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2efdd507c9
o Add WITHOUT_IPV6 knob (Requested by Jens Rehsack <rehsack@liwing.de> in ports/53754, implemented in a slightly different way). o Add GIF and animated GIF write support by default in GD and add WITH_LZW knob to enable the LZW compression algorithm (patented in some countries). o Removed gd_gif_out.diff patch and added many new patches. PR: ports/53754, ports/53879 Requested by: Jens Rehsack <rehsack@liwing.de> Submitted by: Alex Dupre <sysadmin@alexdupre.com> (maintainer)
940 lines
25 KiB
C
940 lines
25 KiB
C
--- ext/gd/libgd/gd_lzw_out.c.orig Sat Jun 28 15:47:56 2003
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+++ ext/gd/libgd/gd_lzw_out.c Sat Jun 28 16:01:04 2003
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@@ -0,0 +1,936 @@
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+#ifdef HAVE_MALLOC_H
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+ #include <malloc.h>
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+#endif
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+#include <stdio.h>
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+#include <math.h>
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+#include <string.h>
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+#include <stdlib.h>
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+#include "gd.h"
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+
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+/* Code drawn from ppmtogif.c, from the pbmplus package
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+**
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+** Based on GIFENCOD by David Rowley <mgardi@watdscu.waterloo.edu>. A
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+** Lempel-Zim compression based on "compress".
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+**
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+** Modified by Marcel Wijkstra <wijkstra@fwi.uva.nl>
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+**
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+** Copyright (C) 1989 by Jef Poskanzer.
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+**
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+** Permission to use, copy, modify, and distribute this software and its
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+** documentation for any purpose and without fee is hereby granted, provided
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+** that the above copyright notice appear in all copies and that both that
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+** copyright notice and this permission notice appear in supporting
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+** documentation. This software is provided "as is" without express or
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+** implied warranty.
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+**
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+** The Graphics Interchange Format(c) is the Copyright property of
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+** CompuServe Incorporated. GIF(sm) is a Service Mark property of
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+** CompuServe Incorporated.
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+*/
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+
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+/*
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+ * a code_int must be able to hold 2**GIFBITS values of type int, and also -1
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+ */
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+typedef int code_int;
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+
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+#ifdef SIGNED_COMPARE_SLOW
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+typedef unsigned long int count_int;
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+typedef unsigned short int count_short;
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+#else /*SIGNED_COMPARE_SLOW*/
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+typedef long int count_int;
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+#endif /*SIGNED_COMPARE_SLOW*/
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+
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+static int colorstobpp(int colors);
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+static void BumpPixel (void);
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+static int GIFNextPixel (gdImagePtr im);
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+static void GIFEncode (gdIOCtx *fp, int GWidth, int GHeight, int GInterlace, int Background, int Transparent, int BitsPerPixel, int *Red, int *Green, int *Blue, gdImagePtr im);
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+static void GIFAnimEncode(gdIOCtx *fp, int IWidth, int IHeight, int LeftOfs, int TopOfs, int GInterlace, int Transparent, int Delay, int Disposal, int BitsPerPixel, int *Red, int *Green, int *Blue, gdImagePtr im);
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+/*static void Putword (int w, gdIOCtx *fp); */
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+static void compress (int init_bits, gdIOCtx *outfile, gdImagePtr im);
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+static void output (code_int code);
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+static void cl_block (void);
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+static void cl_hash (register count_int hsize);
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+static void char_init (void);
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+static void char_out (int c);
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+static void flush_char (void);
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+/* Allows for reuse */
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+static void init_statics(void);
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+
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+void gdImageLzwCtx(gdImagePtr im, gdIOCtx *out)
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+{
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+ int interlace, transparent, BitsPerPixel;
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+
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+ interlace = im->interlace;
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+ transparent = im->transparent;
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+
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+ BitsPerPixel = colorstobpp(im->colorsTotal);
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+ /* Clear any old values in statics strewn through the GIF code */
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+ init_statics();
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+ /* All set, let's do it. */
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+ GIFEncode(
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+ out, im->sx, im->sy, interlace, 0, transparent, BitsPerPixel,
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+ im->red, im->green, im->blue, im);
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+}
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+
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+void gdImageLzw(gdImagePtr im, FILE *outFile)
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+{
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+ gdIOCtx *out = gdNewFileCtx(outFile);
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+ gdImageLzwCtx(im, out);
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+ out->gd_free(out);
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+}
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+
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+void* gdImageLzwPtr(gdImagePtr im, int *size)
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+{
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+ void *rv;
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+ gdIOCtx *out = gdNewDynamicCtx(2048, NULL);
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+ gdImageLzwCtx(im, out);
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+ rv = gdDPExtractData(out,size);
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+ out->gd_free(out);
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+ return rv;
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+}
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+
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+void gdImageLzwAnimAddCtx(gdImagePtr im, gdIOCtx *out, int LocalCM, int LeftOfs, int TopOfs, int Delay, int Disposal)
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+{
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+ int interlace, transparent, BitsPerPixel;
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+
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+ interlace = im->interlace;
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+ transparent = im->transparent;
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+
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+ BitsPerPixel = colorstobpp(im->colorsTotal);
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+ /* Clear any old values in statics strewn through the GIF code */
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+ init_statics();
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+ /* All set, let's do it. */
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+ GIFAnimEncode(
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+ out, im->sx, im->sy, LeftOfs, TopOfs, interlace, transparent,
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+ Delay, Disposal, BitsPerPixel,
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+ LocalCM > 0 ? im->red : 0, im->green, im->blue, im);
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+}
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+
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+void gdImageLzwAnimAdd(gdImagePtr im, FILE *outFile, int LocalCM, int LeftOfs, int TopOfs, int Delay, int Disposal)
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+{
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+ gdIOCtx *out = gdNewFileCtx(outFile);
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+ gdImageLzwAnimAddCtx(im, out, LocalCM, LeftOfs, TopOfs, Delay, Disposal);
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+ out->gd_free(out);
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+}
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+
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+void* gdImageLzwAnimAddPtr(gdImagePtr im, int *size, int LocalCM, int LeftOfs, int TopOfs, int Delay, int Disposal)
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+{
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+ void *rv;
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+ gdIOCtx *out = gdNewDynamicCtx(2048, NULL);
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+ gdImageLzwAnimAddCtx(im, out, LocalCM, LeftOfs, TopOfs, Delay, Disposal);
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+ rv = gdDPExtractData(out,size);
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+ out->gd_free(out);
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+ return rv;
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+}
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+
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+
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+
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+static int
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+colorstobpp(int colors)
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+{
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+ int bpp = 0;
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+
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+ if ( colors <= 2 )
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+ bpp = 1;
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+ else if ( colors <= 4 )
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+ bpp = 2;
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+ else if ( colors <= 8 )
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+ bpp = 3;
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+ else if ( colors <= 16 )
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+ bpp = 4;
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+ else if ( colors <= 32 )
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+ bpp = 5;
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+ else if ( colors <= 64 )
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+ bpp = 6;
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+ else if ( colors <= 128 )
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+ bpp = 7;
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+ else if ( colors <= 256 )
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+ bpp = 8;
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+ return bpp;
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+ }
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+
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+/*****************************************************************************
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+ *
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+ * GIFENCODE.C - GIF Image compression interface
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+ *
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+ * GIFEncode( FName, GHeight, GWidth, GInterlace, Background, Transparent,
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+ * BitsPerPixel, Red, Green, Blue, gdImagePtr )
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+ *
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+ *****************************************************************************/
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+
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+#define TRUE 1
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+#define FALSE 0
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+
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+static int Width, Height;
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+static int curx, cury;
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+static long CountDown;
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+static int Pass = 0;
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+static int Interlace;
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+
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+/*
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+ * Bump the 'curx' and 'cury' to point to the next pixel
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+ */
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+static void
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+BumpPixel(void)
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+{
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+ /*
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+ * Bump the current X position
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+ */
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+ ++curx;
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+
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+ /*
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+ * If we are at the end of a scan line, set curx back to the beginning
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+ * If we are interlaced, bump the cury to the appropriate spot,
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+ * otherwise, just increment it.
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+ */
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+ if( curx == Width ) {
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+ curx = 0;
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+
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+ if( !Interlace )
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+ ++cury;
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+ else {
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+ switch( Pass ) {
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+
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+ case 0:
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+ cury += 8;
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+ if( cury >= Height ) {
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+ ++Pass;
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+ cury = 4;
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+ }
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+ break;
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+
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+ case 1:
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+ cury += 8;
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+ if( cury >= Height ) {
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+ ++Pass;
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+ cury = 2;
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+ }
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+ break;
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+
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+ case 2:
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+ cury += 4;
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+ if( cury >= Height ) {
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+ ++Pass;
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+ cury = 1;
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+ }
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+ break;
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+
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+ case 3:
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+ cury += 2;
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+ break;
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+ }
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+ }
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+ }
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+}
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+
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+/*
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+ * Return the next pixel from the image
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+ */
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+static int
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+GIFNextPixel(gdImagePtr im)
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+{
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+ int r;
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+
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+ if( CountDown == 0 )
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+ return EOF;
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+
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+ --CountDown;
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+
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+ r = gdImageGetPixel(im, curx, cury);
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+
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+ BumpPixel();
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+
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+ return r;
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+}
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+
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+/* public */
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+
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+static void
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+GIFEncode(gdIOCtx *fp, int GWidth, int GHeight, int GInterlace, int Background, int Transparent, int BitsPerPixel, int *Red, int *Green, int *Blue, gdImagePtr im)
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+{
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+ int B;
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+ int RWidth, RHeight;
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+ int LeftOfs, TopOfs;
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+ int Resolution;
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+ int ColorMapSize;
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+ int InitCodeSize;
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+ int i;
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+
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+ Interlace = GInterlace;
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+
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+ ColorMapSize = 1 << BitsPerPixel;
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+
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+ RWidth = Width = GWidth;
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+ RHeight = Height = GHeight;
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+ LeftOfs = TopOfs = 0;
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+
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+ Resolution = BitsPerPixel;
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+
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+ /*
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+ * Calculate number of bits we are expecting
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+ */
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+ CountDown = (long)Width * (long)Height;
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+
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+ /*
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+ * Indicate which pass we are on (if interlace)
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+ */
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+ Pass = 0;
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+
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+ /*
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+ * The initial code size
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+ */
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+ if( BitsPerPixel <= 1 )
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+ InitCodeSize = 2;
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+ else
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+ InitCodeSize = BitsPerPixel;
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+
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+ /*
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+ * Set up the current x and y position
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+ */
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+ curx = cury = 0;
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+
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+ /*
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+ * Write the Magic header
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+ */
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+ gdPutBuf( Transparent < 0 ? "GIF87a" : "GIF89a", 6, fp );
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+
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+ /*
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+ * Write out the screen width and height
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+ */
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+ Putword( RWidth, fp );
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+ Putword( RHeight, fp );
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+
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+ /*
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+ * Indicate that there is a global colour map
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+ */
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+ B = 0x80; /* Yes, there is a color map */
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+
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+ /*
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+ * OR in the resolution
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+ */
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+ B |= (Resolution - 1) << 5;
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+
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+ /*
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+ * OR in the Bits per Pixel
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+ */
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+ B |= (BitsPerPixel - 1);
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+
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+ /*
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+ * Write it out
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+ */
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+ gdPutC( B, fp );
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+
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+ /*
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+ * Write out the Background colour
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+ */
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+ gdPutC( Background, fp );
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+
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+ /*
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+ * Byte of 0's (future expansion)
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+ */
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+ gdPutC( 0, fp );
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+
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+ /*
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+ * Write out the Global Colour Map
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+ */
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+ for( i=0; i<ColorMapSize; ++i ) {
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+ gdPutC( Red[i], fp );
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+ gdPutC( Green[i], fp );
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+ gdPutC( Blue[i], fp );
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+ }
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+
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+ /*
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+ * Write out extension for transparent colour index, if necessary.
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+ */
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+ if ( Transparent >= 0 ) {
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+ gdPutC( '!', fp );
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+ gdPutC( 0xf9, fp );
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+ gdPutC( 4, fp );
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+ gdPutC( 1, fp );
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+ gdPutC( 0, fp );
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+ gdPutC( 0, fp );
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+ gdPutC( (unsigned char) Transparent, fp );
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+ gdPutC( 0, fp );
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+ }
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+
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+ /*
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+ * Write an Image separator
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+ */
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+ gdPutC( ',', fp );
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+
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+ /*
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+ * Write the Image header
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+ */
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+
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+ Putword( LeftOfs, fp );
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+ Putword( TopOfs, fp );
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+ Putword( Width, fp );
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+ Putword( Height, fp );
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+
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+ /*
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+ * Write out whether or not the image is interlaced
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+ */
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+ if( Interlace )
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+ gdPutC( 0x40, fp );
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+ else
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+ gdPutC( 0x00, fp );
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+
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+ /*
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+ * Write out the initial code size
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+ */
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+ gdPutC( InitCodeSize, fp );
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+
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+ /*
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+ * Go and actually compress the data
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+ */
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+ compress( InitCodeSize+1, fp, im );
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+
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+ /*
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+ * Write out a Zero-length packet (to end the series)
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+ */
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+ gdPutC( 0, fp );
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+
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+ /*
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+ * Write the GIF file terminator
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+ */
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+ gdPutC( ';', fp );
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+}
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+
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+static void
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+GIFAnimEncode(gdIOCtx *fp, int IWidth, int IHeight, int LeftOfs, int TopOfs, int GInterlace, int Transparent, int Delay, int Disposal, int BitsPerPixel, int *Red, int *Green, int *Blue, gdImagePtr im)
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+{
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+ int ColorMapSize;
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+ int InitCodeSize;
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+ int i;
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+
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+ if (LeftOfs < 0) LeftOfs = 0;
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+ if (TopOfs < 0) TopOfs = 0;
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+ if (Delay < 0) Delay = 100;
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+ if (Disposal < 0) Disposal = 2;
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+
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+ Interlace = GInterlace;
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+
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+ ColorMapSize = 1 << BitsPerPixel;
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+
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+ Width = IWidth;
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+ Height = IHeight;
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+
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+ /*
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+ * Calculate number of bits we are expecting
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+ */
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+ CountDown = (long)Width * (long)Height;
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+
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+ /*
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+ * Indicate which pass we are on (if interlace)
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+ */
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+ Pass = 0;
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+
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+ /*
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+ * The initial code size
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+ */
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+ if( BitsPerPixel <= 1 )
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+ InitCodeSize = 2;
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+ else
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+ InitCodeSize = BitsPerPixel;
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+
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+ /*
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+ * Set up the current x and y position
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+ */
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+ curx = cury = 0;
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+
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+ /*
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+ * Write out extension for image animation and looping
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+ */
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+ gdPutC( '!', fp );
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+ gdPutC( 0xf9, fp );
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+ gdPutC( 4, fp );
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+ gdPutC( (Transparent >= 0 ? 1 : 0)
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+ | (Disposal << 2), fp );
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+ gdPutC( (unsigned char)(Delay & 255), fp );
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+ gdPutC( (unsigned char)((Delay >> 8) & 255), fp );
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+ gdPutC( (unsigned char) Transparent, fp );
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+ gdPutC( 0, fp );
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+
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+ /*
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+ * Write an Image separator
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+ */
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+ gdPutC( ',', fp );
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+
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+ /*
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+ * Write the Image header
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+ */
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+
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+ Putword( LeftOfs, fp );
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+ Putword( TopOfs, fp );
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+ Putword( Width, fp );
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+ Putword( Height, fp );
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+
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+ /*
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+ * Write out whether or not the image is interlaced
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+ * and if it includes local colour map.
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+ */
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+ gdPutC( (Interlace ? 0x40 : 0)
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+ | (Red ? 0x80 : 0)
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+ | (Red ? BitsPerPixel - 1 : 0), fp );
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+
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+ /*
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+ * Write out the Local Colour Map
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+ */
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+ if (Red)
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+ for( i=0; i<ColorMapSize; ++i ) {
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+ gdPutC( Red[i], fp );
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+ gdPutC( Green[i], fp );
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+ gdPutC( Blue[i], fp );
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+ }
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+
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+ /*
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+ * Write out the initial code size
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+ */
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+ gdPutC( InitCodeSize, fp );
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+
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+ /*
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+ * Go and actually compress the data
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+ */
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+ compress( InitCodeSize+1, fp, im );
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+
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+ /*
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+ * Write out a Zero-length packet (to end the series)
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+ */
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+ gdPutC( 0, fp );
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+}
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+
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+/* */
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+/* * Write out a word to the GIF file */
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+/* */
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+/*static void */
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+/*Putword(int w, FILE *fp) */
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+/*{ */
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+/* fputc( w & 0xff, fp ); */
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+/* fputc( (w / 256) & 0xff, fp ); */
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+/*} */
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+
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+
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+/***************************************************************************
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+ *
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+ * 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 <ctype.h>
|
|
+
|
|
+#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 [HSIZE];
|
|
+static unsigned short codetab [HSIZE];
|
|
+#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<<GIFBITS))
|
|
+
|
|
+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 gdIOCtx* g_outfile;
|
|
+
|
|
+static int ClearCode;
|
|
+static int EOFCode;
|
|
+
|
|
+static void
|
|
+compress(int init_bits, gdIOCtx *outfile, gdImagePtr im)
|
|
+{
|
|
+ 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( im );
|
|
+
|
|
+ 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( im )) != (unsigned) EOF ) {
|
|
+#else /*SIGNED_COMPARE_SLOW*/
|
|
+ while ( (c = GIFNextPixel( im )) != 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 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();
|
|
+
|
|
+/* fflush( g_outfile ); */
|
|
+/* */
|
|
+/* if( ferror( g_outfile ) ) */
|
|
+/* return; */
|
|
+ }
|
|
+}
|
|
+
|
|
+/*
|
|
+ * 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++ ] = 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 ) {
|
|
+ gdPutC( a_count, g_outfile );
|
|
+ gdPutBuf( accum, a_count, g_outfile );
|
|
+ a_count = 0;
|
|
+ }
|
|
+}
|
|
+
|
|
+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. */
|
|
+ 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;
|
|
+ g_outfile = 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. | */
|
|
+/* +-------------------------------------------------------------------+ */
|