xrdp/libxrdp/xrdp_bitmap_compress.c

/*
   This program 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 program 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 program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

   xrdp: A Remote Desktop Protocol server.
   Copyright (C) Jay Sorg 2004-2006

   bitmap compressor

*/

#include "libxrdp.h"

/*****************************************************************************/
#define IN_PIXEL8(in_ptr, in_x, in_y, in_w, in_last_pixel, in_pixel); \
{ \
  if (in_ptr == 0) \
  { \
    in_pixel = 0; \
  } \
  else if (in_x < in_w) \
  { \
    in_pixel = GETPIXEL8(in_ptr, in_x, in_y, in_w); \
  } \
  else \
  { \
    in_pixel = in_last_pixel; \
  } \
}

/*****************************************************************************/
#define IN_PIXEL16(in_ptr, in_x, in_y, in_w, in_last_pixel, in_pixel); \
{ \
  if (in_ptr == 0) \
  { \
    in_pixel = 0; \
  } \
  else if (in_x < in_w) \
  { \
    in_pixel = GETPIXEL16(in_ptr, in_x, in_y, in_w); \
  } \
  else \
  { \
    in_pixel = in_last_pixel; \
  } \
}

/*****************************************************************************/
/* color */
#define OUT_COLOR_COUNT1(in_count, in_s, in_data) \
{ \
  if (in_count > 0) \
  { \
    if (in_count < 32) \
    { \
      temp = (0x3 << 5) | in_count; \
      out_uint8(in_s, temp); \
      out_uint8(in_s, in_data); \
    } \
    else if (in_count < 256 + 32) \
    { \
      out_uint8(in_s, 0x60); \
      temp = in_count - 32; \
      out_uint8(in_s, temp); \
      out_uint8(in_s, in_data); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf3); \
      out_uint16_le(in_s, in_count); \
      out_uint8(in_s, in_data); \
    } \
  } \
  in_count = 0; \
}

/*****************************************************************************/
/* color */
#define OUT_COLOR_COUNT2(in_count, in_s, in_data) \
{ \
  if (in_count > 0) \
  { \
    if (in_count < 32) \
    { \
      temp = (0x3 << 5) | in_count; \
      out_uint8(in_s, temp); \
      out_uint16_le(in_s, in_data); \
    } \
    else if (in_count < 256 + 32) \
    { \
      out_uint8(in_s, 0x60); \
      temp = in_count - 32; \
      out_uint8(in_s, temp); \
      out_uint16_le(in_s, in_data); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf3); \
      out_uint16_le(in_s, in_count); \
      out_uint16_le(in_s, in_data); \
    } \
  } \
  in_count = 0; \
}

/*****************************************************************************/
/* copy */
#define OUT_COPY_COUNT1(in_count, in_s, in_data) \
{ \
  if (in_count > 0) \
  { \
    if (in_count < 32) \
    { \
      temp = (0x4 << 5) | in_count; \
      out_uint8(in_s, temp); \
      out_uint8a(in_s, in_data->data, in_count); \
    } \
    else if (in_count < 256 + 32) \
    { \
      out_uint8(in_s, 0x80); \
      temp = in_count - 32; \
      out_uint8(in_s, temp); \
      out_uint8a(in_s, in_data->data, in_count); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf4); \
      out_uint16_le(in_s, in_count); \
      out_uint8a(in_s, in_data->data, in_count); \
    } \
  } \
  in_count = 0; \
  init_stream(in_data, 0); \
}

/*****************************************************************************/
/* copy */
#define OUT_COPY_COUNT2(in_count, in_s, in_data) \
{ \
  if (in_count > 0) \
  { \
    if (in_count < 32) \
    { \
      temp = (0x4 << 5) | in_count; \
      out_uint8(in_s, temp); \
      temp = in_count * 2; \
      out_uint8a(in_s, in_data->data, temp); \
    } \
    else if (in_count < 256 + 32) \
    { \
      out_uint8(in_s, 0x80); \
      temp = in_count - 32; \
      out_uint8(in_s, temp); \
      temp = in_count * 2; \
      out_uint8a(in_s, in_data->data, temp); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf4); \
      out_uint16_le(in_s, in_count); \
      temp = in_count * 2; \
      out_uint8a(in_s, in_data->data, temp); \
    } \
  } \
  in_count = 0; \
  init_stream(in_data, 0); \
}

/*****************************************************************************/
/* bicolor */
#define OUT_BICOLOR_COUNT1(in_count, in_s, in_color1, in_color2) \
{ \
  if (in_count > 0) \
  { \
    if (in_count / 2 < 16) \
    { \
      temp = (0xe << 4) | (in_count / 2); \
      out_uint8(in_s, temp); \
      out_uint8(in_s, in_color1); \
      out_uint8(in_s, in_color2); \
    } \
    else if (in_count / 2 < 256 + 16) \
    { \
      out_uint8(in_s, 0xe0); \
      temp = in_count / 2 - 16; \
      out_uint8(in_s, temp); \
      out_uint8(in_s, in_color1); \
      out_uint8(in_s, in_color2); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf8); \
      temp = in_count / 2; \
      out_uint16_le(in_s, temp); \
      out_uint8(in_s, in_color1); \
      out_uint8(in_s, in_color2); \
    } \
  } \
  in_count = 0; \
}

/*****************************************************************************/
/* bicolor */
#define OUT_BICOLOR_COUNT2(in_count, in_s, in_color1, in_color2) \
{ \
  if (in_count > 0) \
  { \
    if (in_count / 2 < 16) \
    { \
      temp = (0xe << 4) | (in_count / 2); \
      out_uint8(in_s, temp); \
      out_uint16_le(in_s, in_color1); \
      out_uint16_le(in_s, in_color2); \
    } \
    else if (in_count / 2 < 256 + 16) \
    { \
      out_uint8(in_s, 0xe0); \
      temp = in_count / 2 - 16; \
      out_uint8(in_s, temp); \
      out_uint16_le(in_s, in_color1); \
      out_uint16_le(in_s, in_color2); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf8); \
      temp = in_count / 2; \
      out_uint16_le(in_s, temp); \
      out_uint16_le(in_s, in_color1); \
      out_uint16_le(in_s, in_color2); \
    } \
  } \
  in_count = 0; \
}

/*****************************************************************************/
/* fill */
#define OUT_FILL_COUNT1(in_count, in_s) \
{ \
  if (in_count > 0) \
  { \
    if (in_count < 32) \
    { \
      out_uint8(in_s, in_count); \
    } \
    else if (in_count < 256 + 32) \
    { \
      out_uint8(in_s, 0x0); \
      temp = in_count - 32; \
      out_uint8(in_s, temp); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf0); \
      out_uint16_le(in_s, in_count); \
    } \
  } \
  in_count = 0; \
}

/*****************************************************************************/
/* fill */
#define OUT_FILL_COUNT2(in_count, in_s) \
{ \
  if (in_count > 0) \
  { \
    if (in_count < 32) \
    { \
      out_uint8(in_s, in_count); \
    } \
    else if (in_count < 256 + 32) \
    { \
      out_uint8(in_s, 0x0); \
      temp = in_count - 32; \
      out_uint8(in_s, temp); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf0); \
      out_uint16_le(in_s, in_count); \
    } \
  } \
  in_count = 0; \
}

/*****************************************************************************/
/* mix */
#define OUT_MIX_COUNT1(in_count, in_s) \
{ \
  if (in_count > 0) \
  { \
    if (in_count < 32) \
    { \
      temp = (0x1 << 5) | in_count; \
      out_uint8(in_s, temp); \
    } \
    else if (in_count < 256 + 32) \
    { \
      out_uint8(in_s, 0x20); \
      temp = in_count - 32; \
      out_uint8(in_s, temp); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf1); \
      out_uint16_le(in_s, in_count); \
    } \
  } \
  in_count = 0; \
}

/*****************************************************************************/
/* mix */
#define OUT_MIX_COUNT2(in_count, in_s) \
{ \
  if (in_count > 0) \
  { \
    if (in_count < 32) \
    { \
      temp = (0x1 << 5) | in_count; \
      out_uint8(in_s, temp); \
    } \
    else if (in_count < 256 + 32) \
    { \
      out_uint8(in_s, 0x20); \
      temp = in_count - 32; \
      out_uint8(in_s, temp); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf1); \
      out_uint16_le(in_s, in_count); \
    } \
  } \
  in_count = 0; \
}

/*****************************************************************************/
/* fom */
#define OUT_FOM_COUNT1(in_count, in_s, in_mask, in_mask_len) \
{ \
  if (in_count > 0) \
  { \
    if ((in_count % 8) == 0 && in_count < 249) \
    { \
      temp = (0x2 << 5) | (in_count / 8); \
      out_uint8(in_s, temp); \
      out_uint8a(in_s, in_mask, in_mask_len); \
    } \
    else if (in_count < 256) \
    { \
      out_uint8(in_s, 0x40); \
      temp = in_count - 1; \
      out_uint8(in_s, temp); \
      out_uint8a(in_s, in_mask, in_mask_len); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf2); \
      out_uint16_le(in_s, in_count); \
      out_uint8a(in_s, in_mask, in_mask_len); \
    } \
  } \
  in_count = 0; \
}

/*****************************************************************************/
/* fom */
#define OUT_FOM_COUNT2(in_count, in_s, in_mask, in_mask_len) \
{ \
  if (in_count > 0) \
  { \
    if ((in_count % 8) == 0 && in_count < 249) \
    { \
      temp = (0x2 << 5) | (in_count / 8); \
      out_uint8(in_s, temp); \
      out_uint8a(in_s, in_mask, in_mask_len); \
    } \
    else if (in_count < 256) \
    { \
      out_uint8(in_s, 0x40); \
      temp = in_count - 1; \
      out_uint8(in_s, temp); \
      out_uint8a(in_s, in_mask, in_mask_len); \
    } \
    else \
    { \
      out_uint8(in_s, 0xf2); \
      out_uint16_le(in_s, in_count); \
      out_uint8a(in_s, in_mask, in_mask_len); \
    } \
  } \
  in_count = 0; \
}

/*****************************************************************************/
#define TEST_FILL \
((last_line == 0 && pixel == 0) || \
 (last_line != 0 && pixel == ypixel))
#define TEST_MIX \
((last_line == 0 && pixel == mix) || \
 (last_line != 0 && pixel == (ypixel ^ mix)))
#define TEST_FOM (TEST_FILL || TEST_MIX)
#define TEST_COLOR (pixel == last_pixel)
#define TEST_BICOLOR \
( \
  (pixel != last_pixel) && \
  ( \
    (!bicolor_spin && pixel == bicolor1 && last_pixel == bicolor2) || \
    (bicolor_spin && pixel == bicolor2 && last_pixel == bicolor1) \
  ) \
)
#define RESET_COUNTS \
{ \
  bicolor_count = 0; \
  fill_count = 0; \
  color_count = 0; \
  mix_count = 0; \
  fom_count = 0; \
  fom_mask_len = 0; \
  bicolor_spin = 0; \
}

/*****************************************************************************/
int APP_CC
xrdp_bitmap_compress(char* in_data, int width, int height,
                     struct stream* s, int bpp, int byte_limit,
                     int start_line, struct stream* temp_s,
                     int e)
{
  char* line;
  char* last_line;
  char fom_mask[8192]; /* good for up to 64K bitmap */
  int lines_sent;
  int pixel;
  int count;
  int color_count;
  int last_pixel;
  int bicolor_count;
  int bicolor1;
  int bicolor2;
  int bicolor_spin;
  int end;
  int i;
  int out_count;
  int ypixel;
  int last_ypixel;
  int fill_count;
  int mix_count;
  int mix;
  int fom_count;
  int fom_mask_len;
  int temp; /* used in macros */

  init_stream(temp_s, 0);
  fom_mask_len = 0;
  last_line = 0;
  lines_sent = 0;
  end = width + e;
  count = 0;
  color_count = 0;
  last_pixel = 0;
  last_ypixel = 0;
  bicolor_count = 0;
  bicolor1 = 0;
  bicolor2 = 0;
  bicolor_spin = 0;
  fill_count = 0;
  mix_count = 0;
  fom_count = 0;
  if (bpp == 8)
  {
    mix = 0xff;
    out_count = end;
    line = in_data + width * start_line;
    while (start_line >= 0 && out_count < 32768)
    {
      i = (s->p - s->data) + count;
      if (i - color_count >= byte_limit &&
          i - bicolor_count >= byte_limit &&
          i - fill_count >= byte_limit &&
          i - mix_count >= byte_limit &&
          i - fom_count >= byte_limit)
      {
        break;
      }
      out_count += end;
      for (i = 0; i < end; i++)
      {
        /* read next pixel */
        IN_PIXEL8(line, i, 0, width, last_pixel, pixel);
        IN_PIXEL8(last_line, i, 0, width, last_ypixel, ypixel);
        if (!TEST_FILL)
        {
          if (fill_count > 3 &&
              fill_count >= color_count &&
              fill_count >= bicolor_count &&
              fill_count >= mix_count &&
              fill_count >= fom_count)
          {
            count -= fill_count;
            OUT_COPY_COUNT1(count, s, temp_s);
            OUT_FILL_COUNT1(fill_count, s);
            RESET_COUNTS;
          }
          fill_count = 0;
        }
        if (!TEST_MIX)
        {
          if (mix_count > 3 &&
              mix_count >= fill_count &&
              mix_count >= bicolor_count &&
              mix_count >= color_count &&
              mix_count >= fom_count)
          {
            count -= mix_count;
            OUT_COPY_COUNT1(count, s, temp_s);
            OUT_MIX_COUNT1(mix_count, s);
            RESET_COUNTS;
          }
          mix_count = 0;
        }
        if (!TEST_COLOR)
        {
          if (color_count > 3 &&
              color_count >= fill_count &&
              color_count >= bicolor_count &&
              color_count >= mix_count &&
              color_count >= fom_count)
          {
            count -= color_count;
            OUT_COPY_COUNT1(count, s, temp_s);
            OUT_COLOR_COUNT1(color_count, s, last_pixel);
            RESET_COUNTS;
          }
          color_count = 0;
        }
        if (!TEST_BICOLOR)
        {
          if (bicolor_count > 3 &&
              bicolor_count >= fill_count &&
              bicolor_count >= color_count &&
              bicolor_count >= mix_count &&
              bicolor_count >= fom_count)
          {
            if ((bicolor_count % 2) == 0)
            {
              count -= bicolor_count;
              OUT_COPY_COUNT1(count, s, temp_s);
              OUT_BICOLOR_COUNT1(bicolor_count, s, bicolor1, bicolor2);
            }
            else
            {
              bicolor_count--;
              count -= bicolor_count;
              OUT_COPY_COUNT1(count, s, temp_s);
              OUT_BICOLOR_COUNT1(bicolor_count, s, bicolor2, bicolor1);
            }
            RESET_COUNTS;
          }
          bicolor_count = 0;
          bicolor1 = last_pixel;
          bicolor2 = pixel;
          bicolor_spin = 0;
        }
        if (!TEST_FOM)
        {
          if (fom_count > 3 &&
              fom_count >= fill_count &&
              fom_count >= color_count &&
              fom_count >= mix_count &&
              fom_count >= bicolor_count)
          {
            count -= fom_count;
            OUT_COPY_COUNT1(count, s, temp_s);
            OUT_FOM_COUNT1(fom_count, s, fom_mask, fom_mask_len);
            RESET_COUNTS;
          }
          fom_count = 0;
          fom_mask_len = 0;
        }
        if (TEST_FILL)
        {
          fill_count++;
        }
        if (TEST_MIX)
        {
          mix_count++;
        }
        if (TEST_COLOR)
        {
          color_count++;
        }
        if (TEST_BICOLOR)
        {
          bicolor_spin = !bicolor_spin;
          bicolor_count++;
        }
        if (TEST_FOM)
        {
          if ((fom_count % 8) == 0)
          {
            fom_mask[fom_mask_len] = 0;
            fom_mask_len++;
          }
          if (pixel == (ypixel ^ mix))
          {
            fom_mask[fom_mask_len - 1] |= (1 << (fom_count % 8));
          }
          fom_count++;
        }
        out_uint8(temp_s, pixel);
        count++;
        last_pixel = pixel;
        last_ypixel = ypixel;
      }
      /* can't take fix, mix, or fom past first line */
      if (last_line == 0)
      {
        if (fill_count > 3 &&
            fill_count >= color_count &&
            fill_count >= bicolor_count &&
            fill_count >= mix_count &&
            fill_count >= fom_count)
        {
          count -= fill_count;
          OUT_COPY_COUNT1(count, s, temp_s);
          OUT_FILL_COUNT1(fill_count, s);
          RESET_COUNTS;
        }
        fill_count = 0;
        if (mix_count > 3 &&
            mix_count >= fill_count &&
            mix_count >= bicolor_count &&
            mix_count >= color_count &&
            mix_count >= fom_count)
        {
          count -= mix_count;
          OUT_COPY_COUNT1(count, s, temp_s);
          OUT_MIX_COUNT1(mix_count, s);
          RESET_COUNTS;
        }
        mix_count = 0;
        if (fom_count > 3 &&
            fom_count >= fill_count &&
            fom_count >= color_count &&
            fom_count >= mix_count &&
            fom_count >= bicolor_count)
        {
          count -= fom_count;
          OUT_COPY_COUNT1(count, s, temp_s);
          OUT_FOM_COUNT1(fom_count, s, fom_mask, fom_mask_len);
          RESET_COUNTS;
        }
        fom_count = 0;
        fom_mask_len = 0;
      }
      last_line = line;
      line = line - width;
      start_line--;
      lines_sent++;
    }
    if (fill_count > 3 &&
        fill_count >= color_count &&
        fill_count >= bicolor_count &&
        fill_count >= mix_count &&
        fill_count >= fom_count)
    {
      count -= fill_count;
      OUT_COPY_COUNT1(count, s, temp_s);
      OUT_FILL_COUNT1(fill_count, s);
    }
    else if (mix_count > 3 &&
             mix_count >= color_count &&
             mix_count >= bicolor_count &&
             mix_count >= fill_count &&
             mix_count >= fom_count)
    {
      count -= mix_count;
      OUT_COPY_COUNT1(count, s, temp_s);
      OUT_MIX_COUNT1(mix_count, s);
    }
    else if (color_count > 3 &&
             color_count >= mix_count &&
             color_count >= bicolor_count &&
             color_count >= fill_count &&
             color_count >= fom_count)
    {
      count -= color_count;
      OUT_COPY_COUNT1(count, s, temp_s);
      OUT_COLOR_COUNT1(color_count, s, last_pixel);
    }
    else if (bicolor_count > 3 &&
             bicolor_count >= mix_count &&
             bicolor_count >= color_count &&
             bicolor_count >= fill_count &&
             bicolor_count >= fom_count)
    {
      if ((bicolor_count % 2) == 0)
      {
        count -= bicolor_count;
        OUT_COPY_COUNT1(count, s, temp_s);
        OUT_BICOLOR_COUNT1(bicolor_count, s, bicolor1, bicolor2);
      }
      else
      {
        bicolor_count--;
        count -= bicolor_count;
        OUT_COPY_COUNT1(count, s, temp_s);
        OUT_BICOLOR_COUNT1(bicolor_count, s, bicolor2, bicolor1);
      }
      count -= bicolor_count;
      OUT_COPY_COUNT1(count, s, temp_s);
      OUT_BICOLOR_COUNT1(bicolor_count, s, bicolor1, bicolor2);
    }
    else if (fom_count > 3 &&
             fom_count >= mix_count &&
             fom_count >= color_count &&
             fom_count >= fill_count &&
             fom_count >= bicolor_count)
    {
      count -= fom_count;
      OUT_COPY_COUNT1(count, s, temp_s);
      OUT_FOM_COUNT1(fom_count, s, fom_mask, fom_mask_len);
    }
    else
    {
      OUT_COPY_COUNT1(count, s, temp_s);
    }
  }
  else if (bpp == 16)
  {
    mix = 0xffff;
    out_count = end * 2;
    line = in_data + width * start_line * 2;
    while (start_line >= 0 && out_count < 32768)
    {
      i = (s->p - s->data) + count * 2;
      if (i - (color_count * 2) >= byte_limit &&
          i - (bicolor_count * 2) >= byte_limit &&
          i - (fill_count * 2) >= byte_limit &&
          i - (mix_count * 2) >= byte_limit &&
          i - (fom_count * 2) >= byte_limit)
      {
        break;
      }
      out_count += end * 2;
      for (i = 0; i < end; i++)
      {
        /* read next pixel */
        IN_PIXEL16(line, i, 0, width, last_pixel, pixel);
        IN_PIXEL16(last_line, i, 0, width, last_ypixel, ypixel);
        if (!TEST_FILL)
        {
          if (fill_count > 3 &&
              fill_count >= color_count &&
              fill_count >= bicolor_count &&
              fill_count >= mix_count &&
              fill_count >= fom_count)
          {
            count -= fill_count;
            OUT_COPY_COUNT2(count, s, temp_s);
            OUT_FILL_COUNT2(fill_count, s);
            RESET_COUNTS;
          }
          fill_count = 0;
        }
        if (!TEST_MIX)
        {
          if (mix_count > 3 &&
              mix_count >= fill_count &&
              mix_count >= bicolor_count &&
              mix_count >= color_count &&
              mix_count >= fom_count)
          {
            count -= mix_count;
            OUT_COPY_COUNT2(count, s, temp_s);
            OUT_MIX_COUNT2(mix_count, s);
            RESET_COUNTS;
          }
          mix_count = 0;
        }
        if (!TEST_COLOR)
        {
          if (color_count > 3 &&
              color_count >= fill_count &&
              color_count >= bicolor_count &&
              color_count >= mix_count &&
              color_count >= fom_count)
          {
            count -= color_count;
            OUT_COPY_COUNT2(count, s, temp_s);
            OUT_COLOR_COUNT2(color_count, s, last_pixel);
            RESET_COUNTS;
          }
          color_count = 0;
        }
        if (!TEST_BICOLOR)
        {
          if (bicolor_count > 3 &&
              bicolor_count >= fill_count &&
              bicolor_count >= color_count &&
              bicolor_count >= mix_count &&
              bicolor_count >= fom_count)
          {
            if ((bicolor_count % 2) == 0)
            {
              count -= bicolor_count;
              OUT_COPY_COUNT2(count, s, temp_s);
              OUT_BICOLOR_COUNT2(bicolor_count, s, bicolor1, bicolor2);
            }
            else
            {
              bicolor_count--;
              count -= bicolor_count;
              OUT_COPY_COUNT2(count, s, temp_s);
              OUT_BICOLOR_COUNT2(bicolor_count, s, bicolor2, bicolor1);
            }
            RESET_COUNTS;
          }
          bicolor_count = 0;
          bicolor1 = last_pixel;
          bicolor2 = pixel;
          bicolor_spin = 0;
        }
        if (!TEST_FOM)
        {
          if (fom_count > 3 &&
              fom_count >= fill_count &&
              fom_count >= color_count &&
              fom_count >= mix_count &&
              fom_count >= bicolor_count)
          {
            count -= fom_count;
            OUT_COPY_COUNT2(count, s, temp_s);
            OUT_FOM_COUNT2(fom_count, s, fom_mask, fom_mask_len);
            RESET_COUNTS;
          }
          fom_count = 0;
          fom_mask_len = 0;
        }
        if (TEST_FILL)
        {
          fill_count++;
        }
        if (TEST_MIX)
        {
          mix_count++;
        }
        if (TEST_COLOR)
        {
          color_count++;
        }
        if (TEST_BICOLOR)
        {
          bicolor_spin = !bicolor_spin;
          bicolor_count++;
        }
        if (TEST_FOM)
        {
          if ((fom_count % 8) == 0)
          {
            fom_mask[fom_mask_len] = 0;
            fom_mask_len++;
          }
          if (pixel == (ypixel ^ mix))
          {
            fom_mask[fom_mask_len - 1] |= (1 << (fom_count % 8));
          }
          fom_count++;
        }
        out_uint16_le(temp_s, pixel);
        count++;
        last_pixel = pixel;
        last_ypixel = ypixel;
      }
      /* can't take fix, mix, or fom past first line */
      if (last_line == 0)
      {
        if (fill_count > 3 &&
            fill_count >= color_count &&
            fill_count >= bicolor_count &&
            fill_count >= mix_count &&
            fill_count >= fom_count)
        {
          count -= fill_count;
          OUT_COPY_COUNT2(count, s, temp_s);
          OUT_FILL_COUNT2(fill_count, s);
          RESET_COUNTS;
        }
        fill_count = 0;
        if (mix_count > 3 &&
            mix_count >= fill_count &&
            mix_count >= bicolor_count &&
            mix_count >= color_count &&
            mix_count >= fom_count)
        {
          count -= mix_count;
          OUT_COPY_COUNT2(count, s, temp_s);
          OUT_MIX_COUNT2(mix_count, s);
          RESET_COUNTS;
        }
        mix_count = 0;
        if (fom_count > 3 &&
            fom_count >= fill_count &&
            fom_count >= color_count &&
            fom_count >= mix_count &&
            fom_count >= bicolor_count)
        {
          count -= fom_count;
          OUT_COPY_COUNT2(count, s, temp_s);
          OUT_FOM_COUNT2(fom_count, s, fom_mask, fom_mask_len);
          RESET_COUNTS;
        }
        fom_count = 0;
        fom_mask_len = 0;
      }
      last_line = line;
      line = line - width * 2;
      start_line--;
      lines_sent++;
    }
    if (fill_count > 3 &&
        fill_count >= color_count &&
        fill_count >= bicolor_count &&
        fill_count >= mix_count &&
        fill_count >= fom_count)
    {
      count -= fill_count;
      OUT_COPY_COUNT2(count, s, temp_s);
      OUT_FILL_COUNT2(fill_count, s);
    }
    else if (mix_count > 3 &&
             mix_count >= color_count &&
             mix_count >= bicolor_count &&
             mix_count >= fill_count &&
             mix_count >= fom_count)
    {
      count -= mix_count;
      OUT_COPY_COUNT2(count, s, temp_s);
      OUT_MIX_COUNT2(mix_count, s);
    }
    else if (color_count > 3 &&
             color_count >= mix_count &&
             color_count >= bicolor_count &&
             color_count >= fill_count &&
             color_count >= fom_count)
    {
      count -= color_count;
      OUT_COPY_COUNT2(count, s, temp_s);
      OUT_COLOR_COUNT2(color_count, s, last_pixel);
    }
    else if (bicolor_count > 3 &&
             bicolor_count >= mix_count &&
             bicolor_count >= color_count &&
             bicolor_count >= fill_count &&
             bicolor_count >= fom_count)
    {
      if ((bicolor_count % 2) == 0)
      {
        count -= bicolor_count;
        OUT_COPY_COUNT2(count, s, temp_s);
        OUT_BICOLOR_COUNT2(bicolor_count, s, bicolor1, bicolor2);
      }
      else
      {
        bicolor_count--;
        count -= bicolor_count;
        OUT_COPY_COUNT2(count, s, temp_s);
        OUT_BICOLOR_COUNT2(bicolor_count, s, bicolor2, bicolor1);
      }
      count -= bicolor_count;
      OUT_COPY_COUNT2(count, s, temp_s);
      OUT_BICOLOR_COUNT2(bicolor_count, s, bicolor1, bicolor2);
    }
    else if (fom_count > 3 &&
             fom_count >= mix_count &&
             fom_count >= color_count &&
             fom_count >= fill_count &&
             fom_count >= bicolor_count)
    {
      count -= fom_count;
      OUT_COPY_COUNT2(count, s, temp_s);
      OUT_FOM_COUNT2(fom_count, s, fom_mask, fom_mask_len);
    }
    else
    {
      OUT_COPY_COUNT2(count, s, temp_s);
    }
  }
  return lines_sent;
}