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worldgen.c
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worldgen.c
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/*
* Copyright (C) 1999 John Olsson
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* Fractal Worldmap Generator Version 2.2
*
* Creator: John Olsson
* Thanks to Carl Burke for interesting discussions and suggestions of
* how to speed up the generation! :)
*
* This program is provided as is, and it's basically a "hack". So if you
* want a better userinterface, you will have to provide it by yourself!
*
* For ideas about how to implement different projections, you can always
* look in WorldMapGenerator.c (the CGI program that generates the gifs
* on my www-page (http://www.lysator.liu.se/~johol/fwmg/fwmg.html).
*
* Please visit my WWW-pages located at: http://www.lysator.liu.se/~johol/
* You can send E-Mail to this adress: [email protected]
*
* I compile this program with: gcc -O3 worldgen.c -lm -o gengif
*
* This program will write the GIF-file to a file which you are
* prompted to specify.
*
* To change size of the generated picture, change the default values
* of the variables XRange och YRange.
*
* You use this program at your own risk! :)
*
*
* When you run the program you are prompted to input three values:
*
* Seed: This the "seed" used to initialize the random number
* generator. So if you use the same seed, you'll get the
* same sequence of random numbers...
*
* Number of faults: This is how many iterations the program will do.
* If you want to know how it works, just enter 1, 2, 3,...
* etc. number of iterations and compare the different
* GIF-files.
*
* PercentWater: This should be a value between 0 and 100 (you can
* input 1000 also, but I don't know what the program
* is up to then! :) The number tells the "ratio"
* between water and land. If you want a world with
* just a few islands, input a large value (EG. 80 or
* above), if you want a world with nearly no oceans,
* a value near 0 would do that.
*
*/
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <string.h>
#include <math.h>
/* These define:s are for the GIF-saver... */
/* 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 void BumpPixel ( void );
static int GIFNextPixel ( void );
static void GIFEncode (FILE* fp, int GWidth, int GHeight, int GInterlace, int Background, int BitsPerPixel, int Red[], int Green[], int Blue[]);
static void Putword ( int w, FILE* fp );
static void compress ( int init_bits, FILE* outfile );
static void output ( code_int code );
static void cl_block ( void );
static void cl_hash ( count_int hsize );
static void writeerr ( void );
static void char_init ( void );
static void char_out ( int c );
static void flush_char ( void );
/* My own definitions */
#ifndef PI
#define PI 3.141593
#endif
/* This value holds the maximum value rand() can generate
*
* RAND_MAX *might* be defined in stdlib.h, if it's not
* you *might* have to change the definition of MAX_RAND...
*/
#ifdef RAND_MAX
#define MAX_RAND RAND_MAX
#else
#define MAX_RAND 0x7FFFFFFF
#endif
/* Function that generates the worldmap */
void GenerateWorldMap();
/* 4-connective floodfill algorithm which I use for constructing
* the ice-caps.*/
void FloodFill4(int x, int y, int OldColor);
int *WorldMapArray;
int XRange = 320;
int YRange = 160;
int Histogram[256];
int FilledPixels;
int Red[49] = {0,0,0,0,0,0,0,0,34,68,102,119,136,153,170,187,
0,34,34,119,187,255,238,221,204,187,170,153,
136,119,85,68,
255,250,245,240,235,230,225,220,215,210,205,200,
195,190,185,180,175};
int Green[49] = {0,0,17,51,85,119,153,204,221,238,255,255,255,
255,255,255,68,102,136,170,221,187,170,136,
136,102,85,85,68,51,51,34,
255,250,245,240,235,230,225,220,215,210,205,200,
195,190,185,180,175};
int Blue[49] = {0,68,102,136,170,187,221,255,255,255,255,255,
255,255,255,255,0,0,0,0,0,34,34,34,34,34,34,
34,34,34,17,0,
255,250,245,240,235,230,225,220,215,210,205,200,
195,190,185,180,175};
float YRangeDiv2, YRangeDivPI;
float *SinIterPhi;
void main(int argc, char **argv)
{
int NumberOfFaults=0, a, j, i, Color, MaxZ=1, MinZ=-1;
int row, TwoColorMode=0;
int index2;
unsigned Seed=0;
int Threshold, Count;
int PercentWater, PercentIce, Cur;
char SaveName[256]; /* 255 character filenames should be enough? */
char SaveFile[256]; /* SaveName + .gif */
FILE * Save;
WorldMapArray = (int *) malloc(XRange*YRange*sizeof(int));
if (WorldMapArray == NULL)
{
fprintf(stderr, "I can't allocate enough memory!\n");
}
SinIterPhi = (float *) malloc(2*XRange*sizeof(float));
if (SinIterPhi == NULL)
{
fprintf(stderr, "I can't allocate enough memory!\n");
}
for (i=0; i<XRange; i++)
{
SinIterPhi[i] = SinIterPhi[i+XRange] = (float)sin(i*2*PI/XRange);
}
fprintf(stderr, "Seed: ");
scanf("%d", &Seed);
fprintf(stderr, "Number of faults: ");
scanf("%d", &NumberOfFaults);
fprintf(stderr, "Percent water: ");
scanf("%d", &PercentWater);
fprintf(stderr, "Percent ice: ");
scanf("%d", &PercentIce);
fprintf(stderr, "Save as (.GIF will be appended): ");
scanf("%8s", SaveName);
srand(Seed);
for (j=0, row=0; j<XRange; j++)
{
WorldMapArray[row] = 0;
for (i=1; i<YRange; i++) WorldMapArray[i+row] = INT_MIN;
row += YRange;
}
/* Define some "constants" which we use frequently */
YRangeDiv2 = YRange/2;
YRangeDivPI = YRange/PI;
/* Generate the map! */
for (a=0; a<NumberOfFaults; a++)
{
GenerateWorldMap();
}
/* Copy data (I have only calculated faults for 1/2 the image.
* I can do this due to symmetry... :) */
index2 = (XRange/2)*YRange;
for (j=0, row=0; j<XRange/2; j++)
{
for (i=1; i<YRange; i++) /* fix */
{
WorldMapArray[row+index2+YRange-i] = WorldMapArray[row+i];
}
row += YRange;
}
/* Reconstruct the real WorldMap from the WorldMapArray and FaultArray */
for (j=0, row=0; j<XRange; j++)
{
/* We have to start somewhere, and the top row was initialized to 0,
* but it might have changed during the iterations... */
Color = WorldMapArray[row];
for (i=1; i<YRange; i++)
{
/* We "fill" all positions with values != INT_MIN with Color */
Cur = WorldMapArray[row+i];
if (Cur != INT_MIN)
{
Color += Cur;
}
WorldMapArray[row+i] = Color;
}
row += YRange;
}
/* Compute MAX and MIN values in WorldMapArray */
for (j=0; j<XRange*YRange; j++)
{
Color = WorldMapArray[j];
if (Color > MaxZ) MaxZ = Color;
if (Color < MinZ) MinZ = Color;
}
/* Compute color-histogram of WorldMapArray.
* This histogram is a very crude aproximation, since all pixels are
* considered of the same size... I will try to change this in a
* later version of this program. */
for (j=0, row=0; j<XRange; j++)
{
for (i=0; i<YRange; i++)
{
Color = WorldMapArray[row+i];
Color = (int)(((float)(Color - MinZ + 1) / (float)(MaxZ-MinZ+1))*30)+1;
Histogram[Color]++;
}
row += YRange;
}
/* Threshold now holds how many pixels PercentWater means */
Threshold = PercentWater*XRange*YRange/100;
/* "Integrate" the histogram to decide where to put sea-level */
for (j=0, Count=0;j<256;j++)
{
Count += Histogram[j];
if (Count > Threshold) break;
}
/* Threshold now holds where sea-level is */
Threshold = j*(MaxZ - MinZ + 1)/30 + MinZ;
if (TwoColorMode)
{
for (j=0, row=0; j<XRange; j++)
{
for (i=0; i<YRange; i++)
{
Color = WorldMapArray[row+i];
if (Color < Threshold)
WorldMapArray[row+i] = 3;
else
WorldMapArray[row+i] = 20;
}
row += YRange;
}
}
else
{
/* Scale WorldMapArray to colorrange in a way that gives you
* a certain Ocean/Land ratio */
for (j=0, row=0; j<XRange; j++)
{
for (i=0; i<YRange; i++)
{
Color = WorldMapArray[row+i];
if (Color < Threshold)
Color = (int)(((float)(Color - MinZ) / (float)(Threshold - MinZ))*15)+1;
else
Color = (int)(((float)(Color - Threshold) / (float)(MaxZ - Threshold))*15)+16;
/* Just in case... I DON't want the GIF-saver to flip out! :) */
if (Color < 1) Color=1;
if (Color > 255) Color=31;
WorldMapArray[row+i] = Color;
}
row += YRange;
}
/* "Recycle" Threshold variable, and, eh, the variable still has something
* like the same meaning... :) */
Threshold = PercentIce*XRange*YRange/100;
if ((Threshold <= 0) || (Threshold > XRange*YRange)) goto Finished;
FilledPixels = 0;
/* i==y, j==x */
for (i=0; i<YRange; i++)
{
for (j=0, row=0; j<XRange; j++)
{
Color = WorldMapArray[row+i];
if (Color < 32) FloodFill4(j,i,Color);
/* FilledPixels is a global variable which FloodFill4 modifies...
* I know it's ugly, but as it is now, this is a hack! :)
*/
if (FilledPixels > Threshold) goto NorthPoleFinished;
row += YRange;
}
}
NorthPoleFinished:
FilledPixels=0;
/* i==y, j==x */
for (i = (YRange - 1); i>0; i--) /* fix */
{
for (j=0, row=0; j<XRange; j++)
{
Color = WorldMapArray[row+i];
if (Color < 32) FloodFill4(j,i,Color);
/* FilledPixels is a global variable which FloodFill4 modifies...
* I know it's ugly, but as it is now, this is a hack! :)
*/
if (FilledPixels > Threshold) goto Finished;
row += YRange;
}
}
Finished:;
}
/* append .gif to SaveFile */
sprintf(SaveFile, "%s.gif", SaveName);
/* open binary SaveFile */
Save = fopen(SaveFile, "wb");
/* Write GIF to savefile */
GIFEncode(Save, XRange, YRange, 1, 0, 8, Red, Green, Blue);
fprintf(stderr, "Map created, saved as %s.\n", SaveFile);
free(WorldMapArray);
exit(0);
}
void FloodFill4(int x, int y, int OldColor)
{
if (WorldMapArray[x*YRange+y] == OldColor)
{
if (WorldMapArray[x*YRange+y] < 16)
WorldMapArray[x*YRange+y] = 32;
else
WorldMapArray[x*YRange+y] += 17;
FilledPixels++;
if (y-1 > 0) FloodFill4( x, y-1, OldColor);
if (y+1 < YRange) FloodFill4( x, y+1, OldColor);
if (x-1 < 0)
FloodFill4(XRange-1, y, OldColor); /* fix */
else
FloodFill4( x-1, y, OldColor);
if (x+1 >= XRange) /* fix */
FloodFill4( 0, y, OldColor);
else
FloodFill4( x+1, y, OldColor);
}
}
void GenerateWorldMap()
{
float Alpha, Beta;
float TanB;
float Result, Delta;
int i, row, N2;
int Theta, Phi, Xsi;
unsigned int flag1;
/* I have to do this because of a bug in rand() in Solaris 1...
* Here's what the man-page says:
*
* "The low bits of the numbers generated are not very random;
* use the middle bits. In particular the lowest bit alter-
* nates between 0 and 1."
*
* So I can't optimize this, but you might if you don't have the
* same bug... */
flag1 = rand() & 1; /*(int)((((float) rand())/MAX_RAND) + 0.5);*/
/* Create a random greatcircle...
* Start with an equator and rotate it */
Alpha = (((float) rand())/MAX_RAND-0.5)*PI; /* Rotate around x-axis */
Beta = (((float) rand())/MAX_RAND-0.5)*PI; /* Rotate around y-axis */
TanB = tan(acos(cos(Alpha)*cos(Beta)));
row = 0;
Xsi = (int)(XRange/2-(XRange/PI)*Beta);
for (Phi=0; Phi<XRange/2; Phi++)
{
Theta = (int)(YRangeDivPI*atan(*(SinIterPhi+Xsi-Phi+XRange)*TanB))+YRangeDiv2;
if (flag1)
{
/* Rise northen hemisphere <=> lower southern */
if (WorldMapArray[row+Theta] != INT_MIN)
WorldMapArray[row+Theta]--;
else
WorldMapArray[row+Theta] = -1;
}
else
{
/* Rise southern hemisphere */
if (WorldMapArray[row+Theta] != INT_MIN)
WorldMapArray[row+Theta]++;
else
WorldMapArray[row+Theta] = 1;
}
row += YRange;
}
}
/*****************************************************************************
*
* GIFENCODE.C - GIF Image compression interface
*
* GIFEncode( FName, GHeight, GWidth, GInterlace, Background,
* BitsPerPixel, Red, Green, Blue, GetPixel )
*
*****************************************************************************/
#define TRUE 1
#define FALSE 0
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()
{
/*
* 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( void )
{
int r;
if( CountDown == 0 )
return EOF;
--CountDown;
r = WorldMapArray[ curx*YRange+cury ];
BumpPixel();
return r;
}
/* public */
static void
GIFEncode( fp, GWidth, GHeight, GInterlace, Background,
BitsPerPixel, Red, Green, Blue)
FILE* fp;
int GWidth, GHeight;
int GInterlace;
int Background;
int BitsPerPixel;
int Red[], Green[], Blue[];
{
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);
/*
* 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
*/
static void
Putword( w, fp )
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 ([email protected])
*
***************************************************************************/
/*
* 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)
*
*/
#include <ctype.h>
#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*/
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**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;
static void
compress( init_bits, outfile)
int init_bits;
FILE* outfile;
{
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( );
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( )) != (unsigned) EOF ) {
#else /*SIGNED_COMPARE_SLOW*/
while ( (c = GIFNextPixel( )) != 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 };
static void
output( code )
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
*/
static void