/* togif.c * =========================================================================== * * PUBLIC DOMAIN NOTICE * National Center for Biotechnology Information (NCBI) * * This software/database is a "United States Government Work" under the * terms of the United States Copyright Act. It was written as part of * the author's official duties as a United States Government employee and * thus cannot be copyrighted. This software/database is freely available * to the public for use. The National Library of Medicine and the U.S. * Government do not place any restriction on its use or reproduction. * We would, however, appreciate having the NCBI and the author cited in * any work or product based on this material * * Although all reasonable efforts have been taken to ensure the accuracy * and reliability of the software and data, the NLM and the U.S. * Government do not and cannot warrant the performance or results that * may be obtained by using this software or data. The NLM and the U.S. * Government disclaim all warranties, express or implied, including * warranties of performance, merchantability or fitness for any particular * purpose. * * =========================================================================== */ /* ** Based on GIFENCOD by David Rowley .A ** Lempel-Zim compression based on "compress". ** ** Modified by Marcel Wijkstra ** ** 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. */ /* +-------------------------------------------------------------------+ */ /* | Copyright 1990, 1991, 1993, David Koblas. (koblas@netcom.com) | */ /* | 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. | */ /* +-------------------------------------------------------------------+ */ /* * * File Name: togif.c * * Author: Alex Smirnov * * Version Creation Date: 10/20/95 * * File Description: * GIF generator * * $Log: togif.c,v $ * Revision 6.2 1999/10/26 15:47:36 vakatov * + gdImageGifEx(), gdFWrite -- to specify an alternative GIF write func * (with V.Chetvernin) * * Revision 6.1 1997/11/26 21:26:31 vakatov * Fixed errors and warnings issued by C and C++ (GNU and Sun) compilers * * Revision 6.0 1997/08/25 18:17:37 madden * Revision changed to 6.0 * * Revision 5.3 1996/12/03 21:48:33 vakatov * Adopted for 32-bit MS-Windows DLLs * * Revision 5.2 1996/11/22 19:44:18 vakatov * Added code to read GIF files: gdImageCreateFromGif() * * Revision 5.1 1996/05/29 14:39:20 vakatov * Allocate memory for the "htab" and "codetab" arrays dynamically rather * than keep these as static arrays -- in order to fit THINK C. * * Revision 5.0 1996/05/28 13:18:57 ostell * Set to revision 5.0 * * Revision 1.3 1996/04/23 21:33:07 kans * includes ncbi.h, uses Nlm_Malloc instead of malloc, etc. * * Revision 1.2 1996/04/19 14:29:19 vakatov * Updated non-NCBI copyright headers. * Added VC log. * */ /* Notes: * * Code drawn from ppmtogif.c, from the pbmplus package. * A code_int must be able to hold 2**GIFBITS values of type int, and also -1. */ /**************************************************************************/ /* INCLUDE */ /**************************************************************************/ #include #include /**************************************************************************/ /* TYPEDEFS */ /**************************************************************************/ 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(int colors); static void BumpPixel (void); static int GIFNextPixel (gdImagePtr im); static void GIFEncode (int GWidth, int GHeight, int GInterlace, int Background, int Transparent, int BitsPerPixel, int *Red, int *Green, int *Blue, gdImagePtr im); static void togifPutw (int w); static void compress (int init_bits, gdImagePtr im); static void output (code_int code); static void cl_block (void); static void cl_hash (register count_int hsize); static void char_init (void); static void char_out (int c); static void flush_char (void); static void init_statics(void); static void done_statics(void); /**************************************************************************/ /* STATIC VARIABLE */ /**************************************************************************/ static gdFWrite s_WriteFunc = NULL; static void* s_WriteData = NULL; static char charbuf; /**************************************************************************/ /* STATIC FUNCTION */ /**************************************************************************/ static int colorstobpp(int colors) { int bpp = 0; 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; return bpp; } /* Default callback for gdImageGifEx() -- to write to a FILE* */ #ifdef __cplusplus extern "C" { static size_t s_Write_FILE(const void* buf, size_t size, void* userdata); } #endif static size_t s_Write_FILE(const void* buf, size_t size, void* userdata) { return fwrite(buf, 1, size, (FILE*)userdata); } /**************************************************************************/ /* DEFINES */ /**************************************************************************/ #define s_WRITE(ptr, size) ((*s_WriteFunc)((ptr), (size), (s_WriteData))) #define s_PUTC(c) (charbuf=(c), s_WRITE(&charbuf, 1)) /**************************************************************************/ /* GLOBAL FUNCTIONS */ /**************************************************************************/ NLM_EXTERN void gdImageGif(gdImagePtr im, FILE* out) { gdImageGifEx(im, 0, out); fflush(out); } NLM_EXTERN void gdImageGifEx(gdImagePtr im, gdFWrite func, void* userdata) { /* Allocate & init any old values in statics strewn through the GIF code */ init_statics(); /* Set the write func and its data */ s_WriteFunc = func ? func : s_Write_FILE; s_WriteData = userdata; /* Do the encoding and write */ GIFEncode(im->sx, im->sy, im->interlace, 0, im->transparent, colorstobpp(im->colorsTotal), /* bits per pixel */ im->red, im->green, im->blue, im); /* Free the temporary structures allocated by init_statics() */ done_statics(); } /***************************************************************************** * * GIFENCODE.C - GIF Image compression interface * * GIFEncode( FName, GHeight, GWidth, GInterlace, Background, Transparent, * BitsPerPixel, Red, Green, Blue, gdImagePtr ) * *****************************************************************************/ 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 */ 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 */ static int GIFNextPixel(gdImagePtr im) { int r; if( CountDown == 0 ) return EOF; --CountDown; r = gdImageGetPixel(im, curx, cury); BumpPixel(); return r; } /* public */ static void GIFEncode(int GWidth, int GHeight, int GInterlace, int Background, int Transparent, int BitsPerPixel, int *Red, int *Green, int *Blue, gdImagePtr im) { 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 */ s_WRITE( Transparent < 0 ? "GIF87a" : "GIF89a", 6 ); /* * Write out the screen width and height */ togifPutw( RWidth ); togifPutw( RHeight ); /* * 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 */ s_PUTC( B ); /* * Write out the Background colour */ s_PUTC( Background ); /* * Byte of 0's (future expansion) */ s_PUTC( 0 ); /* * Write out the Global Colour Map */ for( i=0; i= 0 ) { s_PUTC( '!' ); s_PUTC( 0xf9 ); s_PUTC( 4 ); s_PUTC( 1 ); s_PUTC( 0 ); s_PUTC( 0 ); s_PUTC( (unsigned char) Transparent ); s_PUTC( 0 ); } /* * Write an Image separator */ s_PUTC( ',' ); /* * Write the Image header */ togifPutw( LeftOfs ); togifPutw( TopOfs ); togifPutw( Width ); togifPutw( Height ); /* * Write out whether or not the image is interlaced */ if( Interlace ) s_PUTC( 0x40 ); else s_PUTC( 0x00 ); /* * Write out the initial code size */ s_PUTC( InitCodeSize ); /* * Go and actually compress the data */ compress( InitCodeSize+1, im ); /* * Write out a Zero-length packet (to end the series) */ s_PUTC( 0 ); /* * Write the GIF file terminator */ s_PUTC( ';' ); } /* * Write out a word to the GIF file */ static void togifPutw(int w) { s_PUTC( w & 0xff ); s_PUTC( (w / 256) & 0xff ); } /*************************************************************************** * * GIFCOMPR.C - GIF Image compression routines * * Lempel-Ziv compression based on 'compress'. GIF modifications by * David Rowley (mgardi@watdcsu.waterloo.edu) * ***************************************************************************/ /* * General DEFINEs */ #define GIFBITS 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) * */ #include #define ARGVAL() (*++(*argv) || (--argc && *++argv)) static int n_bits; /* number of bits/code */ static int maxbits = GIFBITS; /* user settable max # bits/code */ static code_int maxcode; /* maximum code, given n_bits */ static code_int maxmaxcode = (code_int)1 << GIFBITS; /* 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*/ static count_int *htab = NULL; static unsigned short *codetab = NULL; #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**GIFBITS 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< 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) = (unsigned short)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 GIFBITS 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 }; 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(); } } /* * Clear out the hash table */ 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 ); } 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; } /****************************************************************************** * * GIF Specific routines * ******************************************************************************/ /* * Number of characters so far in this 'packet' */ static int a_count; /* * Set up the 'byte output' routine */ static void char_init(void) { a_count = 0; } /* * Define the storage for the packet accumulator */ static char accum[ 256 ]; /* * Add a character to the end of the current packet, and if it is 254 * characters, flush the packet to disk. */ static void char_out(int c) { accum[ a_count++ ] = (char)c; if( a_count >= 254 ) flush_char(); } /* * Flush the packet to disk, and reset the accumulator */ static void flush_char(void) { if( a_count > 0 ) { s_PUTC( a_count ); s_WRITE( accum, a_count ); a_count = 0; } } static void done_statics(void) { ASSERT ( (htab != NULL) && (codetab != NULL) ); MemFree( htab ); htab = NULL; MemFree( codetab ); codetab = NULL; } static void init_statics(void) { /* Some of these are properly initialized later. What I'm doing here is making sure code that depends on C's initialization of statics doesn't break when the code gets called more than once. */ ASSERT ( (htab == NULL) && (codetab == NULL) ); htab = (count_int *) MemNew(HSIZE * sizeof(count_int )); codetab = (unsigned short *) MemNew(HSIZE * sizeof(unsigned short)); Width = 0; Height = 0; curx = 0; cury = 0; CountDown = 0; Pass = 0; Interlace = 0; a_count = 0; cur_accum = 0; cur_bits = 0; g_init_bits = 0; ClearCode = 0; EOFCode = 0; free_ent = 0; clear_flg = 0; offset = 0; in_count = 1; out_count = 0; hsize = HSIZE; n_bits = 0; maxbits = GIFBITS; maxcode = 0; maxmaxcode = (code_int)1 << GIFBITS; } /*****************************************************************************/ /*****************************************************************************/ /*****************************************************************************/ /*****************************************************************************/ /* +-------------------------------------------------------------------+ */ /* | Copyright 1990, 1991, 1993, David Koblas. (koblas@netcom.com) | */ /* | 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. | */ /* +-------------------------------------------------------------------+ */ #define MAXCOLORMAPSIZE 256 #define CM_RED 0 #define CM_GREEN 1 #define CM_BLUE 2 #define MAX_LWZ_BITS 12 #define INTERLACE 0x40 #define LOCALCOLORMAP 0x80 #define BitSet(byte, bit) (((byte) & (bit)) == (bit)) #define ReadOK(file,buffer,len) (fread(buffer, len, 1, file) != 0) #define LM_to_uint(a,b) (((b)<<8)|(a)) static struct { int transparent; int delayTime; int inputFlag; int disposal; } Gif89 = { -1, -1, -1, 0 }; static int ReadColorMap (FILE *fd, int number, unsigned char (*buffer)[256]); static int DoExtension (FILE *fd, int label, int *Transparent); static int GetDataBlock (FILE *fd, unsigned char *buf); static int GetCode (FILE *fd, int code_size, int flag); static int LWZReadByte (FILE *fd, int flag, int input_code_size); static void ReadImage (gdImagePtr im, FILE *fd, int len, int height, unsigned char (*cmap)[256], int interlace, int ignore); static int ZeroDataBlock; NLM_EXTERN gdImagePtr gdImageCreateFromGif(FILE *fd) { int imageNumber; int BitPixel; int ColorResolution; int Background; int AspectRatio; int Transparent = (-1); unsigned char buf[16]; unsigned char c; unsigned char ColorMap[3][MAXCOLORMAPSIZE]; unsigned char localColorMap[3][MAXCOLORMAPSIZE]; int imw, imh; int useGlobalColormap; int bitPixel; int imageCount = 0; char version[4]; gdImagePtr im = 0; ZeroDataBlock = FALSE; imageNumber = 1; if (! ReadOK(fd,buf,6)) { return 0; } if (strncmp((char *)buf,"GIF",3) != 0) { return 0; } strncpy(version, (char *)buf + 3, 3); version[3] = '\0'; if ((strcmp(version, "87a") != 0) && (strcmp(version, "89a") != 0)) { return 0; } if (! ReadOK(fd,buf,7)) { return 0; } BitPixel = 2<<(buf[4]&0x07); ColorResolution = (int)(buf[4] & 0x70) >> 4; Background = buf[5]; AspectRatio = buf[6]; if (BitSet(buf[4], LOCALCOLORMAP)) { /* Global Colormap */ if (ReadColorMap(fd, BitPixel, ColorMap)) { return 0; } } for (;;) { if (! ReadOK(fd,&c,1)) { return 0; } if (c == ';') { /* GIF terminator */ int i; if (imageCount < imageNumber) { return 0; } /* Terminator before any image was declared! */ if (!im) { return 0; } /* Check for open colors at the end, so we can reduce colorsTotal and ultimately BitsPerPixel */ for (i=((im->colorsTotal-1)); (i>=0); i--) { if (im->open[i]) { im->colorsTotal--; } else { break; } } return im; } if (c == '!') { /* Extension */ if (! ReadOK(fd,&c,1)) { return 0; } DoExtension(fd, c, &Transparent); continue; } if (c != ',') { /* Not a valid start character */ continue; } ++imageCount; if (! ReadOK(fd,buf,9)) { return 0; } useGlobalColormap = ! BitSet(buf[8], LOCALCOLORMAP); bitPixel = 1<<((buf[8]&0x07)+1); imw = LM_to_uint(buf[4],buf[5]); imh = LM_to_uint(buf[6],buf[7]); if (!(im = gdImageCreate(imw, imh))) { return 0; } im->interlace = BitSet(buf[8], INTERLACE); if (! useGlobalColormap) { if (ReadColorMap(fd, bitPixel, localColorMap)) { return 0; } ReadImage(im, fd, imw, imh, localColorMap, BitSet(buf[8], INTERLACE), imageCount != imageNumber); } else { ReadImage(im, fd, imw, imh, ColorMap, BitSet(buf[8], INTERLACE), imageCount != imageNumber); } if (Transparent != (-1)) { gdImageColorTransparent(im, Transparent); } } } static int ReadColorMap(FILE *fd, int number, unsigned char (*buffer)[256]) { int i; unsigned char rgb[3]; for (i = 0; i < number; ++i) { if (! ReadOK(fd, rgb, sizeof(rgb))) { return TRUE; } buffer[CM_RED][i] = rgb[0] ; buffer[CM_GREEN][i] = rgb[1] ; buffer[CM_BLUE][i] = rgb[2] ; } return FALSE; } static int DoExtension(FILE *fd, int label, int *Transparent) { static unsigned char buf[256]; switch (label) { case 0xf9: /* Graphic Control Extension */ (void) GetDataBlock(fd, (unsigned char*) buf); Gif89.disposal = (buf[0] >> 2) & 0x7; Gif89.inputFlag = (buf[0] >> 1) & 0x1; Gif89.delayTime = LM_to_uint(buf[1],buf[2]); if ((buf[0] & 0x1) != 0) *Transparent = buf[3]; while (GetDataBlock(fd, (unsigned char*) buf) != 0) ; return FALSE; default: break; } while (GetDataBlock(fd, (unsigned char*) buf) != 0) ; return FALSE; } static int GetDataBlock(FILE *fd, unsigned char *buf) { unsigned char count; if (! ReadOK(fd,&count,1)) { return -1; } ZeroDataBlock = count == 0; if ((count != 0) && (! ReadOK(fd, buf, count))) { return -1; } return count; } static int GetCode(FILE *fd, int code_size, int flag) { static unsigned char buf[280]; static int curbit, lastbit, done, last_byte; int i, j, ret; unsigned char count; if (flag) { curbit = 0; lastbit = 0; done = FALSE; return 0; } if ( (curbit+code_size) >= lastbit) { if (done) { if (curbit >= lastbit) { /* Oh well */ } return -1; } buf[0] = buf[last_byte-2]; buf[1] = buf[last_byte-1]; if ((count = (unsigned char)GetDataBlock(fd, &buf[2])) == 0) done = TRUE; last_byte = 2 + count; curbit = (curbit - lastbit) + 16; lastbit = (2+count)*8 ; } ret = 0; for (i = curbit, j = 0; j < code_size; ++i, ++j) ret |= ((buf[ i / 8 ] & (1 << (i % 8))) != 0) << j; curbit += code_size; return ret; } static int LWZReadByte(FILE *fd, int flag, int input_code_size) { static int fresh = FALSE; int code, incode; static int code_size, set_code_size; static int max_code, max_code_size; static int firstcode, oldcode; static int clear_code, end_code; static int table[2][(1<< MAX_LWZ_BITS)]; static int stack[(1<<(MAX_LWZ_BITS))*2], *sp; register int i; if (flag) { set_code_size = input_code_size; code_size = set_code_size+1; clear_code = 1 << set_code_size ; end_code = clear_code + 1; max_code_size = 2*clear_code; max_code = clear_code+2; GetCode(fd, 0, TRUE); fresh = TRUE; for (i = 0; i < clear_code; ++i) { table[0][i] = 0; table[1][i] = i; } for (; i < (1< stack) return *--sp; while ((code = GetCode(fd, code_size, FALSE)) >= 0) { if (code == clear_code) { for (i = 0; i < clear_code; ++i) { table[0][i] = 0; table[1][i] = i; } for (; i < (1< 0) ; if (count != 0) return -2; } incode = code; if (code >= max_code) { *sp++ = firstcode; code = oldcode; } while (code >= clear_code) { *sp++ = table[1][code]; if (code == table[0][code]) { /* Oh well */ } code = table[0][code]; } *sp++ = firstcode = table[1][code]; if ((code = max_code) <(1<= max_code_size) && (max_code_size < (1< stack) return *--sp; } return code; } static void ReadImage(gdImagePtr im, FILE *fd, int len, int height, unsigned char (*cmap)[256], int interlace, int ignore) { unsigned char c; int v; int xpos = 0, ypos = 0, pass = 0; int i; /* Stash the color map into the image */ for (i=0; (ired[i] = cmap[CM_RED][i]; im->green[i] = cmap[CM_GREEN][i]; im->blue[i] = cmap[CM_BLUE][i]; im->open[i] = 1; } /* Many (perhaps most) of these colors will remain marked open. */ im->colorsTotal = gdMaxColors; /* ** Initialize the Compression routines */ if (! ReadOK(fd,&c,1)) { return; } if (LWZReadByte(fd, TRUE, c) < 0) { return; } /* ** If this is an "uninteresting picture" ignore it. */ if (ignore) { while (LWZReadByte(fd, FALSE, c) >= 0) ; return; } while ((v = LWZReadByte(fd,FALSE,c)) >= 0 ) { /* This how we recognize which colors are actually used. */ if (im->open[v]) { im->open[v] = 0; } gdImageSetPixel(im, xpos, ypos, v); ++xpos; if (xpos == len) { xpos = 0; if (interlace) { switch (pass) { case 0: case 1: ypos += 8; break; case 2: ypos += 4; break; case 3: ypos += 2; break; } if (ypos >= height) { ++pass; switch (pass) { case 1: ypos = 4; break; case 2: ypos = 2; break; case 3: ypos = 1; break; default: goto fini; } } } else { ++ypos; } } if (ypos >= height) break; } fini: if (LWZReadByte(fd,FALSE,c)>=0) { /* Ignore extra */ } }