/*****************************************************************************
*   "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_LIBGL_S
#include <gl/gl.h>
#endif /* HAVE_LIBGL_S */

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

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

#define PROGRAM_NAME	"GIF_LIBRARY"

#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;
static unsigned int ScreenBase;

#ifdef SYSV
static char *VersionStr =
        "Gif library module,\t\tEric S. Raymond\n\
	(C) Copyright 1997 Eric S. Raymond\n";
#else
static char *VersionStr =
	PROGRAM_NAME
	"	IBMPC "
	GIF_LIB_VERSION
	"	Eric S. Raymond,	"
	__DATE__ ",   " __TIME__ "\n"
	"(C) Copyright 1997 Eric S. Raymond\n";
#endif /* SYSV */

#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,
					 int ReqGraphMode1,
	       				 int ReqGraphMode2,
	       				 int ReqGraphMode3)
{
    int i;
    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) || defined(HAVE_LIBX11)
    long *RGBBuffer;
    GifColorType ColorMap256[256];
#endif /* HAVE_LIBGL_S || HAVE_LIBX11 */
#ifdef HAVE_LIBX11
    XImage *XImg;
    unsigned long XPixel;
    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;