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-rw-r--r--vendor/github.com/disintegration/imaging/helpers.go280
1 files changed, 280 insertions, 0 deletions
diff --git a/vendor/github.com/disintegration/imaging/helpers.go b/vendor/github.com/disintegration/imaging/helpers.go
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index 0000000..7193e47
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/helpers.go
@@ -0,0 +1,280 @@
+package imaging
+
+import (
+ "errors"
+ "image"
+ "image/color"
+ "image/draw"
+ "image/gif"
+ "image/jpeg"
+ "image/png"
+ "io"
+ "os"
+ "path/filepath"
+ "strings"
+
+ "golang.org/x/image/bmp"
+ "golang.org/x/image/tiff"
+)
+
+// Format is an image file format.
+type Format int
+
+// Image file formats.
+const (
+ JPEG Format = iota
+ PNG
+ GIF
+ TIFF
+ BMP
+)
+
+func (f Format) String() string {
+ switch f {
+ case JPEG:
+ return "JPEG"
+ case PNG:
+ return "PNG"
+ case GIF:
+ return "GIF"
+ case TIFF:
+ return "TIFF"
+ case BMP:
+ return "BMP"
+ default:
+ return "Unsupported"
+ }
+}
+
+var (
+ // ErrUnsupportedFormat means the given image format (or file extension) is unsupported.
+ ErrUnsupportedFormat = errors.New("imaging: unsupported image format")
+)
+
+type fileSystem interface {
+ Create(string) (io.WriteCloser, error)
+ Open(string) (io.ReadCloser, error)
+}
+
+type localFS struct{}
+
+func (localFS) Create(name string) (io.WriteCloser, error) { return os.Create(name) }
+func (localFS) Open(name string) (io.ReadCloser, error) { return os.Open(name) }
+
+var fs fileSystem = localFS{}
+
+// Decode reads an image from r.
+func Decode(r io.Reader) (image.Image, error) {
+ img, _, err := image.Decode(r)
+ return img, err
+}
+
+// Open loads an image from file
+func Open(filename string) (image.Image, error) {
+ file, err := fs.Open(filename)
+ if err != nil {
+ return nil, err
+ }
+ defer file.Close()
+ return Decode(file)
+}
+
+type encodeConfig struct {
+ jpegQuality int
+ gifNumColors int
+ gifQuantizer draw.Quantizer
+ gifDrawer draw.Drawer
+ pngCompressionLevel png.CompressionLevel
+}
+
+var defaultEncodeConfig = encodeConfig{
+ jpegQuality: 95,
+ gifNumColors: 256,
+ gifQuantizer: nil,
+ gifDrawer: nil,
+ pngCompressionLevel: png.DefaultCompression,
+}
+
+// EncodeOption sets an optional parameter for the Encode and Save functions.
+type EncodeOption func(*encodeConfig)
+
+// JPEGQuality returns an EncodeOption that sets the output JPEG quality.
+// Quality ranges from 1 to 100 inclusive, higher is better. Default is 95.
+func JPEGQuality(quality int) EncodeOption {
+ return func(c *encodeConfig) {
+ c.jpegQuality = quality
+ }
+}
+
+// GIFNumColors returns an EncodeOption that sets the maximum number of colors
+// used in the GIF-encoded image. It ranges from 1 to 256. Default is 256.
+func GIFNumColors(numColors int) EncodeOption {
+ return func(c *encodeConfig) {
+ c.gifNumColors = numColors
+ }
+}
+
+// GIFQuantizer returns an EncodeOption that sets the quantizer that is used to produce
+// a palette of the GIF-encoded image.
+func GIFQuantizer(quantizer draw.Quantizer) EncodeOption {
+ return func(c *encodeConfig) {
+ c.gifQuantizer = quantizer
+ }
+}
+
+// GIFDrawer returns an EncodeOption that sets the drawer that is used to convert
+// the source image to the desired palette of the GIF-encoded image.
+func GIFDrawer(drawer draw.Drawer) EncodeOption {
+ return func(c *encodeConfig) {
+ c.gifDrawer = drawer
+ }
+}
+
+// PNGCompressionLevel returns an EncodeOption that sets the compression level
+// of the PNG-encoded image. Default is png.DefaultCompression.
+func PNGCompressionLevel(level png.CompressionLevel) EncodeOption {
+ return func(c *encodeConfig) {
+ c.pngCompressionLevel = level
+ }
+}
+
+// Encode writes the image img to w in the specified format (JPEG, PNG, GIF, TIFF or BMP).
+func Encode(w io.Writer, img image.Image, format Format, opts ...EncodeOption) error {
+ cfg := defaultEncodeConfig
+ for _, option := range opts {
+ option(&cfg)
+ }
+
+ var err error
+ switch format {
+ case JPEG:
+ var rgba *image.RGBA
+ if nrgba, ok := img.(*image.NRGBA); ok {
+ if nrgba.Opaque() {
+ rgba = &image.RGBA{
+ Pix: nrgba.Pix,
+ Stride: nrgba.Stride,
+ Rect: nrgba.Rect,
+ }
+ }
+ }
+ if rgba != nil {
+ err = jpeg.Encode(w, rgba, &jpeg.Options{Quality: cfg.jpegQuality})
+ } else {
+ err = jpeg.Encode(w, img, &jpeg.Options{Quality: cfg.jpegQuality})
+ }
+
+ case PNG:
+ enc := png.Encoder{CompressionLevel: cfg.pngCompressionLevel}
+ err = enc.Encode(w, img)
+
+ case GIF:
+ err = gif.Encode(w, img, &gif.Options{
+ NumColors: cfg.gifNumColors,
+ Quantizer: cfg.gifQuantizer,
+ Drawer: cfg.gifDrawer,
+ })
+
+ case TIFF:
+ err = tiff.Encode(w, img, &tiff.Options{Compression: tiff.Deflate, Predictor: true})
+
+ case BMP:
+ err = bmp.Encode(w, img)
+
+ default:
+ err = ErrUnsupportedFormat
+ }
+ return err
+}
+
+// Save saves the image to file with the specified filename.
+// The format is determined from the filename extension: "jpg" (or "jpeg"), "png", "gif", "tif" (or "tiff") and "bmp" are supported.
+//
+// Examples:
+//
+// // Save the image as PNG.
+// err := imaging.Save(img, "out.png")
+//
+// // Save the image as JPEG with optional quality parameter set to 80.
+// err := imaging.Save(img, "out.jpg", imaging.JPEGQuality(80))
+//
+func Save(img image.Image, filename string, opts ...EncodeOption) (err error) {
+ formats := map[string]Format{
+ ".jpg": JPEG,
+ ".jpeg": JPEG,
+ ".png": PNG,
+ ".tif": TIFF,
+ ".tiff": TIFF,
+ ".bmp": BMP,
+ ".gif": GIF,
+ }
+
+ ext := strings.ToLower(filepath.Ext(filename))
+ f, ok := formats[ext]
+ if !ok {
+ return ErrUnsupportedFormat
+ }
+
+ file, err := fs.Create(filename)
+ if err != nil {
+ return err
+ }
+
+ defer func() {
+ cerr := file.Close()
+ if err == nil {
+ err = cerr
+ }
+ }()
+
+ return Encode(file, img, f, opts...)
+}
+
+// New creates a new image with the specified width and height, and fills it with the specified color.
+func New(width, height int, fillColor color.Color) *image.NRGBA {
+ if width <= 0 || height <= 0 {
+ return &image.NRGBA{}
+ }
+
+ dst := image.NewNRGBA(image.Rect(0, 0, width, height))
+ c := color.NRGBAModel.Convert(fillColor).(color.NRGBA)
+
+ if c.R == 0 && c.G == 0 && c.B == 0 && c.A == 0 {
+ return dst
+ }
+
+ // Fill the first row.
+ i := 0
+ for x := 0; x < width; x++ {
+ dst.Pix[i+0] = c.R
+ dst.Pix[i+1] = c.G
+ dst.Pix[i+2] = c.B
+ dst.Pix[i+3] = c.A
+ i += 4
+ }
+
+ // Copy the first row to other rows.
+ size := width * 4
+ parallel(1, height, func(ys <-chan int) {
+ for y := range ys {
+ i = y * dst.Stride
+ copy(dst.Pix[i:i+size], dst.Pix[0:size])
+ }
+ })
+
+ return dst
+}
+
+// Clone returns a copy of the given image.
+func Clone(img image.Image) *image.NRGBA {
+ src := newScanner(img)
+ dst := image.NewNRGBA(image.Rect(0, 0, src.w, src.h))
+ size := src.w * 4
+ parallel(0, src.h, func(ys <-chan int) {
+ for y := range ys {
+ i := y * dst.Stride
+ src.scan(0, y, src.w, y+1, dst.Pix[i:i+size])
+ }
+ })
+ return dst
+}