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-rw-r--r--vendor/golang.org/x/image/bmp/reader.go219
-rw-r--r--vendor/golang.org/x/image/bmp/writer.go262
2 files changed, 481 insertions, 0 deletions
diff --git a/vendor/golang.org/x/image/bmp/reader.go b/vendor/golang.org/x/image/bmp/reader.go
new file mode 100644
index 00000000..52e25205
--- /dev/null
+++ b/vendor/golang.org/x/image/bmp/reader.go
@@ -0,0 +1,219 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package bmp implements a BMP image decoder and encoder.
+//
+// The BMP specification is at http://www.digicamsoft.com/bmp/bmp.html.
+package bmp // import "golang.org/x/image/bmp"
+
+import (
+ "errors"
+ "image"
+ "image/color"
+ "io"
+)
+
+// ErrUnsupported means that the input BMP image uses a valid but unsupported
+// feature.
+var ErrUnsupported = errors.New("bmp: unsupported BMP image")
+
+func readUint16(b []byte) uint16 {
+ return uint16(b[0]) | uint16(b[1])<<8
+}
+
+func readUint32(b []byte) uint32 {
+ return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+}
+
+// decodePaletted reads an 8 bit-per-pixel BMP image from r.
+// If topDown is false, the image rows will be read bottom-up.
+func decodePaletted(r io.Reader, c image.Config, topDown bool) (image.Image, error) {
+ paletted := image.NewPaletted(image.Rect(0, 0, c.Width, c.Height), c.ColorModel.(color.Palette))
+ if c.Width == 0 || c.Height == 0 {
+ return paletted, nil
+ }
+ var tmp [4]byte
+ y0, y1, yDelta := c.Height-1, -1, -1
+ if topDown {
+ y0, y1, yDelta = 0, c.Height, +1
+ }
+ for y := y0; y != y1; y += yDelta {
+ p := paletted.Pix[y*paletted.Stride : y*paletted.Stride+c.Width]
+ if _, err := io.ReadFull(r, p); err != nil {
+ return nil, err
+ }
+ // Each row is 4-byte aligned.
+ if c.Width%4 != 0 {
+ _, err := io.ReadFull(r, tmp[:4-c.Width%4])
+ if err != nil {
+ return nil, err
+ }
+ }
+ }
+ return paletted, nil
+}
+
+// decodeRGB reads a 24 bit-per-pixel BMP image from r.
+// If topDown is false, the image rows will be read bottom-up.
+func decodeRGB(r io.Reader, c image.Config, topDown bool) (image.Image, error) {
+ rgba := image.NewRGBA(image.Rect(0, 0, c.Width, c.Height))
+ if c.Width == 0 || c.Height == 0 {
+ return rgba, nil
+ }
+ // There are 3 bytes per pixel, and each row is 4-byte aligned.
+ b := make([]byte, (3*c.Width+3)&^3)
+ y0, y1, yDelta := c.Height-1, -1, -1
+ if topDown {
+ y0, y1, yDelta = 0, c.Height, +1
+ }
+ for y := y0; y != y1; y += yDelta {
+ if _, err := io.ReadFull(r, b); err != nil {
+ return nil, err
+ }
+ p := rgba.Pix[y*rgba.Stride : y*rgba.Stride+c.Width*4]
+ for i, j := 0, 0; i < len(p); i, j = i+4, j+3 {
+ // BMP images are stored in BGR order rather than RGB order.
+ p[i+0] = b[j+2]
+ p[i+1] = b[j+1]
+ p[i+2] = b[j+0]
+ p[i+3] = 0xFF
+ }
+ }
+ return rgba, nil
+}
+
+// decodeNRGBA reads a 32 bit-per-pixel BMP image from r.
+// If topDown is false, the image rows will be read bottom-up.
+func decodeNRGBA(r io.Reader, c image.Config, topDown bool) (image.Image, error) {
+ rgba := image.NewNRGBA(image.Rect(0, 0, c.Width, c.Height))
+ if c.Width == 0 || c.Height == 0 {
+ return rgba, nil
+ }
+ y0, y1, yDelta := c.Height-1, -1, -1
+ if topDown {
+ y0, y1, yDelta = 0, c.Height, +1
+ }
+ for y := y0; y != y1; y += yDelta {
+ p := rgba.Pix[y*rgba.Stride : y*rgba.Stride+c.Width*4]
+ if _, err := io.ReadFull(r, p); err != nil {
+ return nil, err
+ }
+ for i := 0; i < len(p); i += 4 {
+ // BMP images are stored in BGRA order rather than RGBA order.
+ p[i+0], p[i+2] = p[i+2], p[i+0]
+ }
+ }
+ return rgba, nil
+}
+
+// Decode reads a BMP image from r and returns it as an image.Image.
+// Limitation: The file must be 8, 24 or 32 bits per pixel.
+func Decode(r io.Reader) (image.Image, error) {
+ c, bpp, topDown, err := decodeConfig(r)
+ if err != nil {
+ return nil, err
+ }
+ switch bpp {
+ case 8:
+ return decodePaletted(r, c, topDown)
+ case 24:
+ return decodeRGB(r, c, topDown)
+ case 32:
+ return decodeNRGBA(r, c, topDown)
+ }
+ panic("unreachable")
+}
+
+// DecodeConfig returns the color model and dimensions of a BMP image without
+// decoding the entire image.
+// Limitation: The file must be 8, 24 or 32 bits per pixel.
+func DecodeConfig(r io.Reader) (image.Config, error) {
+ config, _, _, err := decodeConfig(r)
+ return config, err
+}
+
+func decodeConfig(r io.Reader) (config image.Config, bitsPerPixel int, topDown bool, err error) {
+ // We only support those BMP images that are a BITMAPFILEHEADER
+ // immediately followed by a BITMAPINFOHEADER.
+ const (
+ fileHeaderLen = 14
+ infoHeaderLen = 40
+ v4InfoHeaderLen = 108
+ v5InfoHeaderLen = 124
+ )
+ var b [1024]byte
+ if _, err := io.ReadFull(r, b[:fileHeaderLen+4]); err != nil {
+ if err == io.EOF {
+ err = io.ErrUnexpectedEOF
+ }
+ return image.Config{}, 0, false, err
+ }
+ if string(b[:2]) != "BM" {
+ return image.Config{}, 0, false, errors.New("bmp: invalid format")
+ }
+ offset := readUint32(b[10:14])
+ infoLen := readUint32(b[14:18])
+ if infoLen != infoHeaderLen && infoLen != v4InfoHeaderLen && infoLen != v5InfoHeaderLen {
+ return image.Config{}, 0, false, ErrUnsupported
+ }
+ if _, err := io.ReadFull(r, b[fileHeaderLen+4:fileHeaderLen+infoLen]); err != nil {
+ if err == io.EOF {
+ err = io.ErrUnexpectedEOF
+ }
+ return image.Config{}, 0, false, err
+ }
+ width := int(int32(readUint32(b[18:22])))
+ height := int(int32(readUint32(b[22:26])))
+ if height < 0 {
+ height, topDown = -height, true
+ }
+ if width < 0 || height < 0 {
+ return image.Config{}, 0, false, ErrUnsupported
+ }
+ // We only support 1 plane and 8, 24 or 32 bits per pixel and no
+ // compression.
+ planes, bpp, compression := readUint16(b[26:28]), readUint16(b[28:30]), readUint32(b[30:34])
+ // if compression is set to BITFIELDS, but the bitmask is set to the default bitmask
+ // that would be used if compression was set to 0, we can continue as if compression was 0
+ if compression == 3 && infoLen > infoHeaderLen &&
+ readUint32(b[54:58]) == 0xff0000 && readUint32(b[58:62]) == 0xff00 &&
+ readUint32(b[62:66]) == 0xff && readUint32(b[66:70]) == 0xff000000 {
+ compression = 0
+ }
+ if planes != 1 || compression != 0 {
+ return image.Config{}, 0, false, ErrUnsupported
+ }
+ switch bpp {
+ case 8:
+ if offset != fileHeaderLen+infoLen+256*4 {
+ return image.Config{}, 0, false, ErrUnsupported
+ }
+ _, err = io.ReadFull(r, b[:256*4])
+ if err != nil {
+ return image.Config{}, 0, false, err
+ }
+ pcm := make(color.Palette, 256)
+ for i := range pcm {
+ // BMP images are stored in BGR order rather than RGB order.
+ // Every 4th byte is padding.
+ pcm[i] = color.RGBA{b[4*i+2], b[4*i+1], b[4*i+0], 0xFF}
+ }
+ return image.Config{ColorModel: pcm, Width: width, Height: height}, 8, topDown, nil
+ case 24:
+ if offset != fileHeaderLen+infoLen {
+ return image.Config{}, 0, false, ErrUnsupported
+ }
+ return image.Config{ColorModel: color.RGBAModel, Width: width, Height: height}, 24, topDown, nil
+ case 32:
+ if offset != fileHeaderLen+infoLen {
+ return image.Config{}, 0, false, ErrUnsupported
+ }
+ return image.Config{ColorModel: color.RGBAModel, Width: width, Height: height}, 32, topDown, nil
+ }
+ return image.Config{}, 0, false, ErrUnsupported
+}
+
+func init() {
+ image.RegisterFormat("bmp", "BM????\x00\x00\x00\x00", Decode, DecodeConfig)
+}
diff --git a/vendor/golang.org/x/image/bmp/writer.go b/vendor/golang.org/x/image/bmp/writer.go
new file mode 100644
index 00000000..f07b39db
--- /dev/null
+++ b/vendor/golang.org/x/image/bmp/writer.go
@@ -0,0 +1,262 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bmp
+
+import (
+ "encoding/binary"
+ "errors"
+ "image"
+ "io"
+)
+
+type header struct {
+ sigBM [2]byte
+ fileSize uint32
+ resverved [2]uint16
+ pixOffset uint32
+ dibHeaderSize uint32
+ width uint32
+ height uint32
+ colorPlane uint16
+ bpp uint16
+ compression uint32
+ imageSize uint32
+ xPixelsPerMeter uint32
+ yPixelsPerMeter uint32
+ colorUse uint32
+ colorImportant uint32
+}
+
+func encodePaletted(w io.Writer, pix []uint8, dx, dy, stride, step int) error {
+ var padding []byte
+ if dx < step {
+ padding = make([]byte, step-dx)
+ }
+ for y := dy - 1; y >= 0; y-- {
+ min := y*stride + 0
+ max := y*stride + dx
+ if _, err := w.Write(pix[min:max]); err != nil {
+ return err
+ }
+ if padding != nil {
+ if _, err := w.Write(padding); err != nil {
+ return err
+ }
+ }
+ }
+ return nil
+}
+
+func encodeRGBA(w io.Writer, pix []uint8, dx, dy, stride, step int, opaque bool) error {
+ buf := make([]byte, step)
+ if opaque {
+ for y := dy - 1; y >= 0; y-- {
+ min := y*stride + 0
+ max := y*stride + dx*4
+ off := 0
+ for i := min; i < max; i += 4 {
+ buf[off+2] = pix[i+0]
+ buf[off+1] = pix[i+1]
+ buf[off+0] = pix[i+2]
+ off += 3
+ }
+ if _, err := w.Write(buf); err != nil {
+ return err
+ }
+ }
+ } else {
+ for y := dy - 1; y >= 0; y-- {
+ min := y*stride + 0
+ max := y*stride + dx*4
+ off := 0
+ for i := min; i < max; i += 4 {
+ a := uint32(pix[i+3])
+ if a == 0 {
+ buf[off+2] = 0
+ buf[off+1] = 0
+ buf[off+0] = 0
+ buf[off+3] = 0
+ off += 4
+ continue
+ } else if a == 0xff {
+ buf[off+2] = pix[i+0]
+ buf[off+1] = pix[i+1]
+ buf[off+0] = pix[i+2]
+ buf[off+3] = 0xff
+ off += 4
+ continue
+ }
+ buf[off+2] = uint8(((uint32(pix[i+0]) * 0xffff) / a) >> 8)
+ buf[off+1] = uint8(((uint32(pix[i+1]) * 0xffff) / a) >> 8)
+ buf[off+0] = uint8(((uint32(pix[i+2]) * 0xffff) / a) >> 8)
+ buf[off+3] = uint8(a)
+ off += 4
+ }
+ if _, err := w.Write(buf); err != nil {
+ return err
+ }
+ }
+ }
+ return nil
+}
+
+func encodeNRGBA(w io.Writer, pix []uint8, dx, dy, stride, step int, opaque bool) error {
+ buf := make([]byte, step)
+ if opaque {
+ for y := dy - 1; y >= 0; y-- {
+ min := y*stride + 0
+ max := y*stride + dx*4
+ off := 0
+ for i := min; i < max; i += 4 {
+ buf[off+2] = pix[i+0]
+ buf[off+1] = pix[i+1]
+ buf[off+0] = pix[i+2]
+ off += 3
+ }
+ if _, err := w.Write(buf); err != nil {
+ return err
+ }
+ }
+ } else {
+ for y := dy - 1; y >= 0; y-- {
+ min := y*stride + 0
+ max := y*stride + dx*4
+ off := 0
+ for i := min; i < max; i += 4 {
+ buf[off+2] = pix[i+0]
+ buf[off+1] = pix[i+1]
+ buf[off+0] = pix[i+2]
+ buf[off+3] = pix[i+3]
+ off += 4
+ }
+ if _, err := w.Write(buf); err != nil {
+ return err
+ }
+ }
+ }
+ return nil
+}
+
+func encode(w io.Writer, m image.Image, step int) error {
+ b := m.Bounds()
+ buf := make([]byte, step)
+ for y := b.Max.Y - 1; y >= b.Min.Y; y-- {
+ off := 0
+ for x := b.Min.X; x < b.Max.X; x++ {
+ r, g, b, _ := m.At(x, y).RGBA()
+ buf[off+2] = byte(r >> 8)
+ buf[off+1] = byte(g >> 8)
+ buf[off+0] = byte(b >> 8)
+ off += 3
+ }
+ if _, err := w.Write(buf); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+// Encode writes the image m to w in BMP format.
+func Encode(w io.Writer, m image.Image) error {
+ d := m.Bounds().Size()
+ if d.X < 0 || d.Y < 0 {
+ return errors.New("bmp: negative bounds")
+ }
+ h := &header{
+ sigBM: [2]byte{'B', 'M'},
+ fileSize: 14 + 40,
+ pixOffset: 14 + 40,
+ dibHeaderSize: 40,
+ width: uint32(d.X),
+ height: uint32(d.Y),
+ colorPlane: 1,
+ }
+
+ var step int
+ var palette []byte
+ var opaque bool
+ switch m := m.(type) {
+ case *image.Gray:
+ step = (d.X + 3) &^ 3
+ palette = make([]byte, 1024)
+ for i := 0; i < 256; i++ {
+ palette[i*4+0] = uint8(i)
+ palette[i*4+1] = uint8(i)
+ palette[i*4+2] = uint8(i)
+ palette[i*4+3] = 0xFF
+ }
+ h.imageSize = uint32(d.Y * step)
+ h.fileSize += uint32(len(palette)) + h.imageSize
+ h.pixOffset += uint32(len(palette))
+ h.bpp = 8
+
+ case *image.Paletted:
+ step = (d.X + 3) &^ 3
+ palette = make([]byte, 1024)
+ for i := 0; i < len(m.Palette) && i < 256; i++ {
+ r, g, b, _ := m.Palette[i].RGBA()
+ palette[i*4+0] = uint8(b >> 8)
+ palette[i*4+1] = uint8(g >> 8)
+ palette[i*4+2] = uint8(r >> 8)
+ palette[i*4+3] = 0xFF
+ }
+ h.imageSize = uint32(d.Y * step)
+ h.fileSize += uint32(len(palette)) + h.imageSize
+ h.pixOffset += uint32(len(palette))
+ h.bpp = 8
+ case *image.RGBA:
+ opaque = m.Opaque()
+ if opaque {
+ step = (3*d.X + 3) &^ 3
+ h.bpp = 24
+ } else {
+ step = 4 * d.X
+ h.bpp = 32
+ }
+ h.imageSize = uint32(d.Y * step)
+ h.fileSize += h.imageSize
+ case *image.NRGBA:
+ opaque = m.Opaque()
+ if opaque {
+ step = (3*d.X + 3) &^ 3
+ h.bpp = 24
+ } else {
+ step = 4 * d.X
+ h.bpp = 32
+ }
+ h.imageSize = uint32(d.Y * step)
+ h.fileSize += h.imageSize
+ default:
+ step = (3*d.X + 3) &^ 3
+ h.imageSize = uint32(d.Y * step)
+ h.fileSize += h.imageSize
+ h.bpp = 24
+ }
+
+ if err := binary.Write(w, binary.LittleEndian, h); err != nil {
+ return err
+ }
+ if palette != nil {
+ if err := binary.Write(w, binary.LittleEndian, palette); err != nil {
+ return err
+ }
+ }
+
+ if d.X == 0 || d.Y == 0 {
+ return nil
+ }
+
+ switch m := m.(type) {
+ case *image.Gray:
+ return encodePaletted(w, m.Pix, d.X, d.Y, m.Stride, step)
+ case *image.Paletted:
+ return encodePaletted(w, m.Pix, d.X, d.Y, m.Stride, step)
+ case *image.RGBA:
+ return encodeRGBA(w, m.Pix, d.X, d.Y, m.Stride, step, opaque)
+ case *image.NRGBA:
+ return encodeNRGBA(w, m.Pix, d.X, d.Y, m.Stride, step, opaque)
+ }
+ return encode(w, m, step)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 14:42:54 +0000