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root/radiance/ray/src/gen/genrev.c
Revision: 1.1
Committed: Thu Feb 2 11:16:29 1989 UTC (35 years, 2 months ago) by greg
Content type: text/plain
Branch: MAIN
Log Message:
Initial revision

File Contents

# User Rev Content
1 greg 1.1 /*
2    
3     #ifndef lint
4     static char SCCSid[] = "$SunId$ LBL";
5     #endif
6     * genrev.c - program to generate functions of rotation about z
7     *
8     * The program takes as input the functions of t for z and r
9     * (the radius). If z is increasing, the normal points
10     * outward, inward for decreasing z. Negative radii are forbidden.
11     *
12     * 8/6/86
13     */
14    
15     #include <stdio.h>
16    
17     #define ZNAME "Z_" /* z function name */
18     #define RNAME "R_" /* r function name */
19    
20     #define PI 3.14159265358979323846
21    
22     #define FTINY 1e-9
23     /* orientation */
24     #define OUT 01
25     #define IN 02
26     #define UP 04
27     #define DOWN 010
28    
29     double funvalue(), l_hermite(), argument();
30    
31    
32     main(argc, argv)
33     int argc;
34     char *argv[];
35     {
36     char stmp[256];
37     char *modname;
38     int smooth = 0;
39     double t, lastz, z, nextz, lastr, r, nextr;
40     double lastnz, lastnr, nz, nr, nextnz, nextnr;
41     int i, nseg;
42     int orient;
43    
44     varset("PI", PI);
45     funset("hermite", 5, l_hermite);
46    
47     if (argc < 6)
48     goto userror;
49    
50     for (i = 6; i < argc; i++)
51     if (!strcmp(argv[i], "-e"))
52     scompile(NULL, argv[++i]);
53     else if (!strcmp(argv[i], "-f"))
54     fcompile(argv[++i]);
55     else if (!strcmp(argv[i], "-s"))
56     smooth = 1;
57     else
58     goto userror;
59    
60     sprintf(stmp, "%s(t)=%s;", ZNAME, argv[3]);
61     scompile(NULL, stmp);
62     sprintf(stmp, "%s(t)=%s;", RNAME, argv[4]);
63     scompile(NULL, stmp);
64     nseg = atoi(argv[5]);
65     if (nseg <= 0)
66     goto userror;
67     modname = smooth ? "phong" : argv[1];
68    
69     printhead(argc, argv);
70    
71     lastnz = lastnr = 0.0;
72     t = 0.0;
73     lastz = funvalue(ZNAME, 1, &t);
74     lastr = funvalue(RNAME, 1, &t);
75     t = 1.0/nseg;
76     z = funvalue(ZNAME, 1, &t);
77     r = funvalue(RNAME, 1, &t);
78     computen(&nz, &nr, lastz, lastr, z, r);
79     for (i = 1; i <= nseg; i++) {
80     if (i < nseg) {
81     t = (double)(i+1)/nseg;
82     nextz = funvalue(ZNAME, 1, &t);
83     nextr = funvalue(RNAME, 1, &t);
84     computen(&nextnz, &nextnr, z, r, nextz, nextr);
85     } else
86     nextnz = nextnr = 0.0;
87     orient = 0;
88     if (z < lastz-FTINY)
89     orient |= DOWN;
90     else if (z > lastz+FTINY)
91     orient |= UP;
92     if (r < lastr-FTINY)
93     orient |= IN;
94     else if (r > lastr+FTINY)
95     orient |= OUT;
96     if (!orient)
97     goto endfor;
98     if (smooth) {
99     printf("\n%s texfunc phong\n", argv[1]);
100     printf("4 rev_dx rev_dy rev_dz rev.cal\n");
101     printf("0\n4\n");
102     if (orient&(UP|DOWN)) {
103     t = (nextnz - lastnz)/(z - lastz);
104     printf("\t%15.9g\t%15.9g\n",
105     t, lastnz - t*lastz);
106     } else
107     printf("\t0\t%d\n", orient&IN ? 1 : -1);
108     if (orient&(OUT|IN)) {
109     t = (nextnr - lastnr)/(r - lastr);
110     printf("\t%15.9g\t%15.9g\n",
111     t, lastnr - t*lastr);
112     } else
113     printf("\t0\t%d\n", orient&UP ? 1 : -1);
114     }
115     if (!(orient&(IN|OUT))) {
116     printf("\n%s %s %s.%d\n", modname,
117     orient&DOWN ? "tube" : "cylinder",
118     argv[2], i);
119     printf("0\n0\n7\n");
120     printf("\t0\t0\t%15.9g\n", lastz);
121     printf("\t0\t0\t%15.9g\n", z);
122     printf("\t%15.9g\n", r);
123     } else if (!(orient&(UP|DOWN))) {
124     printf("\n%s ring %s.%d\n", modname, argv[2], i);
125     printf("0\n0\n8\n");
126     printf("\t0\t0\t%15.9g\n", z);
127     printf("\t0\t0\t%15.9g\n", orient&IN ? 1.0 : -1.0);
128     printf("\t%15.9g\t%15.9g\n", lastr, r);
129     } else {
130     printf("\n%s %s %s.%d\n", modname,
131     orient&DOWN ? "cup" : "cone",
132     argv[2], i);
133     printf("0\n0\n8\n");
134     printf("\t0\t0\t%15.9g\n", lastz);
135     printf("\t0\t0\t%15.9g\n", z);
136     printf("\t%15.9g\t%15.9g\n", lastr, r);
137     }
138     endfor:
139     lastz = z; lastr = r;
140     z = nextz; r = nextr;
141     lastnz = nz; lastnr = nr;
142     nz = nextnz; nr = nextnr;
143     }
144     quit(0);
145    
146     userror:
147     fprintf(stderr,
148     "Usage: %s material name z(t) r(t) nseg [-e expr] [-f file] [-s]\n",
149     argv[0]);
150     quit(1);
151     }
152    
153    
154     computen(nzp, nrp, z0, r0, z1, r1) /* compute normal */
155     double *nzp, *nrp, z0, r0, z1, r1;
156     {
157     extern double sqrt();
158     double dr, dz, len;
159    
160     dz = r0 - r1; /* right angle vector */
161     dr = z1 - z0;
162     len = sqrt(dr*dr + dz*dz);
163     *nzp = dz/len;
164     *nrp = dr/len;
165     }
166    
167    
168     eputs(msg)
169     char *msg;
170     {
171     fputs(msg, stderr);
172     }
173    
174    
175     wputs(msg)
176     char *msg;
177     {
178     eputs(msg);
179     }
180    
181    
182     quit(code)
183     {
184     exit(code);
185     }
186    
187    
188     printhead(ac, av) /* print command header */
189     register int ac;
190     register char **av;
191     {
192     putchar('#');
193     while (ac--) {
194     putchar(' ');
195     fputs(*av++, stdout);
196     }
197     putchar('\n');
198     }
199    
200    
201     double
202     l_hermite()
203     {
204     double t;
205    
206     t = argument(5);
207     return( argument(1)*((2.0*t-3.0)*t*t+1.0) +
208     argument(2)*(-2.0*t+3.0)*t*t +
209     argument(3)*((t-2.0)*t+1.0)*t +
210     argument(4)*(t-1.0)*t*t );
211     }