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root/radiance/ray/src/gen/genrev.c
Revision: 2.13
Committed: Sat Dec 7 02:21:42 2019 UTC (4 years, 4 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.12: +2 -2 lines
Log Message:
Changed gen{worm,surf,rev} to accept expressions for number of segments

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: genrev.c,v 2.12 2018/05/04 23:56:49 greg Exp $";
3 #endif
4 /*
5 * genrev.c - program to generate functions of rotation about z
6 *
7 * The program takes as input the functions of t for z and r
8 * (the radius). If z is increasing, the normal points
9 * outward, inward for decreasing z. Negative radii are forbidden.
10 *
11 * 8/6/86
12 */
13
14 #include <stdlib.h>
15 #include <stdio.h>
16 #include <string.h>
17 #include <math.h>
18
19 #include "rtio.h"
20 #include "rterror.h"
21 #include "resolu.h"
22 #include "calcomp.h"
23
24 #define ZNAME "Z`SYS`" /* z function name */
25 #define RNAME "R`SYS`" /* r function name */
26
27 #define PI 3.14159265358979323846
28
29 #define FTINY 1e-9
30 /* orientation */
31 #define OUT 01
32 #define IN 02
33 #define UP 04
34 #define DOWN 010
35
36
37 void
38 computen(nzp, nrp, z0, r0, z1, r1) /* compute normal */
39 double *nzp, *nrp, z0, r0, z1, r1;
40 {
41 double dr, dz, len;
42
43 dz = r0 - r1; /* right angle vector */
44 dr = z1 - z0;
45 len = sqrt(dr*dr + dz*dz);
46 *nzp = dz/len;
47 *nrp = dr/len;
48 }
49
50
51 double
52 l_hermite(char *nm)
53 {
54 double t;
55
56 t = argument(5);
57 return( argument(1)*((2.0*t-3.0)*t*t+1.0) +
58 argument(2)*(-2.0*t+3.0)*t*t +
59 argument(3)*((t-2.0)*t+1.0)*t +
60 argument(4)*(t-1.0)*t*t );
61 }
62
63
64 double
65 l_bezier(char *nm)
66 {
67 double t;
68
69 t = argument(5);
70 return( argument(1) * (1.+t*(-3.+t*(3.-t))) +
71 argument(2) * 3.*t*(1.+t*(-2.+t)) +
72 argument(3) * 3.*t*t*(1.-t) +
73 argument(4) * t*t*t );
74 }
75
76
77 double
78 l_bspline(char *nm)
79 {
80 double t;
81
82 t = argument(5);
83 return( argument(1) * (1./6.+t*(-1./2.+t*(1./2.-1./6.*t))) +
84 argument(2) * (2./3.+t*t*(-1.+1./2.*t)) +
85 argument(3) * (1./6.+t*(1./2.+t*(1./2.-1./2.*t))) +
86 argument(4) * (1./6.*t*t*t) );
87 }
88
89
90 int
91 main(argc, argv)
92 int argc;
93 char *argv[];
94 {
95 char stmp[256];
96 char *modname;
97 int smooth = 0;
98 double t, lastz, z, nextz, lastr, r, nextr;
99 double lastnz, lastnr, nz, nr, nextnz, nextnr;
100 int i, nseg;
101 int orient;
102
103 esupport |= E_VARIABLE|E_FUNCTION|E_RCONST;
104 esupport &= ~(E_OUTCHAN|E_INCHAN);
105 varset("PI", ':', PI);
106 funset("hermite", 5, ':', l_hermite);
107 funset("bezier", 5, ':', l_bezier);
108 funset("bspline", 5, ':', l_bspline);
109
110 if (argc < 6)
111 goto userror;
112
113 for (i = 6; i < argc; i++)
114 if (!strcmp(argv[i], "-e"))
115 scompile(argv[++i], NULL, 0);
116 else if (!strcmp(argv[i], "-f")) {
117 char *fpath = getpath(argv[++i], getrlibpath(), 0);
118 if (fpath == NULL) {
119 fprintf(stderr, "%s: cannot find file '%s'\n",
120 argv[0], argv[i]);
121 quit(1);
122 }
123 fcompile(fpath);
124 } else if (!strcmp(argv[i], "-s"))
125 smooth = 1;
126 else
127 goto userror;
128
129 sprintf(stmp, "%s(t)=%s;", ZNAME, argv[3]);
130 scompile(stmp, NULL, 0);
131 sprintf(stmp, "%s(t)=%s;", RNAME, argv[4]);
132 scompile(stmp, NULL, 0);
133 nseg = eval(argv[5]) + .5;
134 if (nseg <= 0)
135 goto userror;
136 modname = smooth ? "Phong" : argv[1];
137
138 fputs("# ", stdout);
139 printargs(argc, argv, stdout);
140 eclock = 0;
141
142 lastnz = lastnr = 0.0;
143 t = 0.0;
144 lastz = funvalue(ZNAME, 1, &t);
145 lastr = funvalue(RNAME, 1, &t);
146 t = 1.0/nseg;
147 z = funvalue(ZNAME, 1, &t);
148 r = funvalue(RNAME, 1, &t);
149 computen(&nz, &nr, lastz, lastr, z, r);
150 for (i = 1; i <= nseg; i++) {
151 if (i < nseg) {
152 t = (double)(i+1)/nseg;
153 nextz = funvalue(ZNAME, 1, &t);
154 nextr = funvalue(RNAME, 1, &t);
155 computen(&nextnz, &nextnr, z, r, nextz, nextr);
156 } else
157 nextnz = nextnr = 0.0;
158 orient = 0;
159 if (z < lastz-FTINY)
160 orient |= DOWN;
161 else if (z > lastz+FTINY)
162 orient |= UP;
163 if (r < lastr-FTINY)
164 orient |= IN;
165 else if (r > lastr+FTINY)
166 orient |= OUT;
167 if (!orient)
168 goto endfor;
169 if (smooth) {
170 printf("\n%s texfunc Phong\n", argv[1]);
171 printf("4 rev_dx rev_dy rev_dz rev.cal\n");
172 printf("0\n4\n");
173 if (orient&(UP|DOWN)) {
174 t = (nextnz - lastnz)/(z - lastz);
175 printf("\t%18.12g\t%18.12g\n",
176 t, lastnz - t*lastz);
177 } else
178 printf("\t0\t%d\n", orient&IN ? 1 : -1);
179 if (orient&(OUT|IN)) {
180 t = (nextnr - lastnr)/(r - lastr);
181 printf("\t%18.12g\t%18.12g\n",
182 t, lastnr - t*lastr);
183 } else
184 printf("\t0\t%d\n", orient&UP ? 1 : -1);
185 }
186 if (!(orient&(IN|OUT))) {
187 printf("\n%s %s %s.%d\n", modname,
188 orient&DOWN ? "tube" : "cylinder",
189 argv[2], i);
190 printf("0\n0\n7\n");
191 printf("\t0\t0\t%18.12g\n", lastz);
192 printf("\t0\t0\t%18.12g\n", z);
193 printf("\t%18.12g\n", r);
194 } else if (!(orient&(UP|DOWN))) {
195 printf("\n%s ring %s.%d\n", modname, argv[2], i);
196 printf("0\n0\n8\n");
197 printf("\t0\t0\t%18.12g\n", z);
198 printf("\t0\t0\t%18.12g\n", orient&IN ? 1.0 : -1.0);
199 printf("\t%18.12g\t%18.12g\n", lastr, r);
200 } else {
201 printf("\n%s %s %s.%d\n", modname,
202 orient&DOWN ? "cup" : "cone",
203 argv[2], i);
204 printf("0\n0\n8\n");
205 printf("\t0\t0\t%18.12g\n", lastz);
206 printf("\t0\t0\t%18.12g\n", z);
207 printf("\t%18.12g\t%18.12g\n", lastr, r);
208 }
209 endfor:
210 lastz = z; lastr = r;
211 z = nextz; r = nextr;
212 lastnz = nz; lastnr = nr;
213 nz = nextnz; nr = nextnr;
214 }
215 return 0;
216
217 userror:
218 fprintf(stderr,
219 "Usage: %s material name z(t) r(t) nseg [-e expr] [-f file] [-s]\n",
220 argv[0]);
221 return 1;
222 }
223
224