diff options
Diffstat (limited to 'vendor/golang.org/x/image/bmp')
| -rw-r--r-- | vendor/golang.org/x/image/bmp/writer.go | 122 |
1 files changed, 109 insertions, 13 deletions
diff --git a/vendor/golang.org/x/image/bmp/writer.go b/vendor/golang.org/x/image/bmp/writer.go index 6947968..f07b39d 100644 --- a/vendor/golang.org/x/image/bmp/writer.go +++ b/vendor/golang.org/x/image/bmp/writer.go @@ -49,20 +49,91 @@ func encodePaletted(w io.Writer, pix []uint8, dx, dy, stride, step int) error { return nil } -func encodeRGBA(w io.Writer, pix []uint8, dx, dy, stride, step int) error { +func encodeRGBA(w io.Writer, pix []uint8, dx, dy, stride, step int, opaque bool) error { buf := make([]byte, step) - 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 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 + } } - 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 @@ -105,6 +176,7 @@ func Encode(w io.Writer, m image.Image) error { var step int var palette []byte + var opaque bool switch m := m.(type) { case *image.Gray: step = (d.X + 3) &^ 3 @@ -134,6 +206,28 @@ func Encode(w io.Writer, m image.Image) error { 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) @@ -160,7 +254,9 @@ func Encode(w io.Writer, m image.Image) error { 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) + 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) } |