/* ppmtogif.c - read a portable pixmap and produce a GIF file
**
** Based on GIFENCOD by David Rowley <mgardi@watdscu.waterloo.edu>.A
** Lempel-Zim compression based on "compress".
**
** Copyright (C) 1989 by Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
**
** The Graphics Interchange Format(c) is the Copyright property of
** CompuServe Incorporated.  GIF(sm) is a Service Mark property of
** CompuServe Incorporated.
*/

//#include "ppm.h"
//#include "ppmcmap.h"

// 7/5/94 edward - If we're compiling with MW all of these headers are precompiled in TIFast*
#ifndef __MWERKS__

#include <StdIO.h>
#include <Types.h>
#include <Quickdraw.h>
#include <Windows.h>
#include <TextEdit.h>
#include <StandardFile.h>
#include <Errors.h>
#include <Lists.h>
#include "pips.h"
#include "Utilities.h"

#ifdef TE32K				// 5/28/93 edward - include TE32K.h for TE32K
#include "TE32K.h"
#endif
#include "documentRec.h"
#include "prototype.h"
#include "node.h"

#endif

#include <QDOffscreen.h>
#include "GIF.h"
#include "GIFencoder.h"

/* edward - prototypes */
int flush_charOutBuf(void);
int GIFenfwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream);
int GIFenfputc(int c, FILE *stream);
int GIFenfclose(FILE *stream);
int GIFenfflush(FILE *stream);
int GIFenferror(FILE *stream);
void DisposeBuffers(void);
Boolean AllocateBuffers(void);

/*
 * Pointer to function returning an int
 */
typedef int (* ifunptr)();

/*
 * a code_int must be able to hold 2**BITS values of type int, and also -1
 */
typedef int	code_int;

#ifdef SIGNED_COMPARE_SLOW
typedef unsigned long int count_int;
typedef unsigned short int count_short;
#else /*SIGNED_COMPARE_SLOW*/
typedef long int          count_int;
#endif /*SIGNED_COMPARE_SLOW*/

static int colorstobpp ARGS(( int colors ));
static int myCGetPixel ARGS(( int x, int y ));
static int myMGetPixel ARGS(( int x, int y ));
static void BumpPixel ARGS(( void ));
static int GIFNextPixel ARGS(( ifunptr getpixel ));
static void GIFEncode ARGS(( FILE* fp, int GWidth, int GHeight, int GInterlace, int Background, int BitsPerPixel, int Red[], int Green[], int Blue[], ifunptr getpixel ));
static void Putword ARGS(( int w, FILE* fp ));
static void compress ARGS(( int init_bits, FILE* outfile, ifunptr ReadValue ));
static void output ARGS(( code_int code ));
static void cl_block ARGS(( void ));
static void cl_hash ARGS(( count_int hsize ));
static void writeerr ARGS(( void ));
static void char_init ARGS(( void ));
static void char_out ARGS(( int c ));
static void flush_char ARGS(( void ));

#ifdef MACINTOSH
void InitGIFEncoderGlobals(void);

PixMapPtr 	GIFppm;				// the color pixel map ptr
GrafPtr		GIFgrafPtr;			// the B&W off-screen BitMap

OSErr gGIFfileErr;
#define		kWatchCursorOffset		5
short		gWatchCursorIndex;
count_int * htab;
unsigned short * codetab;
#define HSIZE  5003            /* 80% occupancy */
//
// Define the storage for the packet accumulator
//
char * accum;
// the following is for readability only - **do not change**
#define  ACCUM_BUFFER_SIZE 256

short	gWritingToFile;
char * charOutBuf;
short	gCharOutBufLen;
#define  CHAR_OUT_BUF_SIZE 258
#define  CHAR_OUT_FLUSH_LEN 256

#pragma segment graphics

static int colorstobpp(int colors);
static int myCGetPixel(int x, int y);
static int myMGetPixel(int x, int y);
static void BumpPixel(void);
static int GIFNextPixel(ifunptr getpixel);
static void GIFEncode(FILE *fp, int GWidth, int GHeight, int GInterlace, int Background, int BitsPerPixel, int Red[], int Green[], int Blue[], ifunptr getpixel);
static void Putword(int w, FILE *fp);

int flush_charOutBuf(void)
{
	gGIFfileErr = cmd_send_gif( charOutBuf, gCharOutBufLen );
	gCharOutBufLen = 0;
	return gGIFfileErr;
}

#pragma segment graphics
int GIFenfwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
{
	long	len;

	len = size * nmemb;
	
	if ( len <= 0)
		return 0;
	if (gWritingToFile)
	{
		gGIFfileErr = FSWrite( *stream, &len, ptr );
	}
	else
	{
		// if there are any characters in the charOutBuf then flush them
		if (gCharOutBufLen > 0)
			gGIFfileErr = flush_charOutBuf();
		if (gGIFfileErr == noErr)
			gGIFfileErr = cmd_send_gif( (char *)ptr, len );
	}

	wind_set_cursor((gWatchCursorIndex++ % 8) + kWatchCursorOffset);

	return len;
}

#pragma segment graphics
int GIFenfputc(int c, FILE *stream)
{
	long	len;
	unsigned char theChar;
	

	len = 1;
	if (gWritingToFile)
	{
		theChar = (c & 0xff);
		gGIFfileErr = FSWrite( *stream, &len, &theChar );
	}
	else
	{
		charOutBuf[gCharOutBufLen++] = c;
		if (gCharOutBufLen >= CHAR_OUT_FLUSH_LEN)
			gGIFfileErr = flush_charOutBuf();
	}

	if (gGIFfileErr == noErr)
		return 0;
	else
		return EOF;
}

#pragma segment graphics
int GIFenfclose(FILE *stream)
{
	if (gWritingToFile)
	{
		gGIFfileErr = FSClose(*stream);
	}
	else
	{
		if (gCharOutBufLen > 0)
			gGIFfileErr = flush_charOutBuf();
	}
	if (gGIFfileErr == noErr)
		return 0;
	else
		return -1;
}

#pragma segment graphics
int GIFenfflush(FILE *)
{
	return 0;
}

#pragma segment graphics
int GIFenferror(FILE *)
{
	return gGIFfileErr;
}


#pragma segment graphics
void DisposeBuffers(void)
{
	if (htab)
		DisposePtr((Ptr)htab);
	if (codetab)
		DisposePtr((Ptr)codetab);
	if (accum)
		DisposePtr((Ptr)accum);
	if (charOutBuf)
		DisposePtr((Ptr)charOutBuf);
}

#pragma segment graphics
Boolean AllocateBuffers(void)
{
	htab = nil;
	codetab = nil;
	accum = nil;
	charOutBuf = nil;
	htab = (count_int *)NewPtr(HSIZE * sizeof(count_int));
	if (!htab) {
		DisposeBuffers();
		return false;
	}
	codetab = (unsigned short *)NewPtr(HSIZE * sizeof(unsigned short));
	if (!codetab) {
		DisposeBuffers();
		return false;
	}
	accum = (char *)NewPtr(ACCUM_BUFFER_SIZE * sizeof(char));
	if (!accum) {
		DisposeBuffers();
		return false;
	}
	
	// If we're not going to a file then we need the output buffer
	if (!gWritingToFile) {
		charOutBuf = (char *)NewPtr(CHAR_OUT_BUF_SIZE * sizeof(unsigned char));
		if (!charOutBuf) {
			DisposeBuffers();
			return false;
		}
	}

	return true;
}

#pragma segment graphics
Boolean PreFlightGIFBuffers(void)
{
	if (AllocateBuffers())
	{
		DisposeBuffers();
		return true;
	}
	else
		return false;
}


//
//////////////////////////////////////////////////////////////////////////////////
//
// GIFSaveAsGIF - Save the image in the window "whichWindow" in GIF format - either
//			to disk (if theFileRefNum is non-zero) or to the network.
//			the code which compresses consecutive single-byte writes into a single
//			block write is required to get somewhere-near reasonable completion
//			times for the network write process.
//////////////////////////////////////////////////////////////////////////////////
//
#pragma segment graphics
Boolean GIFSaveAsGIF(WindowPtr whichWindow, short theFileRefNum)
{
	short	colors, i;
	int BitsPerPixel;
	int Red[MAXCOLORS], Green[MAXCOLORS], Blue[MAXCOLORS];
	RGBColor		myColors;	
	CTabHandle		myCTabHandle;
	DocumentPeek	theDoc;

	GWorldPtr		gw;
	PixMapHandle	myPixMapHandle;

	InitGIFEncoderGlobals();
	
	gWritingToFile = (theFileRefNum != 0);
	gGIFfileErr = noErr;
	gCharOutBufLen = 0;	// buffer for single character output
	gWatchCursorIndex = -1;		// init the index 
	
	if (wind_type(whichWindow) != NT_GIF)
	{
		old_gif_error("This doesn't look like a GIF image!");
		return (-1);
	}
	
	theDoc = (DocumentPeek)whichWindow;

	if (theDoc->imageType == kGWorldBased)
	{
		gw = theDoc->gw;

	}
	else
	{
		GIFgrafPtr = (GrafPtr)theDoc->gw;
	}


	if (!AllocateBuffers())
	{
		gif_error( kNoMemSave, kDontDoNumber );
		return false;
	}


	for (i = 0; i < MAXCOLORS; i++) {
		Red[i] = 0;
		Green[i] = 0;
		Blue[i] = 0;
	}
	


	if (theDoc->imageType == kGWorldBased)
	{
		if (System7orBetter)			// Get the PixMap pointer the approved way
			myPixMapHandle = GetGWorldPixMap(gw);
		else
			myPixMapHandle = gw->portPixMap;

		if ( !LockPixels( myPixMapHandle ))
		{
			gif_error( kNoPixelLock, kDontDoNumber );
			DisposeBuffers();
			return false;
		}
		else
		{

			GIFppm = *myPixMapHandle;
			myCTabHandle = 	GIFppm->pmTable; /*color map for this pixMap*/

			colors = (*myCTabHandle)->ctSize + 1;	// ctSize is Number Of Colors - 1
			for (i = 0; i < colors; i++)
			{
				myColors = (*myCTabHandle)->ctTable[i].rgb;
				Red[i] = myColors.red >> 8;
				Green[i] = myColors.green >> 8;
				Blue[i] = myColors.blue >> 8;
			}

			BitsPerPixel = colorstobpp( colors );
			
			if (!BitsPerPixel)
			{
				gif_error( k2ManyColors, kDontDoNumber );
			}
			else
			{
				GIFEncode(
					&theFileRefNum, GIFppm->bounds.right, GIFppm->bounds.bottom, 
					false, 0, BitsPerPixel,
					Red, Green, Blue, myCGetPixel );
				}
			UnlockPixels( myPixMapHandle );
		}
	}
	else
	{		// black & white
		colors = 2;

		Red[0] = 255;
		Green[0] = 255;
		Blue[0] = 255;

		BitsPerPixel = colorstobpp( colors );

		GIFEncode(
			&theFileRefNum, GIFgrafPtr->portBits.bounds.right, GIFgrafPtr->portBits.bounds.bottom, 
			false, 0, BitsPerPixel,
			Red, Green, Blue, myMGetPixel );
	}
	
	DisposeBuffers();
	//
	// NOTE: - returns FALSE when it succeeds - this reverse logic is required
	//		by the code which calls this routine and is not a problem as long
	//		as it is documented.  Right?
	//
	return (gGIFfileErr);
}	//	GIFSaveAsGIF

#endif



#pragma segment graphics
static int colorstobpp(int colors)
{
	int bpp;

	if ( colors <= 2 )
		bpp = 1;
	else if ( colors <= 4 )
		bpp = 2;
	else if ( colors <= 8 )
		bpp = 3;
	else if ( colors <= 16 )
		bpp = 4;
	else if ( colors <= 32 )
		bpp = 5;
	else if ( colors <= 64 )
		bpp = 6;
	else if ( colors <= 128 )
		bpp = 7;
	else if ( colors <= 256 )
		bpp = 8;
	else
		bpp = 0;		// error condition

	return bpp;
}

//
///////////////////////////////////////////////////////////////////////////////////
// myCGetPixel - return the color index of a pixel given its "x" and "y"
//		coordinates.  This version works for Color (GWorld-based) images.
///////////////////////////////////////////////////////////////////////////////////
//
#pragma segment graphics
static int myCGetPixel(int x, int y)
{
	int color;
	long	startPos;
	gif_pixel * qdptr;

	startPos = (long) (y) * (long) (GIFppm->rowBytes & 0x7FFF) + (long)0;
	qdptr = (gif_pixel *) &(GIFppm->baseAddr[startPos]);
	color = qdptr[x];
	return color;
}
//
///////////////////////////////////////////////////////////////////////////////////
// myMGetPixel - return the color index of a pixel given its "x" and "y"
//		coordinates.  This version works for Monochrome (BitMap-based) images.
///////////////////////////////////////////////////////////////////////////////////
//
#pragma segment graphics
static int myMGetPixel(int x, int y)
{
	int color;
	long	startPos;
	gif_pixel * qdptr;

	startPos = (long) (y) * (long) (GIFgrafPtr->portBits.rowBytes & 0x7FFF);
	qdptr = (gif_pixel *) &(GIFgrafPtr->portBits.baseAddr[startPos]);
	color = qdptr[x >> 3];

	color &= (1 << (7 - (x & 7)));
	if (color != 0)
		color = 1;
	return color;
}


/*****************************************************************************
 *
 * GIFENCODE.C    - GIF Image compression interface
 *
 * GIFEncode( FName, GHeight, GWidth, GInterlace, Background,
 *            BitsPerPixel, Red, Green, Blue, getpixel )
 *
 *****************************************************************************/

// TI 4.2a4 - define TRUE and FALSE only if currently undef'd
#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif

static int Width, Height;
static int curx, cury;
static long CountDown;
static int Pass = 0;
static int Interlace;

/*
 * Bump the 'curx' and 'cury' to point to the next pixel
 */
#pragma segment graphics
static void BumpPixel(void)
{
	/*
	 * Bump the current X position
	 */
	++curx;

	/*
	 * If we are at the end of a scan line, set curx back to the beginning
	 * If we are interlaced, bump the cury to the appropriate spot,
	 * otherwise, just increment it.
	 */
	if( curx == Width )
	{
		curx = 0;

		if( !Interlace )
			 ++cury;
		else
		{
			switch( Pass )
			{
				case 0:
					cury += 8;
					if( cury >= Height )
					{
						++Pass;
						cury = 4;
					}
					break;

				case 1:
					cury += 8;
					if( cury >= Height )
					{
						++Pass;
						cury = 2;
					}
					break;

				case 2:
					cury += 4;
					if( cury >= Height )
					{
						++Pass;
						cury = 1;
					}
					break;

				case 3:
					cury += 2;
					break;
			}
		}
	}
}

/*
 * Return the next pixel from the image
 */
#pragma segment graphics
static int GIFNextPixel(ifunptr getpixel)
{
	int r;

	if( CountDown == 0 )
		return EOF;

	--CountDown;

	r = ( * getpixel )( curx, cury );

	BumpPixel();

	return r;
}

/* public */

#pragma segment graphics
static void GIFEncode(FILE *fp, int GWidth, int GHeight, int GInterlace, int Background, int BitsPerPixel, int Red[], int Green[], int Blue[], ifunptr getpixel)
{
	int B;
	int RWidth, RHeight;
	int LeftOfs, TopOfs;
	int Resolution;
	int ColorMapSize;
	int InitCodeSize;
	int i;

	Interlace = GInterlace;

	ColorMapSize = 1 << BitsPerPixel;

	RWidth = Width = GWidth;
	RHeight = Height = GHeight;
	LeftOfs = TopOfs = 0;

	Resolution = BitsPerPixel;

	/*
	 * Calculate number of bits we are expecting
	 */
	CountDown = (long)Width * (long)Height;

	/*
	 * Indicate which pass we are on (if interlace)
	 */
	Pass = 0;

	/*
	 * The initial code size
	 */
	if( BitsPerPixel <= 1 )
		InitCodeSize = 2;
	else
		InitCodeSize = BitsPerPixel;

	/*
	 * Set up the current x and y position
	 */
	curx = cury = 0;

	/*
	 * Write the Magic header
	 */
	fwrite( "GIF87a", 1, 6, fp );

	/*
	 * Write out the screen width and height
	 */
	Putword( RWidth, fp );
	Putword( RHeight, fp );

	/*
	 * Indicate that there is a global colour map
	 */
	B = 0x80;       /* Yes, there is a color map */

	/*
	 * OR in the resolution
	 */
	B |= (Resolution - 1) << 5;

	/*
	 * OR in the Bits per Pixel
	 */
	B |= (BitsPerPixel - 1);

	/*
	 * Write it out
	 */
	fputc( B, fp );

	/*
	 * Write out the Background colour
	 */
	fputc( Background, fp );

	/*
	 * Byte of 0's (future expansion)
	 */
	fputc( 0, fp );

	/*
	 * Write out the Global Colour Map
	 */
	for( i=0; i<ColorMapSize; ++i )
	{
		fputc( Red[i], fp );
		fputc( Green[i], fp );
		fputc( Blue[i], fp );
	}

	/*
	 * Write an Image separator
	 */
	fputc( ',', fp );

	/*
	 * Write the Image header
	 */

	Putword( LeftOfs, fp );
	Putword( TopOfs, fp );
	Putword( Width, fp );
	Putword( Height, fp );

	/*
	 * Write out whether or not the image is interlaced
	 */
	if( Interlace )
		fputc( 0x40, fp );
	else
		fputc( 0x00, fp );

	/*
	 * Write out the initial code size
	 */
	fputc( InitCodeSize, fp );

	/*
	 * Go and actually compress the data
	 */
	compress( InitCodeSize+1, fp, getpixel );

	/*
	 * Write out a Zero-length packet (to end the series)
	 */
	fputc( 0, fp );

	/*
	 * Write the GIF file terminator
	 */
	fputc( ';', fp );

	/*
	 * And close the file
	 */
	fclose( fp );
}

/*
 * Write out a word to the GIF file
 */
#pragma segment graphics
static void Putword(int w, FILE *fp)
{
	fputc( w & 0xff, fp );
	fputc( (w / 256) & 0xff, fp );
}


/***************************************************************************
 *
 *  GIFCOMPR.C       - GIF Image compression routines
 *
 *  Lempel-Ziv compression based on 'compress'.  GIF modifications by
 *  David Rowley (mgardi@watdcsu.waterloo.edu)
 *
 ***************************************************************************/

/*
 * General DEFINEs
 */

#define BITS    12

#define HSIZE  5003            /* 80% occupancy */

#ifdef NO_UCHAR
 typedef char   char_type;
#else /*NO_UCHAR*/
 typedef	unsigned char   char_type;
#endif /*NO_UCHAR*/

/*
 *
 * GIF Image compression - modified 'compress'
 *
 * Based on: compress.c - File compression ala IEEE Computer, June 1984.
 *
 * By Authors:  Spencer W. Thomas       (decvax!harpo!utah-cs!utah-gr!thomas)
 *              Jim McKie               (decvax!mcvax!jim)
 *              Steve Davies            (decvax!vax135!petsd!peora!srd)
 *              Ken Turkowski           (decvax!decwrl!turtlevax!ken)
 *              James A. Woods          (decvax!ihnp4!ames!jaw)
 *              Joe Orost               (decvax!vax135!petsd!joe)
 *
 */
 // TI 4.2a4
#ifndef __MWERKS__
#include <ctype.h>
#endif

#define ARGVAL() (*++(*argv) || (--argc && *++argv))

static int n_bits;			/* number of bits/code */
static int maxbits = BITS;		/* user settable max # bits/code */
static code_int maxcode;		  /* maximum code, given n_bits */
static code_int maxmaxcode = (code_int)1 << BITS; /* should NEVER generate this code */
#ifdef COMPATIBLE	       /* But wrong! */
# define MAXCODE(n_bits)	((code_int) 1 << (n_bits) - 1)
#else /*COMPATIBLE*/
# define MAXCODE(n_bits)	(((code_int) 1 << (n_bits)) - 1)
#endif /*COMPATIBLE*/

#ifndef MACINTOSH
static count_int htab [HSIZE];
static unsigned short codetab [HSIZE];
#endif

#define HashTabOf(i)       htab[i]
#define CodeTabOf(i)    codetab[i]

static code_int hsize = HSIZE;		 /* for dynamic table sizing */

/*
 * To save much memory, we overlay the table used by compress() with those
 * used by decompress().  The tab_prefix table is the same size and type
 * as the codetab.  The tab_suffix table needs 2**BITS characters.  We
 * get this from the beginning of htab.  The output stack uses the rest
 * of htab, and contains characters.  There is plenty of room for any
 * possible stack (stack used to be 8000 characters).
 */

#define tab_prefixof(i) CodeTabOf(i)
#define tab_suffixof(i)	((char_type*)(htab))[i]
#define de_stack	       ((char_type*)&tab_suffixof((code_int)1<<BITS))

static code_int free_ent = 0;		  /* first unused entry */

/*
 * block compression parameters -- after all codes are used up,
 * and compression rate changes, start over.
 */
static int clear_flg = 0;

static int offset;
static long int in_count = 1;	    /* length of input */
static long int out_count = 0;	   /* # of codes output (for debugging) */

/*
 * compress stdin to stdout
 *
 * Algorithm:  use open addressing double hashing (no chaining) on the
 * prefix code / next character combination.  We do a variant of Knuth's
 * algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
 * secondary probe.  Here, the modular division first probe is gives way
 * to a faster exclusive-or manipulation.  Also do block compression with
 * an adaptive reset, whereby the code table is cleared when the compression
 * ratio decreases, but after the table fills.  The variable-length output
 * codes are re-sized at this point, and a special CLEAR code is generated
 * for the decompressor.  Late addition:  construct the table according to
 * file size for noticeable speed improvement on small files.  Please direct
 * questions about this implementation to ames!jaw.
 */

static int g_init_bits;
static FILE* g_outfile;

static int ClearCode;
static int EOFCode;

#pragma segment graphics
static void compress(int init_bits, FILE *outfile, ifunptr ReadValue)
{
	register long fcode;
	register code_int i /* = 0 */;
	register int c;
	register code_int ent;
	register code_int disp;
	register code_int hsize_reg;
	register int hshift;

	/*
	 * Set up the globals:  g_init_bits - initial number of bits
	 *						g_outfile   - pointer to output file
	 */
	g_init_bits = init_bits;
	g_outfile = outfile;

	/*
	 * Set up the necessary values
	 */
	offset = 0;
	out_count = 0;
	clear_flg = 0;
	in_count = 1;
	maxcode = MAXCODE(n_bits = g_init_bits);

	ClearCode = (1 << (init_bits - 1));
	EOFCode = ClearCode + 1;
	free_ent = ClearCode + 2;

	char_init();

	ent = GIFNextPixel( ReadValue );

	hshift = 0;
	for ( fcode = (long) hsize;  fcode < 65536L; fcode *= 2L )
	++hshift;
	hshift = 8 - hshift;		/* set hash code range bound */

	hsize_reg = hsize;
	cl_hash( (count_int) hsize_reg);		/* clear hash table */

	output( (code_int)ClearCode );

#ifdef SIGNED_COMPARE_SLOW
	while ( (c = GIFNextPixel( ReadValue )) != (unsigned) EOF ) {
#else /*SIGNED_COMPARE_SLOW*/
	while ( (c = GIFNextPixel( ReadValue )) != EOF ) {	/* } */
#endif /*SIGNED_COMPARE_SLOW*/

	++in_count;

	fcode = (long) (((long) c << maxbits) + ent);
	i = (((code_int)c << hshift) ^ ent);	/* xor hashing */

	if ( HashTabOf (i) == fcode ) {
		ent = CodeTabOf (i);
		continue;
	}
	else if ( (long)HashTabOf (i) < 0 )	  /* empty slot */
		goto nomatch;
	disp = hsize_reg - i;	   /* secondary hash (after G. Knott) */
	if ( i == 0 )
		disp = 1;
probe:
	if ( (i -= disp) < 0 )
		i += hsize_reg;

	if ( HashTabOf (i) == fcode ) {
		ent = CodeTabOf (i);
		continue;
	}
	if ( (long)HashTabOf (i) > 0 )
		goto probe;
nomatch:
	output ( (code_int) ent );
	++out_count;
	ent = c;
#ifdef SIGNED_COMPARE_SLOW
	if ( (unsigned) free_ent < (unsigned) maxmaxcode) {
#else /*SIGNED_COMPARE_SLOW*/
	if ( free_ent < maxmaxcode ) {	/* } */
#endif /*SIGNED_COMPARE_SLOW*/
		CodeTabOf (i) = free_ent++; /* code -> hashtable */
		HashTabOf (i) = fcode;
	}
	else
		cl_block();
	}
	/*
	 * Put out the final code.
	 */
	output( (code_int)ent );
	++out_count;
	output( (code_int) EOFCode );
}

/*****************************************************************
 * TAG( output )
 *
 * Output the given code.
 * Inputs:
 *	  code:   A n_bits-bit integer.  If == -1, then EOF.  This assumes
 *		  that n_bits =< (long)wordsize - 1.
 * Outputs:
 *	  Outputs code to the file.
 * Assumptions:
 *	  Chars are 8 bits long.
 * Algorithm:
 *	  Maintain a BITS character long buffer (so that 8 codes will
 * fit in it exactly).  Use the VAX insv instruction to insert each
 * code in turn.  When the buffer fills up empty it and start over.
 */

static unsigned long cur_accum = 0;
static int cur_bits = 0;

static unsigned long masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F,
								 0x001F, 0x003F, 0x007F, 0x00FF,
								 0x01FF, 0x03FF, 0x07FF, 0x0FFF,
								 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF };

#pragma segment graphics
static void output(code_int code)
{
	cur_accum &= masks[ cur_bits ];

	if( cur_bits > 0 )
		cur_accum |= ((long)code << cur_bits);
	else
		cur_accum = code;

	cur_bits += n_bits;

	while( cur_bits >= 8 )
	{
		char_out( (unsigned int)(cur_accum & 0xff) );
		cur_accum >>= 8;
		cur_bits -= 8;
	}

	/*
	 * If the next entry is going to be too big for the code size,
	 * then increase it, if possible.
	 */
   if ( free_ent > maxcode || clear_flg )
   {
		if( clear_flg )
		{
			maxcode = MAXCODE (n_bits = g_init_bits);
			clear_flg = 0;
		}
		else
		{
			++n_bits;
			if ( n_bits == maxbits )
				maxcode = maxmaxcode;
			else
				maxcode = MAXCODE(n_bits);
		}
	}

	if( code == EOFCode )
	{
	/*
	 * At EOF, write the rest of the buffer.
	 */
	while( cur_bits > 0 )
	{
		char_out( (unsigned int)(cur_accum & 0xff) );
		cur_accum >>= 8;
		cur_bits -= 8;
	}

	flush_char();

	fflush( g_outfile );

	if( ferror( g_outfile ) )
		writeerr();
	}
}

/*
 * Clear out the hash table
 */
#pragma segment graphics
static void cl_block (void)		 /* table clear for block compress */
{

	cl_hash ( (count_int) hsize );
	free_ent = ClearCode + 2;
	clear_flg = 1;

	output( (code_int)ClearCode );
}

#pragma segment graphics
static void cl_hash(register count_int hsize)	  /* reset code table */
{
	register count_int *htab_p = htab+hsize;

	register long i;
	register long m1 = -1;

	i = hsize - 16;
	do {				/* might use Sys V memset(3) here */
		*(htab_p-16) = m1;
		*(htab_p-15) = m1;
		*(htab_p-14) = m1;
		*(htab_p-13) = m1;
		*(htab_p-12) = m1;
		*(htab_p-11) = m1;
		*(htab_p-10) = m1;
		*(htab_p-9) = m1;
		*(htab_p-8) = m1;
		*(htab_p-7) = m1;
		*(htab_p-6) = m1;
		*(htab_p-5) = m1;
		*(htab_p-4) = m1;
		*(htab_p-3) = m1;
		*(htab_p-2) = m1;
		*(htab_p-1) = m1;
		htab_p -= 16;
	} while ((i -= 16) >= 0);

	for ( i += 16; i > 0; --i )
		*--htab_p = m1;
}

#pragma segment graphics
static void writeerr(void)
{
	gif_error( kNoWriteErr, gGIFfileErr );
}

/******************************************************************************
 *
 * GIF Specific routines
 *
 ******************************************************************************/

/*
 * Number of characters so far in this 'packet'
 */
static int a_count;

/*
 * Set up the 'byte output' routine
 */
#pragma segment graphics
static void char_init(void)
{
	a_count = 0;
}

#ifndef MACINTOSH
/*
 * Define the storage for the packet accumulator
 */
static char accum[ 256 ];
#endif

/*
 * Add a character to the end of the current packet, and if it is 254
 * characters, flush the packet to disk.
 */
#pragma segment graphics
static void char_out(int c)
{
	accum[ a_count++ ] = c;
	if( a_count >= 254 )
		flush_char();
}

/*
 * Flush the packet to disk, and reset the accumulator
 */
#pragma segment graphics
static void flush_char(void)
{
	if( a_count > 0 ) {
		fputc( a_count, g_outfile );
		fwrite( accum, 1, a_count, g_outfile );
		a_count = 0;
	}
}

#ifdef MACINTOSH
//
//////////////////////////////////////////////////////////////////////////////////
//
// InitGIFEncoderGlobals - init the globals used by the encoder functions.  this
//			is necessary since we may call these functions several times during a
//			single run of the program, so static initialization is not sufficient.
//////////////////////////////////////////////////////////////////////////////////
//
#pragma segment graphics
void InitGIFEncoderGlobals(void)
{
	Pass = 0;
	maxbits = BITS;                /* user settable max # bits/code */
	maxmaxcode = (code_int)1 << BITS; /* should NEVER generate this code */
	hsize = HSIZE;                 /* for dynamic table sizing */
	free_ent = 0;                  /* first unused entry */
	clear_flg = 0;
	in_count = 1;            /* length of input */
	out_count = 0;           /* # of codes output (for debugging) */
	cur_accum = 0;
	cur_bits = 0;
}
#endif



/* The End */