dev2gif.c

giflib-4.1.6.tar.gz,最新的GIF 解码库

/*****************************************************************************
 *   "Gif-Lib" - Yet another gif library.
 *
 * Written by:  Gershon Elber            IBM PC Ver 1.1,    Jun. 1989
 *****************************************************************************
 * Module to dump graphic devices into a GIF file. Current supported devices:
 * 1. EGA, VGA, SVGA (800x600), Hercules on the IBM PC (#define __MSDOS__).
 * 2. SGI 4D Irix using gl library (#define SGI_GL__).
 * 3. X11 using libX.a (#define __X11__).
 * 4. (2 & 3 have been changed to HAVE_GL_S and HAVE_LIBX11 and should be set
 * by the configure script.)
 *****************************************************************************
 * History:
 * 22 Jun 89 - Version 1.0 by Gershon Elber.
 * 12 Aug 90 - Version 1.1 by Gershon Elber (added devices).
 ****************************************************************************/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#ifdef __MSDOS__
#include <dos.h>
#include <alloc.h>
#include <graphics.h>
#endif /* __MSDOS__ */

#ifdef HAVE_LIBX11
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#endif /* HAVE_LIBX11 */

#ifdef HAVE_LIBGL_S
#include <gl/gl.h>
#endif /* HAVE_LIBGL_S */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "gif_lib.h"

#define SVGA_SPECIAL 999    /* 800 by 600 Super VGA mode. */

static int GraphDriver = -1,    /* Device parameters - reasonable values. */
   GraphMode = -1, ScreenColorBits = 1;
static long ScreenXMax = 100, ScreenYMax = 100;

#ifdef __MSDOS__
static unsigned int ScreenBase;
#endif /* __MSDOS__ */

#if defined(HAVE_LIBGL_S) || defined(HAVE_LIBX11)
GifByteType *GlblGifBuffer = NULL, *GlblGifBufferPtr = NULL;
#endif /* HAVE_LIBGL_S || HAVE_LIBX11 */

#ifdef HAVE_LIBGL_S
static int QuantizeRGBBuffer(int Width, int Height, long *RGBBuffer,
                             GifColorType * ColorMap,
                             GifByteType * GIFBuffer);
#endif /* HAVE_LIBGL_S */

static void GetScanLine(GifPixelType * ScanLine, int Y);
static int HandleGifError(GifFileType * GifFile);

/******************************************************************************
 * Dump the given Device, into given File as GIF format:
 * Return 0 on success, -1 if device not supported, or GIF-LIB error number.
 * Device is selected via the ReqGraphDriver. Device mode is selected via
 * ReqGraphMode1/2 as follows:
 * 1. IBM PC Hercules card: HERCMONO (one mode only) in ReqGraphMode1,
 *    ReqGraphMode2/3 are ignored.
 * 2. IBM PC EGA card: EGALO/EGAHI in ReqGraphMode1,
 *    ReqGraphMode2/3 are ignored.
 * 3. IBM PC EGA64 card: EGA64LO/EGA64HI in ReqGraphMode1,
 *    ReqGraphMode2/3 are ignored.
 * 4. IBM PC EGAMONO card: EGAMONOHI (one mode only) in ReqGraphMode1,
 *    ReqGraphMode2/3 are ignored.
 * 5. IBM PC VGA card: VGALO/VGAMED/VGAHI in ReqGraphMode1,
 *    ReqGraphMode2/3 are ignored.
 * 6. IBM PC SVGA card: ReqGraphMode1/2 are both ignored. Fixed mode (800x600
 *    16 colors) is assumed.
 * 7. SGI 4D using GL: window id to dump (as returned by winget()) in
 *    ReqGraphMode1, ReqGraphMode2/3 are ignored.
 * 8. X11: Window id in ReqGraphMode1, Display id in ReqGraphMode2, Color
 *    map id in  ReqGraphMode3.
 *****************************************************************************/
int
DumpScreen2Gif(const char *FileName,
               int ReqGraphDriver,
               long ReqGraphMode1,
               long ReqGraphMode2,
               long ReqGraphMode3) {

    int i, j, k;
    GifPixelType *ScanLine;
    GifFileType *GifFile;
    ColorMapObject *ColorMap = NULL;
#ifdef __MSDOS__
    static GifColorType MonoChromeColorMap[] = {
        {0, 0, 0},
        {255, 255, 255}
    };
    /* I have no idea what default EGA64 (4 colors) should be (I guessed...). */
    static GifColorType EGA64ColorMap[] = {
        {0, 0, 0},    /* 0. Black */
        {255, 0, 0},    /* 1. Red */
        {0, 255, 0},    /* 2. Green */
        {0, 0, 255},    /* 3. Blue */
    };
    static GifColorType EGAColorMap[] = {
        {0, 0, 0},    /* 0. Black */
        {0, 0, 170},    /* 1. Blue */
        {0, 170, 0},    /* 2. Green */
        {0, 170, 170},    /* 3. Cyan */
        {170, 0, 0},    /* 4. Red */
        {170, 0, 170},    /* 5. Magenta */
        {170, 170, 0},    /* 6. Brown */
        {170, 170, 170},    /* 7. LightGray */
        {85, 85, 85},    /* 8. DarkGray */
        {85, 85, 255},    /* 9. LightBlue */
        {85, 255, 85},    /* 10. LightGreen */
        {85, 255, 255},    /* 11. LightCyan */
        {255, 85, 85},    /* 12. LightRed */
        {255, 85, 255},    /* 13. LightMagenta */
        {255, 255, 85},    /* 14. Yellow */
        {255, 255, 255},    /* 15. White */
    };
#endif /* __MSDOS__ */
#if defined(HAVE_LIBGL_S)
    long *RGBBuffer;
#ifndef HAVE_LIBX11
    GifColorType ColorMap256[256];
#endif /* Undefined HAVE_LIBX11 */
#endif /* HAVE_LIBGL_S */
#ifdef HAVE_LIBX11
    XImage *XImg;
    unsigned long XPixel;
    GifColorType ColorMap256[256];
    XColor XColorTable[256];    /* Up to 256 colors in X. */
    XWindowAttributes WinAttr;
#endif /* HAVE_LIBX11 */
    switch (ReqGraphDriver) {    /* Return on non supported screens. */
#ifdef __MSDOS__
      case HERCMONO:
          ScreenXMax = 720;
          ScreenYMax = 350;
          ScreenColorBits = 1;
          ScreenBase = 0xb000;
          ColorMap = MakeMapObject(2, MonoChromeColorMap);
          break;
      case EGA:
          switch (ReqGraphMode1) {
            case EGALO:
                ScreenYMax = 200;
                break;
            case EGAHI:
                ScreenYMax = 350;
                break;
            default:
                return -1;
          }
          ScreenXMax = 640;
          ScreenColorBits = 4;
          ScreenBase = 0xa000;
          ColorMap = MakeMapObject(16, EGAColorMap);
          break;
      case EGA64:
          switch (ReqGraphMode1) {
            case EGA64LO:
                ScreenYMax = 200;
                break;
            case EGA64HI:
                ScreenYMax = 350;
                break;
            default:
                return -1;
          }
          ScreenXMax = 640;
          ScreenColorBits = 2;
          ScreenBase = 0xa000;
          ColorMap = MakeMapObject(4, EGA64ColorMap);
          break;
      case EGAMONO:
          switch (ReqGraphMode1) {
            case EGAMONOHI:
                ScreenYMax = 350;
                break;
            default:
                return -1;
          }
          ScreenXMax = 640;
          ScreenColorBits = 1;
          ScreenBase = 0xa000;
          ColorMap = MakeMapObject(2, MonoChromeColorMap);
          break;
      case VGA:
          switch (ReqGraphMode1) {
            case VGALO:
                ScreenYMax = 200;
                break;
            case VGAMED:
                ScreenYMax = 350;
                break;
            case VGAHI:
                ScreenYMax = 480;
                break;
            default:
                return -1;
          }
          ScreenXMax = 640;
          ScreenColorBits = 4;
          ScreenBase = 0xa000;
          ColorMap = MakeMapObject(16, EGAColorMap);
          break;
      case SVGA_SPECIAL:
          ScreenXMax = 800;
          ScreenYMax = 600;
          ScreenColorBits = 4;
          ScreenBase = 0xa000;
          ColorMap = MakeMapObject(16, EGAColorMap);
          break;
#endif /* __MSDOS__ */
#ifdef HAVE_LIBGL_S
      case GIF_DUMP_SGI_WINDOW:
          winset(ReqGraphMode1);    /* Select window as active window. */
          getsize(&ScreenXMax, &ScreenYMax);

          RGBBuffer = (long *)malloc(sizeof(long) * ScreenXMax * ScreenYMax);
          readsource(SRC_FRONT);
          if (lrectread((short)0, (short)0, (short)(ScreenXMax - 1),
                        (short)(ScreenYMax - 1), RGBBuffer) !=
                 ScreenXMax * ScreenYMax) {    /* Get data. */
              free(RGBBuffer);
              return -1;
          }
          GlblGifBuffer = (GifByteType *) malloc(sizeof(GifByteType) *
                                                 ScreenXMax * ScreenYMax);
          i = QuantizeRGBBuffer(ScreenXMax, ScreenYMax, RGBBuffer,
                                ColorMap256, GlblGifBuffer);
          /* Find minimum color map size to hold all quantized colors. */
          for (ScreenColorBits = 1;
               (1 << ScreenColorBits) < i && ScreenColorBits < 8;
               ScreenColorBits++) ;

          /* Start to dump with top line as GIF expects it. */
          GlblGifBufferPtr = GlblGifBuffer + ScreenXMax * (ScreenYMax - 1);
          ColorMap = MakeMapObject(256, ColorMap256);
          free(RGBBuffer);
          break;
#endif /* HAVE_LIBGL_S */
#ifdef HAVE_LIBX11
      case GIF_DUMP_X_WINDOW:
          XGetWindowAttributes((Display *) ReqGraphMode2,
                               (Window) ReqGraphMode1, &WinAttr);
          ScreenXMax = WinAttr.width;
          ScreenYMax = WinAttr.height;