thomson@cs.utah.edu (Rich Thomson) (09/20/89)
For those of you that have the Utah Raster Toolkit, here's a little format
converter I hacked up from xgif. It could be alot smarter, but it's only a
hack.
-- Rich
-=-=-=-=-=-=--==-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
: Run this shell script with "sh" not "csh"
PATH=/bin:/usr/bin:/usr/ucb:/etc:$PATH
export PATH
all=false
if [ x$1 = x-a ]; then
all=true
fi
echo Extracting Makefile
sed 's/^X//' <<'//go.sysin dd *' >Makefile
X# You must edit the CFLAGS and LIBS macros to tell the compiler where to
X# find the Raster Toolkit include files and library.
XOBJS = gifload.o gif2rle.o
X
XCFLAGS = -g -I/u/alpha1/urt/include
XLIBS = /u/alpha1/urt/lib/librle.a
X
Xgif2rle: $(OBJS)
X $(CC) -o gif2rle $(OBJS) $(LIBS)
X
X$(OBJS): gif2rle.h
X
Xclean:
X rm -rf $(OBJS) gif2rle
//go.sysin dd *
if [ `wc -c < Makefile` != 328 ]; then
made=false
echo error transmitting Makefile --
echo length should be 328, not `wc -c < Makefile`
else
made=true
fi
if $made; then
chmod 644 Makefile
echo -n ' '; ls -ld Makefile
fi
echo Extracting gif2rle.c
sed 's/^X//' <<'//go.sysin dd *' >gif2rle.c
X/*
X * gif.c - displays GIF pictures on an X11 display
X *
X * Author: John Bradley, University of Pennsylvania
X * (bradley@cis.upenn.edu)
X */
X
X#define MAIN
X#include "gif2rle.h"
X#include "svfb_global.h"
X
X
X/*******************************************/
Xmain(argc, argv)
X int argc;
X char *argv[];
X/*******************************************/
X{
X int i;
X char *fname;
X
X cmd = argv[0];
X fname = NULL;
X
X if (argc > 2)
X Syntax();
X else if (argc == 2)
X fname = argv[1];
X else
X fname = "-";
X
X /****************** Open/Read the File *****************/
X LoadGIF(fname);
X
X DumpRLE();
X}
X
X#define GET_INDEX(x,y) *(Image + (y)*BytesPerScanline + (x))
X
XDumpRLE()
X {
X rle_pixel *rows[3];
X int i, x, y;
X byte *ptr;
X
X sv_globals.svfb_fd = stdout;
X sv_globals.sv_xmin = 0;
X sv_globals.sv_ymin = 0;
X sv_globals.sv_xmax = Width-1;
X sv_globals.sv_ymax = Height-1;
X sv_globals.sv_ncolors = 3;
X sv_globals.sv_alpha = 0;
X sv_setup(RUN_DISPATCH, &sv_globals);
X
X for (i = 0; i < 3; i++)
X if ((rows[i] = (rle_pixel *) malloc(Width*sizeof(rle_pixel))) == NULL)
X FatalError("couldn't allocate RLE row!");
X
X for (y = 0; y < Height; y++)
X {
X for (x = 0; x < Width; x++)
X {
X i = (int) GET_INDEX(x, (Height-1)-y);
X rows[0][x] = (rle_pixel) Red[i];
X rows[1][x] = (rle_pixel) Green[i];
X rows[2][x] = (rle_pixel) Blue[i];
X }
X
X sv_putrow(rows, Width, &sv_globals);
X }
X
X sv_puteof(&sv_globals);
X }
X
X/***********************************/
XSyntax()
X{
X printf("Usage: %s [filename]\n",cmd);
X exit(1);
X}
X
X
X/***********************************/
XFatalError (identifier)
X char *identifier;
X{
X fprintf(stderr, "%s: %s\n",cmd, identifier);
X exit(-1);
X}
//go.sysin dd *
if [ `wc -c < gif2rle.c` != 1777 ]; then
made=false
echo error transmitting gif2rle.c --
echo length should be 1777, not `wc -c < gif2rle.c`
else
made=true
fi
if $made; then
chmod 644 gif2rle.c
echo -n ' '; ls -ld gif2rle.c
fi
echo Extracting gif2rle.h
sed 's/^X//' <<'//go.sysin dd *' >gif2rle.h
X/*
X * xgif.h - header file for xgif, but you probably already knew as much
X */
X
X
X#define REVDATE "Rev: 2/13/89"
X#define MAXEXPAND 16
X
X/* include files */
X#include <stdio.h>
X#include <math.h>
X#include <ctype.h>
X
X#ifndef MAIN
X#define WHERE extern
X#else
X#define WHERE
X#endif
X
X#define False 0
X#define True 1
X
Xtypedef unsigned char byte;
X
X#define CENTERX(f,x,str) ((x)-XTextWidth(f,str,strlen(str))/2)
X#define CENTERY(f,y) ((y)-((f->ascent+f->descent)/2)+f->ascent)
X
X
X/* global vars */
Xextern int Width, Height, BytesPerScanline;
Xextern byte *Image;
Xextern byte Red[], Green[], Blue[];
XWHERE char *cmd;
//go.sysin dd *
if [ `wc -c < gif2rle.h` != 612 ]; then
made=false
echo error transmitting gif2rle.h --
echo length should be 612, not `wc -c < gif2rle.h`
else
made=true
fi
if $made; then
chmod 644 gif2rle.h
echo -n ' '; ls -ld gif2rle.h
fi
echo Extracting gifload.c
sed 's/^X//' <<'//go.sysin dd *' >gifload.c
X/*
X * gifload.c is based strongly on...
X *
X * gif2ras.c - Converts from a Compuserve GIF (tm) image to a Sun Raster image.
X *
X * Copyright (c) 1988, 1989 by Patrick J. Naughton
X *
X * Author: Patrick J. Naughton
X * naughton@wind.sun.com
X *
X * Permission to use, copy, modify, and distribute this software and its
X * documentation for any purpose and without fee is hereby granted,
X * provided that the above copyright notice appear in all copies and that
X * both that copyright notice and this permission notice appear in
X * supporting documentation.
X *
X * This file is provided AS IS with no warranties of any kind. The author
X * shall have no liability with respect to the infringement of copyrights,
X * trade secrets or any patents by this file or any part thereof. In no
X * event will the author be liable for any lost revenue or profits or
X * other special, indirect and consequential damages.
X *
X */
X
X#include "gif2rle.h"
X
Xtypedef int boolean;
X
X#define NEXTBYTE (*ptr++)
X#define IMAGESEP 0x2c
X#define INTERLACEMASK 0x40
X#define COLORMAPMASK 0x80
X
XFILE *fp;
X
Xint BitOffset = 0, /* Bit Offset of next code */
X XC = 0, YC = 0, /* Output X and Y coords of current pixel */
X Pass = 0, /* Used by output routine if interlaced pic */
X OutCount = 0, /* Decompressor output 'stack count' */
X RWidth, RHeight, /* screen dimensions */
X Width, Height, /* image dimensions */
X LeftOfs, TopOfs, /* image offset */
X BitsPerPixel, /* Bits per pixel, read from GIF header */
X BytesPerScanline, /* bytes per scanline in output raster */
X ColorMapSize, /* number of colors */
X Background, /* background color */
X CodeSize, /* Code size, read from GIF header */
X InitCodeSize, /* Starting code size, used during Clear */
X Code, /* Value returned by ReadCode */
X MaxCode, /* limiting value for current code size */
X ClearCode, /* GIF clear code */
X EOFCode, /* GIF end-of-information code */
X CurCode, OldCode, InCode, /* Decompressor variables */
X FirstFree, /* First free code, generated per GIF spec */
X FreeCode, /* Decompressor, next free slot in hash table */
X FinChar, /* Decompressor variable */
X BitMask, /* AND mask for data size */
X ReadMask; /* Code AND mask for current code size */
X
Xboolean Interlace, HasColormap;
X
Xbyte *Image; /* The result array */
Xbyte *RawGIF; /* The heap array to hold it, raw */
Xbyte *Raster; /* The raster data stream, unblocked */
X
X /* The hash table used by the decompressor */
Xint Prefix[4096];
Xint Suffix[4096];
X
X /* An output array used by the decompressor */
Xint OutCode[1025];
X
X /* The color map, read from the GIF header */
Xbyte Red[256], Green[256], Blue[256], used[256];
Xint numused;
X
Xchar *id = "GIF87a";
X
X
X
X/*****************************/
XLoadGIF(fname)
X char *fname;
X/*****************************/
X{
X int filesize;
X register byte ch, ch1;
X register byte *ptr, *ptr1;
X register int i;
X
X if (strcmp(fname,"-")==0) { fp = stdin; fname = "<stdin>"; }
X else fp = fopen(fname,"r");
X
X if (!fp) FatalError("file not found");
X
X /* find the size of the file */
X fseek(fp, 0L, 2);
X filesize = ftell(fp);
X fseek(fp, 0L, 0);
X
X if (!(ptr = RawGIF = (byte *) malloc(filesize)))
X FatalError("not enough memory to read gif file");
X
X if (!(Raster = (byte *) malloc(filesize)))
X FatalError("not enough memory to read gif file");
X
X if (fread(ptr, filesize, 1, fp) != 1)
X FatalError("GIF data read failed");
X
X if (strncmp(ptr, id, 6))
X FatalError("not a GIF file");
X
X ptr += 6;
X
X/* Get variables from the GIF screen descriptor */
X
X ch = NEXTBYTE;
X RWidth = ch + 0x100 * NEXTBYTE; /* screen dimensions... not used. */
X ch = NEXTBYTE;
X RHeight = ch + 0x100 * NEXTBYTE;
X
X
X ch = NEXTBYTE;
X HasColormap = ((ch & COLORMAPMASK) ? True : False);
X
X BitsPerPixel = (ch & 7) + 1;
X ColorMapSize = 1 << BitsPerPixel;
X BitMask = ColorMapSize - 1;
X
X Background = NEXTBYTE; /* background color... not used. */
X
X if (NEXTBYTE) /* supposed to be NULL */
X FatalError("corrupt GIF file (bad screen descriptor)");
X
X
X/* Read in global colormap. */
X
X if (HasColormap)
X {
X for (i = 0; i < ColorMapSize; i++)
X {
X Red[i] = NEXTBYTE;
X Green[i] = NEXTBYTE;
X Blue[i] = NEXTBYTE;
X used[i] = 0;
X }
X
X numused = 0;
X }
X
X/* Check for image seperator */
X
X if (NEXTBYTE != IMAGESEP)
X FatalError("corrupt GIF file (no image separator)");
X
X/* Now read in values from the image descriptor */
X
X ch = NEXTBYTE;
X LeftOfs = ch + 0x100 * NEXTBYTE;
X ch = NEXTBYTE;
X TopOfs = ch + 0x100 * NEXTBYTE;
X ch = NEXTBYTE;
X Width = ch + 0x100 * NEXTBYTE;
X ch = NEXTBYTE;
X Height = ch + 0x100 * NEXTBYTE;
X Interlace = ((NEXTBYTE & INTERLACEMASK) ? True : False);
X
X
X/* Note that I ignore the possible existence of a local color map.
X * I'm told there aren't many files around that use them, and the spec
X * says it's defined for future use. This could lead to an error
X * reading some files.
X */
X
X/* Start reading the raster data. First we get the intial code size
X * and compute decompressor constant values, based on this code size.
X */
X
X CodeSize = NEXTBYTE;
X ClearCode = (1 << CodeSize);
X EOFCode = ClearCode + 1;
X FreeCode = FirstFree = ClearCode + 2;
X
X/* The GIF spec has it that the code size is the code size used to
X * compute the above values is the code size given in the file, but the
X * code size used in compression/decompression is the code size given in
X * the file plus one. (thus the ++).
X */
X
X CodeSize++;
X InitCodeSize = CodeSize;
X MaxCode = (1 << CodeSize);
X ReadMask = MaxCode - 1;
X
X/* Read the raster data. Here we just transpose it from the GIF array
X * to the Raster array, turning it from a series of blocks into one long
X * data stream, which makes life much easier for ReadCode().
X */
X
X ptr1 = Raster;
X do {
X ch = ch1 = NEXTBYTE;
X while (ch--) *ptr1++ = NEXTBYTE;
X if ((Raster - ptr1) > filesize)
X FatalError("corrupt GIF file (unblock)");
X } while(ch1);
X
X free(RawGIF); /* We're done with the raw data now... */
X
X
X /* Allocate the Image */
X Image = (byte *) malloc(Width*Height);
X if (!Image) FatalError("not enough memory for Image");
X
X BytesPerScanline = Width;
X
X
X/* Decompress the file, continuing until you see the GIF EOF code.
X * One obvious enhancement is to add checking for corrupt files here.
X */
X
X Code = ReadCode();
X while (Code != EOFCode) {
X
X/* Clear code sets everything back to its initial value, then reads the
X * immediately subsequent code as uncompressed data.
X */
X
X if (Code == ClearCode) {
X CodeSize = InitCodeSize;
X MaxCode = (1 << CodeSize);
X ReadMask = MaxCode - 1;
X FreeCode = FirstFree;
X CurCode = OldCode = Code = ReadCode();
X FinChar = CurCode & BitMask;
X AddToPixel(FinChar);
X }
X else {
X
X/* If not a clear code, then must be data: save same as CurCode and InCode */
X
X CurCode = InCode = Code;
X
X/* If greater or equal to FreeCode, not in the hash table yet;
X * repeat the last character decoded
X */
X
X if (CurCode >= FreeCode) {
X CurCode = OldCode;
X OutCode[OutCount++] = FinChar;
X }
X
X/* Unless this code is raw data, pursue the chain pointed to by CurCode
X * through the hash table to its end; each code in the chain puts its
X * associated output code on the output queue.
X */
X
X while (CurCode > BitMask) {
X if (OutCount > 1024) {
X FatalError("Corrupt GIF file (OutCount)!");
X }
X OutCode[OutCount++] = Suffix[CurCode];
X CurCode = Prefix[CurCode];
X }
X
X/* The last code in the chain is treated as raw data. */
X
X FinChar = CurCode & BitMask;
X OutCode[OutCount++] = FinChar;
X
X/* Now we put the data out to the Output routine.
X * It's been stacked LIFO, so deal with it that way...
X */
X
X for (i = OutCount - 1; i >= 0; i--)
X AddToPixel(OutCode[i]);
X OutCount = 0;
X
X/* Build the hash table on-the-fly. No table is stored in the file. */
X
X Prefix[FreeCode] = OldCode;
X Suffix[FreeCode] = FinChar;
X OldCode = InCode;
X
X/* Point to the next slot in the table. If we exceed the current
X * MaxCode value, increment the code size unless it's already 12. If it
X * is, do nothing: the next code decompressed better be CLEAR
X */
X
X FreeCode++;
X if (FreeCode >= MaxCode) {
X if (CodeSize < 12) {
X CodeSize++;
X MaxCode *= 2;
X ReadMask = (1 << CodeSize) - 1;
X }
X }
X }
X Code = ReadCode();
X }
X
X free(Raster);
X
X if (fp != stdin)
X fclose(fp);
X}
X
X
X/* Fetch the next code from the raster data stream. The codes can be
X * any length from 3 to 12 bits, packed into 8-bit bytes, so we have to
X * maintain our location in the Raster array as a BIT Offset. We compute
X * the byte Offset into the raster array by dividing this by 8, pick up
X * three bytes, compute the bit Offset into our 24-bit chunk, shift to
X * bring the desired code to the bottom, then mask it off and return it.
X */
XReadCode()
X{
Xint RawCode, ByteOffset;
X
X ByteOffset = BitOffset / 8;
X RawCode = Raster[ByteOffset] + (0x100 * Raster[ByteOffset + 1]);
X if (CodeSize >= 8)
X RawCode += (0x10000 * Raster[ByteOffset + 2]);
X RawCode >>= (BitOffset % 8);
X BitOffset += CodeSize;
X return(RawCode & ReadMask);
X}
X
X
XAddToPixel(Index)
Xbyte Index;
X{
X if (YC<Height)
X *(Image + YC * BytesPerScanline + XC) = Index;
X
X if (!used[Index]) { used[Index]=1; numused++; }
X
X/* Update the X-coordinate, and if it overflows, update the Y-coordinate */
X
X if (++XC == Width) {
X
X/* If a non-interlaced picture, just increment YC to the next scan line.
X * If it's interlaced, deal with the interlace as described in the GIF
X * spec. Put the decoded scan line out to the screen if we haven't gone
X * past the bottom of it
X */
X
X XC = 0;
X if (!Interlace) YC++;
X else {
X switch (Pass) {
X case 0:
X YC += 8;
X if (YC >= Height) {
X Pass++;
X YC = 4;
X }
X break;
X case 1:
X YC += 8;
X if (YC >= Height) {
X Pass++;
X YC = 2;
X }
X break;
X case 2:
X YC += 4;
X if (YC >= Height) {
X Pass++;
X YC = 1;
X }
X break;
X case 3:
X YC += 2;
X break;
X default:
X break;
X }
X }
X }
X}
//go.sysin dd *
if [ `wc -c < gifload.c` != 10222 ]; then
made=false
echo error transmitting gifload.c --
echo length should be 10222, not `wc -c < gifload.c`
else
made=true
fi
if $made; then
chmod 644 gifload.c
echo -n ' '; ls -ld gifload.c
fi
Rich Thomson thomson@cs.utah.edu {bellcore,hplabs,uunet}!utah-cs!thomson
"Tyranny, like hell, is not easily conquered; yet we have this consolation with
us, that the harder the conflict, the more glorious the triumph. What we obtain
too cheap, we esteem too lightly." Thomas Paine, _The Crisis_, Dec. 23rd, 1776