = \"%v\": %w", l, err)
+				}
+				layers = layersInt
+			} else {
+				return nil, gozxing.NewWriterException(
+					"IllegalArgumentException: EncodeHintType_AZTEC_LAYERS %v", l)
+			}
+		}
+	}
+
+	aztec, err := encoder.EncodeStringWithParams(contents, eccPercent, layers, charset)
+	if err != nil {
+		return nil, err
+	}
+	return renderResult(aztec, width, height)
+}
+
+func renderResult(code *encoder.AztecCode, width, height int) (*gozxing.BitMatrix, error) {
+	input := code.GetMatrix()
+	if input == nil {
+		return nil, gozxing.NewWriterException("IllegalStateException")
+	}
+	inputWidth := input.GetWidth()
+	inputHeight := input.GetHeight()
+	outputWidth := width
+	if outputWidth < inputWidth {
+		outputWidth = inputWidth
+	}
+	outputHeight := height
+	if outputHeight < inputHeight {
+		outputHeight = inputHeight
+	}
+
+	multiple := outputWidth / inputWidth
+	if h := outputHeight / inputHeight; multiple > h {
+		multiple = h
+	}
+	leftPadding := (outputWidth - (inputWidth * multiple)) / 2
+	topPadding := (outputHeight - (inputHeight * multiple)) / 2
+
+	output, err := gozxing.NewBitMatrix(outputWidth, outputHeight)
+	if err != nil {
+		return nil, gozxing.WrapWriterException(err)
+	}
+
+	for inputY, outputY := 0, topPadding; inputY < inputHeight; inputY, outputY = inputY+1, outputY+multiple {
+		// Write the contents of this row of the barcode
+		for inputX, outputX := 0, leftPadding; inputX < inputWidth; inputX, outputX = inputX+1, outputX+multiple {
+			if input.Get(inputX, inputY) {
+				output.SetRegion(outputX, outputY, multiple, multiple)
+			}
+		}
+	}
+	return output, nil
+}