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root/radiance/ray/src/gen/gensurf.c
Revision: 2.2
Committed: Thu Jan 30 14:11:39 1992 UTC (32 years, 2 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.1: +132 -11 lines
Log Message:
added ability to get point values from a file

File Contents

# User Rev Content
1 greg 1.1 #ifndef lint
2     static char SCCSid[] = "$SunId$ LBL";
3     #endif
4 greg 1.2
5 greg 1.7 /* Copyright (c) 1989 Regents of the University of California */
6    
7 greg 1.2 /*
8 greg 1.1 * 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 greg 1.5 #include "standard.h"
20 greg 1.1
21 greg 2.2 char XNAME[] = "X`SYS`"; /* x function name */
22     char YNAME[] = "Y`SYS`"; /* y function name */
23     char ZNAME[] = "Z`SYS`"; /* z function name */
24 greg 1.1
25 greg 1.4 #define ABS(x) ((x)>=0 ? (x) : -(x))
26    
27 greg 1.3 #define pvect(p) printf(vformat, (p)[0], (p)[1], (p)[2])
28 greg 1.1
29     char vformat[] = "%15.9g %15.9g %15.9g\n";
30 greg 1.3 char tsargs[] = "4 surf_dx surf_dy surf_dz surf.cal\n";
31     char texname[] = "Phong";
32 greg 1.1
33 greg 1.3 int smooth = 0; /* apply smoothing? */
34 greg 1.1
35 greg 1.3 char *modname, *surfname;
36 greg 1.1
37 greg 2.2 /* 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 greg 1.3
47 greg 2.2 double l_hermite(), l_bezier(), l_bspline(), l_dataval();
48     extern double funvalue(), argument();
49    
50 greg 1.3 typedef struct {
51     FVECT p; /* vertex position */
52     FVECT n; /* average normal */
53     } POINT;
54    
55    
56 greg 1.1 main(argc, argv)
57     int argc;
58     char *argv[];
59     {
60 greg 1.9 extern long eclock;
61 greg 1.3 POINT *row0, *row1, *row2, *rp;
62 greg 1.1 int i, j, m, n;
63     char stmp[256];
64    
65 greg 1.13 varset("PI", ':', PI);
66 greg 1.14 funset("hermite", 5, ':', l_hermite);
67     funset("bezier", 5, ':', l_bezier);
68     funset("bspline", 5, ':', l_bspline);
69 greg 1.1
70     if (argc < 8)
71     goto userror;
72    
73     for (i = 8; i < argc; i++)
74     if (!strcmp(argv[i], "-e"))
75 greg 1.10 scompile(argv[++i], NULL, 0);
76 greg 1.1 else if (!strcmp(argv[i], "-f"))
77     fcompile(argv[++i]);
78 greg 1.3 else if (!strcmp(argv[i], "-s"))
79     smooth++;
80 greg 1.1 else
81     goto userror;
82    
83 greg 1.3 modname = argv[1];
84     surfname = argv[2];
85 greg 1.1 m = atoi(argv[6]);
86     n = atoi(argv[7]);
87     if (m <= 0 || n <= 0)
88     goto userror;
89 greg 2.2 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 greg 1.4 row0 = (POINT *)malloc((n+3)*sizeof(POINT));
111     row1 = (POINT *)malloc((n+3)*sizeof(POINT));
112     row2 = (POINT *)malloc((n+3)*sizeof(POINT));
113 greg 1.3 if (row0 == NULL || row1 == NULL || row2 == NULL) {
114 greg 1.1 fprintf(stderr, "%s: out of memory\n", argv[0]);
115     quit(1);
116     }
117 greg 1.4 row0++; row1++; row2++;
118 greg 1.3 /* print header */
119 greg 1.1 printhead(argc, argv);
120 greg 1.9 eclock = 0;
121 greg 1.4 /* initialize */
122     comprow(-1.0/m, row0, n);
123 greg 1.3 comprow(0.0, row1, n);
124     comprow(1.0/m, row2, n);
125 greg 1.4 compnorms(row0, row1, row2, n);
126 greg 1.3 /* for each row */
127 greg 1.1 for (i = 0; i < m; i++) {
128     /* compute next row */
129 greg 1.3 rp = row0;
130 greg 1.1 row0 = row1;
131 greg 1.3 row1 = row2;
132     row2 = rp;
133 greg 1.4 comprow((double)(i+2)/m, row2, n);
134     compnorms(row0, row1, row2, n);
135 greg 1.1
136     for (j = 0; j < n; j++) {
137 greg 1.3 /* 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 greg 1.1 }
145     }
146    
147     quit(0);
148    
149     userror:
150     fprintf(stderr, "Usage: %s material name ", argv[0]);
151 greg 1.3 fprintf(stderr, "x(s,t) y(s,t) z(s,t) m n [-s][-e expr][-f file]\n");
152 greg 1.1 quit(1);
153 greg 2.2 }
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     size = (m+1)*(n+1)*pointsize;
169     if (pointsize == 3)
170     datarec.flags |= TRIPLETS;
171     dp = (FLOAT *)malloc(size*sizeof(FLOAT));
172     if ((datarec.data = dp) == NULL) {
173     fputs("Out of memory\n", stderr);
174     exit(1);
175     }
176     if (!strcmp(file, "-")) {
177     file = "<stdin>";
178     fp = stdin;
179     } else if ((fp = fopen(file, "r")) == NULL) {
180     fputs(file, stderr);
181     fputs(": cannot open\n", stderr);
182     exit(1);
183     }
184     while (size > 0 && fgetword(word, sizeof(word), fp) != NULL) {
185     if (!isflt(word)) {
186     fprintf(stderr, "%s: garbled data value: %s\n",
187     file, word);
188     exit(1);
189     }
190     *dp++ = atof(word);
191     size--;
192     }
193     if (size == (m+n+1)*pointsize) { /* no border after all */
194     dp = (FLOAT *)realloc((char *)datarec.data,
195     m*n*pointsize*sizeof(FLOAT));
196     if (dp != NULL)
197     datarec.data = dp;
198     datarec.flags &= ~HASBORDER;
199     size = 0;
200     }
201     if (size || fgetword(word, sizeof(word), fp) != NULL) {
202     fputs(file, stderr);
203     fputs(": bad number of data points\n", stderr);
204     exit(1);
205     }
206     fclose(fp);
207     }
208    
209    
210     double
211     l_dataval(nam) /* return recorded data value */
212     char *nam;
213     {
214     double u, v;
215     register int i, j;
216     register FLOAT *dp;
217     double d00, d01, d10, d11;
218     /* compute coordinates */
219     u = argument(1); v = argument(2);
220     if (datarec.flags & HASBORDER) {
221     i = u *= datarec.m;
222     j = v *= datarec.n;
223     } else {
224     i = u = u*(datarec.m+1) - .5;
225     j = v = v*(datarec.n+1) - .5;
226     }
227     if (i < 0) i = 0;
228     else if (i > datarec.m-2) i = datarec.m-2;
229     if (j < 0) j = 0;
230     else if (j > datarec.n-2) j = datarec.n-2;
231     /* compute value */
232     if (datarec.flags & TRIPLETS) {
233     dp = datarec.data + 3*(j*datarec.n + i);
234     if (nam == YNAME)
235     dp++;
236     else if (nam == ZNAME)
237     dp += 2;
238     d00 = dp[0]; d01 = dp[3];
239     dp += 3*datarec.n;
240     d10 = dp[0]; d11 = dp[3];
241     } else {
242     dp = datarec.data + j*datarec.n + i;
243     d00 = dp[0]; d01 = dp[1];
244     dp += datarec.n;
245     d10 = dp[0]; d11 = dp[1];
246     }
247     /* bilinear interpolation */
248     return((j+1-v)*((i+1-u)*d00+(u-i)*d01)+(v-j)*((i+1-u)*d10+(u-i)*d11));
249 greg 1.1 }
250    
251    
252 greg 1.3 putsquare(p0, p1, p2, p3) /* put out a square */
253     POINT *p0, *p1, *p2, *p3;
254     {
255     static int nout = 0;
256     FVECT norm[4];
257     int axis;
258     FVECT v1, v2, vc1, vc2;
259     int ok1, ok2;
260     /* compute exact normals */
261     fvsum(v1, p1->p, p0->p, -1.0);
262     fvsum(v2, p2->p, p0->p, -1.0);
263     fcross(vc1, v1, v2);
264     ok1 = normalize(vc1) != 0.0;
265     fvsum(v1, p2->p, p3->p, -1.0);
266     fvsum(v2, p1->p, p3->p, -1.0);
267     fcross(vc2, v1, v2);
268     ok2 = normalize(vc2) != 0.0;
269     if (!(ok1 | ok2))
270     return;
271     /* compute normal interpolation */
272     axis = norminterp(norm, p0, p1, p2, p3);
273    
274     /* put out quadrilateral? */
275     if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
276     printf("\n%s ", modname);
277     if (axis != -1) {
278     printf("texfunc %s\n", texname);
279     printf(tsargs);
280     printf("0\n13\t%d\n", axis);
281     pvect(norm[0]);
282     pvect(norm[1]);
283     pvect(norm[2]);
284     fvsum(v1, norm[3], vc1, -0.5);
285     fvsum(v1, v1, vc2, -0.5);
286     pvect(v1);
287     printf("\n%s ", texname);
288     }
289     printf("polygon %s.%d\n", surfname, ++nout);
290     printf("0\n0\n12\n");
291     pvect(p0->p);
292     pvect(p1->p);
293     pvect(p3->p);
294     pvect(p2->p);
295     return;
296     }
297     /* put out triangles? */
298     if (ok1) {
299     printf("\n%s ", modname);
300     if (axis != -1) {
301     printf("texfunc %s\n", texname);
302     printf(tsargs);
303     printf("0\n13\t%d\n", axis);
304     pvect(norm[0]);
305     pvect(norm[1]);
306     pvect(norm[2]);
307     fvsum(v1, norm[3], vc1, -1.0);
308     pvect(v1);
309     printf("\n%s ", texname);
310     }
311     printf("polygon %s.%d\n", surfname, ++nout);
312     printf("0\n0\n9\n");
313     pvect(p0->p);
314     pvect(p1->p);
315     pvect(p2->p);
316     }
317     if (ok2) {
318     printf("\n%s ", modname);
319     if (axis != -1) {
320     printf("texfunc %s\n", texname);
321     printf(tsargs);
322     printf("0\n13\t%d\n", axis);
323     pvect(norm[0]);
324     pvect(norm[1]);
325     pvect(norm[2]);
326     fvsum(v2, norm[3], vc2, -1.0);
327     pvect(v2);
328     printf("\n%s ", texname);
329     }
330     printf("polygon %s.%d\n", surfname, ++nout);
331     printf("0\n0\n9\n");
332     pvect(p2->p);
333     pvect(p1->p);
334     pvect(p3->p);
335     }
336     }
337    
338    
339 greg 1.1 comprow(s, row, siz) /* compute row of values */
340     double s;
341 greg 1.3 register POINT *row;
342 greg 1.1 int siz;
343     {
344 greg 1.4 double st[2];
345 greg 1.8 int end;
346 greg 1.4 register int i;
347 greg 1.8
348     if (smooth) {
349     i = -1; /* compute one past each end */
350     end = siz+1;
351     } else {
352     if (s < -FTINY || s > 1.0+FTINY)
353     return;
354     i = 0;
355     end = siz;
356     }
357 greg 1.1 st[0] = s;
358 greg 1.8 while (i <= end) {
359 greg 1.4 st[1] = (double)i/siz;
360     row[i].p[0] = funvalue(XNAME, 2, st);
361     row[i].p[1] = funvalue(YNAME, 2, st);
362     row[i].p[2] = funvalue(ZNAME, 2, st);
363 greg 1.8 i++;
364 greg 1.1 }
365 greg 1.3 }
366    
367    
368     compnorms(r0, r1, r2, siz) /* compute row of averaged normals */
369     register POINT *r0, *r1, *r2;
370     int siz;
371     {
372 greg 1.11 FVECT v1, v2;
373 greg 1.4 register int i;
374 greg 1.3
375     if (!smooth) /* not needed if no smoothing */
376     return;
377     /* compute middle points */
378 greg 1.4 while (siz-- >= 0) {
379 greg 1.11 fvsum(v1, r2[0].p, r0[0].p, -1.0);
380     fvsum(v2, r1[1].p, r1[-1].p, -1.0);
381 greg 1.3 fcross(r1[0].n, v1, v2);
382     normalize(r1[0].n);
383     r0++; r1++; r2++;
384     }
385     }
386    
387    
388     int
389     norminterp(resmat, p0, p1, p2, p3) /* compute normal interpolation */
390     register FVECT resmat[4];
391     POINT *p0, *p1, *p2, *p3;
392     {
393     #define u ((ax+1)%3)
394     #define v ((ax+2)%3)
395    
396     register int ax;
397 greg 1.12 MAT4 eqnmat;
398 greg 1.3 FVECT v1;
399     register int i, j;
400    
401     if (!smooth) /* no interpolation if no smoothing */
402     return(-1);
403     /* find dominant axis */
404     VCOPY(v1, p0->n);
405     fvsum(v1, v1, p1->n, 1.0);
406     fvsum(v1, v1, p2->n, 1.0);
407     fvsum(v1, v1, p3->n, 1.0);
408 greg 1.4 ax = ABS(v1[0]) > ABS(v1[1]) ? 0 : 1;
409     ax = ABS(v1[ax]) > ABS(v1[2]) ? ax : 2;
410 greg 1.3 /* assign equation matrix */
411     eqnmat[0][0] = p0->p[u]*p0->p[v];
412     eqnmat[0][1] = p0->p[u];
413     eqnmat[0][2] = p0->p[v];
414     eqnmat[0][3] = 1.0;
415     eqnmat[1][0] = p1->p[u]*p1->p[v];
416     eqnmat[1][1] = p1->p[u];
417     eqnmat[1][2] = p1->p[v];
418     eqnmat[1][3] = 1.0;
419     eqnmat[2][0] = p2->p[u]*p2->p[v];
420     eqnmat[2][1] = p2->p[u];
421     eqnmat[2][2] = p2->p[v];
422     eqnmat[2][3] = 1.0;
423     eqnmat[3][0] = p3->p[u]*p3->p[v];
424     eqnmat[3][1] = p3->p[u];
425     eqnmat[3][2] = p3->p[v];
426     eqnmat[3][3] = 1.0;
427     /* invert matrix (solve system) */
428 greg 1.4 if (!invmat(eqnmat, eqnmat))
429 greg 1.3 return(-1); /* no solution */
430     /* compute result matrix */
431     for (j = 0; j < 4; j++)
432     for (i = 0; i < 3; i++)
433 greg 1.4 resmat[j][i] = eqnmat[j][0]*p0->n[i] +
434     eqnmat[j][1]*p1->n[i] +
435     eqnmat[j][2]*p2->n[i] +
436     eqnmat[j][3]*p3->n[i];
437 greg 1.3 return(ax);
438    
439     #undef u
440     #undef v
441     }
442    
443    
444     /*
445     * invmat - computes the inverse of mat into inverse. Returns 1
446     * if there exists an inverse, 0 otherwise. It uses Gaussian Elimination
447     * method.
448     */
449    
450     invmat(inverse,mat)
451 greg 1.12 MAT4 inverse, mat;
452 greg 1.3 {
453     #define SWAP(a,b,t) (t=a,a=b,b=t)
454    
455 greg 1.12 MAT4 m4tmp;
456 greg 1.3 register int i,j,k;
457     register double temp;
458    
459 greg 1.12 copymat4(m4tmp, mat);
460 greg 1.4 /* set inverse to identity */
461     for (i = 0; i < 4; i++)
462     for (j = 0; j < 4; j++)
463     inverse[i][j] = i==j ? 1.0 : 0.0;
464 greg 1.3
465     for(i = 0; i < 4; i++) {
466 greg 1.11 /* Look for row with largest pivot and swap rows */
467 greg 1.4 temp = FTINY; j = -1;
468     for(k = i; k < 4; k++)
469     if(ABS(m4tmp[k][i]) > temp) {
470     temp = ABS(m4tmp[k][i]);
471     j = k;
472     }
473 greg 1.11 if(j == -1) /* No replacing row -> no inverse */
474 greg 1.4 return(0);
475     if (j != i)
476     for(k = 0; k < 4; k++) {
477     SWAP(m4tmp[i][k],m4tmp[j][k],temp);
478     SWAP(inverse[i][k],inverse[j][k],temp);
479     }
480 greg 1.3
481     temp = m4tmp[i][i];
482     for(k = 0; k < 4; k++) {
483     m4tmp[i][k] /= temp;
484     inverse[i][k] /= temp;
485     }
486     for(j = 0; j < 4; j++) {
487     if(j != i) {
488     temp = m4tmp[j][i];
489     for(k = 0; k < 4; k++) {
490     m4tmp[j][k] -= m4tmp[i][k]*temp;
491     inverse[j][k] -= inverse[i][k]*temp;
492     }
493     }
494     }
495     }
496     return(1);
497 greg 1.4
498 greg 1.3 #undef SWAP
499 greg 1.1 }
500    
501    
502     eputs(msg)
503     char *msg;
504     {
505     fputs(msg, stderr);
506     }
507    
508    
509     wputs(msg)
510     char *msg;
511     {
512     eputs(msg);
513     }
514    
515    
516     quit(code)
517     {
518     exit(code);
519     }
520    
521    
522     printhead(ac, av) /* print command header */
523     register int ac;
524     register char **av;
525     {
526     putchar('#');
527     while (ac--) {
528     putchar(' ');
529     fputs(*av++, stdout);
530     }
531     putchar('\n');
532     }
533    
534    
535     double
536     l_hermite()
537     {
538     double t;
539    
540     t = argument(5);
541     return( argument(1)*((2.0*t-3.0)*t*t+1.0) +
542     argument(2)*(-2.0*t+3.0)*t*t +
543     argument(3)*((t-2.0)*t+1.0)*t +
544     argument(4)*(t-1.0)*t*t );
545 greg 1.6 }
546    
547    
548     double
549     l_bezier()
550     {
551     double t;
552    
553     t = argument(5);
554     return( argument(1) * (1.+t*(-3.+t*(3.-t))) +
555     argument(2) * 3.*t*(1.+t*(-2.+t)) +
556     argument(3) * 3.*t*t*(1.-t) +
557     argument(4) * t*t*t );
558 greg 1.7 }
559    
560    
561     double
562     l_bspline()
563     {
564     double t;
565    
566     t = argument(5);
567     return( argument(1) * (1./6.+t*(-1./2.+t*(1./2.-1./6.*t))) +
568     argument(2) * (2./3.+t*t*(-1.+1./2.*t)) +
569     argument(3) * (1./6.+t*(1./2.+t*(1./2.-1./2.*t))) +
570     argument(4) * (1./6.*t*t*t) );
571 greg 1.1 }