| 1 |
greg |
1.1 |
#ifndef lint
|
| 2 |
schorsch |
1.2 |
static const char RCSid[] = "$Id: genflake.c,v 1.1 2003/02/22 02:07:26 greg Exp $";
|
| 3 |
greg |
1.1 |
#endif
|
| 4 |
|
|
/*
|
| 5 |
|
|
* genflake.c - program to make snowflakes
|
| 6 |
|
|
*
|
| 7 |
|
|
* 11/12/86
|
| 8 |
|
|
*
|
| 9 |
|
|
* cc genflake.c primout.o mfio.o syscalls.o misc.o
|
| 10 |
|
|
*/
|
| 11 |
|
|
|
| 12 |
|
|
#include "meta.h"
|
| 13 |
|
|
|
| 14 |
|
|
#include "random.h"
|
| 15 |
|
|
|
| 16 |
|
|
#define FSIZE 6144
|
| 17 |
|
|
#define FACT(a) (int)((a)*5321L/FSIZE)
|
| 18 |
|
|
#define CENTER 8192
|
| 19 |
|
|
|
| 20 |
|
|
char *progname;
|
| 21 |
|
|
|
| 22 |
|
|
int branch = 6; /* number of branches */
|
| 23 |
|
|
|
| 24 |
|
|
main(argc, argv)
|
| 25 |
|
|
int argc;
|
| 26 |
|
|
char *argv[];
|
| 27 |
|
|
{
|
| 28 |
|
|
int i;
|
| 29 |
|
|
int seed = 0;
|
| 30 |
|
|
int nflakes = 1;
|
| 31 |
|
|
|
| 32 |
|
|
progname = argv[0];
|
| 33 |
|
|
for (i = 1; i < argc && argv[i][0] == '-'; i++)
|
| 34 |
|
|
switch (argv[i][1]) {
|
| 35 |
|
|
case 's': /* seed */
|
| 36 |
|
|
seed = atoi(argv[++i]);
|
| 37 |
|
|
break;
|
| 38 |
|
|
case 'b': /* number of branches */
|
| 39 |
|
|
branch = atoi(argv[++i]);
|
| 40 |
|
|
break;
|
| 41 |
|
|
case 'n': /* number of flakes */
|
| 42 |
|
|
nflakes = atoi(argv[++i]);
|
| 43 |
|
|
break;
|
| 44 |
|
|
default:
|
| 45 |
|
|
fprintf(stderr, "%s: unknown option: %s\n",
|
| 46 |
|
|
progname, argv[i]);
|
| 47 |
|
|
exit(1);
|
| 48 |
|
|
}
|
| 49 |
|
|
while (seed-- > 0)
|
| 50 |
|
|
random();
|
| 51 |
|
|
while (nflakes-- > 0) {
|
| 52 |
|
|
genflake(0, 0, 0, FSIZE, branch);
|
| 53 |
|
|
pglob(PEOP, 0200, NULL);
|
| 54 |
|
|
}
|
| 55 |
|
|
writeof(stdout);
|
| 56 |
|
|
exit(0);
|
| 57 |
|
|
}
|
| 58 |
|
|
|
| 59 |
|
|
|
| 60 |
|
|
genflake(x0, y0, x1, y1, nb) /* make a flake */
|
| 61 |
|
|
int x0, y0, x1, y1;
|
| 62 |
|
|
int nb;
|
| 63 |
|
|
{
|
| 64 |
|
|
int bx0, by0, bx1, by1;
|
| 65 |
|
|
int i;
|
| 66 |
|
|
|
| 67 |
|
|
symvect(x0, y0, x1, y1);
|
| 68 |
|
|
for (i = 0; i < nb; i++) {
|
| 69 |
|
|
bx0 = random()%FSIZE;
|
| 70 |
|
|
by0 = y0 + (y1-y0)*(long)bx0/FSIZE;
|
| 71 |
|
|
bx0 = x0 + (x1-x0)*(long)bx0/FSIZE;
|
| 72 |
|
|
bx1 = FACT(y0-y1);
|
| 73 |
|
|
by1 = FACT(x1-x0);
|
| 74 |
|
|
if (random()&1) {
|
| 75 |
|
|
bx1 += (x1-x0)/2;
|
| 76 |
|
|
by1 += (y1-y0)/2;
|
| 77 |
|
|
} else {
|
| 78 |
|
|
bx1 -= (x1-x0)/2;
|
| 79 |
|
|
by1 -= (y1-y0)/2;
|
| 80 |
|
|
}
|
| 81 |
|
|
bx1 = bx0 + bx1*(i+1)/(2*nb);
|
| 82 |
|
|
by1 = by0 + by1*(i+1)/(2*nb);
|
| 83 |
|
|
genflake(bx0, by0, bx1, by1, i);
|
| 84 |
|
|
}
|
| 85 |
|
|
}
|
| 86 |
|
|
|
| 87 |
|
|
|
| 88 |
|
|
symvect(x0, y0, x1, y1) /* output with symmetry */
|
| 89 |
|
|
int x0, y0, x1, y1;
|
| 90 |
|
|
{
|
| 91 |
|
|
symvect2(x0, y0, x1, y1);
|
| 92 |
|
|
symvect2(x0, -y0, x1, -y1);
|
| 93 |
|
|
symvect2(-x0, y0, -x1, y1);
|
| 94 |
|
|
symvect2(-x0, -y0, -x1, -y1);
|
| 95 |
|
|
}
|
| 96 |
|
|
|
| 97 |
|
|
|
| 98 |
|
|
symvect2(x0, y0, x1, y1)
|
| 99 |
|
|
int x0, y0, x1, y1;
|
| 100 |
|
|
{
|
| 101 |
|
|
int x0p, x1p, y0p, y1p;
|
| 102 |
|
|
|
| 103 |
|
|
plseg(0, CENTER+x0, CENTER+y0, CENTER+x1, CENTER+y1);
|
| 104 |
|
|
plseg(0, CENTER+x0/2+FACT(-y0), CENTER+y0/2+FACT(x0),
|
| 105 |
|
|
CENTER+x1/2+FACT(-y1), CENTER+y1/2+FACT(x1));
|
| 106 |
|
|
plseg(0, CENTER+x0/2+FACT(y0), CENTER+y0/2+FACT(-x0),
|
| 107 |
|
|
CENTER+x1/2+FACT(y1), CENTER+y1/2+FACT(-x1));
|
| 108 |
|
|
}
|
