src/meta/genflake.c

#ifndef lint
static const char       RCSid[] = "$Id$";
#endif
/*
 *  genflake.c - program to make snowflakes
 *
 *      11/12/86
 *
 *  cc genflake.c primout.o mfio.o syscalls.o misc.o
 */

#include  "meta.h"

#include  "random.h"

#define  FSIZE          6144
#define  FACT(a)        (int)((a)*5321L/FSIZE)
#define  CENTER         8192

char  *progname;

int  branch = 6;                /* number of branches */

main(argc, argv)
int  argc;
char  *argv[];
{
        int  i;
        int  seed = 0;
        int  nflakes = 1;
        
#ifdef  CPM
        fixargs("genflake", &argc, &argv);
#endif
        progname = argv[0];
        for (i = 1; i < argc && argv[i][0] == '-'; i++)
                switch (argv[i][1]) {
                case 's':                       /* seed */
                        seed = atoi(argv[++i]);
                        break;
                case 'b':                       /* number of branches */
                        branch = atoi(argv[++i]);
                        break;
                case 'n':                       /* number of flakes */
                        nflakes = atoi(argv[++i]);
                        break;
                default:
                        fprintf(stderr, "%s: unknown option: %s\n",
                                        progname, argv[i]);
                        exit(1);
                }
        while (seed-- > 0)
                random();
        while (nflakes-- > 0) {
                genflake(0, 0, 0, FSIZE, branch);
                pglob(PEOP, 0200, NULL);
        }
        writeof(stdout);
        exit(0);
}


genflake(x0, y0, x1, y1, nb)                    /* make a flake */
int  x0, y0, x1, y1;
int  nb;
{
        int  bx0, by0, bx1, by1;
        int  i;
        
        symvect(x0, y0, x1, y1);
        for (i = 0; i < nb; i++) {
                bx0 = random()%FSIZE;
                by0 = y0 + (y1-y0)*(long)bx0/FSIZE;
                bx0 = x0 + (x1-x0)*(long)bx0/FSIZE;
                bx1 = FACT(y0-y1);
                by1 = FACT(x1-x0);
                if (random()&1) {
                        bx1 += (x1-x0)/2;
                        by1 += (y1-y0)/2;
                } else {
                        bx1 -= (x1-x0)/2;
                        by1 -= (y1-y0)/2;
                }
                bx1 = bx0 + bx1*(i+1)/(2*nb);
                by1 = by0 + by1*(i+1)/(2*nb);
                genflake(bx0, by0, bx1, by1, i);
        }
}


symvect(x0, y0, x1, y1)                 /* output with symmetry */
int  x0, y0, x1, y1;
{
        symvect2(x0, y0, x1, y1);
        symvect2(x0, -y0, x1, -y1);
        symvect2(-x0, y0, -x1, y1);
        symvect2(-x0, -y0, -x1, -y1);
}


symvect2(x0, y0, x1, y1)
int  x0, y0, x1, y1;
{
        int  x0p, x1p, y0p, y1p;
        
        plseg(0, CENTER+x0, CENTER+y0, CENTER+x1, CENTER+y1);
        plseg(0, CENTER+x0/2+FACT(-y0), CENTER+y0/2+FACT(x0),
                 CENTER+x1/2+FACT(-y1), CENTER+y1/2+FACT(x1));
        plseg(0, CENTER+x0/2+FACT(y0), CENTER+y0/2+FACT(-x0),
                 CENTER+x1/2+FACT(y1), CENTER+y1/2+FACT(-x1));
}
Revision:	1.1
Committed:	Sat Feb 22 02:07:26 2003 UTC (21 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R5
Log Message:	Changes and check-in for 3.5 release Includes new source files and modifications not recorded for many years See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release
#	Content
1	#ifndef lint
2	static const char RCSid[] = "$Id$";
3	#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	#ifdef CPM
33	fixargs("genflake", &argc, &argv);
34	#endif
35	progname = argv[0];
36	for (i = 1; i < argc && argv[i][0] == '-'; i++)
37	switch (argv[i][1]) {
38	case 's': /* seed */
39	seed = atoi(argv[++i]);
40	break;
41	case 'b': /* number of branches */
42	branch = atoi(argv[++i]);
43	break;
44	case 'n': /* number of flakes */
45	nflakes = atoi(argv[++i]);
46	break;
47	default:
48	fprintf(stderr, "%s: unknown option: %s\n",
49	progname, argv[i]);
50	exit(1);
51	}
52	while (seed-- > 0)
53	random();
54	while (nflakes-- > 0) {
55	genflake(0, 0, 0, FSIZE, branch);
56	pglob(PEOP, 0200, NULL);
57	}
58	writeof(stdout);
59	exit(0);
60	}
61
62
63	genflake(x0, y0, x1, y1, nb) /* make a flake */
64	int x0, y0, x1, y1;
65	int nb;
66	{
67	int bx0, by0, bx1, by1;
68	int i;
69
70	symvect(x0, y0, x1, y1);
71	for (i = 0; i < nb; i++) {
72	bx0 = random()%FSIZE;
73	by0 = y0 + (y1-y0)*(long)bx0/FSIZE;
74	bx0 = x0 + (x1-x0)*(long)bx0/FSIZE;
75	bx1 = FACT(y0-y1);
76	by1 = FACT(x1-x0);
77	if (random()&1) {
78	bx1 += (x1-x0)/2;
79	by1 += (y1-y0)/2;
80	} else {
81	bx1 -= (x1-x0)/2;
82	by1 -= (y1-y0)/2;
83	}
84	bx1 = bx0 + bx1(i+1)/(2nb);
85	by1 = by0 + by1(i+1)/(2nb);
86	genflake(bx0, by0, bx1, by1, i);
87	}
88	}
89
90
91	symvect(x0, y0, x1, y1) /* output with symmetry */
92	int x0, y0, x1, y1;
93	{
94	symvect2(x0, y0, x1, y1);
95	symvect2(x0, -y0, x1, -y1);
96	symvect2(-x0, y0, -x1, y1);
97	symvect2(-x0, -y0, -x1, -y1);
98	}
99
100
101	symvect2(x0, y0, x1, y1)
102	int x0, y0, x1, y1;
103	{
104	int x0p, x1p, y0p, y1p;
105
106	plseg(0, CENTER+x0, CENTER+y0, CENTER+x1, CENTER+y1);
107	plseg(0, CENTER+x0/2+FACT(-y0), CENTER+y0/2+FACT(x0),
108	CENTER+x1/2+FACT(-y1), CENTER+y1/2+FACT(x1));
109	plseg(0, CENTER+x0/2+FACT(y0), CENTER+y0/2+FACT(-x0),
110	CENTER+x1/2+FACT(y1), CENTER+y1/2+FACT(-x1));
111	}