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root/radiance/ray/src/cv/bsdfrep.c
Revision: 2.7
Committed: Thu Nov 8 22:05:04 2012 UTC (11 years, 5 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.6: +5 -7 lines
Log Message:
Took sort out so it is done only once

File Contents

# User Rev Content
1 greg 2.1 #ifndef lint
2 greg 2.7 static const char RCSid[] = "$Id: bsdfrep.c,v 2.6 2012/11/08 00:31:17 greg Exp $";
3 greg 2.1 #endif
4     /*
5     * Support BSDF representation as radial basis functions.
6     *
7     * G. Ward
8     */
9    
10     #define _USE_MATH_DEFINES
11     #include <stdlib.h>
12 greg 2.2 #include <string.h>
13 greg 2.1 #include <math.h>
14     #include "rtio.h"
15     #include "resolu.h"
16     #include "bsdfrep.h"
17 greg 2.5 /* active grid resolution */
18     int grid_res = GRIDRES;
19    
20 greg 2.4 /* coverage/symmetry using INP_QUAD? flags */
21 greg 2.1 int inp_coverage = 0;
22     /* all incident angles in-plane so far? */
23     int single_plane_incident = -1;
24    
25     /* input/output orientations */
26     int input_orient = 0;
27     int output_orient = 0;
28    
29     /* processed incident DSF measurements */
30     RBFNODE *dsf_list = NULL;
31    
32     /* RBF-linking matrices (edges) */
33     MIGRATION *mig_list = NULL;
34    
35     /* current input direction */
36     double theta_in_deg, phi_in_deg;
37    
38     /* Register new input direction */
39     int
40     new_input_direction(double new_theta, double new_phi)
41     {
42     if (!input_orient) /* check input orientation */
43     input_orient = 1 - 2*(new_theta > 90.);
44     else if (input_orient > 0 ^ new_theta < 90.) {
45     fprintf(stderr,
46     "%s: Cannot handle input angles on both sides of surface\n",
47     progname);
48     return(0);
49     }
50     /* normalize angle ranges */
51     while (new_theta < -180.)
52     new_theta += 360.;
53     while (new_theta > 180.)
54     new_theta -= 360.;
55     if (new_theta < 0) {
56     new_theta = -new_theta;
57     new_phi += 180.;
58     }
59 greg 2.6 if ((theta_in_deg = new_theta) < 1.0)
60     return(1); /* don't rely on phi near normal */
61 greg 2.1 while (new_phi < 0)
62     new_phi += 360.;
63     while (new_phi >= 360.)
64     new_phi -= 360.;
65     if (single_plane_incident > 0) /* check input coverage */
66     single_plane_incident = (round(new_phi) == round(phi_in_deg));
67     else if (single_plane_incident < 0)
68     single_plane_incident = 1;
69     phi_in_deg = new_phi;
70     if ((1. < new_phi) & (new_phi < 89.))
71     inp_coverage |= INP_QUAD1;
72     else if ((91. < new_phi) & (new_phi < 179.))
73     inp_coverage |= INP_QUAD2;
74     else if ((181. < new_phi) & (new_phi < 269.))
75     inp_coverage |= INP_QUAD3;
76     else if ((271. < new_phi) & (new_phi < 359.))
77     inp_coverage |= INP_QUAD4;
78     return(1);
79     }
80    
81     /* Apply symmetry to the given vector based on distribution */
82     int
83     use_symmetry(FVECT vec)
84     {
85     double phi = get_phi360(vec);
86    
87     switch (inp_coverage) {
88     case INP_QUAD1|INP_QUAD2|INP_QUAD3|INP_QUAD4:
89     break;
90     case INP_QUAD1|INP_QUAD2:
91     if ((-FTINY > phi) | (phi > 180.+FTINY))
92     goto mir_y;
93     break;
94     case INP_QUAD2|INP_QUAD3:
95     if ((90.-FTINY > phi) | (phi > 270.+FTINY))
96     goto mir_x;
97     break;
98     case INP_QUAD3|INP_QUAD4:
99     if ((180.-FTINY > phi) | (phi > 360.+FTINY))
100     goto mir_y;
101     break;
102     case INP_QUAD4|INP_QUAD1:
103     if ((270.-FTINY > phi) & (phi > 90.+FTINY))
104     goto mir_x;
105     break;
106     case INP_QUAD1:
107     if ((-FTINY > phi) | (phi > 90.+FTINY))
108     switch ((int)(phi*(1./90.))) {
109     case 1: goto mir_x;
110     case 2: goto mir_xy;
111     case 3: goto mir_y;
112     }
113     break;
114     case INP_QUAD2:
115     if ((90.-FTINY > phi) | (phi > 180.+FTINY))
116     switch ((int)(phi*(1./90.))) {
117     case 0: goto mir_x;
118     case 2: goto mir_y;
119     case 3: goto mir_xy;
120     }
121     break;
122     case INP_QUAD3:
123     if ((180.-FTINY > phi) | (phi > 270.+FTINY))
124     switch ((int)(phi*(1./90.))) {
125     case 0: goto mir_xy;
126     case 1: goto mir_y;
127     case 3: goto mir_x;
128     }
129     break;
130     case INP_QUAD4:
131     if ((270.-FTINY > phi) | (phi > 360.+FTINY))
132     switch ((int)(phi*(1./90.))) {
133     case 0: goto mir_y;
134     case 1: goto mir_xy;
135     case 2: goto mir_x;
136     }
137     break;
138     default:
139     fprintf(stderr, "%s: Illegal input coverage (%d)\n",
140     progname, inp_coverage);
141     exit(1);
142     }
143     return(0); /* in range */
144     mir_x:
145     vec[0] = -vec[0];
146     return(MIRROR_X);
147     mir_y:
148     vec[1] = -vec[1];
149     return(MIRROR_Y);
150     mir_xy:
151     vec[0] = -vec[0];
152     vec[1] = -vec[1];
153     return(MIRROR_X|MIRROR_Y);
154     }
155    
156     /* Reverse symmetry based on what was done before */
157     void
158     rev_symmetry(FVECT vec, int sym)
159     {
160     if (sym & MIRROR_X)
161     vec[0] = -vec[0];
162     if (sym & MIRROR_Y)
163     vec[1] = -vec[1];
164     }
165    
166     /* Reverse symmetry for an RBF distribution */
167     void
168     rev_rbf_symmetry(RBFNODE *rbf, int sym)
169     {
170     int n;
171    
172     rev_symmetry(rbf->invec, sym);
173     if (sym & MIRROR_X)
174     for (n = rbf->nrbf; n-- > 0; )
175 greg 2.5 rbf->rbfa[n].gx = grid_res-1 - rbf->rbfa[n].gx;
176 greg 2.1 if (sym & MIRROR_Y)
177     for (n = rbf->nrbf; n-- > 0; )
178 greg 2.5 rbf->rbfa[n].gy = grid_res-1 - rbf->rbfa[n].gy;
179 greg 2.1 }
180    
181 greg 2.6 /* Rotate RBF to correspond to given incident vector */
182     void
183     rotate_rbf(RBFNODE *rbf, const FVECT invec)
184     {
185     static const FVECT vnorm = {.0, .0, 1.};
186     const double phi = atan2(invec[1],invec[0]) -
187     atan2(rbf->invec[1],rbf->invec[0]);
188     FVECT outvec;
189     int pos[2];
190     int n;
191     #ifdef DEBUG
192 greg 2.7 double tdiff = 180./M_PI*fabs(acos(invec[2])-acos(rbf->invec[2]));
193     if (tdiff >= 1.5)
194     fprintf(stderr,
195 greg 2.6 "%s: Warning - rotated theta differs by %.1f degrees\n",
196 greg 2.7 progname, tdiff);
197 greg 2.6 #endif
198     for (n = rbf->nrbf; n-- > 0; ) {
199     ovec_from_pos(outvec, rbf->rbfa[n].gx, rbf->rbfa[n].gy);
200     spinvector(outvec, outvec, vnorm, phi);
201     pos_from_vec(pos, outvec);
202     rbf->rbfa[n].gx = pos[0];
203     rbf->rbfa[n].gy = pos[1];
204     }
205     VCOPY(rbf->invec, invec);
206     }
207    
208 greg 2.1 /* Compute volume associated with Gaussian lobe */
209     double
210     rbf_volume(const RBFVAL *rbfp)
211     {
212     double rad = R2ANG(rbfp->crad);
213    
214     return((2.*M_PI) * rbfp->peak * rad*rad);
215     }
216    
217     /* Compute outgoing vector from grid position */
218     void
219     ovec_from_pos(FVECT vec, int xpos, int ypos)
220     {
221     double uv[2];
222     double r2;
223    
224 greg 2.5 SDsquare2disk(uv, (1./grid_res)*(xpos+.5), (1./grid_res)*(ypos+.5));
225 greg 2.1 /* uniform hemispherical projection */
226     r2 = uv[0]*uv[0] + uv[1]*uv[1];
227     vec[0] = vec[1] = sqrt(2. - r2);
228     vec[0] *= uv[0];
229     vec[1] *= uv[1];
230     vec[2] = output_orient*(1. - r2);
231     }
232    
233     /* Compute grid position from normalized input/output vector */
234     void
235     pos_from_vec(int pos[2], const FVECT vec)
236     {
237     double sq[2]; /* uniform hemispherical projection */
238     double norm = 1./sqrt(1. + fabs(vec[2]));
239    
240     SDdisk2square(sq, vec[0]*norm, vec[1]*norm);
241    
242 greg 2.5 pos[0] = (int)(sq[0]*grid_res);
243     pos[1] = (int)(sq[1]*grid_res);
244 greg 2.1 }
245    
246     /* Evaluate RBF for DSF at the given normalized outgoing direction */
247     double
248     eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
249     {
250     double res = .0;
251     const RBFVAL *rbfp;
252     FVECT odir;
253     double sig2;
254     int n;
255    
256     if (rp == NULL)
257     return(.0);
258     rbfp = rp->rbfa;
259     for (n = rp->nrbf; n--; rbfp++) {
260     ovec_from_pos(odir, rbfp->gx, rbfp->gy);
261     sig2 = R2ANG(rbfp->crad);
262     sig2 = (DOT(odir,outvec) - 1.) / (sig2*sig2);
263     if (sig2 > -19.)
264     res += rbfp->peak * exp(sig2);
265     }
266     return(res);
267     }
268    
269     /* Insert a new directional scattering function in our global list */
270     int
271     insert_dsf(RBFNODE *newrbf)
272     {
273     RBFNODE *rbf, *rbf_last;
274     int pos;
275     /* check for redundant meas. */
276     for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
277     if (DOT(rbf->invec, newrbf->invec) >= 1.-FTINY) {
278     fprintf(stderr,
279     "%s: Duplicate incident measurement (ignored)\n",
280     progname);
281     free(newrbf);
282     return(-1);
283     }
284     /* keep in ascending theta order */
285     for (rbf_last = NULL, rbf = dsf_list; rbf != NULL;
286     rbf_last = rbf, rbf = rbf->next)
287     if (single_plane_incident && input_orient*rbf->invec[2] <
288     input_orient*newrbf->invec[2])
289     break;
290     if (rbf_last == NULL) { /* insert new node in list */
291     newrbf->ord = 0;
292     newrbf->next = dsf_list;
293     dsf_list = newrbf;
294     } else {
295     newrbf->ord = rbf_last->ord + 1;
296     newrbf->next = rbf;
297     rbf_last->next = newrbf;
298     }
299     rbf_last = newrbf;
300     while (rbf != NULL) { /* update ordinal positions */
301     rbf->ord = rbf_last->ord + 1;
302     rbf_last = rbf;
303     rbf = rbf->next;
304     }
305     return(newrbf->ord);
306     }
307    
308     /* Get the DSF indicated by its ordinal position */
309     RBFNODE *
310     get_dsf(int ord)
311     {
312     RBFNODE *rbf;
313    
314     for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
315 greg 2.3 if (rbf->ord == ord)
316 greg 2.1 return(rbf);
317     return(NULL);
318     }
319    
320     /* Get triangle surface orientation (unnormalized) */
321     void
322     tri_orient(FVECT vres, const FVECT v1, const FVECT v2, const FVECT v3)
323     {
324     FVECT v2minus1, v3minus2;
325    
326     VSUB(v2minus1, v2, v1);
327     VSUB(v3minus2, v3, v2);
328     VCROSS(vres, v2minus1, v3minus2);
329     }
330    
331     /* Determine if vertex order is reversed (inward normal) */
332     int
333     is_rev_tri(const FVECT v1, const FVECT v2, const FVECT v3)
334     {
335     FVECT tor;
336    
337     tri_orient(tor, v1, v2, v3);
338    
339     return(DOT(tor, v2) < 0.);
340     }
341    
342     /* Find vertices completing triangles on either side of the given edge */
343     int
344     get_triangles(RBFNODE *rbfv[2], const MIGRATION *mig)
345     {
346 greg 2.4 const MIGRATION *ej1, *ej2;
347 greg 2.1 RBFNODE *tv;
348    
349     rbfv[0] = rbfv[1] = NULL;
350     if (mig == NULL)
351     return(0);
352 greg 2.4 for (ej1 = mig->rbfv[0]->ejl; ej1 != NULL;
353     ej1 = nextedge(mig->rbfv[0],ej1)) {
354     if (ej1 == mig)
355 greg 2.1 continue;
356 greg 2.4 tv = opp_rbf(mig->rbfv[0],ej1);
357 greg 2.1 for (ej2 = tv->ejl; ej2 != NULL; ej2 = nextedge(tv,ej2))
358     if (opp_rbf(tv,ej2) == mig->rbfv[1]) {
359     rbfv[is_rev_tri(mig->rbfv[0]->invec,
360     mig->rbfv[1]->invec,
361     tv->invec)] = tv;
362     break;
363     }
364     }
365     return((rbfv[0] != NULL) + (rbfv[1] != NULL));
366     }
367    
368 greg 2.4 /* Clear our BSDF representation and free memory */
369     void
370     clear_bsdf_rep(void)
371     {
372     while (mig_list != NULL) {
373     MIGRATION *mig = mig_list;
374     mig_list = mig->next;
375     free(mig);
376     }
377     while (dsf_list != NULL) {
378     RBFNODE *rbf = dsf_list;
379     dsf_list = rbf->next;
380     free(rbf);
381     }
382     inp_coverage = 0;
383     single_plane_incident = -1;
384     input_orient = output_orient = 0;
385 greg 2.5 grid_res = GRIDRES;
386 greg 2.4 }
387    
388 greg 2.1 /* Write our BSDF mesh interpolant out to the given binary stream */
389     void
390     save_bsdf_rep(FILE *ofp)
391     {
392     RBFNODE *rbf;
393     MIGRATION *mig;
394     int i, n;
395     /* finish header */
396 greg 2.2 fprintf(ofp, "SYMMETRY=%d\n", !single_plane_incident * inp_coverage);
397     fprintf(ofp, "IO_SIDES= %d %d\n", input_orient, output_orient);
398 greg 2.5 fprintf(ofp, "GRIDRES=%d\n", grid_res);
399 greg 2.1 fputformat(BSDFREP_FMT, ofp);
400     fputc('\n', ofp);
401     /* write each DSF */
402     for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
403     putint(rbf->ord, 4, ofp);
404     putflt(rbf->invec[0], ofp);
405     putflt(rbf->invec[1], ofp);
406     putflt(rbf->invec[2], ofp);
407     putflt(rbf->vtotal, ofp);
408     putint(rbf->nrbf, 4, ofp);
409     for (i = 0; i < rbf->nrbf; i++) {
410     putflt(rbf->rbfa[i].peak, ofp);
411     putint(rbf->rbfa[i].crad, 2, ofp);
412     putint(rbf->rbfa[i].gx, 1, ofp);
413     putint(rbf->rbfa[i].gy, 1, ofp);
414     }
415     }
416     putint(-1, 4, ofp); /* terminator */
417     /* write each migration matrix */
418 greg 2.2 for (mig = mig_list; mig != NULL; mig = mig->next) {
419     int zerocnt = 0;
420 greg 2.1 putint(mig->rbfv[0]->ord, 4, ofp);
421     putint(mig->rbfv[1]->ord, 4, ofp);
422 greg 2.2 /* write out as sparse data */
423 greg 2.1 n = mtx_nrows(mig) * mtx_ncols(mig);
424 greg 2.2 for (i = 0; i < n; i++) {
425 greg 2.3 if (zerocnt == 0xff) {
426     putint(0xff, 1, ofp); zerocnt = 0;
427 greg 2.2 }
428     if (mig->mtx[i] != 0) {
429     putint(zerocnt, 1, ofp); zerocnt = 0;
430     putflt(mig->mtx[i], ofp);
431     } else
432     ++zerocnt;
433     }
434     putint(zerocnt, 1, ofp);
435 greg 2.1 }
436     putint(-1, 4, ofp); /* terminator */
437     putint(-1, 4, ofp);
438     if (fflush(ofp) == EOF) {
439     fprintf(stderr, "%s: error writing BSDF interpolant\n",
440     progname);
441     exit(1);
442     }
443     }
444    
445 greg 2.2 /* Check header line for critical information */
446     static int
447     headline(char *s, void *p)
448     {
449     char fmt[32];
450    
451     if (!strncmp(s, "SYMMETRY=", 9)) {
452     inp_coverage = atoi(s+9);
453     single_plane_incident = !inp_coverage;
454     return(0);
455     }
456     if (!strncmp(s, "IO_SIDES=", 9)) {
457     sscanf(s+9, "%d %d", &input_orient, &output_orient);
458     return(0);
459     }
460 greg 2.5 if (!strncmp(s, "GRIDRES=", 8)) {
461     sscanf(s+8, "%d", &grid_res);
462     return(0);
463     }
464 greg 2.2 if (formatval(fmt, s) && strcmp(fmt, BSDFREP_FMT))
465     return(-1);
466     return(0);
467     }
468    
469 greg 2.1 /* Read a BSDF mesh interpolant from the given binary stream */
470     int
471     load_bsdf_rep(FILE *ifp)
472     {
473     RBFNODE rbfh;
474     int from_ord, to_ord;
475     int i;
476 greg 2.4
477     clear_bsdf_rep();
478 greg 2.5 if (ifp == NULL)
479     return(0);
480 greg 2.2 if (getheader(ifp, headline, NULL) < 0 || single_plane_incident < 0 |
481     !input_orient | !output_orient) {
482 greg 2.1 fprintf(stderr, "%s: missing/bad format for BSDF interpolant\n",
483     progname);
484     return(0);
485     }
486     rbfh.next = NULL; /* read each DSF */
487     rbfh.ejl = NULL;
488     while ((rbfh.ord = getint(4, ifp)) >= 0) {
489     RBFNODE *newrbf;
490    
491     rbfh.invec[0] = getflt(ifp);
492     rbfh.invec[1] = getflt(ifp);
493     rbfh.invec[2] = getflt(ifp);
494 greg 2.3 rbfh.vtotal = getflt(ifp);
495 greg 2.1 rbfh.nrbf = getint(4, ifp);
496     newrbf = (RBFNODE *)malloc(sizeof(RBFNODE) +
497     sizeof(RBFVAL)*(rbfh.nrbf-1));
498     if (newrbf == NULL)
499     goto memerr;
500     memcpy(newrbf, &rbfh, sizeof(RBFNODE));
501     for (i = 0; i < rbfh.nrbf; i++) {
502     newrbf->rbfa[i].peak = getflt(ifp);
503     newrbf->rbfa[i].crad = getint(2, ifp) & 0xffff;
504     newrbf->rbfa[i].gx = getint(1, ifp) & 0xff;
505     newrbf->rbfa[i].gy = getint(1, ifp) & 0xff;
506     }
507     if (feof(ifp))
508     goto badEOF;
509     /* insert in global list */
510     if (insert_dsf(newrbf) != rbfh.ord) {
511     fprintf(stderr, "%s: error adding DSF\n", progname);
512     return(0);
513     }
514     }
515     /* read each migration matrix */
516     while ((from_ord = getint(4, ifp)) >= 0 &&
517     (to_ord = getint(4, ifp)) >= 0) {
518     RBFNODE *from_rbf = get_dsf(from_ord);
519     RBFNODE *to_rbf = get_dsf(to_ord);
520     MIGRATION *newmig;
521     int n;
522    
523     if ((from_rbf == NULL) | (to_rbf == NULL)) {
524     fprintf(stderr,
525     "%s: bad DSF reference in migration edge\n",
526     progname);
527     return(0);
528     }
529     n = from_rbf->nrbf * to_rbf->nrbf;
530     newmig = (MIGRATION *)malloc(sizeof(MIGRATION) +
531     sizeof(float)*(n-1));
532     if (newmig == NULL)
533     goto memerr;
534     newmig->rbfv[0] = from_rbf;
535     newmig->rbfv[1] = to_rbf;
536 greg 2.2 memset(newmig->mtx, 0, sizeof(float)*n);
537     for (i = 0; ; ) { /* read sparse data */
538     int zc = getint(1, ifp) & 0xff;
539     if ((i += zc) >= n)
540     break;
541 greg 2.3 if (zc == 0xff)
542     continue;
543 greg 2.2 newmig->mtx[i++] = getflt(ifp);
544     }
545 greg 2.1 if (feof(ifp))
546     goto badEOF;
547     /* insert in edge lists */
548     newmig->enxt[0] = from_rbf->ejl;
549     from_rbf->ejl = newmig;
550     newmig->enxt[1] = to_rbf->ejl;
551     to_rbf->ejl = newmig;
552     /* push onto global list */
553     newmig->next = mig_list;
554     mig_list = newmig;
555     }
556     return(1); /* success! */
557     memerr:
558     fprintf(stderr, "%s: Out of memory in load_bsdf_rep()\n", progname);
559     exit(1);
560     badEOF:
561     fprintf(stderr, "%s: Unexpected EOF in load_bsdf_rep()\n", progname);
562     return(0);
563     }