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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/writer.go | |
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/writer.go')
-rw-r--r-- | vendor/golang.org/x/image/bmp/writer.go | 262 |
1 files changed, 262 insertions, 0 deletions
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) +} |