forked from Shiloh/githaven
135 lines
2.8 KiB
Go
Vendored
135 lines
2.8 KiB
Go
Vendored
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
|
|
}
|