ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/radiance/ray/src/gen/gensurf.c
Revision: 2.7
Committed: Tue Mar 11 22:48:20 2003 UTC (21 years, 1 month ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.6: +65 -6 lines
Log Message:
Created man page for obj2mesh and added -o option to gensurf

File Contents

# User Rev Content
1 greg 1.1 #ifndef lint
2 greg 2.7 static const char RCSid[] = "$Id$";
3 greg 1.1 #endif
4 greg 1.2 /*
5 greg 1.1 * gensurf.c - program to generate functional surfaces
6     *
7     * Parametric functions x(s,t), y(s,t) and z(s,t)
8     * specify the surface, which is tesselated into an m by n
9     * array of paired triangles.
10     * The surface normal is defined by the right hand
11     * rule applied to (s,t).
12     *
13     * 4/3/87
14 greg 2.6 *
15     * 4/16/02 Added conditional vertex output
16 greg 1.1 */
17    
18 greg 1.5 #include "standard.h"
19 greg 1.1
20 greg 2.6 char XNAME[] = "X`SYS"; /* x function name */
21     char YNAME[] = "Y`SYS"; /* y function name */
22     char ZNAME[] = "Z`SYS"; /* z function name */
23    
24     char VNAME[] = "valid"; /* valid vertex name */
25 greg 1.1
26 greg 1.4 #define ABS(x) ((x)>=0 ? (x) : -(x))
27    
28 greg 1.3 #define pvect(p) printf(vformat, (p)[0], (p)[1], (p)[2])
29 greg 1.1
30     char vformat[] = "%15.9g %15.9g %15.9g\n";
31 greg 1.3 char tsargs[] = "4 surf_dx surf_dy surf_dz surf.cal\n";
32     char texname[] = "Phong";
33 greg 1.1
34 greg 1.3 int smooth = 0; /* apply smoothing? */
35 greg 2.7 int objout = 0; /* output .OBJ format? */
36 greg 1.1
37 greg 1.3 char *modname, *surfname;
38 greg 1.1
39 greg 2.2 /* recorded data flags */
40     #define HASBORDER 01
41     #define TRIPLETS 02
42     /* a data structure */
43     struct {
44     int flags; /* data type */
45     short m, n; /* number of s and t values */
46     FLOAT *data; /* the data itself, s major sort */
47     } datarec; /* our recorded data */
48 greg 1.3
49 greg 2.2 double l_hermite(), l_bezier(), l_bspline(), l_dataval();
50     extern double funvalue(), argument();
51    
52 greg 1.3 typedef struct {
53 greg 2.7 int valid; /* point is valid (vertex number) */
54 greg 1.3 FVECT p; /* vertex position */
55     FVECT n; /* average normal */
56 greg 2.7 FLOAT uv[2]; /* (u,v) position */
57 greg 1.3 } POINT;
58    
59    
60 greg 1.1 main(argc, argv)
61     int argc;
62     char *argv[];
63     {
64 greg 1.9 extern long eclock;
65 greg 1.3 POINT *row0, *row1, *row2, *rp;
66 greg 1.1 int i, j, m, n;
67     char stmp[256];
68    
69 greg 1.13 varset("PI", ':', PI);
70 greg 1.14 funset("hermite", 5, ':', l_hermite);
71     funset("bezier", 5, ':', l_bezier);
72     funset("bspline", 5, ':', l_bspline);
73 greg 1.1
74     if (argc < 8)
75     goto userror;
76    
77     for (i = 8; i < argc; i++)
78     if (!strcmp(argv[i], "-e"))
79 greg 1.10 scompile(argv[++i], NULL, 0);
80 greg 1.1 else if (!strcmp(argv[i], "-f"))
81     fcompile(argv[++i]);
82 greg 1.3 else if (!strcmp(argv[i], "-s"))
83     smooth++;
84 greg 2.7 else if (!strcmp(argv[i], "-o"))
85     objout++;
86 greg 1.1 else
87     goto userror;
88    
89 greg 1.3 modname = argv[1];
90     surfname = argv[2];
91 greg 1.1 m = atoi(argv[6]);
92     n = atoi(argv[7]);
93     if (m <= 0 || n <= 0)
94     goto userror;
95 greg 2.2 if (!strcmp(argv[5], "-") || access(argv[5], 4) == 0) { /* file? */
96     funset(ZNAME, 2, ':', l_dataval);
97     if (!strcmp(argv[5],argv[3]) && !strcmp(argv[5],argv[4])) {
98     loaddata(argv[5], m, n, 3);
99     funset(XNAME, 2, ':', l_dataval);
100     funset(YNAME, 2, ':', l_dataval);
101     } else {
102     loaddata(argv[5], m, n, 1);
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     }
108     } else {
109     sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]);
110     scompile(stmp, NULL, 0);
111     sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]);
112     scompile(stmp, NULL, 0);
113     sprintf(stmp, "%s(s,t)=%s;", ZNAME, argv[5]);
114     scompile(stmp, NULL, 0);
115     }
116 greg 1.4 row0 = (POINT *)malloc((n+3)*sizeof(POINT));
117     row1 = (POINT *)malloc((n+3)*sizeof(POINT));
118     row2 = (POINT *)malloc((n+3)*sizeof(POINT));
119 greg 1.3 if (row0 == NULL || row1 == NULL || row2 == NULL) {
120 greg 1.1 fprintf(stderr, "%s: out of memory\n", argv[0]);
121     quit(1);
122     }
123 greg 1.4 row0++; row1++; row2++;
124 greg 1.3 /* print header */
125 greg 1.1 printhead(argc, argv);
126 greg 1.9 eclock = 0;
127 greg 1.4 /* initialize */
128     comprow(-1.0/m, row0, n);
129 greg 1.3 comprow(0.0, row1, n);
130     comprow(1.0/m, row2, n);
131 greg 1.4 compnorms(row0, row1, row2, n);
132 greg 2.7 if (objout)
133     putobjrow(row1, n);
134 greg 1.3 /* for each row */
135 greg 1.1 for (i = 0; i < m; i++) {
136     /* compute next row */
137 greg 1.3 rp = row0;
138 greg 1.1 row0 = row1;
139 greg 1.3 row1 = row2;
140     row2 = rp;
141 greg 1.4 comprow((double)(i+2)/m, row2, n);
142     compnorms(row0, row1, row2, n);
143 greg 2.7 if (objout)
144     putobjrow(row1, n);
145 greg 1.1
146     for (j = 0; j < n; j++) {
147 greg 2.6 int orient = (j & 1);
148 greg 1.3 /* put polygons */
149 greg 2.7 if (!(row0[j].valid && row1[j+1].valid))
150 greg 2.6 orient = 1;
151 greg 2.7 else if (!(row1[j].valid && row0[j+1].valid))
152 greg 2.6 orient = 0;
153     if (orient)
154 greg 1.3 putsquare(&row0[j], &row1[j],
155     &row0[j+1], &row1[j+1]);
156     else
157     putsquare(&row1[j], &row1[j+1],
158     &row0[j], &row0[j+1]);
159 greg 1.1 }
160     }
161    
162     quit(0);
163    
164     userror:
165     fprintf(stderr, "Usage: %s material name ", argv[0]);
166 greg 1.3 fprintf(stderr, "x(s,t) y(s,t) z(s,t) m n [-s][-e expr][-f file]\n");
167 greg 1.1 quit(1);
168 greg 2.2 }
169    
170    
171     loaddata(file, m, n, pointsize) /* load point data from file */
172     char *file;
173     int m, n;
174     int pointsize;
175     {
176     FILE *fp;
177     char word[64];
178     register int size;
179     register FLOAT *dp;
180    
181     datarec.flags = HASBORDER; /* assume border values */
182 greg 2.3 datarec.m = m+1;
183     datarec.n = n+1;
184     size = datarec.m*datarec.n*pointsize;
185 greg 2.2 if (pointsize == 3)
186     datarec.flags |= TRIPLETS;
187     dp = (FLOAT *)malloc(size*sizeof(FLOAT));
188     if ((datarec.data = dp) == NULL) {
189     fputs("Out of memory\n", stderr);
190     exit(1);
191     }
192     if (!strcmp(file, "-")) {
193     file = "<stdin>";
194     fp = stdin;
195     } else if ((fp = fopen(file, "r")) == NULL) {
196     fputs(file, stderr);
197     fputs(": cannot open\n", stderr);
198     exit(1);
199     }
200     while (size > 0 && fgetword(word, sizeof(word), fp) != NULL) {
201     if (!isflt(word)) {
202     fprintf(stderr, "%s: garbled data value: %s\n",
203     file, word);
204     exit(1);
205     }
206     *dp++ = atof(word);
207     size--;
208     }
209     if (size == (m+n+1)*pointsize) { /* no border after all */
210     dp = (FLOAT *)realloc((char *)datarec.data,
211     m*n*pointsize*sizeof(FLOAT));
212     if (dp != NULL)
213     datarec.data = dp;
214     datarec.flags &= ~HASBORDER;
215 greg 2.3 datarec.m = m;
216     datarec.n = n;
217 greg 2.2 size = 0;
218     }
219 greg 2.3 if (datarec.m < 2 || datarec.n < 2 || size != 0 ||
220     fgetword(word, sizeof(word), fp) != NULL) {
221 greg 2.2 fputs(file, stderr);
222     fputs(": bad number of data points\n", stderr);
223     exit(1);
224     }
225     fclose(fp);
226     }
227    
228    
229     double
230     l_dataval(nam) /* return recorded data value */
231     char *nam;
232     {
233     double u, v;
234     register int i, j;
235     register FLOAT *dp;
236     double d00, d01, d10, d11;
237     /* compute coordinates */
238     u = argument(1); v = argument(2);
239     if (datarec.flags & HASBORDER) {
240 greg 2.3 i = u *= datarec.m-1;
241     j = v *= datarec.n-1;
242 greg 2.2 } else {
243 greg 2.3 i = u = u*datarec.m - .5;
244     j = v = v*datarec.n - .5;
245 greg 2.2 }
246     if (i < 0) i = 0;
247     else if (i > datarec.m-2) i = datarec.m-2;
248     if (j < 0) j = 0;
249     else if (j > datarec.n-2) j = datarec.n-2;
250     /* compute value */
251     if (datarec.flags & TRIPLETS) {
252 greg 2.3 dp = datarec.data + 3*(j*datarec.m + i);
253     if (nam == ZNAME)
254     dp += 2;
255     else if (nam == YNAME)
256 greg 2.2 dp++;
257     d00 = dp[0]; d01 = dp[3];
258 greg 2.3 dp += 3*datarec.m;
259 greg 2.2 d10 = dp[0]; d11 = dp[3];
260     } else {
261 greg 2.3 dp = datarec.data + j*datarec.m + i;
262 greg 2.2 d00 = dp[0]; d01 = dp[1];
263 greg 2.3 dp += datarec.m;
264 greg 2.2 d10 = dp[0]; d11 = dp[1];
265     }
266     /* bilinear interpolation */
267     return((j+1-v)*((i+1-u)*d00+(u-i)*d01)+(v-j)*((i+1-u)*d10+(u-i)*d11));
268 greg 1.1 }
269    
270    
271 greg 2.7 putobjrow(rp, n) /* output vertex row to .OBJ */
272     register POINT *rp;
273     int n;
274     {
275     static int nverts = 0;
276    
277     for ( ; n-- >= 0; rp++) {
278     if (!rp->valid)
279     continue;
280     fputs("v ", stdout);
281     printf(vformat, rp->p[0], rp->p[1], rp->p[2]);
282     if (smooth)
283     printf("\tvn %.9g %.9g %.9g\n",
284     rp->n[0], rp->n[1], rp->n[2]);
285     printf("\tvt %.9g %.9g\n", rp->uv[0], rp->uv[1]);
286     rp->valid = ++nverts;
287     }
288     }
289    
290    
291 greg 1.3 putsquare(p0, p1, p2, p3) /* put out a square */
292     POINT *p0, *p1, *p2, *p3;
293     {
294     static int nout = 0;
295     FVECT norm[4];
296     int axis;
297     FVECT v1, v2, vc1, vc2;
298     int ok1, ok2;
299     /* compute exact normals */
300 greg 2.7 ok1 = (p0->valid && p1->valid && p2->valid);
301 greg 2.6 if (ok1) {
302     fvsum(v1, p1->p, p0->p, -1.0);
303     fvsum(v2, p2->p, p0->p, -1.0);
304     fcross(vc1, v1, v2);
305     ok1 = (normalize(vc1) != 0.0);
306     }
307 greg 2.7 ok2 = (p1->valid && p2->valid && p3->valid);
308 greg 2.6 if (ok2) {
309     fvsum(v1, p2->p, p3->p, -1.0);
310     fvsum(v2, p1->p, p3->p, -1.0);
311     fcross(vc2, v1, v2);
312     ok2 = (normalize(vc2) != 0.0);
313     }
314 greg 1.3 if (!(ok1 | ok2))
315     return;
316 greg 2.7 if (objout) { /* output .OBJ faces */
317     int p0n=0, p1n=0, p2n=0, p3n=0;
318     if (smooth) {
319     p0n = p0->valid;
320     p1n = p1->valid;
321     p2n = p2->valid;
322     p3n = p3->valid;
323     }
324     if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
325     printf("f %d/%d/%d %d/%d/%d %d/%d/%d %d/%d/%d\n",
326     p0->valid, p0n, p0->valid,
327     p1->valid, p1n, p1->valid,
328     p3->valid, p3n, p3->valid,
329     p2->valid, p2n, p2->valid);
330     return;
331     }
332     if (ok1)
333     printf("f %d/%d/%d %d/%d/%d %d/%d/%d\n",
334     p0->valid, p0n, p0->valid,
335     p1->valid, p1n, p1->valid,
336     p2->valid, p2n, p2->valid);
337     if (ok2)
338     printf("f %d/%d/%d %d/%d/%d %d/%d/%d\n",
339     p2->valid, p2n, p2->valid,
340     p1->valid, p1n, p1->valid,
341     p3->valid, p3n, p3->valid);
342     return;
343     }
344 greg 1.3 /* compute normal interpolation */
345     axis = norminterp(norm, p0, p1, p2, p3);
346    
347     /* put out quadrilateral? */
348     if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
349     printf("\n%s ", modname);
350     if (axis != -1) {
351     printf("texfunc %s\n", texname);
352     printf(tsargs);
353     printf("0\n13\t%d\n", axis);
354     pvect(norm[0]);
355     pvect(norm[1]);
356     pvect(norm[2]);
357     fvsum(v1, norm[3], vc1, -0.5);
358     fvsum(v1, v1, vc2, -0.5);
359     pvect(v1);
360     printf("\n%s ", texname);
361     }
362     printf("polygon %s.%d\n", surfname, ++nout);
363     printf("0\n0\n12\n");
364     pvect(p0->p);
365     pvect(p1->p);
366     pvect(p3->p);
367     pvect(p2->p);
368     return;
369     }
370     /* put out triangles? */
371     if (ok1) {
372     printf("\n%s ", modname);
373     if (axis != -1) {
374     printf("texfunc %s\n", texname);
375     printf(tsargs);
376     printf("0\n13\t%d\n", axis);
377     pvect(norm[0]);
378     pvect(norm[1]);
379     pvect(norm[2]);
380     fvsum(v1, norm[3], vc1, -1.0);
381     pvect(v1);
382     printf("\n%s ", texname);
383     }
384     printf("polygon %s.%d\n", surfname, ++nout);
385     printf("0\n0\n9\n");
386     pvect(p0->p);
387     pvect(p1->p);
388     pvect(p2->p);
389     }
390     if (ok2) {
391     printf("\n%s ", modname);
392     if (axis != -1) {
393     printf("texfunc %s\n", texname);
394     printf(tsargs);
395     printf("0\n13\t%d\n", axis);
396     pvect(norm[0]);
397     pvect(norm[1]);
398     pvect(norm[2]);
399     fvsum(v2, norm[3], vc2, -1.0);
400     pvect(v2);
401     printf("\n%s ", texname);
402     }
403     printf("polygon %s.%d\n", surfname, ++nout);
404     printf("0\n0\n9\n");
405     pvect(p2->p);
406     pvect(p1->p);
407     pvect(p3->p);
408     }
409     }
410    
411    
412 greg 1.1 comprow(s, row, siz) /* compute row of values */
413     double s;
414 greg 1.3 register POINT *row;
415 greg 1.1 int siz;
416     {
417 greg 1.4 double st[2];
418 greg 1.8 int end;
419 greg 2.6 int checkvalid;
420 greg 1.4 register int i;
421 greg 1.8
422     if (smooth) {
423     i = -1; /* compute one past each end */
424     end = siz+1;
425     } else {
426     if (s < -FTINY || s > 1.0+FTINY)
427     return;
428     i = 0;
429     end = siz;
430     }
431 greg 1.1 st[0] = s;
432 greg 2.6 checkvalid = (fundefined(VNAME) == 2);
433 greg 1.8 while (i <= end) {
434 greg 1.4 st[1] = (double)i/siz;
435 greg 2.6 if (checkvalid && funvalue(VNAME, 2, st) <= 0.0) {
436     row[i].valid = 0;
437     row[i].p[0] = row[i].p[1] = row[i].p[2] = 0.0;
438 greg 2.7 row[i].uv[0] = row[i].uv[1] = 0.0;
439 greg 2.6 } else {
440     row[i].valid = 1;
441     row[i].p[0] = funvalue(XNAME, 2, st);
442     row[i].p[1] = funvalue(YNAME, 2, st);
443     row[i].p[2] = funvalue(ZNAME, 2, st);
444 greg 2.7 row[i].uv[0] = st[0];
445     row[i].uv[1] = st[1];
446 greg 2.6 }
447 greg 1.8 i++;
448 greg 1.1 }
449 greg 1.3 }
450    
451    
452     compnorms(r0, r1, r2, siz) /* compute row of averaged normals */
453     register POINT *r0, *r1, *r2;
454     int siz;
455     {
456 greg 1.11 FVECT v1, v2;
457 greg 1.3
458     if (!smooth) /* not needed if no smoothing */
459     return;
460 greg 2.6 /* compute row 1 normals */
461 greg 1.4 while (siz-- >= 0) {
462 greg 2.6 if (!r1[0].valid)
463     continue;
464     if (!r0[0].valid) {
465     if (!r2[0].valid) {
466     r1[0].n[0] = r1[0].n[1] = r1[0].n[2] = 0.0;
467     continue;
468     }
469     fvsum(v1, r2[0].p, r1[0].p, -1.0);
470     } else if (!r2[0].valid)
471     fvsum(v1, r1[0].p, r0[0].p, -1.0);
472     else
473     fvsum(v1, r2[0].p, r0[0].p, -1.0);
474     if (!r1[-1].valid) {
475     if (!r1[1].valid) {
476     r1[0].n[0] = r1[0].n[1] = r1[0].n[2] = 0.0;
477     continue;
478     }
479     fvsum(v2, r1[1].p, r1[0].p, -1.0);
480     } else if (!r1[1].valid)
481     fvsum(v2, r1[0].p, r1[-1].p, -1.0);
482     else
483     fvsum(v2, r1[1].p, r1[-1].p, -1.0);
484 greg 1.3 fcross(r1[0].n, v1, v2);
485     normalize(r1[0].n);
486     r0++; r1++; r2++;
487     }
488     }
489    
490    
491     int
492     norminterp(resmat, p0, p1, p2, p3) /* compute normal interpolation */
493     register FVECT resmat[4];
494     POINT *p0, *p1, *p2, *p3;
495     {
496     #define u ((ax+1)%3)
497     #define v ((ax+2)%3)
498    
499     register int ax;
500 greg 1.12 MAT4 eqnmat;
501 greg 1.3 FVECT v1;
502     register int i, j;
503    
504     if (!smooth) /* no interpolation if no smoothing */
505     return(-1);
506     /* find dominant axis */
507     VCOPY(v1, p0->n);
508     fvsum(v1, v1, p1->n, 1.0);
509     fvsum(v1, v1, p2->n, 1.0);
510     fvsum(v1, v1, p3->n, 1.0);
511 greg 1.4 ax = ABS(v1[0]) > ABS(v1[1]) ? 0 : 1;
512     ax = ABS(v1[ax]) > ABS(v1[2]) ? ax : 2;
513 greg 1.3 /* assign equation matrix */
514     eqnmat[0][0] = p0->p[u]*p0->p[v];
515     eqnmat[0][1] = p0->p[u];
516     eqnmat[0][2] = p0->p[v];
517     eqnmat[0][3] = 1.0;
518     eqnmat[1][0] = p1->p[u]*p1->p[v];
519     eqnmat[1][1] = p1->p[u];
520     eqnmat[1][2] = p1->p[v];
521     eqnmat[1][3] = 1.0;
522     eqnmat[2][0] = p2->p[u]*p2->p[v];
523     eqnmat[2][1] = p2->p[u];
524     eqnmat[2][2] = p2->p[v];
525     eqnmat[2][3] = 1.0;
526     eqnmat[3][0] = p3->p[u]*p3->p[v];
527     eqnmat[3][1] = p3->p[u];
528     eqnmat[3][2] = p3->p[v];
529     eqnmat[3][3] = 1.0;
530     /* invert matrix (solve system) */
531 greg 2.5 if (!invmat4(eqnmat, eqnmat))
532 greg 1.3 return(-1); /* no solution */
533     /* compute result matrix */
534     for (j = 0; j < 4; j++)
535     for (i = 0; i < 3; i++)
536 greg 1.4 resmat[j][i] = eqnmat[j][0]*p0->n[i] +
537     eqnmat[j][1]*p1->n[i] +
538     eqnmat[j][2]*p2->n[i] +
539     eqnmat[j][3]*p3->n[i];
540 greg 1.3 return(ax);
541    
542     #undef u
543     #undef v
544 greg 1.1 }
545    
546    
547 greg 2.6 void
548 greg 1.1 eputs(msg)
549     char *msg;
550     {
551     fputs(msg, stderr);
552     }
553    
554    
555 greg 2.6 void
556 greg 1.1 wputs(msg)
557     char *msg;
558     {
559     eputs(msg);
560     }
561    
562    
563 greg 2.6 void
564 greg 1.1 quit(code)
565 greg 2.4 int code;
566 greg 1.1 {
567     exit(code);
568     }
569    
570    
571     printhead(ac, av) /* print command header */
572     register int ac;
573     register char **av;
574     {
575     putchar('#');
576     while (ac--) {
577     putchar(' ');
578     fputs(*av++, stdout);
579     }
580     putchar('\n');
581     }
582    
583    
584     double
585     l_hermite()
586     {
587     double t;
588    
589     t = argument(5);
590     return( argument(1)*((2.0*t-3.0)*t*t+1.0) +
591     argument(2)*(-2.0*t+3.0)*t*t +
592     argument(3)*((t-2.0)*t+1.0)*t +
593     argument(4)*(t-1.0)*t*t );
594 greg 1.6 }
595    
596    
597     double
598     l_bezier()
599     {
600     double t;
601    
602     t = argument(5);
603     return( argument(1) * (1.+t*(-3.+t*(3.-t))) +
604     argument(2) * 3.*t*(1.+t*(-2.+t)) +
605     argument(3) * 3.*t*t*(1.-t) +
606     argument(4) * t*t*t );
607 greg 1.7 }
608    
609    
610     double
611     l_bspline()
612     {
613     double t;
614    
615     t = argument(5);
616     return( argument(1) * (1./6.+t*(-1./2.+t*(1./2.-1./6.*t))) +
617     argument(2) * (2./3.+t*t*(-1.+1./2.*t)) +
618     argument(3) * (1./6.+t*(1./2.+t*(1./2.-1./2.*t))) +
619     argument(4) * (1./6.*t*t*t) );
620 greg 1.1 }