XImg = XGetImage((Display *) ReqGraphMode2,                           (Window) ReqGraphMode1,                           0, 0, ScreenXMax - 1, ScreenYMax - 1,                           AllPlanes, XYPixmap);          GlblGifBuffer = (GifByteType *)malloc(sizeof(GifByteType) *                                                 ScreenXMax * ScreenYMax);          /* Scan the image for all different colors exists. */          for (i = 0; i < 256; i++)              XColorTable[i].pixel = 0;          k = FALSE;          for (i = 0; i < ScreenXMax; i++)              for (j = 0; j < ScreenYMax; j++) {                  XPixel = XGetPixel(XImg, i, j);                  if (XPixel > 255) {                      if (!k) {                          /* Make sure we state it once only. */                          fprintf(stderr, "X Color table - truncated.\n");                          k = TRUE;                      }                      XPixel = 255;                  }                  XColorTable[XPixel].pixel = XPixel;              }          /* Find the RGB representation of the colors. */          XQueryColors((Display *) ReqGraphMode2,                       (Colormap) ReqGraphMode3, XColorTable, 256);          /* Count number of active colors (Note color 0 is always in) */          /* and create the Gif color map from it.  */          ColorMap = MakeMapObject(256, ColorMap256);          ColorMap->Colors[0].Red = ColorMap->Colors[0].Green =             ColorMap->Colors[0].Blue = 0;          for (i = j = 1; i < 256; i++)              if (XColorTable[i].pixel) {                  ColorMap->Colors[j].Red = XColorTable[i].red / 256;                  ColorMap->Colors[j].Green = XColorTable[i].green / 256;                  ColorMap->Colors[j].Blue = XColorTable[i].blue / 256;                  /* Save the X color index into the Gif table: */                  XColorTable[i].pixel = j++;              }          /* and set the number of colors in the Gif color map. */          for (ScreenColorBits = 1;               (1 << ScreenColorBits) < j && ScreenColorBits < 8;               ScreenColorBits++) ;          /* Prepare the Gif image buffer as indices into the Gif color */          /* map from the X image.  */          GlblGifBufferPtr = GlblGifBuffer;          for (i = 0; i < ScreenXMax; i++)              for (j = 0; j < ScreenYMax; j++)                  *GlblGifBufferPtr++ =                     XColorTable[XGetPixel(XImg, j, i) & 0xff].pixel;          XDestroyImage(XImg);          GlblGifBufferPtr = GlblGifBuffer;          ColorMap = MakeMapObject(256, ColorMap256);          break;#endif /* HAVE_LIBX11 */      default:          return -1;    }    ScanLine = (GifPixelType *)malloc(sizeof(GifPixelType) * ScreenXMax);    GraphDriver = ReqGraphDriver;    GraphMode = ReqGraphMode1;    if ((GifFile = EGifOpenFileName(FileName, FALSE)) == NULL ||        EGifPutScreenDesc(GifFile, ScreenXMax, ScreenYMax, ScreenColorBits,                          0, ColorMap) == GIF_ERROR ||        EGifPutImageDesc(GifFile, 0, 0, ScreenXMax, ScreenYMax, FALSE,                         NULL) == GIF_ERROR) {        free((char *)ScanLine);#if defined(HAVE_LIBGL_S) || defined(HAVE_LIBX11)        free((char *)GlblGifBuffer);#endif        return HandleGifError(GifFile);    }    for (i = 0; i < ScreenYMax; i++) {        GetScanLine(ScanLine, i);        if (EGifPutLine(GifFile, ScanLine, ScreenXMax) == GIF_ERROR) {            free((char *)ScanLine);#if defined(HAVE_LIBGL_S) || defined(HAVE_LIBX11)            free((char *)GlblGifBuffer);#endif            return HandleGifError(GifFile);        }    }    if (EGifCloseFile(GifFile) == GIF_ERROR) {        free((char *)ScanLine);#if defined(HAVE_LIBGL_S) || defined(HAVE_LIBX11)        free((char *)GlblGifBuffer);#endif        return HandleGifError(GifFile);    }    free((char *)ScanLine);#if defined(HAVE_LIBGL_S) || defined(HAVE_LIBX11)    free((char *)GlblGifBuffer);#endif    return 0;}#ifdef HAVE_LIBGL_S/****************************************************************************** * Quantize the given 24 bit (8 per RGB) into 256 colors. *****************************************************************************/static intQuantizeRGBBuffer(int Width,                  int Height,                  long *RGBBuffer,                  GifColorType * ColorMap,                  GifByteType * GIFBuffer) {    int i;    GifByteType *RedInput, *GreenInput, *BlueInput;    /* Convert the RGB Buffer into 3 seperated buffers: */    RedInput = (GifByteType *) malloc(sizeof(GifByteType) * Width * Height);    GreenInput = (GifByteType *) malloc(sizeof(GifByteType) * Width * Height);    BlueInput = (GifByteType *) malloc(sizeof(GifByteType) * Width * Height);    for (i = 0; i < Width * Height; i++) {        RedInput[i] = RGBBuffer[i] & 0xff;        GreenInput[i] = (RGBBuffer[i] >> 8) & 0xff;        BlueInput[i] = (RGBBuffer[i] >> 16) & 0xff;    }    for (i = 0; i < 256; i++)        ColorMap[i].Red = ColorMap[i].Green = ColorMap[i].Blue = 0;    i = 256;    QuantizeBuffer(Width, Height, &i,                   RedInput, GreenInput, BlueInput, GIFBuffer, ColorMap);    free(RedInput);    free(GreenInput);    free(BlueInput);    return i;    /* Real number of colors in color table. */}#endif /* HAVE_LIBGL_S *//****************************************************************************** * Update the given scan line buffer with the pixel levels of the Y line. * This routine is device specific, so make sure you know was you are doing *****************************************************************************/static voidGetScanLine(GifPixelType * ScanLine,            int Y) {    #ifdef __MSDOS__    unsigned char ScreenByte;    int i, j, k;    unsigned int BufferOffset, Bit;    union REGS InRegs, OutRegs;#endif /* __MSDOS__ */    switch (GraphDriver) {#ifdef __MSDOS__      case HERCMONO:          BufferOffset = 0x2000 * (Y % 4) + (Y / 4) * (ScreenXMax / 8);          /* In one scan lines we have ScreenXMax / 8 bytes: */          for (i = 0, k = 0; i < ScreenXMax / 8; i++) {              ScreenByte = (unsigned char)peekb(ScreenBase, BufferOffset++);              for (j = 0, Bit = 0x80; j < 8; j++) {                  ScanLine[k++] = (ScreenByte & Bit ? 1 : 0);                  Bit >>= 1;              }          }          break;      case EGA:      case EGA64:      case EGAMONO:      case VGA:      case SVGA_SPECIAL:          InRegs.x.dx = Y;          InRegs.h.bh = 0;          InRegs.h.ah = 0x0d;    /* BIOS Read dot. */          for (i = 0; i < ScreenXMax; i++) {              InRegs.x.cx = i;              int86(0x10, &InRegs, &OutRegs);              ScanLine[i] = OutRegs.h.al;          }          /* Makr this line as done by putting a xored dot on the left. */          InRegs.x.dx = Y;          InRegs.h.bh = 0;          InRegs.h.ah = 0x0c;    /* BIOS Write dot (xor mode). */          InRegs.h.al = 0x81;    /* Xor with color 1. */          InRegs.x.cx = 0;          int86(0x10, &InRegs, &OutRegs);          InRegs.x.dx = Y;          InRegs.h.bh = 0;          InRegs.h.ah = 0x0c;    /* BIOS Write dot (xor mode). */          InRegs.h.al = 0x81;    /* Xor with color 1. */          InRegs.x.cx = 1;          int86(0x10, &InRegs, &OutRegs);          if (Y == ScreenYMax - 1) {    /* Last row - clear all marks we                                         * made. */              for (i = 0; i < ScreenYMax; i++) {                  InRegs.h.bh = 0;                  InRegs.h.ah = 0x0c;    /* BIOS Write dot (xor mode). */                  InRegs.h.al = 0x81;    /* Xor back with color 1. */                  InRegs.x.dx = i;                  InRegs.x.cx = 0;                  int86(0x10, &InRegs, &OutRegs);                  InRegs.h.bh = 0;                  InRegs.h.ah = 0x0c;    /* BIOS Write dot (xor mode). */                  InRegs.h.al = 0x81;    /* Xor back with color 1. */                  InRegs.x.dx = i;                  InRegs.x.cx = 1;                  int86(0x10, &InRegs, &OutRegs);              }          }          break;#endif /* __MSDOS__ */#ifdef HAVE_LIBGL_S      case GIF_DUMP_SGI_WINDOW:          memcpy(ScanLine, GlblGifBufferPtr,                 ScreenXMax * sizeof(GifPixelType));          GlblGifBufferPtr -= ScreenXMax;          break;#endif /* HAVE_LIBGL_S */#ifdef HAVE_LIBX11      case GIF_DUMP_X_WINDOW:          memcpy(ScanLine, GlblGifBufferPtr,                 ScreenXMax * sizeof(GifPixelType));          GlblGifBufferPtr += ScreenXMax;          break;#endif /* HAVE_LIBX11 */      default:          break;    }}/****************************************************************************** * Handle last GIF error. Try to close the file and free all allocated memory. *****************************************************************************/static intHandleGifError(GifFileType * GifFile) {    int i = GifLastError();    if (EGifCloseFile(GifFile) == GIF_ERROR) {        GifLastError();    }    return i;}