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root/radiance/ray/src/gen/genworm.c
Revision: 1.2
Committed: Sun Sep 10 16:45:18 1989 UTC (34 years, 7 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.1: +3 -1 lines
Log Message:
fixed location of SCCSid

File Contents

# Content
1 /* Copyright (c) 1989 Regents of the University of California */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ LBL";
5 #endif
6
7 /*
8 * genworm.c - program to generate worms (strings with varying thickness).
9 *
10 * The program takes as input the functions of t for x, y,
11 * z and r (the radius). Cylinders and cones will be
12 * joined by spheres. Negative radii are forbidden.
13 *
14 * 9/24/87
15 */
16
17 #include <stdio.h>
18
19 #include "fvect.h"
20
21 #define XNAME "X_" /* x function name */
22 #define YNAME "Y_" /* y function name */
23 #define ZNAME "Z_" /* z function name */
24 #define RNAME "R_" /* r function name */
25
26 #define PI 3.14159265358979323846
27
28 #define FTINY 1e-7
29
30 #define max(a,b) ((a) > (b) ? (a) : (b))
31
32
33 double funvalue(), l_hermite(), argument();
34
35
36 main(argc, argv)
37 int argc;
38 char *argv[];
39 {
40 char stmp[256];
41 double t, f, lastr, r;
42 FVECT lastp, p;
43 int i, nseg;
44
45 varset("PI", PI, NULL);
46 funset("hermite", 5, l_hermite);
47
48 if (argc < 8)
49 goto userror;
50
51 for (i = 8; i < argc; i++)
52 if (!strcmp(argv[i], "-e"))
53 scompile(NULL, argv[++i]);
54 else if (!strcmp(argv[i], "-f"))
55 fcompile(argv[++i]);
56 else
57 goto userror;
58
59 sprintf(stmp, "%s(t)=%s;", XNAME, argv[3]);
60 scompile(NULL, stmp);
61 sprintf(stmp, "%s(t)=%s;", YNAME, argv[4]);
62 scompile(NULL, stmp);
63 sprintf(stmp, "%s(t)=%s;", ZNAME, argv[5]);
64 scompile(NULL, stmp);
65 sprintf(stmp, "%s(t)=%s;", RNAME, argv[6]);
66 scompile(NULL, stmp);
67 nseg = atoi(argv[7]);
68 if (nseg <= 0)
69 goto userror;
70
71 printhead(argc, argv);
72
73 for (i = 0; i <= nseg; i++) {
74 t = (double)i/nseg;
75 p[0] = funvalue(XNAME, 1, &t);
76 p[1] = funvalue(YNAME, 1, &t);
77 p[2] = funvalue(ZNAME, 1, &t);
78 r = funvalue(RNAME, 1, &t);
79 if (i)
80 if (lastr <= r+FTINY && lastr >= r-FTINY) {
81 printf("\n%s cylinder %s.c%d\n",
82 argv[1], argv[2], i);
83 printf("0\n0\n7\n");
84 printf("%18.12g %18.12g %18.12g\n",
85 lastp[0], lastp[1], lastp[2]);
86 printf("%18.12g %18.12g %18.12g\n",
87 p[0], p[1], p[2]);
88 printf("%18.12g\n", r);
89 } else {
90 printf("\n%s cone %s.c%d\n",
91 argv[1], argv[2], i);
92 printf("0\n0\n8\n");
93 f = (lastr - r)/dist2(lastp,p);
94 printf("%18.12g %18.12g %18.12g\n",
95 lastp[0] + f*lastr*(p[0] - lastp[0]),
96 lastp[1] + f*lastr*(p[1] - lastp[1]),
97 lastp[2] + f*lastr*(p[2] - lastp[2]));
98 printf("%18.12g %18.12g %18.12g\n",
99 p[0] + f*r*(p[0] - lastp[0]),
100 p[1] + f*r*(p[1] - lastp[1]),
101 p[2] + f*r*(p[2] - lastp[2]));
102 f = 1.0 - (lastr-r)*f;
103 f = f <= 0.0 ? 0.0 : sqrt(f);
104 printf("%18.12g %18.12g\n", f*lastr, f*r);
105 }
106 printf("\n%s sphere %s.s%d\n", argv[1], argv[2], i);
107 printf("0\n0\n4 %18.12g %18.12g %18.12g %18.12g\n",
108 p[0], p[1], p[2], r);
109 VCOPY(lastp, p);
110 lastr = r;
111 }
112 quit(0);
113
114 userror:
115 fprintf(stderr,
116 "Usage: %s material name x(t) y(t) z(t) r(t) nseg [-e expr] [-f file]\n",
117 argv[0]);
118 quit(1);
119 }
120
121
122 eputs(msg)
123 char *msg;
124 {
125 fputs(msg, stderr);
126 }
127
128
129 wputs(msg)
130 char *msg;
131 {
132 eputs(msg);
133 }
134
135
136 quit(code)
137 {
138 exit(code);
139 }
140
141
142 printhead(ac, av) /* print command header */
143 register int ac;
144 register char **av;
145 {
146 putchar('#');
147 while (ac--) {
148 putchar(' ');
149 fputs(*av++, stdout);
150 }
151 putchar('\n');
152 }
153
154
155 double
156 l_hermite()
157 {
158 double t;
159
160 t = argument(5);
161 return( argument(1)*((2.0*t-3.0)*t*t+1.0) +
162 argument(2)*(-2.0*t+3.0)*t*t +
163 argument(3)*((t-2.0)*t+1.0)*t +
164 argument(4)*(t-1.0)*t*t );
165 }