1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: bsdf_m.c,v 3.21 2012/05/02 16:28:45 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* bsdf_m.c |
6 |
* |
7 |
* Definitions supporting BSDF matrices |
8 |
* |
9 |
* Created by Greg Ward on 2/2/11. |
10 |
* Copyright 2011 Anyhere Software. All rights reserved. |
11 |
* |
12 |
*/ |
13 |
|
14 |
#define _USE_MATH_DEFINES |
15 |
#include "rtio.h" |
16 |
#include <stdlib.h> |
17 |
#include <math.h> |
18 |
#include <ctype.h> |
19 |
#include "ezxml.h" |
20 |
#include "bsdf.h" |
21 |
#include "bsdf_m.h" |
22 |
|
23 |
/* Function return codes */ |
24 |
#define RC_GOOD 1 |
25 |
#define RC_FAIL 0 |
26 |
#define RC_FORMERR (-1) |
27 |
#define RC_DATERR (-2) |
28 |
#define RC_UNSUPP (-3) |
29 |
#define RC_INTERR (-4) |
30 |
#define RC_MEMERR (-5) |
31 |
|
32 |
#define MAXLATS 46 /* maximum number of latitudes */ |
33 |
|
34 |
/* BSDF angle specification */ |
35 |
typedef struct { |
36 |
char name[64]; /* basis name */ |
37 |
int nangles; /* total number of directions */ |
38 |
struct { |
39 |
float tmin; /* starting theta */ |
40 |
int nphis; /* number of phis (0 term) */ |
41 |
} lat[MAXLATS+1]; /* latitudes */ |
42 |
} ANGLE_BASIS; |
43 |
|
44 |
#define MAXABASES 7 /* limit on defined bases */ |
45 |
|
46 |
static ANGLE_BASIS abase_list[MAXABASES] = { |
47 |
{ |
48 |
"LBNL/Klems Full", 145, |
49 |
{ {0., 1}, |
50 |
{5., 8}, |
51 |
{15., 16}, |
52 |
{25., 20}, |
53 |
{35., 24}, |
54 |
{45., 24}, |
55 |
{55., 24}, |
56 |
{65., 16}, |
57 |
{75., 12}, |
58 |
{90., 0} } |
59 |
}, { |
60 |
"LBNL/Klems Half", 73, |
61 |
{ {0., 1}, |
62 |
{6.5, 8}, |
63 |
{19.5, 12}, |
64 |
{32.5, 16}, |
65 |
{46.5, 20}, |
66 |
{61.5, 12}, |
67 |
{76.5, 4}, |
68 |
{90., 0} } |
69 |
}, { |
70 |
"LBNL/Klems Quarter", 41, |
71 |
{ {0., 1}, |
72 |
{9., 8}, |
73 |
{27., 12}, |
74 |
{46., 12}, |
75 |
{66., 8}, |
76 |
{90., 0} } |
77 |
} |
78 |
}; |
79 |
|
80 |
static int nabases = 3; /* current number of defined bases */ |
81 |
|
82 |
static int |
83 |
fequal(double a, double b) |
84 |
{ |
85 |
if (b != 0) |
86 |
a = a/b - 1.; |
87 |
return (a <= 1e-6) & (a >= -1e-6); |
88 |
} |
89 |
|
90 |
/* Returns the given tag's character content or empty string if none */ |
91 |
#ifdef ezxml_txt |
92 |
#undef ezxml_txt |
93 |
static char * |
94 |
ezxml_txt(ezxml_t xml) |
95 |
{ |
96 |
if (xml == NULL) |
97 |
return ""; |
98 |
return xml->txt; |
99 |
} |
100 |
#endif |
101 |
|
102 |
/* Convert error to standard BSDF code */ |
103 |
static SDError |
104 |
convert_errcode(int ec) |
105 |
{ |
106 |
switch (ec) { |
107 |
case RC_GOOD: |
108 |
return SDEnone; |
109 |
case RC_FORMERR: |
110 |
return SDEformat; |
111 |
case RC_DATERR: |
112 |
return SDEdata; |
113 |
case RC_UNSUPP: |
114 |
return SDEsupport; |
115 |
case RC_INTERR: |
116 |
return SDEinternal; |
117 |
case RC_MEMERR: |
118 |
return SDEmemory; |
119 |
} |
120 |
return SDEunknown; |
121 |
} |
122 |
|
123 |
/* Allocate a BSDF matrix of the given size */ |
124 |
static SDMat * |
125 |
SDnewMatrix(int ni, int no) |
126 |
{ |
127 |
SDMat *sm; |
128 |
|
129 |
if ((ni <= 0) | (no <= 0)) { |
130 |
strcpy(SDerrorDetail, "Empty BSDF matrix request"); |
131 |
return NULL; |
132 |
} |
133 |
sm = (SDMat *)malloc(sizeof(SDMat) + (ni*no - 1)*sizeof(float)); |
134 |
if (sm == NULL) { |
135 |
sprintf(SDerrorDetail, "Cannot allocate %dx%d BSDF matrix", |
136 |
ni, no); |
137 |
return NULL; |
138 |
} |
139 |
memset(sm, 0, sizeof(SDMat)-sizeof(float)); |
140 |
sm->ninc = ni; |
141 |
sm->nout = no; |
142 |
|
143 |
return sm; |
144 |
} |
145 |
|
146 |
/* Free a BSDF matrix */ |
147 |
#define SDfreeMatrix free |
148 |
|
149 |
/* get vector for this angle basis index (front exiting) */ |
150 |
static int |
151 |
fo_getvec(FVECT v, double ndxr, void *p) |
152 |
{ |
153 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
154 |
int ndx = (int)ndxr; |
155 |
double randX = ndxr - ndx; |
156 |
double rx[2]; |
157 |
int li; |
158 |
double pol, azi, d; |
159 |
|
160 |
if ((ndxr < 0) | (ndx >= ab->nangles)) |
161 |
return RC_FAIL; |
162 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
163 |
ndx -= ab->lat[li].nphis; |
164 |
SDmultiSamp(rx, 2, randX); |
165 |
pol = M_PI/180.*( (1.-rx[0])*ab->lat[li].tmin + |
166 |
rx[0]*ab->lat[li+1].tmin ); |
167 |
azi = 2.*M_PI*(ndx + rx[1] - .5)/ab->lat[li].nphis; |
168 |
v[2] = d = cos(pol); |
169 |
d = sqrt(1. - d*d); /* sin(pol) */ |
170 |
v[0] = cos(azi)*d; |
171 |
v[1] = sin(azi)*d; |
172 |
return RC_GOOD; |
173 |
} |
174 |
|
175 |
/* get index corresponding to the given vector (front exiting) */ |
176 |
static int |
177 |
fo_getndx(const FVECT v, void *p) |
178 |
{ |
179 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
180 |
int li, ndx; |
181 |
double pol, azi; |
182 |
|
183 |
if (v == NULL) |
184 |
return -1; |
185 |
if ((v[2] < 0) | (v[2] > 1.)) |
186 |
return -1; |
187 |
pol = 180.0/M_PI*acos(v[2]); |
188 |
azi = 180.0/M_PI*atan2(v[1], v[0]); |
189 |
if (azi < 0.0) azi += 360.0; |
190 |
for (li = 1; ab->lat[li].tmin <= pol; li++) |
191 |
if (!ab->lat[li].nphis) |
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return -1; |
193 |
--li; |
194 |
ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5); |
195 |
if (ndx >= ab->lat[li].nphis) ndx = 0; |
196 |
while (li--) |
197 |
ndx += ab->lat[li].nphis; |
198 |
return ndx; |
199 |
} |
200 |
|
201 |
/* compute square of real value */ |
202 |
static double sq(double x) { return x*x; } |
203 |
|
204 |
/* get projected solid angle for this angle basis index (universal) */ |
205 |
static double |
206 |
io_getohm(int ndx, void *p) |
207 |
{ |
208 |
static int last_li = -1; |
209 |
static double last_ohm; |
210 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
211 |
int li; |
212 |
double theta, theta1; |
213 |
|
214 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
215 |
return -1.; |
216 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
217 |
ndx -= ab->lat[li].nphis; |
218 |
if (li == last_li) /* cached latitude? */ |
219 |
return last_ohm; |
220 |
last_li = li; |
221 |
theta = M_PI/180. * ab->lat[li].tmin; |
222 |
theta1 = M_PI/180. * ab->lat[li+1].tmin; |
223 |
return last_ohm = M_PI*(sq(cos(theta)) - sq(cos(theta1))) / |
224 |
(double)ab->lat[li].nphis; |
225 |
} |
226 |
|
227 |
/* get vector for this angle basis index (back incident) */ |
228 |
static int |
229 |
bi_getvec(FVECT v, double ndxr, void *p) |
230 |
{ |
231 |
if (!fo_getvec(v, ndxr, p)) |
232 |
return RC_FAIL; |
233 |
|
234 |
v[0] = -v[0]; |
235 |
v[1] = -v[1]; |
236 |
v[2] = -v[2]; |
237 |
|
238 |
return RC_GOOD; |
239 |
} |
240 |
|
241 |
/* get index corresponding to the vector (back incident) */ |
242 |
static int |
243 |
bi_getndx(const FVECT v, void *p) |
244 |
{ |
245 |
FVECT v2; |
246 |
|
247 |
v2[0] = -v[0]; |
248 |
v2[1] = -v[1]; |
249 |
v2[2] = -v[2]; |
250 |
|
251 |
return fo_getndx(v2, p); |
252 |
} |
253 |
|
254 |
/* get vector for this angle basis index (back exiting) */ |
255 |
static int |
256 |
bo_getvec(FVECT v, double ndxr, void *p) |
257 |
{ |
258 |
if (!fo_getvec(v, ndxr, p)) |
259 |
return RC_FAIL; |
260 |
|
261 |
v[2] = -v[2]; |
262 |
|
263 |
return RC_GOOD; |
264 |
} |
265 |
|
266 |
/* get index corresponding to the vector (back exiting) */ |
267 |
static int |
268 |
bo_getndx(const FVECT v, void *p) |
269 |
{ |
270 |
FVECT v2; |
271 |
|
272 |
v2[0] = v[0]; |
273 |
v2[1] = v[1]; |
274 |
v2[2] = -v[2]; |
275 |
|
276 |
return fo_getndx(v2, p); |
277 |
} |
278 |
|
279 |
/* get vector for this angle basis index (front incident) */ |
280 |
static int |
281 |
fi_getvec(FVECT v, double ndxr, void *p) |
282 |
{ |
283 |
if (!fo_getvec(v, ndxr, p)) |
284 |
return RC_FAIL; |
285 |
|
286 |
v[0] = -v[0]; |
287 |
v[1] = -v[1]; |
288 |
|
289 |
return RC_GOOD; |
290 |
} |
291 |
|
292 |
/* get index corresponding to the vector (front incident) */ |
293 |
static int |
294 |
fi_getndx(const FVECT v, void *p) |
295 |
{ |
296 |
FVECT v2; |
297 |
|
298 |
v2[0] = -v[0]; |
299 |
v2[1] = -v[1]; |
300 |
v2[2] = v[2]; |
301 |
|
302 |
return fo_getndx(v2, p); |
303 |
} |
304 |
|
305 |
/* load custom BSDF angle basis */ |
306 |
static int |
307 |
load_angle_basis(ezxml_t wab) |
308 |
{ |
309 |
char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName")); |
310 |
ezxml_t wbb; |
311 |
int i; |
312 |
|
313 |
if (!abname || !*abname) |
314 |
return RC_FAIL; |
315 |
for (i = nabases; i--; ) |
316 |
if (!strcasecmp(abname, abase_list[i].name)) |
317 |
return RC_GOOD; /* assume it's the same */ |
318 |
if (nabases >= MAXABASES) { |
319 |
sprintf(SDerrorDetail, "Out of angle bases reading '%s'", |
320 |
abname); |
321 |
return RC_INTERR; |
322 |
} |
323 |
strcpy(abase_list[nabases].name, abname); |
324 |
abase_list[nabases].nangles = 0; |
325 |
for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock"); |
326 |
wbb != NULL; i++, wbb = wbb->next) { |
327 |
if (i >= MAXLATS) { |
328 |
sprintf(SDerrorDetail, "Too many latitudes for '%s'", |
329 |
abname); |
330 |
return RC_INTERR; |
331 |
} |
332 |
abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt( |
333 |
ezxml_child(ezxml_child(wbb, |
334 |
"ThetaBounds"), "UpperTheta"))); |
335 |
if (!i) |
336 |
abase_list[nabases].lat[0].tmin = 0; |
337 |
else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb, |
338 |
"ThetaBounds"), "LowerTheta"))), |
339 |
abase_list[nabases].lat[i].tmin)) { |
340 |
sprintf(SDerrorDetail, "Theta values disagree in '%s'", |
341 |
abname); |
342 |
return RC_DATERR; |
343 |
} |
344 |
abase_list[nabases].nangles += |
345 |
abase_list[nabases].lat[i].nphis = |
346 |
atoi(ezxml_txt(ezxml_child(wbb, "nPhis"))); |
347 |
if (abase_list[nabases].lat[i].nphis <= 0 || |
348 |
(abase_list[nabases].lat[i].nphis == 1 && |
349 |
abase_list[nabases].lat[i].tmin > FTINY)) { |
350 |
sprintf(SDerrorDetail, "Illegal phi count in '%s'", |
351 |
abname); |
352 |
return RC_DATERR; |
353 |
} |
354 |
} |
355 |
abase_list[nabases++].lat[i].nphis = 0; |
356 |
return RC_GOOD; |
357 |
} |
358 |
|
359 |
/* compute min. proj. solid angle and max. direct hemispherical scattering */ |
360 |
static int |
361 |
get_extrema(SDSpectralDF *df) |
362 |
{ |
363 |
SDMat *dp = (SDMat *)df->comp[0].dist; |
364 |
double *ohma; |
365 |
int i, o; |
366 |
/* initialize extrema */ |
367 |
df->minProjSA = M_PI; |
368 |
df->maxHemi = .0; |
369 |
ohma = (double *)malloc(dp->nout*sizeof(double)); |
370 |
if (ohma == NULL) |
371 |
return RC_MEMERR; |
372 |
/* get outgoing solid angles */ |
373 |
for (o = dp->nout; o--; ) |
374 |
if ((ohma[o] = mBSDF_outohm(dp,o)) < df->minProjSA) |
375 |
df->minProjSA = ohma[o]; |
376 |
/* compute hemispherical sums */ |
377 |
for (i = dp->ninc; i--; ) { |
378 |
double hemi = .0; |
379 |
for (o = dp->nout; o--; ) |
380 |
hemi += ohma[o] * mBSDF_value(dp, i, o); |
381 |
if (hemi > df->maxHemi) |
382 |
df->maxHemi = hemi; |
383 |
} |
384 |
free(ohma); |
385 |
/* need incoming solid angles, too? */ |
386 |
if ((dp->ib_ohm != dp->ob_ohm) | (dp->ib_priv != dp->ob_priv)) { |
387 |
double ohm; |
388 |
for (i = dp->ninc; i--; ) |
389 |
if ((ohm = mBSDF_incohm(dp,i)) < df->minProjSA) |
390 |
df->minProjSA = ohm; |
391 |
} |
392 |
return (df->maxHemi <= 1.01); |
393 |
} |
394 |
|
395 |
/* load BSDF distribution for this wavelength */ |
396 |
static int |
397 |
load_bsdf_data(SDData *sd, ezxml_t wdb, int rowinc) |
398 |
{ |
399 |
SDSpectralDF *df; |
400 |
SDMat *dp; |
401 |
char *sdata; |
402 |
int tfront; |
403 |
int inbi, outbi; |
404 |
int i; |
405 |
/* allocate BSDF component */ |
406 |
sdata = ezxml_txt(ezxml_child(wdb, "WavelengthDataDirection")); |
407 |
if (!sdata) |
408 |
return RC_FAIL; |
409 |
/* |
410 |
* Remember that front and back are reversed from WINDOW 6 orientations |
411 |
* Favor their "Front" (incoming light) since that's more often valid |
412 |
*/ |
413 |
tfront = !strcasecmp(sdata, "Transmission Back"); |
414 |
if (!strcasecmp(sdata, "Transmission Front") || |
415 |
tfront & (sd->tf == NULL)) { |
416 |
if (sd->tf != NULL) |
417 |
SDfreeSpectralDF(sd->tf); |
418 |
if ((sd->tf = SDnewSpectralDF(1)) == NULL) |
419 |
return RC_MEMERR; |
420 |
df = sd->tf; |
421 |
} else if (!strcasecmp(sdata, "Reflection Front")) { |
422 |
if (sd->rb != NULL) /* note back-front reversal */ |
423 |
SDfreeSpectralDF(sd->rb); |
424 |
if ((sd->rb = SDnewSpectralDF(1)) == NULL) |
425 |
return RC_MEMERR; |
426 |
df = sd->rb; |
427 |
} else if (!strcasecmp(sdata, "Reflection Back")) { |
428 |
if (sd->rf != NULL) /* note front-back reversal */ |
429 |
SDfreeSpectralDF(sd->rf); |
430 |
if ((sd->rf = SDnewSpectralDF(1)) == NULL) |
431 |
return RC_MEMERR; |
432 |
df = sd->rf; |
433 |
} else |
434 |
return RC_FAIL; |
435 |
/* XXX should also check "ScatteringDataType" for consistency? */ |
436 |
/* get angle bases */ |
437 |
sdata = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis")); |
438 |
if (!sdata || !*sdata) { |
439 |
sprintf(SDerrorDetail, "Missing column basis for BSDF '%s'", |
440 |
sd->name); |
441 |
return RC_FORMERR; |
442 |
} |
443 |
for (inbi = nabases; inbi--; ) |
444 |
if (!strcasecmp(sdata, abase_list[inbi].name)) |
445 |
break; |
446 |
if (inbi < 0) { |
447 |
sprintf(SDerrorDetail, "Undefined ColumnAngleBasis '%s'", sdata); |
448 |
return RC_FORMERR; |
449 |
} |
450 |
sdata = ezxml_txt(ezxml_child(wdb,"RowAngleBasis")); |
451 |
if (!sdata || !*sdata) { |
452 |
sprintf(SDerrorDetail, "Missing row basis for BSDF '%s'", |
453 |
sd->name); |
454 |
return RC_FORMERR; |
455 |
} |
456 |
for (outbi = nabases; outbi--; ) |
457 |
if (!strcasecmp(sdata, abase_list[outbi].name)) |
458 |
break; |
459 |
if (outbi < 0) { |
460 |
sprintf(SDerrorDetail, "Undefined RowAngleBasis '%s'", sdata); |
461 |
return RC_FORMERR; |
462 |
} |
463 |
/* allocate BSDF matrix */ |
464 |
dp = SDnewMatrix(abase_list[inbi].nangles, abase_list[outbi].nangles); |
465 |
if (dp == NULL) |
466 |
return RC_MEMERR; |
467 |
dp->ib_priv = &abase_list[inbi]; |
468 |
dp->ob_priv = &abase_list[outbi]; |
469 |
if (df == sd->tf) { |
470 |
if (tfront) { |
471 |
dp->ib_vec = &fi_getvec; |
472 |
dp->ib_ndx = &fi_getndx; |
473 |
dp->ob_vec = &bo_getvec; |
474 |
dp->ob_ndx = &bo_getndx; |
475 |
} else { |
476 |
dp->ib_vec = &bi_getvec; |
477 |
dp->ib_ndx = &bi_getndx; |
478 |
dp->ob_vec = &fo_getvec; |
479 |
dp->ob_ndx = &fo_getndx; |
480 |
} |
481 |
} else if (df == sd->rf) { |
482 |
dp->ib_vec = &fi_getvec; |
483 |
dp->ib_ndx = &fi_getndx; |
484 |
dp->ob_vec = &fo_getvec; |
485 |
dp->ob_ndx = &fo_getndx; |
486 |
} else /* df == sd->rb */ { |
487 |
dp->ib_vec = &bi_getvec; |
488 |
dp->ib_ndx = &bi_getndx; |
489 |
dp->ob_vec = &bo_getvec; |
490 |
dp->ob_ndx = &bo_getndx; |
491 |
} |
492 |
dp->ib_ohm = &io_getohm; |
493 |
dp->ob_ohm = &io_getohm; |
494 |
df->comp[0].cspec[0] = c_dfcolor; /* XXX monochrome for now */ |
495 |
df->comp[0].dist = dp; |
496 |
df->comp[0].func = &SDhandleMtx; |
497 |
/* read BSDF data */ |
498 |
sdata = ezxml_txt(ezxml_child(wdb, "ScatteringData")); |
499 |
if (!sdata || !*sdata) { |
500 |
sprintf(SDerrorDetail, "Missing BSDF ScatteringData in '%s'", |
501 |
sd->name); |
502 |
return RC_FORMERR; |
503 |
} |
504 |
for (i = 0; i < dp->ninc*dp->nout; i++) { |
505 |
char *sdnext = fskip(sdata); |
506 |
if (sdnext == NULL) { |
507 |
sprintf(SDerrorDetail, |
508 |
"Bad/missing BSDF ScatteringData in '%s'", |
509 |
sd->name); |
510 |
return RC_FORMERR; |
511 |
} |
512 |
while (isspace(*sdnext)) |
513 |
sdnext++; |
514 |
if (*sdnext == ',') sdnext++; |
515 |
if (rowinc) { |
516 |
int r = i/dp->nout; |
517 |
int c = i - r*dp->nout; |
518 |
mBSDF_value(dp,r,c) = atof(sdata); |
519 |
} else |
520 |
dp->bsdf[i] = atof(sdata); |
521 |
sdata = sdnext; |
522 |
} |
523 |
return get_extrema(df); |
524 |
} |
525 |
|
526 |
/* Subtract minimum (diffuse) scattering amount from BSDF */ |
527 |
static double |
528 |
subtract_min(SDMat *sm) |
529 |
{ |
530 |
float minv = sm->bsdf[0]; |
531 |
int n = sm->ninc*sm->nout; |
532 |
int i; |
533 |
|
534 |
for (i = n; --i; ) |
535 |
if (sm->bsdf[i] < minv) |
536 |
minv = sm->bsdf[i]; |
537 |
|
538 |
if (minv <= FTINY) |
539 |
return .0; |
540 |
|
541 |
for (i = n; i--; ) |
542 |
sm->bsdf[i] -= minv; |
543 |
|
544 |
return minv*M_PI; /* be sure to include multiplier */ |
545 |
} |
546 |
|
547 |
/* Extract and separate diffuse portion of BSDF */ |
548 |
static void |
549 |
extract_diffuse(SDValue *dv, SDSpectralDF *df) |
550 |
{ |
551 |
int n; |
552 |
|
553 |
if (df == NULL || df->ncomp <= 0) { |
554 |
dv->spec = c_dfcolor; |
555 |
dv->cieY = .0; |
556 |
return; |
557 |
} |
558 |
dv->spec = df->comp[0].cspec[0]; |
559 |
dv->cieY = subtract_min((SDMat *)df->comp[0].dist); |
560 |
/* in case of multiple components */ |
561 |
for (n = df->ncomp; --n; ) { |
562 |
double ymin = subtract_min((SDMat *)df->comp[n].dist); |
563 |
c_cmix(&dv->spec, dv->cieY, &dv->spec, ymin, &df->comp[n].cspec[0]); |
564 |
dv->cieY += ymin; |
565 |
} |
566 |
df->maxHemi -= dv->cieY; /* adjust maximum hemispherical */ |
567 |
/* make sure everything is set */ |
568 |
c_ccvt(&dv->spec, C_CSXY+C_CSSPEC); |
569 |
} |
570 |
|
571 |
/* Load a BSDF matrix from an open XML file */ |
572 |
SDError |
573 |
SDloadMtx(SDData *sd, ezxml_t wtl) |
574 |
{ |
575 |
ezxml_t wld, wdb; |
576 |
int rowIn; |
577 |
char *txt; |
578 |
int rval; |
579 |
/* basic checks and data ordering */ |
580 |
txt = ezxml_txt(ezxml_child(ezxml_child(wtl, |
581 |
"DataDefinition"), "IncidentDataStructure")); |
582 |
if (txt == NULL || !*txt) { |
583 |
sprintf(SDerrorDetail, |
584 |
"BSDF \"%s\": missing IncidentDataStructure", |
585 |
sd->name); |
586 |
return SDEformat; |
587 |
} |
588 |
if (!strcasecmp(txt, "Rows")) |
589 |
rowIn = 1; |
590 |
else if (!strcasecmp(txt, "Columns")) |
591 |
rowIn = 0; |
592 |
else { |
593 |
sprintf(SDerrorDetail, |
594 |
"BSDF \"%s\": unsupported IncidentDataStructure", |
595 |
sd->name); |
596 |
return SDEsupport; |
597 |
} |
598 |
/* get angle bases */ |
599 |
for (wld = ezxml_child(ezxml_child(wtl, "DataDefinition"), "AngleBasis"); |
600 |
wld != NULL; wld = wld->next) { |
601 |
rval = load_angle_basis(wld); |
602 |
if (rval < 0) |
603 |
return convert_errcode(rval); |
604 |
} |
605 |
/* load BSDF components */ |
606 |
for (wld = ezxml_child(wtl, "WavelengthData"); |
607 |
wld != NULL; wld = wld->next) { |
608 |
if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")), |
609 |
"Visible")) |
610 |
continue; /* just visible for now */ |
611 |
for (wdb = ezxml_child(wld, "WavelengthDataBlock"); |
612 |
wdb != NULL; wdb = wdb->next) |
613 |
if ((rval = load_bsdf_data(sd, wdb, rowIn)) < 0) |
614 |
return convert_errcode(rval); |
615 |
} |
616 |
/* separate diffuse components */ |
617 |
extract_diffuse(&sd->rLambFront, sd->rf); |
618 |
extract_diffuse(&sd->rLambBack, sd->rb); |
619 |
extract_diffuse(&sd->tLamb, sd->tf); |
620 |
/* return success */ |
621 |
return SDEnone; |
622 |
} |
623 |
|
624 |
/* Get Matrix BSDF value */ |
625 |
static int |
626 |
SDgetMtxBSDF(float coef[SDmaxCh], const FVECT outVec, |
627 |
const FVECT inVec, SDComponent *sdc) |
628 |
{ |
629 |
const SDMat *dp; |
630 |
int i_ndx, o_ndx; |
631 |
/* check arguments */ |
632 |
if ((coef == NULL) | (outVec == NULL) | (inVec == NULL) | (sdc == NULL) |
633 |
|| (dp = (SDMat *)sdc->dist) == NULL) |
634 |
return 0; |
635 |
/* get angle indices */ |
636 |
i_ndx = mBSDF_incndx(dp, inVec); |
637 |
o_ndx = mBSDF_outndx(dp, outVec); |
638 |
/* try reciprocity if necessary */ |
639 |
if ((i_ndx < 0) & (o_ndx < 0)) { |
640 |
i_ndx = mBSDF_incndx(dp, outVec); |
641 |
o_ndx = mBSDF_outndx(dp, inVec); |
642 |
} |
643 |
if ((i_ndx < 0) | (o_ndx < 0)) |
644 |
return 0; /* nothing from this component */ |
645 |
coef[0] = mBSDF_value(dp, i_ndx, o_ndx); |
646 |
return 1; /* XXX monochrome for now */ |
647 |
} |
648 |
|
649 |
/* Query solid angle for vector(s) */ |
650 |
static SDError |
651 |
SDqueryMtxProjSA(double *psa, const FVECT v1, const RREAL *v2, |
652 |
int qflags, SDComponent *sdc) |
653 |
{ |
654 |
const SDMat *dp; |
655 |
double inc_psa, out_psa; |
656 |
/* check arguments */ |
657 |
if ((psa == NULL) | (v1 == NULL) | (sdc == NULL) || |
658 |
(dp = (SDMat *)sdc->dist) == NULL) |
659 |
return SDEargument; |
660 |
if (v2 == NULL) |
661 |
v2 = v1; |
662 |
/* get projected solid angles */ |
663 |
out_psa = mBSDF_outohm(dp, mBSDF_outndx(dp, v1)); |
664 |
inc_psa = mBSDF_incohm(dp, mBSDF_incndx(dp, v2)); |
665 |
if ((v1 != v2) & (out_psa <= 0) & (inc_psa <= 0)) { |
666 |
inc_psa = mBSDF_outohm(dp, mBSDF_outndx(dp, v2)); |
667 |
out_psa = mBSDF_incohm(dp, mBSDF_incndx(dp, v1)); |
668 |
} |
669 |
|
670 |
switch (qflags) { /* record based on flag settings */ |
671 |
case SDqueryMax: |
672 |
if (inc_psa > psa[0]) |
673 |
psa[0] = inc_psa; |
674 |
if (out_psa > psa[0]) |
675 |
psa[0] = out_psa; |
676 |
break; |
677 |
case SDqueryMin+SDqueryMax: |
678 |
if (inc_psa > psa[1]) |
679 |
psa[1] = inc_psa; |
680 |
if (out_psa > psa[1]) |
681 |
psa[1] = out_psa; |
682 |
/* fall through */ |
683 |
case SDqueryVal: |
684 |
if (qflags == SDqueryVal) |
685 |
psa[0] = M_PI; |
686 |
/* fall through */ |
687 |
case SDqueryMin: |
688 |
if ((inc_psa > 0) & (inc_psa < psa[0])) |
689 |
psa[0] = inc_psa; |
690 |
if ((out_psa > 0) & (out_psa < psa[0])) |
691 |
psa[0] = out_psa; |
692 |
break; |
693 |
} |
694 |
/* make sure it's legal */ |
695 |
return (psa[0] <= 0) ? SDEinternal : SDEnone; |
696 |
} |
697 |
|
698 |
/* Compute new cumulative distribution from BSDF */ |
699 |
static int |
700 |
make_cdist(SDMatCDst *cd, const FVECT inVec, SDMat *dp, int rev) |
701 |
{ |
702 |
const unsigned maxval = ~0; |
703 |
double *cmtab, scale; |
704 |
int o; |
705 |
|
706 |
cmtab = (double *)malloc((cd->calen+1)*sizeof(double)); |
707 |
if (cmtab == NULL) |
708 |
return 0; |
709 |
cmtab[0] = .0; |
710 |
for (o = 0; o < cd->calen; o++) { |
711 |
if (rev) |
712 |
cmtab[o+1] = mBSDF_value(dp, o, cd->indx) * |
713 |
(*dp->ib_ohm)(o, dp->ib_priv); |
714 |
else |
715 |
cmtab[o+1] = mBSDF_value(dp, cd->indx, o) * |
716 |
(*dp->ob_ohm)(o, dp->ob_priv); |
717 |
cmtab[o+1] += cmtab[o]; |
718 |
} |
719 |
cd->cTotal = cmtab[cd->calen]; |
720 |
scale = (double)maxval / cd->cTotal; |
721 |
cd->carr[0] = 0; |
722 |
for (o = 1; o < cd->calen; o++) |
723 |
cd->carr[o] = scale*cmtab[o] + .5; |
724 |
cd->carr[cd->calen] = maxval; |
725 |
free(cmtab); |
726 |
return 1; |
727 |
} |
728 |
|
729 |
/* Get cumulative distribution for matrix BSDF */ |
730 |
static const SDCDst * |
731 |
SDgetMtxCDist(const FVECT inVec, SDComponent *sdc) |
732 |
{ |
733 |
SDMat *dp; |
734 |
int reverse; |
735 |
SDMatCDst myCD; |
736 |
SDMatCDst *cd, *cdlast; |
737 |
/* check arguments */ |
738 |
if ((inVec == NULL) | (sdc == NULL) || |
739 |
(dp = (SDMat *)sdc->dist) == NULL) |
740 |
return NULL; |
741 |
memset(&myCD, 0, sizeof(myCD)); |
742 |
myCD.indx = mBSDF_incndx(dp, inVec); |
743 |
if (myCD.indx >= 0) { |
744 |
myCD.ob_priv = dp->ob_priv; |
745 |
myCD.ob_vec = dp->ob_vec; |
746 |
myCD.calen = dp->nout; |
747 |
reverse = 0; |
748 |
} else { /* try reciprocity */ |
749 |
myCD.indx = mBSDF_outndx(dp, inVec); |
750 |
if (myCD.indx < 0) |
751 |
return NULL; |
752 |
myCD.ob_priv = dp->ib_priv; |
753 |
myCD.ob_vec = dp->ib_vec; |
754 |
myCD.calen = dp->ninc; |
755 |
reverse = 1; |
756 |
} |
757 |
cdlast = NULL; /* check for it in cache list */ |
758 |
for (cd = (SDMatCDst *)sdc->cdList; cd != NULL; |
759 |
cdlast = cd, cd = cd->next) |
760 |
if (cd->indx == myCD.indx && (cd->calen == myCD.calen) & |
761 |
(cd->ob_priv == myCD.ob_priv) & |
762 |
(cd->ob_vec == myCD.ob_vec)) |
763 |
break; |
764 |
if (cd == NULL) { /* need to allocate new entry */ |
765 |
cd = (SDMatCDst *)malloc(sizeof(SDMatCDst) + |
766 |
sizeof(myCD.carr[0])*myCD.calen); |
767 |
if (cd == NULL) |
768 |
return NULL; |
769 |
*cd = myCD; /* compute cumulative distribution */ |
770 |
if (!make_cdist(cd, inVec, dp, reverse)) { |
771 |
free(cd); |
772 |
return NULL; |
773 |
} |
774 |
cdlast = cd; |
775 |
} |
776 |
if (cdlast != NULL) { /* move entry to head of cache list */ |
777 |
cdlast->next = cd->next; |
778 |
cd->next = (SDMatCDst *)sdc->cdList; |
779 |
sdc->cdList = (SDCDst *)cd; |
780 |
} |
781 |
return (SDCDst *)cd; /* ready to go */ |
782 |
} |
783 |
|
784 |
/* Sample cumulative distribution */ |
785 |
static SDError |
786 |
SDsampMtxCDist(FVECT ioVec, double randX, const SDCDst *cdp) |
787 |
{ |
788 |
const unsigned maxval = ~0; |
789 |
const SDMatCDst *mcd = (const SDMatCDst *)cdp; |
790 |
const unsigned target = randX*maxval; |
791 |
int i, iupper, ilower; |
792 |
/* check arguments */ |
793 |
if ((ioVec == NULL) | (mcd == NULL)) |
794 |
return SDEargument; |
795 |
/* binary search to find index */ |
796 |
ilower = 0; iupper = mcd->calen; |
797 |
while ((i = (iupper + ilower) >> 1) != ilower) |
798 |
if (target >= mcd->carr[i]) |
799 |
ilower = i; |
800 |
else |
801 |
iupper = i; |
802 |
/* localize random position */ |
803 |
randX = (randX*maxval - mcd->carr[ilower]) / |
804 |
(double)(mcd->carr[iupper] - mcd->carr[ilower]); |
805 |
/* convert index to vector */ |
806 |
if ((*mcd->ob_vec)(ioVec, i+randX, mcd->ob_priv)) |
807 |
return SDEnone; |
808 |
strcpy(SDerrorDetail, "Matrix BSDF sampling fault"); |
809 |
return SDEinternal; |
810 |
} |
811 |
|
812 |
/* Fixed resolution BSDF methods */ |
813 |
SDFunc SDhandleMtx = { |
814 |
&SDgetMtxBSDF, |
815 |
&SDqueryMtxProjSA, |
816 |
&SDgetMtxCDist, |
817 |
&SDsampMtxCDist, |
818 |
&SDfreeMatrix, |
819 |
}; |