diff options
Diffstat (limited to 'vendor/github.com/boombuler/barcode/scaledbarcode.go')
| -rw-r--r-- | vendor/github.com/boombuler/barcode/scaledbarcode.go | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/vendor/github.com/boombuler/barcode/scaledbarcode.go b/vendor/github.com/boombuler/barcode/scaledbarcode.go new file mode 100644 index 000000000..152b18017 --- /dev/null +++ b/vendor/github.com/boombuler/barcode/scaledbarcode.go @@ -0,0 +1,134 @@ +package barcode + +import ( + "errors" + "fmt" + "image" + "image/color" + "math" +) + +type wrapFunc func(x, y int) color.Color + +type scaledBarcode struct { + wrapped Barcode + wrapperFunc wrapFunc + rect image.Rectangle +} + +type intCSscaledBC struct { + scaledBarcode +} + +func (bc *scaledBarcode) Content() string { + return bc.wrapped.Content() +} + +func (bc *scaledBarcode) Metadata() Metadata { + return bc.wrapped.Metadata() +} + +func (bc *scaledBarcode) ColorModel() color.Model { + return bc.wrapped.ColorModel() +} + +func (bc *scaledBarcode) Bounds() image.Rectangle { + return bc.rect +} + +func (bc *scaledBarcode) At(x, y int) color.Color { + return bc.wrapperFunc(x, y) +} + +func (bc *intCSscaledBC) CheckSum() int { + if cs, ok := bc.wrapped.(BarcodeIntCS); ok { + return cs.CheckSum() + } + return 0 +} + +// Scale returns a resized barcode with the given width and height. +func Scale(bc Barcode, width, height int) (Barcode, error) { + switch bc.Metadata().Dimensions { + case 1: + return scale1DCode(bc, width, height) + case 2: + return scale2DCode(bc, width, height) + } + + return nil, errors.New("unsupported barcode format") +} + +func newScaledBC(wrapped Barcode, wrapperFunc wrapFunc, rect image.Rectangle) Barcode { + result := &scaledBarcode{ + wrapped: wrapped, + wrapperFunc: wrapperFunc, + rect: rect, + } + + if _, ok := wrapped.(BarcodeIntCS); ok { + return &intCSscaledBC{*result} + } + return result +} + +func scale2DCode(bc Barcode, width, height int) (Barcode, error) { + orgBounds := bc.Bounds() + orgWidth := orgBounds.Max.X - orgBounds.Min.X + orgHeight := orgBounds.Max.Y - orgBounds.Min.Y + + factor := int(math.Min(float64(width)/float64(orgWidth), float64(height)/float64(orgHeight))) + if factor <= 0 { + return nil, fmt.Errorf("can not scale barcode to an image smaller than %dx%d", orgWidth, orgHeight) + } + + offsetX := (width - (orgWidth * factor)) / 2 + offsetY := (height - (orgHeight * factor)) / 2 + + wrap := func(x, y int) color.Color { + if x < offsetX || y < offsetY { + return color.White + } + x = (x - offsetX) / factor + y = (y - offsetY) / factor + if x >= orgWidth || y >= orgHeight { + return color.White + } + return bc.At(x, y) + } + + return newScaledBC( + bc, + wrap, + image.Rect(0, 0, width, height), + ), nil +} + +func scale1DCode(bc Barcode, width, height int) (Barcode, error) { + orgBounds := bc.Bounds() + orgWidth := orgBounds.Max.X - orgBounds.Min.X + factor := int(float64(width) / float64(orgWidth)) + + if factor <= 0 { + return nil, fmt.Errorf("can not scale barcode to an image smaller than %dx1", orgWidth) + } + offsetX := (width - (orgWidth * factor)) / 2 + + wrap := func(x, y int) color.Color { + if x < offsetX { + return color.White + } + x = (x - offsetX) / factor + + if x >= orgWidth { + return color.White + } + return bc.At(x, 0) + } + + return newScaledBC( + bc, + wrap, + image.Rect(0, 0, width, height), + ), nil +} |
