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root/radiance/ray/src/gen/gensurf.c
Revision: 2.3
Committed: Wed Feb 5 21:05:00 1992 UTC (32 years, 1 month ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.2: +18 -13 lines
Log Message:
bug fixes

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 * gensurf.c - program to generate functional surfaces
9 *
10 * Parametric functions x(s,t), y(s,t) and z(s,t)
11 * specify the surface, which is tesselated into an m by n
12 * array of paired triangles.
13 * The surface normal is defined by the right hand
14 * rule applied to (s,t).
15 *
16 * 4/3/87
17 */
18
19 #include "standard.h"
20
21 char XNAME[] = "X`SYS`"; /* x function name */
22 char YNAME[] = "Y`SYS`"; /* y function name */
23 char ZNAME[] = "Z`SYS`"; /* z function name */
24
25 #define ABS(x) ((x)>=0 ? (x) : -(x))
26
27 #define pvect(p) printf(vformat, (p)[0], (p)[1], (p)[2])
28
29 char vformat[] = "%15.9g %15.9g %15.9g\n";
30 char tsargs[] = "4 surf_dx surf_dy surf_dz surf.cal\n";
31 char texname[] = "Phong";
32
33 int smooth = 0; /* apply smoothing? */
34
35 char *modname, *surfname;
36
37 /* recorded data flags */
38 #define HASBORDER 01
39 #define TRIPLETS 02
40 /* a data structure */
41 struct {
42 int flags; /* data type */
43 short m, n; /* number of s and t values */
44 FLOAT *data; /* the data itself, s major sort */
45 } datarec; /* our recorded data */
46
47 double l_hermite(), l_bezier(), l_bspline(), l_dataval();
48 extern double funvalue(), argument();
49
50 typedef struct {
51 FVECT p; /* vertex position */
52 FVECT n; /* average normal */
53 } POINT;
54
55
56 main(argc, argv)
57 int argc;
58 char *argv[];
59 {
60 extern long eclock;
61 POINT *row0, *row1, *row2, *rp;
62 int i, j, m, n;
63 char stmp[256];
64
65 varset("PI", ':', PI);
66 funset("hermite", 5, ':', l_hermite);
67 funset("bezier", 5, ':', l_bezier);
68 funset("bspline", 5, ':', l_bspline);
69
70 if (argc < 8)
71 goto userror;
72
73 for (i = 8; i < argc; i++)
74 if (!strcmp(argv[i], "-e"))
75 scompile(argv[++i], NULL, 0);
76 else if (!strcmp(argv[i], "-f"))
77 fcompile(argv[++i]);
78 else if (!strcmp(argv[i], "-s"))
79 smooth++;
80 else
81 goto userror;
82
83 modname = argv[1];
84 surfname = argv[2];
85 m = atoi(argv[6]);
86 n = atoi(argv[7]);
87 if (m <= 0 || n <= 0)
88 goto userror;
89 if (!strcmp(argv[5], "-") || access(argv[5], 4) == 0) { /* file? */
90 funset(ZNAME, 2, ':', l_dataval);
91 if (!strcmp(argv[5],argv[3]) && !strcmp(argv[5],argv[4])) {
92 loaddata(argv[5], m, n, 3);
93 funset(XNAME, 2, ':', l_dataval);
94 funset(YNAME, 2, ':', l_dataval);
95 } else {
96 loaddata(argv[5], m, n, 1);
97 sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]);
98 scompile(stmp, NULL, 0);
99 sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]);
100 scompile(stmp, NULL, 0);
101 }
102 } else {
103 sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]);
104 scompile(stmp, NULL, 0);
105 sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]);
106 scompile(stmp, NULL, 0);
107 sprintf(stmp, "%s(s,t)=%s;", ZNAME, argv[5]);
108 scompile(stmp, NULL, 0);
109 }
110 row0 = (POINT *)malloc((n+3)*sizeof(POINT));
111 row1 = (POINT *)malloc((n+3)*sizeof(POINT));
112 row2 = (POINT *)malloc((n+3)*sizeof(POINT));
113 if (row0 == NULL || row1 == NULL || row2 == NULL) {
114 fprintf(stderr, "%s: out of memory\n", argv[0]);
115 quit(1);
116 }
117 row0++; row1++; row2++;
118 /* print header */
119 printhead(argc, argv);
120 eclock = 0;
121 /* initialize */
122 comprow(-1.0/m, row0, n);
123 comprow(0.0, row1, n);
124 comprow(1.0/m, row2, n);
125 compnorms(row0, row1, row2, n);
126 /* for each row */
127 for (i = 0; i < m; i++) {
128 /* compute next row */
129 rp = row0;
130 row0 = row1;
131 row1 = row2;
132 row2 = rp;
133 comprow((double)(i+2)/m, row2, n);
134 compnorms(row0, row1, row2, n);
135
136 for (j = 0; j < n; j++) {
137 /* put polygons */
138 if ((i+j) & 1)
139 putsquare(&row0[j], &row1[j],
140 &row0[j+1], &row1[j+1]);
141 else
142 putsquare(&row1[j], &row1[j+1],
143 &row0[j], &row0[j+1]);
144 }
145 }
146
147 quit(0);
148
149 userror:
150 fprintf(stderr, "Usage: %s material name ", argv[0]);
151 fprintf(stderr, "x(s,t) y(s,t) z(s,t) m n [-s][-e expr][-f file]\n");
152 quit(1);
153 }
154
155
156 loaddata(file, m, n, pointsize) /* load point data from file */
157 char *file;
158 int m, n;
159 int pointsize;
160 {
161 extern char *fgetword();
162 FILE *fp;
163 char word[64];
164 register int size;
165 register FLOAT *dp;
166
167 datarec.flags = HASBORDER; /* assume border values */
168 datarec.m = m+1;
169 datarec.n = n+1;
170 size = datarec.m*datarec.n*pointsize;
171 if (pointsize == 3)
172 datarec.flags |= TRIPLETS;
173 dp = (FLOAT *)malloc(size*sizeof(FLOAT));
174 if ((datarec.data = dp) == NULL) {
175 fputs("Out of memory\n", stderr);
176 exit(1);
177 }
178 if (!strcmp(file, "-")) {
179 file = "<stdin>";
180 fp = stdin;
181 } else if ((fp = fopen(file, "r")) == NULL) {
182 fputs(file, stderr);
183 fputs(": cannot open\n", stderr);
184 exit(1);
185 }
186 while (size > 0 && fgetword(word, sizeof(word), fp) != NULL) {
187 if (!isflt(word)) {
188 fprintf(stderr, "%s: garbled data value: %s\n",
189 file, word);
190 exit(1);
191 }
192 *dp++ = atof(word);
193 size--;
194 }
195 if (size == (m+n+1)*pointsize) { /* no border after all */
196 dp = (FLOAT *)realloc((char *)datarec.data,
197 m*n*pointsize*sizeof(FLOAT));
198 if (dp != NULL)
199 datarec.data = dp;
200 datarec.flags &= ~HASBORDER;
201 datarec.m = m;
202 datarec.n = n;
203 size = 0;
204 }
205 if (datarec.m < 2 || datarec.n < 2 || size != 0 ||
206 fgetword(word, sizeof(word), fp) != NULL) {
207 fputs(file, stderr);
208 fputs(": bad number of data points\n", stderr);
209 exit(1);
210 }
211 fclose(fp);
212 }
213
214
215 double
216 l_dataval(nam) /* return recorded data value */
217 char *nam;
218 {
219 double u, v;
220 register int i, j;
221 register FLOAT *dp;
222 double d00, d01, d10, d11;
223 /* compute coordinates */
224 u = argument(1); v = argument(2);
225 if (datarec.flags & HASBORDER) {
226 i = u *= datarec.m-1;
227 j = v *= datarec.n-1;
228 } else {
229 i = u = u*datarec.m - .5;
230 j = v = v*datarec.n - .5;
231 }
232 if (i < 0) i = 0;
233 else if (i > datarec.m-2) i = datarec.m-2;
234 if (j < 0) j = 0;
235 else if (j > datarec.n-2) j = datarec.n-2;
236 /* compute value */
237 if (datarec.flags & TRIPLETS) {
238 dp = datarec.data + 3*(j*datarec.m + i);
239 if (nam == ZNAME)
240 dp += 2;
241 else if (nam == YNAME)
242 dp++;
243 d00 = dp[0]; d01 = dp[3];
244 dp += 3*datarec.m;
245 d10 = dp[0]; d11 = dp[3];
246 } else {
247 dp = datarec.data + j*datarec.m + i;
248 d00 = dp[0]; d01 = dp[1];
249 dp += datarec.m;
250 d10 = dp[0]; d11 = dp[1];
251 }
252 /* bilinear interpolation */
253 return((j+1-v)*((i+1-u)*d00+(u-i)*d01)+(v-j)*((i+1-u)*d10+(u-i)*d11));
254 }
255
256
257 putsquare(p0, p1, p2, p3) /* put out a square */
258 POINT *p0, *p1, *p2, *p3;
259 {
260 static int nout = 0;
261 FVECT norm[4];
262 int axis;
263 FVECT v1, v2, vc1, vc2;
264 int ok1, ok2;
265 /* compute exact normals */
266 fvsum(v1, p1->p, p0->p, -1.0);
267 fvsum(v2, p2->p, p0->p, -1.0);
268 fcross(vc1, v1, v2);
269 ok1 = normalize(vc1) != 0.0;
270 fvsum(v1, p2->p, p3->p, -1.0);
271 fvsum(v2, p1->p, p3->p, -1.0);
272 fcross(vc2, v1, v2);
273 ok2 = normalize(vc2) != 0.0;
274 if (!(ok1 | ok2))
275 return;
276 /* compute normal interpolation */
277 axis = norminterp(norm, p0, p1, p2, p3);
278
279 /* put out quadrilateral? */
280 if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
281 printf("\n%s ", modname);
282 if (axis != -1) {
283 printf("texfunc %s\n", texname);
284 printf(tsargs);
285 printf("0\n13\t%d\n", axis);
286 pvect(norm[0]);
287 pvect(norm[1]);
288 pvect(norm[2]);
289 fvsum(v1, norm[3], vc1, -0.5);
290 fvsum(v1, v1, vc2, -0.5);
291 pvect(v1);
292 printf("\n%s ", texname);
293 }
294 printf("polygon %s.%d\n", surfname, ++nout);
295 printf("0\n0\n12\n");
296 pvect(p0->p);
297 pvect(p1->p);
298 pvect(p3->p);
299 pvect(p2->p);
300 return;
301 }
302 /* put out triangles? */
303 if (ok1) {
304 printf("\n%s ", modname);
305 if (axis != -1) {
306 printf("texfunc %s\n", texname);
307 printf(tsargs);
308 printf("0\n13\t%d\n", axis);
309 pvect(norm[0]);
310 pvect(norm[1]);
311 pvect(norm[2]);
312 fvsum(v1, norm[3], vc1, -1.0);
313 pvect(v1);
314 printf("\n%s ", texname);
315 }
316 printf("polygon %s.%d\n", surfname, ++nout);
317 printf("0\n0\n9\n");
318 pvect(p0->p);
319 pvect(p1->p);
320 pvect(p2->p);
321 }
322 if (ok2) {
323 printf("\n%s ", modname);
324 if (axis != -1) {
325 printf("texfunc %s\n", texname);
326 printf(tsargs);
327 printf("0\n13\t%d\n", axis);
328 pvect(norm[0]);
329 pvect(norm[1]);
330 pvect(norm[2]);
331 fvsum(v2, norm[3], vc2, -1.0);
332 pvect(v2);
333 printf("\n%s ", texname);
334 }
335 printf("polygon %s.%d\n", surfname, ++nout);
336 printf("0\n0\n9\n");
337 pvect(p2->p);
338 pvect(p1->p);
339 pvect(p3->p);
340 }
341 }
342
343
344 comprow(s, row, siz) /* compute row of values */
345 double s;
346 register POINT *row;
347 int siz;
348 {
349 double st[2];
350 int end;
351 register int i;
352
353 if (smooth) {
354 i = -1; /* compute one past each end */
355 end = siz+1;
356 } else {
357 if (s < -FTINY || s > 1.0+FTINY)
358 return;
359 i = 0;
360 end = siz;
361 }
362 st[0] = s;
363 while (i <= end) {
364 st[1] = (double)i/siz;
365 row[i].p[0] = funvalue(XNAME, 2, st);
366 row[i].p[1] = funvalue(YNAME, 2, st);
367 row[i].p[2] = funvalue(ZNAME, 2, st);
368 i++;
369 }
370 }
371
372
373 compnorms(r0, r1, r2, siz) /* compute row of averaged normals */
374 register POINT *r0, *r1, *r2;
375 int siz;
376 {
377 FVECT v1, v2;
378 register int i;
379
380 if (!smooth) /* not needed if no smoothing */
381 return;
382 /* compute middle points */
383 while (siz-- >= 0) {
384 fvsum(v1, r2[0].p, r0[0].p, -1.0);
385 fvsum(v2, r1[1].p, r1[-1].p, -1.0);
386 fcross(r1[0].n, v1, v2);
387 normalize(r1[0].n);
388 r0++; r1++; r2++;
389 }
390 }
391
392
393 int
394 norminterp(resmat, p0, p1, p2, p3) /* compute normal interpolation */
395 register FVECT resmat[4];
396 POINT *p0, *p1, *p2, *p3;
397 {
398 #define u ((ax+1)%3)
399 #define v ((ax+2)%3)
400
401 register int ax;
402 MAT4 eqnmat;
403 FVECT v1;
404 register int i, j;
405
406 if (!smooth) /* no interpolation if no smoothing */
407 return(-1);
408 /* find dominant axis */
409 VCOPY(v1, p0->n);
410 fvsum(v1, v1, p1->n, 1.0);
411 fvsum(v1, v1, p2->n, 1.0);
412 fvsum(v1, v1, p3->n, 1.0);
413 ax = ABS(v1[0]) > ABS(v1[1]) ? 0 : 1;
414 ax = ABS(v1[ax]) > ABS(v1[2]) ? ax : 2;
415 /* assign equation matrix */
416 eqnmat[0][0] = p0->p[u]*p0->p[v];
417 eqnmat[0][1] = p0->p[u];
418 eqnmat[0][2] = p0->p[v];
419 eqnmat[0][3] = 1.0;
420 eqnmat[1][0] = p1->p[u]*p1->p[v];
421 eqnmat[1][1] = p1->p[u];
422 eqnmat[1][2] = p1->p[v];
423 eqnmat[1][3] = 1.0;
424 eqnmat[2][0] = p2->p[u]*p2->p[v];
425 eqnmat[2][1] = p2->p[u];
426 eqnmat[2][2] = p2->p[v];
427 eqnmat[2][3] = 1.0;
428 eqnmat[3][0] = p3->p[u]*p3->p[v];
429 eqnmat[3][1] = p3->p[u];
430 eqnmat[3][2] = p3->p[v];
431 eqnmat[3][3] = 1.0;
432 /* invert matrix (solve system) */
433 if (!invmat(eqnmat, eqnmat))
434 return(-1); /* no solution */
435 /* compute result matrix */
436 for (j = 0; j < 4; j++)
437 for (i = 0; i < 3; i++)
438 resmat[j][i] = eqnmat[j][0]*p0->n[i] +
439 eqnmat[j][1]*p1->n[i] +
440 eqnmat[j][2]*p2->n[i] +
441 eqnmat[j][3]*p3->n[i];
442 return(ax);
443
444 #undef u
445 #undef v
446 }
447
448
449 /*
450 * invmat - computes the inverse of mat into inverse. Returns 1
451 * if there exists an inverse, 0 otherwise. It uses Gaussian Elimination
452 * method.
453 */
454
455 invmat(inverse,mat)
456 MAT4 inverse, mat;
457 {
458 #define SWAP(a,b,t) (t=a,a=b,b=t)
459
460 MAT4 m4tmp;
461 register int i,j,k;
462 register double temp;
463
464 copymat4(m4tmp, mat);
465 /* set inverse to identity */
466 for (i = 0; i < 4; i++)
467 for (j = 0; j < 4; j++)
468 inverse[i][j] = i==j ? 1.0 : 0.0;
469
470 for(i = 0; i < 4; i++) {
471 /* Look for row with largest pivot and swap rows */
472 temp = FTINY; j = -1;
473 for(k = i; k < 4; k++)
474 if(ABS(m4tmp[k][i]) > temp) {
475 temp = ABS(m4tmp[k][i]);
476 j = k;
477 }
478 if(j == -1) /* No replacing row -> no inverse */
479 return(0);
480 if (j != i)
481 for(k = 0; k < 4; k++) {
482 SWAP(m4tmp[i][k],m4tmp[j][k],temp);
483 SWAP(inverse[i][k],inverse[j][k],temp);
484 }
485
486 temp = m4tmp[i][i];
487 for(k = 0; k < 4; k++) {
488 m4tmp[i][k] /= temp;
489 inverse[i][k] /= temp;
490 }
491 for(j = 0; j < 4; j++) {
492 if(j != i) {
493 temp = m4tmp[j][i];
494 for(k = 0; k < 4; k++) {
495 m4tmp[j][k] -= m4tmp[i][k]*temp;
496 inverse[j][k] -= inverse[i][k]*temp;
497 }
498 }
499 }
500 }
501 return(1);
502
503 #undef SWAP
504 }
505
506
507 eputs(msg)
508 char *msg;
509 {
510 fputs(msg, stderr);
511 }
512
513
514 wputs(msg)
515 char *msg;
516 {
517 eputs(msg);
518 }
519
520
521 quit(code)
522 {
523 exit(code);
524 }
525
526
527 printhead(ac, av) /* print command header */
528 register int ac;
529 register char **av;
530 {
531 putchar('#');
532 while (ac--) {
533 putchar(' ');
534 fputs(*av++, stdout);
535 }
536 putchar('\n');
537 }
538
539
540 double
541 l_hermite()
542 {
543 double t;
544
545 t = argument(5);
546 return( argument(1)*((2.0*t-3.0)*t*t+1.0) +
547 argument(2)*(-2.0*t+3.0)*t*t +
548 argument(3)*((t-2.0)*t+1.0)*t +
549 argument(4)*(t-1.0)*t*t );
550 }
551
552
553 double
554 l_bezier()
555 {
556 double t;
557
558 t = argument(5);
559 return( argument(1) * (1.+t*(-3.+t*(3.-t))) +
560 argument(2) * 3.*t*(1.+t*(-2.+t)) +
561 argument(3) * 3.*t*t*(1.-t) +
562 argument(4) * t*t*t );
563 }
564
565
566 double
567 l_bspline()
568 {
569 double t;
570
571 t = argument(5);
572 return( argument(1) * (1./6.+t*(-1./2.+t*(1./2.-1./6.*t))) +
573 argument(2) * (2./3.+t*t*(-1.+1./2.*t)) +
574 argument(3) * (1./6.+t*(1./2.+t*(1./2.-1./2.*t))) +
575 argument(4) * (1./6.*t*t*t) );
576 }