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root/radiance/ray/src/gen/genrev.c
Revision: 1.5
Committed: Wed Mar 7 11:14:40 1990 UTC (34 years ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.4: +17 -3 lines
Log Message:
added bezier and bspline functions

File Contents

# Content
1 #ifndef lint
2 static char SCCSid[] = "$SunId$ LBL";
3 #endif
4
5 /* Copyright (c) 1989 Regents of the University of California */
6
7 /*
8 * genrev.c - program to generate functions of rotation about z
9 *
10 * The program takes as input the functions of t for z and r
11 * (the radius). If z is increasing, the normal points
12 * outward, inward for decreasing z. Negative radii are forbidden.
13 *
14 * 8/6/86
15 */
16
17 #include <stdio.h>
18
19 #define ZNAME "Z_" /* z function name */
20 #define RNAME "R_" /* r function name */
21
22 #define PI 3.14159265358979323846
23
24 #define FTINY 1e-9
25 /* orientation */
26 #define OUT 01
27 #define IN 02
28 #define UP 04
29 #define DOWN 010
30
31 double funvalue(), l_hermite(), l_bezier(), l_bspline(), argument();
32
33
34 main(argc, argv)
35 int argc;
36 char *argv[];
37 {
38 char stmp[256];
39 char *modname;
40 int smooth = 0;
41 double t, lastz, z, nextz, lastr, r, nextr;
42 double lastnz, lastnr, nz, nr, nextnz, nextnr;
43 int i, nseg;
44 int orient;
45
46 varset("PI", PI);
47 funset("hermite", 5, l_hermite);
48 funset("bezier", 5, l_bezier);
49 funset("bspline", 5, l_bspline);
50
51 if (argc < 6)
52 goto userror;
53
54 for (i = 6; i < argc; i++)
55 if (!strcmp(argv[i], "-e"))
56 scompile(NULL, argv[++i]);
57 else if (!strcmp(argv[i], "-f"))
58 fcompile(argv[++i]);
59 else if (!strcmp(argv[i], "-s"))
60 smooth = 1;
61 else
62 goto userror;
63
64 sprintf(stmp, "%s(t)=%s;", ZNAME, argv[3]);
65 scompile(NULL, stmp);
66 sprintf(stmp, "%s(t)=%s;", RNAME, argv[4]);
67 scompile(NULL, stmp);
68 nseg = atoi(argv[5]);
69 if (nseg <= 0)
70 goto userror;
71 modname = smooth ? "Phong" : argv[1];
72
73 printhead(argc, argv);
74
75 lastnz = lastnr = 0.0;
76 t = 0.0;
77 lastz = funvalue(ZNAME, 1, &t);
78 lastr = funvalue(RNAME, 1, &t);
79 t = 1.0/nseg;
80 z = funvalue(ZNAME, 1, &t);
81 r = funvalue(RNAME, 1, &t);
82 computen(&nz, &nr, lastz, lastr, z, r);
83 for (i = 1; i <= nseg; i++) {
84 if (i < nseg) {
85 t = (double)(i+1)/nseg;
86 nextz = funvalue(ZNAME, 1, &t);
87 nextr = funvalue(RNAME, 1, &t);
88 computen(&nextnz, &nextnr, z, r, nextz, nextr);
89 } else
90 nextnz = nextnr = 0.0;
91 orient = 0;
92 if (z < lastz-FTINY)
93 orient |= DOWN;
94 else if (z > lastz+FTINY)
95 orient |= UP;
96 if (r < lastr-FTINY)
97 orient |= IN;
98 else if (r > lastr+FTINY)
99 orient |= OUT;
100 if (!orient)
101 goto endfor;
102 if (smooth) {
103 printf("\n%s texfunc Phong\n", argv[1]);
104 printf("4 rev_dx rev_dy rev_dz rev.cal\n");
105 printf("0\n4\n");
106 if (orient&(UP|DOWN)) {
107 t = (nextnz - lastnz)/(z - lastz);
108 printf("\t%15.9g\t%15.9g\n",
109 t, lastnz - t*lastz);
110 } else
111 printf("\t0\t%d\n", orient&IN ? 1 : -1);
112 if (orient&(OUT|IN)) {
113 t = (nextnr - lastnr)/(r - lastr);
114 printf("\t%15.9g\t%15.9g\n",
115 t, lastnr - t*lastr);
116 } else
117 printf("\t0\t%d\n", orient&UP ? 1 : -1);
118 }
119 if (!(orient&(IN|OUT))) {
120 printf("\n%s %s %s.%d\n", modname,
121 orient&DOWN ? "tube" : "cylinder",
122 argv[2], i);
123 printf("0\n0\n7\n");
124 printf("\t0\t0\t%15.9g\n", lastz);
125 printf("\t0\t0\t%15.9g\n", z);
126 printf("\t%15.9g\n", r);
127 } else if (!(orient&(UP|DOWN))) {
128 printf("\n%s ring %s.%d\n", modname, argv[2], i);
129 printf("0\n0\n8\n");
130 printf("\t0\t0\t%15.9g\n", z);
131 printf("\t0\t0\t%15.9g\n", orient&IN ? 1.0 : -1.0);
132 printf("\t%15.9g\t%15.9g\n", lastr, r);
133 } else {
134 printf("\n%s %s %s.%d\n", modname,
135 orient&DOWN ? "cup" : "cone",
136 argv[2], i);
137 printf("0\n0\n8\n");
138 printf("\t0\t0\t%15.9g\n", lastz);
139 printf("\t0\t0\t%15.9g\n", z);
140 printf("\t%15.9g\t%15.9g\n", lastr, r);
141 }
142 endfor:
143 lastz = z; lastr = r;
144 z = nextz; r = nextr;
145 lastnz = nz; lastnr = nr;
146 nz = nextnz; nr = nextnr;
147 }
148 quit(0);
149
150 userror:
151 fprintf(stderr,
152 "Usage: %s material name z(t) r(t) nseg [-e expr] [-f file] [-s]\n",
153 argv[0]);
154 quit(1);
155 }
156
157
158 computen(nzp, nrp, z0, r0, z1, r1) /* compute normal */
159 double *nzp, *nrp, z0, r0, z1, r1;
160 {
161 extern double sqrt();
162 double dr, dz, len;
163
164 dz = r0 - r1; /* right angle vector */
165 dr = z1 - z0;
166 len = sqrt(dr*dr + dz*dz);
167 *nzp = dz/len;
168 *nrp = dr/len;
169 }
170
171
172 eputs(msg)
173 char *msg;
174 {
175 fputs(msg, stderr);
176 }
177
178
179 wputs(msg)
180 char *msg;
181 {
182 eputs(msg);
183 }
184
185
186 quit(code)
187 {
188 exit(code);
189 }
190
191
192 printhead(ac, av) /* print command header */
193 register int ac;
194 register char **av;
195 {
196 putchar('#');
197 while (ac--) {
198 putchar(' ');
199 fputs(*av++, stdout);
200 }
201 putchar('\n');
202 }
203
204
205 double
206 l_hermite()
207 {
208 double t;
209
210 t = argument(5);
211 return( argument(1)*((2.0*t-3.0)*t*t+1.0) +
212 argument(2)*(-2.0*t+3.0)*t*t +
213 argument(3)*((t-2.0)*t+1.0)*t +
214 argument(4)*(t-1.0)*t*t );
215 }
216
217
218 double
219 l_bezier()
220 {
221 double t;
222
223 t = argument(5);
224 return( argument(1) * (1.+t*(-3.+t*(3.-t))) +
225 argument(2) * 3.*t*(1.+t*(-2.+t)) +
226 argument(3) * 3.*t*t*(1.-t) +
227 argument(4) * t*t*t );
228 }
229
230
231 double
232 l_bspline()
233 {
234 double t;
235
236 t = argument(5);
237 return( argument(1) * (1./6.+t*(-1./2.+t*(1./2.-1./6.*t))) +
238 argument(2) * (2./3.+t*t*(-1.+1./2.*t)) +
239 argument(3) * (1./6.+t*(1./2.+t*(1./2.-1./2.*t))) +
240 argument(4) * (1./6.*t*t*t) );
241 }