packer-cn/vendor/github.com/mitchellh/go-vnc/encoding.go

70 lines
1.9 KiB
Go

package vnc
import (
"encoding/binary"
"io"
)
// An Encoding implements a method for encoding pixel data that is
// sent by the server to the client.
type Encoding interface {
// The number that uniquely identifies this encoding type.
Type() int32
// Read reads the contents of the encoded pixel data from the reader.
// This should return a new Encoding implementation that contains
// the proper data.
Read(*ClientConn, *Rectangle, io.Reader) (Encoding, error)
}
// RawEncoding is raw pixel data sent by the server.
//
// See RFC 6143 Section 7.7.1
type RawEncoding struct {
Colors []Color
}
func (*RawEncoding) Type() int32 {
return 0
}
func (*RawEncoding) Read(c *ClientConn, rect *Rectangle, r io.Reader) (Encoding, error) {
bytesPerPixel := c.PixelFormat.BPP / 8
pixelBytes := make([]uint8, bytesPerPixel)
var byteOrder binary.ByteOrder = binary.LittleEndian
if c.PixelFormat.BigEndian {
byteOrder = binary.BigEndian
}
colors := make([]Color, int(rect.Height)*int(rect.Width))
for y := uint16(0); y < rect.Height; y++ {
for x := uint16(0); x < rect.Width; x++ {
if _, err := io.ReadFull(r, pixelBytes); err != nil {
return nil, err
}
var rawPixel uint32
if c.PixelFormat.BPP == 8 {
rawPixel = uint32(pixelBytes[0])
} else if c.PixelFormat.BPP == 16 {
rawPixel = uint32(byteOrder.Uint16(pixelBytes))
} else if c.PixelFormat.BPP == 32 {
rawPixel = byteOrder.Uint32(pixelBytes)
}
color := &colors[int(y)*int(rect.Width)+int(x)]
if c.PixelFormat.TrueColor {
color.R = uint16((rawPixel >> c.PixelFormat.RedShift) & uint32(c.PixelFormat.RedMax))
color.G = uint16((rawPixel >> c.PixelFormat.GreenShift) & uint32(c.PixelFormat.GreenMax))
color.B = uint16((rawPixel >> c.PixelFormat.BlueShift) & uint32(c.PixelFormat.BlueMax))
} else {
*color = c.ColorMap[rawPixel]
}
}
}
return &RawEncoding{colors}, nil
}