1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: bsdf.c,v 2.6 2010/09/03 23:53:50 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* Routines for handling BSDF data |
6 |
*/ |
7 |
|
8 |
#include "standard.h" |
9 |
#include "bsdf.h" |
10 |
#include "paths.h" |
11 |
#include "ezxml.h" |
12 |
#include <ctype.h> |
13 |
|
14 |
#define MAXLATS 46 /* maximum number of latitudes */ |
15 |
|
16 |
/* BSDF angle specification */ |
17 |
typedef struct { |
18 |
char name[64]; /* basis name */ |
19 |
int nangles; /* total number of directions */ |
20 |
struct { |
21 |
float tmin; /* starting theta */ |
22 |
short nphis; /* number of phis (0 term) */ |
23 |
} lat[MAXLATS+1]; /* latitudes */ |
24 |
} ANGLE_BASIS; |
25 |
|
26 |
#define MAXABASES 7 /* limit on defined bases */ |
27 |
|
28 |
static ANGLE_BASIS abase_list[MAXABASES] = { |
29 |
{ |
30 |
"LBNL/Klems Full", 145, |
31 |
{ {-5., 1}, |
32 |
{5., 8}, |
33 |
{15., 16}, |
34 |
{25., 20}, |
35 |
{35., 24}, |
36 |
{45., 24}, |
37 |
{55., 24}, |
38 |
{65., 16}, |
39 |
{75., 12}, |
40 |
{90., 0} } |
41 |
}, { |
42 |
"LBNL/Klems Half", 73, |
43 |
{ {-6.5, 1}, |
44 |
{6.5, 8}, |
45 |
{19.5, 12}, |
46 |
{32.5, 16}, |
47 |
{46.5, 20}, |
48 |
{61.5, 12}, |
49 |
{76.5, 4}, |
50 |
{90., 0} } |
51 |
}, { |
52 |
"LBNL/Klems Quarter", 41, |
53 |
{ {-9., 1}, |
54 |
{9., 8}, |
55 |
{27., 12}, |
56 |
{46., 12}, |
57 |
{66., 8}, |
58 |
{90., 0} } |
59 |
} |
60 |
}; |
61 |
|
62 |
static int nabases = 3; /* current number of defined bases */ |
63 |
|
64 |
#define FEQ(a,b) ((a)-(b) <= 1e-7 && (b)-(a) <= 1e-7) |
65 |
|
66 |
// returns the name of the given tag |
67 |
#ifdef ezxml_name |
68 |
#undef ezxml_name |
69 |
static char * |
70 |
ezxml_name(ezxml_t xml) |
71 |
{ |
72 |
if (xml == NULL) |
73 |
return(NULL); |
74 |
return(xml->name); |
75 |
} |
76 |
#endif |
77 |
|
78 |
// returns the given tag's character content or empty string if none |
79 |
#ifdef ezxml_txt |
80 |
#undef ezxml_txt |
81 |
static char * |
82 |
ezxml_txt(ezxml_t xml) |
83 |
{ |
84 |
if (xml == NULL) |
85 |
return(""); |
86 |
return(xml->txt); |
87 |
} |
88 |
#endif |
89 |
|
90 |
|
91 |
static int |
92 |
ab_getvec( /* get vector for this angle basis index */ |
93 |
FVECT v, |
94 |
int ndx, |
95 |
void *p |
96 |
) |
97 |
{ |
98 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
99 |
int li; |
100 |
double pol, azi, d; |
101 |
|
102 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
103 |
return(0); |
104 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
105 |
ndx -= ab->lat[li].nphis; |
106 |
pol = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin); |
107 |
azi = 2.*PI*ndx/ab->lat[li].nphis; |
108 |
v[2] = d = cos(pol); |
109 |
d = sqrt(1. - d*d); /* sin(pol) */ |
110 |
v[0] = cos(azi)*d; |
111 |
v[1] = sin(azi)*d; |
112 |
return(1); |
113 |
} |
114 |
|
115 |
|
116 |
static int |
117 |
ab_getndx( /* get index corresponding to the given vector */ |
118 |
FVECT v, |
119 |
void *p |
120 |
) |
121 |
{ |
122 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
123 |
int li, ndx; |
124 |
double pol, azi, d; |
125 |
|
126 |
if ((v[2] < -1.0) | (v[2] > 1.0)) |
127 |
return(-1); |
128 |
pol = 180.0/PI*acos(v[2]); |
129 |
azi = 180.0/PI*atan2(v[1], v[0]); |
130 |
if (azi < 0.0) azi += 360.0; |
131 |
for (li = 1; ab->lat[li].tmin <= pol; li++) |
132 |
if (!ab->lat[li].nphis) |
133 |
return(-1); |
134 |
--li; |
135 |
ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5); |
136 |
if (ndx >= ab->lat[li].nphis) ndx = 0; |
137 |
while (li--) |
138 |
ndx += ab->lat[li].nphis; |
139 |
return(ndx); |
140 |
} |
141 |
|
142 |
|
143 |
static double |
144 |
ab_getohm( /* get solid angle for this angle basis index */ |
145 |
int ndx, |
146 |
void *p |
147 |
) |
148 |
{ |
149 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
150 |
int li; |
151 |
double theta, theta1; |
152 |
|
153 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
154 |
return(0); |
155 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
156 |
ndx -= ab->lat[li].nphis; |
157 |
theta1 = PI/180. * ab->lat[li+1].tmin; |
158 |
if (ab->lat[li].nphis == 1) { /* special case */ |
159 |
if (ab->lat[li].tmin > FTINY) |
160 |
error(USER, "unsupported BSDF coordinate system"); |
161 |
return(2.*PI*(1. - cos(theta1))); |
162 |
} |
163 |
theta = PI/180. * ab->lat[li].tmin; |
164 |
return(2.*PI*(cos(theta) - cos(theta1))/(double)ab->lat[li].nphis); |
165 |
} |
166 |
|
167 |
|
168 |
static int |
169 |
ab_getvecR( /* get reverse vector for this angle basis index */ |
170 |
FVECT v, |
171 |
int ndx, |
172 |
void *p |
173 |
) |
174 |
{ |
175 |
if (!ab_getvec(v, ndx, p)) |
176 |
return(0); |
177 |
|
178 |
v[0] = -v[0]; |
179 |
v[1] = -v[1]; |
180 |
v[2] = -v[2]; |
181 |
|
182 |
return(1); |
183 |
} |
184 |
|
185 |
|
186 |
static int |
187 |
ab_getndxR( /* get index corresponding to the reverse vector */ |
188 |
FVECT v, |
189 |
void *p |
190 |
) |
191 |
{ |
192 |
FVECT v2; |
193 |
|
194 |
v2[0] = -v[0]; |
195 |
v2[1] = -v[1]; |
196 |
v2[2] = -v[2]; |
197 |
|
198 |
return ab_getndx(v2, p); |
199 |
} |
200 |
|
201 |
|
202 |
static void |
203 |
load_angle_basis( /* load custom BSDF angle basis */ |
204 |
ezxml_t wab |
205 |
) |
206 |
{ |
207 |
char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName")); |
208 |
ezxml_t wbb; |
209 |
int i; |
210 |
|
211 |
if (!abname || !*abname) |
212 |
return; |
213 |
for (i = nabases; i--; ) |
214 |
if (!strcmp(abname, abase_list[i].name)) |
215 |
return; /* assume it's the same */ |
216 |
if (nabases >= MAXABASES) |
217 |
error(INTERNAL, "too many angle bases"); |
218 |
strcpy(abase_list[nabases].name, abname); |
219 |
abase_list[nabases].nangles = 0; |
220 |
for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock"); |
221 |
wbb != NULL; i++, wbb = wbb->next) { |
222 |
if (i >= MAXLATS) |
223 |
error(INTERNAL, "too many latitudes in custom basis"); |
224 |
abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt( |
225 |
ezxml_child(ezxml_child(wbb, |
226 |
"ThetaBounds"), "UpperTheta"))); |
227 |
if (!i) |
228 |
abase_list[nabases].lat[i].tmin = |
229 |
-abase_list[nabases].lat[i+1].tmin; |
230 |
else if (!FEQ(atof(ezxml_txt(ezxml_child(ezxml_child(wbb, |
231 |
"ThetaBounds"), "LowerTheta"))), |
232 |
abase_list[nabases].lat[i].tmin)) |
233 |
error(WARNING, "theta values disagree in custom basis"); |
234 |
abase_list[nabases].nangles += |
235 |
abase_list[nabases].lat[i].nphis = |
236 |
atoi(ezxml_txt(ezxml_child(wbb, "nPhis"))); |
237 |
} |
238 |
abase_list[nabases++].lat[i].nphis = 0; |
239 |
} |
240 |
|
241 |
|
242 |
static double |
243 |
to_meters( /* return factor to convert given unit to meters */ |
244 |
const char *unit |
245 |
) |
246 |
{ |
247 |
if (unit == NULL) return(1.); /* safe assumption? */ |
248 |
if (!strcasecmp(unit, "Meter")) return(1.); |
249 |
if (!strcasecmp(unit, "Foot")) return(.3048); |
250 |
if (!strcasecmp(unit, "Inch")) return(.0254); |
251 |
if (!strcasecmp(unit, "Centimeter")) return(.01); |
252 |
sprintf(errmsg, "unknown dimensional unit '%s'", unit); |
253 |
error(USER, errmsg); |
254 |
} |
255 |
|
256 |
|
257 |
static void |
258 |
load_geometry( /* load geometric dimensions and description (if any) */ |
259 |
struct BSDF_data *dp, |
260 |
ezxml_t wdb |
261 |
) |
262 |
{ |
263 |
ezxml_t geom; |
264 |
double cfact; |
265 |
const char *fmt, *mgfstr; |
266 |
|
267 |
dp->dim[0] = dp->dim[1] = dp->dim[2] = 0; |
268 |
dp->mgf = NULL; |
269 |
if ((geom = ezxml_child(wdb, "Width")) != NULL) |
270 |
dp->dim[0] = atof(ezxml_txt(geom)) * |
271 |
to_meters(ezxml_attr(geom, "unit")); |
272 |
if ((geom = ezxml_child(wdb, "Height")) != NULL) |
273 |
dp->dim[1] = atof(ezxml_txt(geom)) * |
274 |
to_meters(ezxml_attr(geom, "unit")); |
275 |
if ((geom = ezxml_child(wdb, "Thickness")) != NULL) |
276 |
dp->dim[2] = atof(ezxml_txt(geom)) * |
277 |
to_meters(ezxml_attr(geom, "unit")); |
278 |
if ((geom = ezxml_child(wdb, "Geometry")) == NULL || |
279 |
(mgfstr = ezxml_txt(geom)) == NULL) |
280 |
return; |
281 |
if ((fmt = ezxml_attr(geom, "format")) != NULL && |
282 |
strcasecmp(fmt, "MGF")) { |
283 |
sprintf(errmsg, "unrecognized geometry format '%s'", fmt); |
284 |
error(WARNING, errmsg); |
285 |
return; |
286 |
} |
287 |
cfact = to_meters(ezxml_attr(geom, "unit")); |
288 |
dp->mgf = (char *)malloc(strlen(mgfstr)+32); |
289 |
if (dp->mgf == NULL) |
290 |
error(SYSTEM, "out of memory in load_geometry"); |
291 |
if (cfact < 0.99 || cfact > 1.01) |
292 |
sprintf(dp->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr); |
293 |
else |
294 |
strcpy(dp->mgf, mgfstr); |
295 |
} |
296 |
|
297 |
|
298 |
static void |
299 |
load_bsdf_data( /* load BSDF distribution for this wavelength */ |
300 |
struct BSDF_data *dp, |
301 |
ezxml_t wdb |
302 |
) |
303 |
{ |
304 |
char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis")); |
305 |
char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis")); |
306 |
char *sdata; |
307 |
int i; |
308 |
|
309 |
if ((!cbasis || !*cbasis) | (!rbasis || !*rbasis)) { |
310 |
error(WARNING, "missing column/row basis for BSDF"); |
311 |
return; |
312 |
} |
313 |
for (i = nabases; i--; ) |
314 |
if (!strcmp(cbasis, abase_list[i].name)) { |
315 |
dp->ninc = abase_list[i].nangles; |
316 |
dp->ib_priv = (void *)&abase_list[i]; |
317 |
dp->ib_vec = ab_getvecR; |
318 |
dp->ib_ndx = ab_getndxR; |
319 |
dp->ib_ohm = ab_getohm; |
320 |
break; |
321 |
} |
322 |
if (i < 0) { |
323 |
sprintf(errmsg, "undefined ColumnAngleBasis '%s'", cbasis); |
324 |
error(WARNING, errmsg); |
325 |
return; |
326 |
} |
327 |
for (i = nabases; i--; ) |
328 |
if (!strcmp(rbasis, abase_list[i].name)) { |
329 |
dp->nout = abase_list[i].nangles; |
330 |
dp->ob_priv = (void *)&abase_list[i]; |
331 |
dp->ob_vec = ab_getvec; |
332 |
dp->ob_ndx = ab_getndx; |
333 |
dp->ob_ohm = ab_getohm; |
334 |
break; |
335 |
} |
336 |
if (i < 0) { |
337 |
sprintf(errmsg, "undefined RowAngleBasis '%s'", cbasis); |
338 |
error(WARNING, errmsg); |
339 |
return; |
340 |
} |
341 |
/* read BSDF data */ |
342 |
sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData")); |
343 |
if (!sdata || !*sdata) { |
344 |
error(WARNING, "missing BSDF ScatteringData"); |
345 |
return; |
346 |
} |
347 |
dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout); |
348 |
if (dp->bsdf == NULL) |
349 |
error(SYSTEM, "out of memory in load_bsdf_data"); |
350 |
for (i = 0; i < dp->ninc*dp->nout; i++) { |
351 |
char *sdnext = fskip(sdata); |
352 |
if (sdnext == NULL) { |
353 |
error(WARNING, "bad/missing BSDF ScatteringData"); |
354 |
free(dp->bsdf); dp->bsdf = NULL; |
355 |
return; |
356 |
} |
357 |
while (*sdnext && isspace(*sdnext)) |
358 |
sdnext++; |
359 |
if (*sdnext == ',') sdnext++; |
360 |
dp->bsdf[i] = atof(sdata); |
361 |
sdata = sdnext; |
362 |
} |
363 |
while (isspace(*sdata)) |
364 |
sdata++; |
365 |
if (*sdata) { |
366 |
sprintf(errmsg, "%d extra characters after BSDF ScatteringData", |
367 |
(int)strlen(sdata)); |
368 |
error(WARNING, errmsg); |
369 |
} |
370 |
} |
371 |
|
372 |
|
373 |
static int |
374 |
check_bsdf_data( /* check that BSDF data is sane */ |
375 |
struct BSDF_data *dp |
376 |
) |
377 |
{ |
378 |
double *omega_iarr, *omega_oarr; |
379 |
double dom, contrib, hemi_total, full_total; |
380 |
int nneg; |
381 |
FVECT v; |
382 |
int i, o; |
383 |
|
384 |
if (dp == NULL || dp->bsdf == NULL) |
385 |
return(0); |
386 |
omega_iarr = (double *)calloc(dp->ninc, sizeof(double)); |
387 |
omega_oarr = (double *)calloc(dp->nout, sizeof(double)); |
388 |
if ((omega_iarr == NULL) | (omega_oarr == NULL)) |
389 |
error(SYSTEM, "out of memory in check_bsdf_data"); |
390 |
/* incoming projected solid angles */ |
391 |
hemi_total = .0; |
392 |
for (i = dp->ninc; i--; ) { |
393 |
dom = getBSDF_incohm(dp,i); |
394 |
if (dom <= .0) { |
395 |
error(WARNING, "zero/negative incoming solid angle"); |
396 |
continue; |
397 |
} |
398 |
if (!getBSDF_incvec(v,dp,i) || v[2] > FTINY) { |
399 |
error(WARNING, "illegal incoming BSDF direction"); |
400 |
free(omega_iarr); free(omega_oarr); |
401 |
return(0); |
402 |
} |
403 |
hemi_total += omega_iarr[i] = dom * -v[2]; |
404 |
} |
405 |
if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) { |
406 |
sprintf(errmsg, "incoming BSDF hemisphere off by %.1f%%", |
407 |
100.*(hemi_total/PI - 1.)); |
408 |
error(WARNING, errmsg); |
409 |
} |
410 |
dom = PI / hemi_total; /* fix normalization */ |
411 |
for (i = dp->ninc; i--; ) |
412 |
omega_iarr[i] *= dom; |
413 |
/* outgoing projected solid angles */ |
414 |
hemi_total = .0; |
415 |
for (o = dp->nout; o--; ) { |
416 |
dom = getBSDF_outohm(dp,o); |
417 |
if (dom <= .0) { |
418 |
error(WARNING, "zero/negative outgoing solid angle"); |
419 |
continue; |
420 |
} |
421 |
if (!getBSDF_outvec(v,dp,o) || v[2] < -FTINY) { |
422 |
error(WARNING, "illegal outgoing BSDF direction"); |
423 |
free(omega_iarr); free(omega_oarr); |
424 |
return(0); |
425 |
} |
426 |
hemi_total += omega_oarr[o] = dom * v[2]; |
427 |
} |
428 |
if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) { |
429 |
sprintf(errmsg, "outgoing BSDF hemisphere off by %.1f%%", |
430 |
100.*(hemi_total/PI - 1.)); |
431 |
error(WARNING, errmsg); |
432 |
} |
433 |
dom = PI / hemi_total; /* fix normalization */ |
434 |
for (o = dp->nout; o--; ) |
435 |
omega_oarr[o] *= dom; |
436 |
nneg = 0; /* check outgoing totals */ |
437 |
for (i = 0; i < dp->ninc; i++) { |
438 |
hemi_total = .0; |
439 |
for (o = dp->nout; o--; ) { |
440 |
double f = BSDF_value(dp,i,o); |
441 |
if (f >= .0) |
442 |
hemi_total += f*omega_oarr[o]; |
443 |
else { |
444 |
nneg += (f < -FTINY); |
445 |
BSDF_value(dp,i,o) = .0f; |
446 |
} |
447 |
} |
448 |
if (hemi_total > 1.02) { |
449 |
sprintf(errmsg, |
450 |
"incoming BSDF direction %d passes %.1f%% of light", |
451 |
i, 100.*hemi_total); |
452 |
error(WARNING, errmsg); |
453 |
} |
454 |
} |
455 |
if (nneg) { |
456 |
sprintf(errmsg, "%d negative BSDF values (ignored)", nneg); |
457 |
error(WARNING, errmsg); |
458 |
} |
459 |
full_total = .0; /* reverse roles and check again */ |
460 |
for (o = 0; o < dp->nout; o++) { |
461 |
hemi_total = .0; |
462 |
for (i = dp->ninc; i--; ) |
463 |
hemi_total += BSDF_value(dp,i,o) * omega_iarr[i]; |
464 |
|
465 |
if (hemi_total > 1.02) { |
466 |
sprintf(errmsg, |
467 |
"outgoing BSDF direction %d collects %.1f%% of light", |
468 |
o, 100.*hemi_total); |
469 |
error(WARNING, errmsg); |
470 |
} |
471 |
full_total += hemi_total*omega_oarr[o]; |
472 |
} |
473 |
full_total /= PI; |
474 |
if (full_total > 1.02) { |
475 |
sprintf(errmsg, "BSDF transfers %.1f%% of light", |
476 |
100.*full_total); |
477 |
error(WARNING, errmsg); |
478 |
} |
479 |
free(omega_iarr); free(omega_oarr); |
480 |
return(1); |
481 |
} |
482 |
|
483 |
|
484 |
struct BSDF_data * |
485 |
load_BSDF( /* load BSDF data from file */ |
486 |
char *fname |
487 |
) |
488 |
{ |
489 |
char *path; |
490 |
ezxml_t fl, wtl, wld, wdb; |
491 |
struct BSDF_data *dp; |
492 |
|
493 |
path = getpath(fname, getrlibpath(), R_OK); |
494 |
if (path == NULL) { |
495 |
sprintf(errmsg, "cannot find BSDF file \"%s\"", fname); |
496 |
error(WARNING, errmsg); |
497 |
return(NULL); |
498 |
} |
499 |
fl = ezxml_parse_file(path); |
500 |
if (fl == NULL) { |
501 |
sprintf(errmsg, "cannot open BSDF \"%s\"", path); |
502 |
error(WARNING, errmsg); |
503 |
return(NULL); |
504 |
} |
505 |
if (ezxml_error(fl)[0]) { |
506 |
sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl)); |
507 |
error(WARNING, errmsg); |
508 |
ezxml_free(fl); |
509 |
return(NULL); |
510 |
} |
511 |
if (strcmp(ezxml_name(fl), "WindowElement")) { |
512 |
sprintf(errmsg, |
513 |
"BSDF \"%s\": top level node not 'WindowElement'", |
514 |
path); |
515 |
error(WARNING, errmsg); |
516 |
ezxml_free(fl); |
517 |
return(NULL); |
518 |
} |
519 |
wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer"); |
520 |
load_angle_basis(ezxml_child(ezxml_child(wtl, |
521 |
"DataDefinition"), "AngleBasis")); |
522 |
dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data)); |
523 |
load_geometry(dp, ezxml_child(wtl, "Material")); |
524 |
for (wld = ezxml_child(wtl, "WavelengthData"); |
525 |
wld != NULL; wld = wld->next) { |
526 |
if (strcmp(ezxml_txt(ezxml_child(wld,"Wavelength")), "Visible")) |
527 |
continue; |
528 |
wdb = ezxml_child(wld, "WavelengthDataBlock"); |
529 |
if (wdb == NULL) continue; |
530 |
if (strcmp(ezxml_txt(ezxml_child(wdb,"WavelengthDataDirection")), |
531 |
"Transmission Front")) |
532 |
continue; |
533 |
load_bsdf_data(dp, wdb); /* load front BTDF */ |
534 |
break; /* ignore the rest */ |
535 |
} |
536 |
ezxml_free(fl); /* done with XML file */ |
537 |
if (!check_bsdf_data(dp)) { |
538 |
sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path); |
539 |
error(WARNING, errmsg); |
540 |
free_BSDF(dp); |
541 |
dp = NULL; |
542 |
} |
543 |
return(dp); |
544 |
} |
545 |
|
546 |
|
547 |
void |
548 |
free_BSDF( /* free BSDF data structure */ |
549 |
struct BSDF_data *b |
550 |
) |
551 |
{ |
552 |
if (b == NULL) |
553 |
return; |
554 |
if (b->mgf != NULL) |
555 |
free(b->mgf); |
556 |
if (b->bsdf != NULL) |
557 |
free(b->bsdf); |
558 |
free(b); |
559 |
} |
560 |
|
561 |
|
562 |
int |
563 |
r_BSDF_incvec( /* compute random input vector at given location */ |
564 |
FVECT v, |
565 |
struct BSDF_data *b, |
566 |
int i, |
567 |
double rv, |
568 |
MAT4 xm |
569 |
) |
570 |
{ |
571 |
FVECT pert; |
572 |
double rad; |
573 |
int j; |
574 |
|
575 |
if (!getBSDF_incvec(v, b, i)) |
576 |
return(0); |
577 |
rad = sqrt(getBSDF_incohm(b, i) / PI); |
578 |
multisamp(pert, 3, rv); |
579 |
for (j = 0; j < 3; j++) |
580 |
v[j] += rad*(2.*pert[j] - 1.); |
581 |
if (xm != NULL) |
582 |
multv3(v, v, xm); |
583 |
return(normalize(v) != 0.0); |
584 |
} |
585 |
|
586 |
|
587 |
int |
588 |
r_BSDF_outvec( /* compute random output vector at given location */ |
589 |
FVECT v, |
590 |
struct BSDF_data *b, |
591 |
int o, |
592 |
double rv, |
593 |
MAT4 xm |
594 |
) |
595 |
{ |
596 |
FVECT pert; |
597 |
double rad; |
598 |
int j; |
599 |
|
600 |
if (!getBSDF_outvec(v, b, o)) |
601 |
return(0); |
602 |
rad = sqrt(getBSDF_outohm(b, o) / PI); |
603 |
multisamp(pert, 3, rv); |
604 |
for (j = 0; j < 3; j++) |
605 |
v[j] += rad*(2.*pert[j] - 1.); |
606 |
if (xm != NULL) |
607 |
multv3(v, v, xm); |
608 |
return(normalize(v) != 0.0); |
609 |
} |
610 |
|
611 |
|
612 |
static int |
613 |
addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */ |
614 |
char *xfarg[], |
615 |
FVECT xp, |
616 |
FVECT yp, |
617 |
FVECT zp |
618 |
) |
619 |
{ |
620 |
static char bufs[3][16]; |
621 |
int bn = 0; |
622 |
char **xfp = xfarg; |
623 |
double theta; |
624 |
|
625 |
if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) { |
626 |
/* Special case for X' along Z-axis */ |
627 |
theta = -atan2(yp[0], yp[1]); |
628 |
*xfp++ = "-ry"; |
629 |
*xfp++ = xp[2] < 0.0 ? "90" : "-90"; |
630 |
*xfp++ = "-rz"; |
631 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
632 |
*xfp++ = bufs[bn++]; |
633 |
return(xfp - xfarg); |
634 |
} |
635 |
theta = atan2(yp[2], zp[2]); |
636 |
if (!FEQ(theta,0.0)) { |
637 |
*xfp++ = "-rx"; |
638 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
639 |
*xfp++ = bufs[bn++]; |
640 |
} |
641 |
theta = asin(-xp[2]); |
642 |
if (!FEQ(theta,0.0)) { |
643 |
*xfp++ = "-ry"; |
644 |
sprintf(bufs[bn], " %f", theta*(180./PI)); |
645 |
*xfp++ = bufs[bn++]; |
646 |
} |
647 |
theta = atan2(xp[1], xp[0]); |
648 |
if (!FEQ(theta,0.0)) { |
649 |
*xfp++ = "-rz"; |
650 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
651 |
*xfp++ = bufs[bn++]; |
652 |
} |
653 |
*xfp = NULL; |
654 |
return(xfp - xfarg); |
655 |
} |
656 |
|
657 |
|
658 |
int |
659 |
getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */ |
660 |
MAT4 xm, |
661 |
FVECT nrm, |
662 |
UpDir ud, |
663 |
char *xfbuf |
664 |
) |
665 |
{ |
666 |
char *xfargs[7]; |
667 |
XF myxf; |
668 |
FVECT updir, xdest, ydest; |
669 |
int i; |
670 |
|
671 |
updir[0] = updir[1] = updir[2] = 0.; |
672 |
switch (ud) { |
673 |
case UDzneg: |
674 |
updir[2] = -1.; |
675 |
break; |
676 |
case UDyneg: |
677 |
updir[1] = -1.; |
678 |
break; |
679 |
case UDxneg: |
680 |
updir[0] = -1.; |
681 |
break; |
682 |
case UDxpos: |
683 |
updir[0] = 1.; |
684 |
break; |
685 |
case UDypos: |
686 |
updir[1] = 1.; |
687 |
break; |
688 |
case UDzpos: |
689 |
updir[2] = 1.; |
690 |
break; |
691 |
case UDunknown: |
692 |
return(0); |
693 |
} |
694 |
fcross(xdest, updir, nrm); |
695 |
if (normalize(xdest) == 0.0) |
696 |
return(0); |
697 |
fcross(ydest, nrm, xdest); |
698 |
xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs); |
699 |
copymat4(xm, myxf.xfm); |
700 |
if (xfbuf == NULL) |
701 |
return(1); |
702 |
/* return xf arguments as well */ |
703 |
for (i = 0; xfargs[i] != NULL; i++) { |
704 |
*xfbuf++ = ' '; |
705 |
strcpy(xfbuf, xfargs[i]); |
706 |
while (*xfbuf) ++xfbuf; |
707 |
} |
708 |
return(1); |
709 |
} |