common/rfb/PixelFormat.inl

/* Copyright 2009-2014 Pierre Ossman for Cendio AB
 * 
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this software; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
 * USA.
 */

namespace rfb {


inline Pixel PixelFormat::pixelFromBuffer(const rdr::U8* buffer) const
{
  Pixel p;

  p = 0;

  if (bigEndian) {
    switch (bpp) {
    case 32:
      p |= ((Pixel)*(buffer++)) << 24;
      p |= ((Pixel)*(buffer++)) << 16;
    case 16:
      p |= ((Pixel)*(buffer++)) << 8;
    case 8:
      p |= *buffer;
    }
  } else {
    p |= buffer[0];
    if (bpp >= 16) {
      p |= ((Pixel)buffer[1]) << 8;
      if (bpp == 32) {
        p |= ((Pixel)buffer[2]) << 16;
        p |= ((Pixel)buffer[3]) << 24;
      }
    }
  }

  return p;
}


inline void PixelFormat::bufferFromPixel(rdr::U8* buffer, Pixel p) const
{
  if (bigEndian) {
    switch (bpp) {
    case 32:
      *(buffer++) = (p >> 24) & 0xff;
      *(buffer++) = (p >> 16) & 0xff;
    case 16:
      *(buffer++) = (p >>  8) & 0xff;
    case 8:
      *(buffer++) = (p >>  0) & 0xff;
    }
  } else {
    buffer[0] = (p >>  0) & 0xff;
    if (bpp >= 16) {
      buffer[1] = (p >>  8) & 0xff;
      if (bpp == 32) {
        buffer[2] = (p >> 16) & 0xff;
        buffer[3] = (p >> 24) & 0xff;
      }
    }
  }
}


inline Pixel PixelFormat::pixelFromRGB(rdr::U16 red, rdr::U16 green, rdr::U16 blue, ColourMap* cm) const
{
  if (trueColour) {
    Pixel p;

    /* We don't need to mask since we shift out unwanted bits */
    p = ((Pixel)red >> (16 - redBits)) << redShift;
    p |= ((Pixel)green >> (16 - greenBits)) << greenShift;
    p |= ((Pixel)blue >> (16 - blueBits)) << blueShift;
  } else if (cm) {
    // Try to find the closest pixel by Cartesian distance
    int colours = 1 << depth;
    int diff = 256 * 256 * 4;
    int col = 0;
    for (int i=0; i<colours; i++) {
      int r, g, b;
      cm->lookup(i, &r, &g, &b);
      int rd = (r-red) >> 8;
      int gd = (g-green) >> 8;
      int bd = (b-blue) >> 8;
      int d = rd*rd + gd*gd + bd*bd;
      if (d < diff) {
        col = i;
        diff = d;
      }
    }
    return col;
  } else {
    // XXX just return 0 for colour map?
    return 0;
  }
}


inline Pixel PixelFormat::pixelFromRGB(rdr::U8 red, rdr::U8 green, rdr::U8 blue, ColourMap* cm) const
{
  if (trueColour) {
    Pixel p;

    p = ((Pixel)red >> (8 - redBits)) << redShift;
    p |= ((Pixel)green >> (8 - greenBits)) << greenShift;
    p |= ((Pixel)blue >> (8 - blueBits)) << blueShift;

    return p;
  } else {
    return pixelFromRGB((rdr::U16)(red << 8 | red),
                        (rdr::U16)(green << 8 | green),
                        (rdr::U16)(blue << 8 | blue), cm);
  }
}


inline void PixelFormat::rgbFromPixel(Pixel p, ColourMap* cm, rdr::U16 *r, rdr::U16 *g, rdr::U16 *b) const
{
  if (trueColour) {
    int mb, rb, gb, bb;

    /* Bit replication is much cheaper than multiplication and division */

    mb = minBits;
    rb = redBits;
    gb = greenBits;
    bb = blueBits;

    *r = (p >> redShift) << (16 - rb);
    *g = (p >> greenShift) << (16 - gb);
    *b = (p >> blueShift) << (16 - bb);

    while (mb < 16) {
      *r = *r | (*r >> rb);
      *g = *g | (*g >> gb);
      *b = *b | (*b >> bb);
      mb <<= 1;
      rb <<= 1;
      gb <<= 1;
      bb <<= 1;
    }
  } else if (cm) {
    int ir, ig, ib;
    cm->lookup(p, &ir, &ig, &ib);
    *r = ir;
    *g = ig;
    *b = ib;
  } else {
    // XXX just return 0 for colour map?
    *r = 0;
    *g = 0;
    *b = 0;
  }
}


inline void PixelFormat::rgbFromPixel(Pixel p, ColourMap* cm, rdr::U8 *r, rdr::U8 *g, rdr::U8 *b) const
{
  if (trueColour) {
    int mb, rb, gb, bb;

    /* Bit replication is much cheaper than multiplication and division */

    mb = minBits;
    rb = redBits;
    gb = greenBits;
    bb = blueBits;

    *r = (p >> redShift) << (8 - rb);
    *g = (p >> greenShift) << (8 - gb);
    *b = (p >> blueShift) << (8 - bb);

    while (mb < 8) {
      *r = *r | (*r >> rb);
      *g = *g | (*g >> gb);
      *b = *b | (*b >> bb);
      mb <<= 1;
      rb <<= 1;
      gb <<= 1;
      bb <<= 1;
    }
  } else {
    rdr::U16 r2, g2, b2;

    rgbFromPixel(p, cm, &r2, &g2, &b2);

    *r = r2 >> 8;
    *g = g2 >> 8;
    *b = b2 >> 8;
  }
}


}