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author | Wim <wim@42.be> | 2020-12-31 14:48:12 +0100 |
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committer | GitHub <noreply@github.com> | 2020-12-31 14:48:12 +0100 |
commit | 4f20ebead36876a88391bf033d1de3e4cf0228da (patch) | |
tree | 70b6fd79c6a5e00c958c29a7bd3926f074e76ba6 /vendor/golang.org/x/image/bmp | |
parent | a9f89dbc645aafc68daa9fc8d589f55104b535c7 (diff) | |
download | matterbridge-msglm-4f20ebead36876a88391bf033d1de3e4cf0228da.tar.gz matterbridge-msglm-4f20ebead36876a88391bf033d1de3e4cf0228da.tar.bz2 matterbridge-msglm-4f20ebead36876a88391bf033d1de3e4cf0228da.zip |
Update vendor for next release (#1343)
Diffstat (limited to 'vendor/golang.org/x/image/bmp')
-rw-r--r-- | vendor/golang.org/x/image/bmp/reader.go | 219 | ||||
-rw-r--r-- | vendor/golang.org/x/image/bmp/writer.go | 262 |
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) +} |