1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: bsdf_m.c,v 3.6 2011/02/21 22:50:37 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 |
* |
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*/ |
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|
14 |
#include "rtio.h" |
15 |
#include <stdlib.h> |
16 |
#include <math.h> |
17 |
#include <ctype.h> |
18 |
#include "ezxml.h" |
19 |
#include "bsdf.h" |
20 |
#include "bsdf_m.h" |
21 |
|
22 |
/* Function return codes */ |
23 |
#define RC_GOOD 1 |
24 |
#define RC_FAIL 0 |
25 |
#define RC_FORMERR (-1) |
26 |
#define RC_DATERR (-2) |
27 |
#define RC_UNSUPP (-3) |
28 |
#define RC_INTERR (-4) |
29 |
#define RC_MEMERR (-5) |
30 |
|
31 |
#define MAXLATS 46 /* maximum number of latitudes */ |
32 |
|
33 |
/* BSDF angle specification */ |
34 |
typedef struct { |
35 |
char name[64]; /* basis name */ |
36 |
int nangles; /* total number of directions */ |
37 |
struct { |
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float tmin; /* starting theta */ |
39 |
int nphis; /* number of phis (0 term) */ |
40 |
} lat[MAXLATS+1]; /* latitudes */ |
41 |
} ANGLE_BASIS; |
42 |
|
43 |
#define MAXABASES 7 /* limit on defined bases */ |
44 |
|
45 |
static ANGLE_BASIS abase_list[MAXABASES] = { |
46 |
{ |
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"LBNL/Klems Full", 145, |
48 |
{ {-5., 1}, |
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{5., 8}, |
50 |
{15., 16}, |
51 |
{25., 20}, |
52 |
{35., 24}, |
53 |
{45., 24}, |
54 |
{55., 24}, |
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{65., 16}, |
56 |
{75., 12}, |
57 |
{90., 0} } |
58 |
}, { |
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"LBNL/Klems Half", 73, |
60 |
{ {-6.5, 1}, |
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{6.5, 8}, |
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{19.5, 12}, |
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{32.5, 16}, |
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{46.5, 20}, |
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{61.5, 12}, |
66 |
{76.5, 4}, |
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{90., 0} } |
68 |
}, { |
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"LBNL/Klems Quarter", 41, |
70 |
{ {-9., 1}, |
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{9., 8}, |
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{27., 12}, |
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{46., 12}, |
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{66., 8}, |
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{90., 0} } |
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} |
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}; |
78 |
|
79 |
static int nabases = 3; /* current number of defined bases */ |
80 |
|
81 |
static int |
82 |
fequal(double a, double b) |
83 |
{ |
84 |
if (b != .0) |
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a = a/b - 1.; |
86 |
return (a <= 1e-6) & (a >= -1e-6); |
87 |
} |
88 |
|
89 |
/* returns the name of the given tag */ |
90 |
#ifdef ezxml_name |
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#undef ezxml_name |
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static char * |
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ezxml_name(ezxml_t xml) |
94 |
{ |
95 |
if (xml == NULL) |
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return NULL; |
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return xml->name; |
98 |
} |
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#endif |
100 |
|
101 |
/* returns the given tag's character content or empty string if none */ |
102 |
#ifdef ezxml_txt |
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#undef ezxml_txt |
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static char * |
105 |
ezxml_txt(ezxml_t xml) |
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{ |
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if (xml == NULL) |
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return ""; |
109 |
return xml->txt; |
110 |
} |
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#endif |
112 |
|
113 |
/* Convert error to standard BSDF code */ |
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static SDError |
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convert_errcode(int ec) |
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{ |
117 |
switch (ec) { |
118 |
case RC_GOOD: |
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return SDEnone; |
120 |
case RC_FORMERR: |
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return SDEformat; |
122 |
case RC_DATERR: |
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return SDEdata; |
124 |
case RC_UNSUPP: |
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return SDEsupport; |
126 |
case RC_INTERR: |
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return SDEinternal; |
128 |
case RC_MEMERR: |
129 |
return SDEmemory; |
130 |
} |
131 |
return SDEunknown; |
132 |
} |
133 |
|
134 |
/* Allocate a BSDF matrix of the given size */ |
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static SDMat * |
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SDnewMatrix(int ni, int no) |
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{ |
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SDMat *sm; |
139 |
|
140 |
if ((ni <= 0) | (no <= 0)) { |
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strcpy(SDerrorDetail, "Empty BSDF matrix request"); |
142 |
return NULL; |
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} |
144 |
sm = (SDMat *)malloc(sizeof(SDMat) + (ni*no - 1)*sizeof(float)); |
145 |
if (sm == NULL) { |
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sprintf(SDerrorDetail, "Cannot allocate %dx%d BSDF matrix", |
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ni, no); |
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return NULL; |
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} |
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memset(sm, 0, sizeof(SDMat)-sizeof(float)); |
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sm->ninc = ni; |
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sm->nout = no; |
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|
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return sm; |
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} |
156 |
|
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/* Free a BSDF matrix */ |
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#define SDfreeMatrix free |
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|
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/* get vector for this angle basis index */ |
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static int |
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ab_getvec(FVECT v, int ndx, double randX, void *p) |
163 |
{ |
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ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
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double rx[2]; |
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int li; |
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double pol, azi, d; |
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|
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if ((ndx < 0) | (ndx >= ab->nangles)) |
170 |
return RC_FAIL; |
171 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
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ndx -= ab->lat[li].nphis; |
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SDmultiSamp(rx, 2, randX); |
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pol = M_PI/180.*( (1.-rx[0])*ab->lat[li].tmin + |
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rx[0]*ab->lat[li+1].tmin ); |
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azi = 2.*M_PI*(ndx + rx[1] - .5)/ab->lat[li].nphis; |
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v[2] = d = cos(pol); |
178 |
d = sqrt(1. - d*d); /* sin(pol) */ |
179 |
v[0] = cos(azi)*d; |
180 |
v[1] = sin(azi)*d; |
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return RC_GOOD; |
182 |
} |
183 |
|
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/* get index corresponding to the given vector */ |
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static int |
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ab_getndx(const FVECT v, void *p) |
187 |
{ |
188 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
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int li, ndx; |
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double pol, azi, d; |
191 |
|
192 |
if (v == NULL) |
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return -1; |
194 |
if ((v[2] < .0) | (v[2] > 1.0)) |
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return -1; |
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pol = 180.0/M_PI*acos(v[2]); |
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azi = 180.0/M_PI*atan2(v[1], v[0]); |
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if (azi < 0.0) azi += 360.0; |
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for (li = 1; ab->lat[li].tmin <= pol; li++) |
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if (!ab->lat[li].nphis) |
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return -1; |
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--li; |
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ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5); |
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if (ndx >= ab->lat[li].nphis) ndx = 0; |
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while (li--) |
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ndx += ab->lat[li].nphis; |
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return ndx; |
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} |
209 |
|
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/* compute square of real value */ |
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static double sq(double x) { return x*x; } |
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|
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/* get projected solid angle for this angle basis index */ |
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static double |
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ab_getohm(int ndx, void *p) |
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{ |
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static int last_li = -1; |
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static double last_ohm; |
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ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
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int li; |
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double theta, theta1; |
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|
223 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
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return -1.; |
225 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
226 |
ndx -= ab->lat[li].nphis; |
227 |
if (li == last_li) /* cached latitude? */ |
228 |
return last_ohm; |
229 |
last_li = li; |
230 |
theta1 = M_PI/180. * ab->lat[li+1].tmin; |
231 |
if (ab->lat[li].nphis == 1) /* special case */ |
232 |
return last_ohm = M_PI*(1. - sq(cos(theta1))); |
233 |
theta = M_PI/180. * ab->lat[li].tmin; |
234 |
return last_ohm = M_PI*(sq(cos(theta)) - sq(cos(theta1))) / |
235 |
(double)ab->lat[li].nphis; |
236 |
} |
237 |
|
238 |
/* get reverse vector for this angle basis index */ |
239 |
static int |
240 |
ab_getvecR(FVECT v, int ndx, double randX, void *p) |
241 |
{ |
242 |
int na = (*(ANGLE_BASIS *)p).nangles; |
243 |
|
244 |
if (!ab_getvec(v, ndx, randX, p)) |
245 |
return RC_FAIL; |
246 |
|
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v[0] = -v[0]; |
248 |
v[1] = -v[1]; |
249 |
v[2] = -v[2]; |
250 |
|
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return RC_GOOD; |
252 |
} |
253 |
|
254 |
/* get index corresponding to the reverse vector */ |
255 |
static int |
256 |
ab_getndxR(const FVECT v, void *p) |
257 |
{ |
258 |
FVECT v2; |
259 |
|
260 |
v2[0] = -v[0]; |
261 |
v2[1] = -v[1]; |
262 |
v2[2] = -v[2]; |
263 |
|
264 |
return ab_getndx(v2, p); |
265 |
} |
266 |
|
267 |
/* load custom BSDF angle basis */ |
268 |
static int |
269 |
load_angle_basis(ezxml_t wab) |
270 |
{ |
271 |
char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName")); |
272 |
ezxml_t wbb; |
273 |
int i; |
274 |
|
275 |
if (!abname || !*abname) |
276 |
return RC_FAIL; |
277 |
for (i = nabases; i--; ) |
278 |
if (!strcasecmp(abname, abase_list[i].name)) |
279 |
return RC_GOOD; /* assume it's the same */ |
280 |
if (nabases >= MAXABASES) { |
281 |
sprintf(SDerrorDetail, "Out of angle bases reading '%s'", |
282 |
abname); |
283 |
return RC_INTERR; |
284 |
} |
285 |
strcpy(abase_list[nabases].name, abname); |
286 |
abase_list[nabases].nangles = 0; |
287 |
for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock"); |
288 |
wbb != NULL; i++, wbb = wbb->next) { |
289 |
if (i >= MAXLATS) { |
290 |
sprintf(SDerrorDetail, "Too many latitudes for '%s'", |
291 |
abname); |
292 |
return RC_INTERR; |
293 |
} |
294 |
abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt( |
295 |
ezxml_child(ezxml_child(wbb, |
296 |
"ThetaBounds"), "UpperTheta"))); |
297 |
if (!i) |
298 |
abase_list[nabases].lat[i].tmin = |
299 |
-abase_list[nabases].lat[i+1].tmin; |
300 |
else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb, |
301 |
"ThetaBounds"), "LowerTheta"))), |
302 |
abase_list[nabases].lat[i].tmin)) { |
303 |
sprintf(SDerrorDetail, "Theta values disagree in '%s'", |
304 |
abname); |
305 |
return RC_DATERR; |
306 |
} |
307 |
abase_list[nabases].nangles += |
308 |
abase_list[nabases].lat[i].nphis = |
309 |
atoi(ezxml_txt(ezxml_child(wbb, "nPhis"))); |
310 |
if (abase_list[nabases].lat[i].nphis <= 0 || |
311 |
(abase_list[nabases].lat[i].nphis == 1 && |
312 |
abase_list[nabases].lat[i].tmin > FTINY)) { |
313 |
sprintf(SDerrorDetail, "Illegal phi count in '%s'", |
314 |
abname); |
315 |
return RC_DATERR; |
316 |
} |
317 |
} |
318 |
abase_list[nabases++].lat[i].nphis = 0; |
319 |
return RC_GOOD; |
320 |
} |
321 |
|
322 |
/* compute min. proj. solid angle and max. direct hemispherical scattering */ |
323 |
static int |
324 |
get_extrema(SDSpectralDF *df) |
325 |
{ |
326 |
SDMat *dp = (SDMat *)df->comp[0].dist; |
327 |
double *ohma; |
328 |
int i, o; |
329 |
/* initialize extrema */ |
330 |
df->minProjSA = M_PI; |
331 |
df->maxHemi = .0; |
332 |
ohma = (double *)malloc(dp->nout*sizeof(double)); |
333 |
if (ohma == NULL) |
334 |
return RC_MEMERR; |
335 |
/* get outgoing solid angles */ |
336 |
for (o = dp->nout; o--; ) |
337 |
if ((ohma[o] = mBSDF_outohm(dp,o)) < df->minProjSA) |
338 |
df->minProjSA = ohma[o]; |
339 |
/* compute hemispherical sums */ |
340 |
for (i = dp->ninc; i--; ) { |
341 |
double hemi = .0; |
342 |
for (o = dp->nout; o--; ) |
343 |
hemi += ohma[o] * mBSDF_value(dp, i, o); |
344 |
if (hemi > df->maxHemi) |
345 |
df->maxHemi = hemi; |
346 |
} |
347 |
free(ohma); |
348 |
/* need incoming solid angles, too? */ |
349 |
if ((dp->ib_ohm != dp->ob_ohm) | (dp->ib_priv != dp->ob_priv)) { |
350 |
double ohm; |
351 |
for (i = dp->ninc; i--; ) |
352 |
if ((ohm = mBSDF_incohm(dp,i)) < df->minProjSA) |
353 |
df->minProjSA = ohm; |
354 |
} |
355 |
return (df->maxHemi <= 1.01); |
356 |
} |
357 |
|
358 |
/* load BSDF distribution for this wavelength */ |
359 |
static int |
360 |
load_bsdf_data(SDData *sd, ezxml_t wdb, int rowinc) |
361 |
{ |
362 |
SDSpectralDF *df; |
363 |
SDMat *dp; |
364 |
char *sdata; |
365 |
int tback; |
366 |
int inbi, outbi; |
367 |
int i; |
368 |
/* allocate BSDF component */ |
369 |
sdata = ezxml_txt(ezxml_child(wdb, "WavelengthDataDirection")); |
370 |
if ((tback = !strcasecmp(sdata, "Transmission Back")) || |
371 |
(sd->tf == NULL && |
372 |
!strcasecmp(sdata, "Transmission Front"))) { |
373 |
if (sd->tf != NULL) |
374 |
SDfreeSpectralDF(sd->tf); |
375 |
if ((sd->tf = SDnewSpectralDF(1)) == NULL) |
376 |
return RC_MEMERR; |
377 |
df = sd->tf; |
378 |
} else if (!strcasecmp(sdata, "Reflection Front")) { |
379 |
if (sd->rb != NULL) /* note back-front reversal */ |
380 |
SDfreeSpectralDF(sd->rb); |
381 |
if ((sd->rb = SDnewSpectralDF(1)) == NULL) |
382 |
return RC_MEMERR; |
383 |
df = sd->rb; |
384 |
} else if (!strcasecmp(sdata, "Reflection Back")) { |
385 |
if (sd->rf != NULL) /* note front-back reversal */ |
386 |
SDfreeSpectralDF(sd->rf); |
387 |
if ((sd->rf = SDnewSpectralDF(1)) == NULL) |
388 |
return RC_MEMERR; |
389 |
df = sd->rf; |
390 |
} else |
391 |
return RC_FAIL; |
392 |
/* XXX should also check "ScatteringDataType" for consistency? */ |
393 |
/* get angle bases */ |
394 |
sdata = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis")); |
395 |
if (!sdata || !*sdata) { |
396 |
sprintf(SDerrorDetail, "Missing column basis for BSDF '%s'", |
397 |
sd->name); |
398 |
return RC_FORMERR; |
399 |
} |
400 |
for (inbi = nabases; inbi--; ) |
401 |
if (!strcasecmp(sdata, abase_list[inbi].name)) |
402 |
break; |
403 |
if (inbi < 0) { |
404 |
sprintf(SDerrorDetail, "Undefined ColumnAngleBasis '%s'", sdata); |
405 |
return RC_FORMERR; |
406 |
} |
407 |
sdata = ezxml_txt(ezxml_child(wdb,"RowAngleBasis")); |
408 |
if (!sdata || !*sdata) { |
409 |
sprintf(SDerrorDetail, "Missing row basis for BSDF '%s'", |
410 |
sd->name); |
411 |
return RC_FORMERR; |
412 |
} |
413 |
for (outbi = nabases; outbi--; ) |
414 |
if (!strcasecmp(sdata, abase_list[outbi].name)) |
415 |
break; |
416 |
if (outbi < 0) { |
417 |
sprintf(SDerrorDetail, "Undefined RowAngleBasis '%s'", sdata); |
418 |
return RC_FORMERR; |
419 |
} |
420 |
/* allocate BSDF matrix */ |
421 |
dp = SDnewMatrix(abase_list[inbi].nangles, abase_list[outbi].nangles); |
422 |
if (dp == NULL) |
423 |
return RC_MEMERR; |
424 |
dp->ib_priv = &abase_list[inbi]; |
425 |
dp->ob_priv = &abase_list[outbi]; |
426 |
if (df == sd->tf) { |
427 |
if (tback) { |
428 |
dp->ib_vec = &ab_getvecR; |
429 |
dp->ib_ndx = &ab_getndxR; |
430 |
dp->ob_vec = &ab_getvec; |
431 |
dp->ob_ndx = &ab_getndx; |
432 |
} else { |
433 |
dp->ib_vec = &ab_getvec; |
434 |
dp->ib_ndx = &ab_getndx; |
435 |
dp->ob_vec = &ab_getvecR; |
436 |
dp->ob_ndx = &ab_getndxR; |
437 |
} |
438 |
} else if (df == sd->rf) { |
439 |
dp->ib_vec = &ab_getvec; |
440 |
dp->ib_ndx = &ab_getndx; |
441 |
dp->ob_vec = &ab_getvec; |
442 |
dp->ob_ndx = &ab_getndx; |
443 |
} else /* df == sd->rb */ { |
444 |
dp->ib_vec = &ab_getvecR; |
445 |
dp->ib_ndx = &ab_getndxR; |
446 |
dp->ob_vec = &ab_getvecR; |
447 |
dp->ob_ndx = &ab_getndxR; |
448 |
} |
449 |
dp->ib_ohm = &ab_getohm; |
450 |
dp->ob_ohm = &ab_getohm; |
451 |
df->comp[0].cspec[0] = c_dfcolor; /* XXX monochrome for now */ |
452 |
df->comp[0].dist = dp; |
453 |
df->comp[0].func = &SDhandleMtx; |
454 |
/* read BSDF data */ |
455 |
sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData")); |
456 |
if (!sdata || !*sdata) { |
457 |
sprintf(SDerrorDetail, "Missing BSDF ScatteringData in '%s'", |
458 |
sd->name); |
459 |
return RC_FORMERR; |
460 |
} |
461 |
for (i = 0; i < dp->ninc*dp->nout; i++) { |
462 |
char *sdnext = fskip(sdata); |
463 |
if (sdnext == NULL) { |
464 |
sprintf(SDerrorDetail, |
465 |
"Bad/missing BSDF ScatteringData in '%s'", |
466 |
sd->name); |
467 |
return RC_FORMERR; |
468 |
} |
469 |
while (*sdnext && isspace(*sdnext)) |
470 |
sdnext++; |
471 |
if (*sdnext == ',') sdnext++; |
472 |
if (rowinc) { |
473 |
int r = i/dp->nout; |
474 |
int c = i - c*dp->nout; |
475 |
mBSDF_value(dp,r,c) = atof(sdata); |
476 |
} else |
477 |
dp->bsdf[i] = atof(sdata); |
478 |
sdata = sdnext; |
479 |
} |
480 |
return get_extrema(df); |
481 |
} |
482 |
|
483 |
/* Subtract minimum (diffuse) scattering amount from BSDF */ |
484 |
static double |
485 |
subtract_min(SDMat *sm) |
486 |
{ |
487 |
float minv = sm->bsdf[0]; |
488 |
int n = sm->ninc*sm->nout; |
489 |
int i; |
490 |
|
491 |
for (i = n; --i; ) |
492 |
if (sm->bsdf[i] < minv) |
493 |
minv = sm->bsdf[i]; |
494 |
for (i = n; i--; ) |
495 |
sm->bsdf[i] -= minv; |
496 |
|
497 |
return minv*M_PI; /* be sure to include multiplier */ |
498 |
} |
499 |
|
500 |
/* Extract and separate diffuse portion of BSDF */ |
501 |
static void |
502 |
extract_diffuse(SDValue *dv, SDSpectralDF *df) |
503 |
{ |
504 |
int n; |
505 |
|
506 |
if (df == NULL || df->ncomp <= 0) { |
507 |
dv->spec = c_dfcolor; |
508 |
dv->cieY = .0; |
509 |
return; |
510 |
} |
511 |
dv->spec = df->comp[0].cspec[0]; |
512 |
dv->cieY = subtract_min((SDMat *)df->comp[0].dist); |
513 |
/* in case of multiple components */ |
514 |
for (n = df->ncomp; --n; ) { |
515 |
double ymin = subtract_min((SDMat *)df->comp[n].dist); |
516 |
c_cmix(&dv->spec, dv->cieY, &dv->spec, ymin, &df->comp[n].cspec[0]); |
517 |
dv->cieY += ymin; |
518 |
} |
519 |
df->maxHemi -= dv->cieY; /* adjust minimum hemispherical */ |
520 |
/* make sure everything is set */ |
521 |
c_ccvt(&dv->spec, C_CSXY+C_CSSPEC); |
522 |
} |
523 |
|
524 |
/* Load a BSDF matrix from an open XML file */ |
525 |
SDError |
526 |
SDloadMtx(SDData *sd, ezxml_t wtl) |
527 |
{ |
528 |
ezxml_t wld, wdb; |
529 |
int rowIn; |
530 |
struct BSDF_data *dp; |
531 |
char *txt; |
532 |
int rval; |
533 |
|
534 |
txt = ezxml_txt(ezxml_child(ezxml_child(wtl, |
535 |
"DataDefinition"), "IncidentDataStructure")); |
536 |
if (txt == NULL || !*txt) { |
537 |
sprintf(SDerrorDetail, |
538 |
"BSDF \"%s\": missing IncidentDataStructure", |
539 |
sd->name); |
540 |
return SDEformat; |
541 |
} |
542 |
if (!strcasecmp(txt, "Rows")) |
543 |
rowIn = 1; |
544 |
else if (!strcasecmp(txt, "Columns")) |
545 |
rowIn = 0; |
546 |
else { |
547 |
sprintf(SDerrorDetail, |
548 |
"BSDF \"%s\": unsupported IncidentDataStructure", |
549 |
sd->name); |
550 |
return SDEsupport; |
551 |
} |
552 |
/* get angle basis */ |
553 |
rval = load_angle_basis(ezxml_child(ezxml_child(wtl, |
554 |
"DataDefinition"), "AngleBasis")); |
555 |
if (rval < 0) |
556 |
return convert_errcode(rval); |
557 |
/* load BSDF components */ |
558 |
for (wld = ezxml_child(wtl, "WavelengthData"); |
559 |
wld != NULL; wld = wld->next) { |
560 |
if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")), |
561 |
"Visible")) |
562 |
continue; /* just visible for now */ |
563 |
for (wdb = ezxml_child(wld, "WavelengthDataBlock"); |
564 |
wdb != NULL; wdb = wdb->next) |
565 |
if ((rval = load_bsdf_data(sd, wdb, rowIn)) < 0) |
566 |
return convert_errcode(rval); |
567 |
} |
568 |
/* separate diffuse components */ |
569 |
extract_diffuse(&sd->rLambFront, sd->rf); |
570 |
extract_diffuse(&sd->rLambBack, sd->rb); |
571 |
extract_diffuse(&sd->tLamb, sd->tf); |
572 |
/* return success */ |
573 |
return SDEnone; |
574 |
} |
575 |
|
576 |
/* Get Matrix BSDF value */ |
577 |
static int |
578 |
SDgetMtxBSDF(float coef[SDmaxCh], const FVECT outVec, |
579 |
const FVECT inVec, const void *dist) |
580 |
{ |
581 |
const SDMat *dp = (const SDMat *)dist; |
582 |
int i_ndx, o_ndx; |
583 |
/* get angle indices */ |
584 |
i_ndx = mBSDF_incndx(dp, inVec); |
585 |
o_ndx = mBSDF_outndx(dp, outVec); |
586 |
/* try reciprocity if necessary */ |
587 |
if ((i_ndx < 0) & (o_ndx < 0)) { |
588 |
i_ndx = mBSDF_incndx(dp, outVec); |
589 |
o_ndx = mBSDF_outndx(dp, inVec); |
590 |
} |
591 |
if ((i_ndx < 0) | (o_ndx < 0)) |
592 |
return 0; /* nothing from this component */ |
593 |
coef[0] = mBSDF_value(dp, i_ndx, o_ndx); |
594 |
return 1; /* XXX monochrome for now */ |
595 |
} |
596 |
|
597 |
/* Query solid angle for vector */ |
598 |
static SDError |
599 |
SDqueryMtxProjSA(double *psa, const FVECT vec, int qflags, const void *dist) |
600 |
{ |
601 |
const SDMat *dp = (const SDMat *)dist; |
602 |
double inc_psa, out_psa; |
603 |
/* check arguments */ |
604 |
if ((psa == NULL) | (vec == NULL) | (dp == NULL)) |
605 |
return SDEargument; |
606 |
/* get projected solid angles */ |
607 |
inc_psa = mBSDF_incohm(dp, mBSDF_incndx(dp, vec)); |
608 |
out_psa = mBSDF_outohm(dp, mBSDF_outndx(dp, vec)); |
609 |
|
610 |
switch (qflags) { /* record based on flag settings */ |
611 |
case SDqueryVal: |
612 |
psa[0] = .0; |
613 |
/* fall through */ |
614 |
case SDqueryMax: |
615 |
if (inc_psa > psa[0]) |
616 |
psa[0] = inc_psa; |
617 |
if (out_psa > psa[0]) |
618 |
psa[0] = out_psa; |
619 |
break; |
620 |
case SDqueryMin+SDqueryMax: |
621 |
if (inc_psa > psa[0]) |
622 |
psa[1] = inc_psa; |
623 |
if (out_psa > psa[0]) |
624 |
psa[1] = out_psa; |
625 |
/* fall through */ |
626 |
case SDqueryMin: |
627 |
if ((inc_psa > .0) & (inc_psa < psa[0])) |
628 |
psa[0] = inc_psa; |
629 |
if ((out_psa > .0) & (out_psa < psa[0])) |
630 |
psa[0] = out_psa; |
631 |
break; |
632 |
} |
633 |
/* make sure it's legal */ |
634 |
return (psa[0] <= .0) ? SDEinternal : SDEnone; |
635 |
} |
636 |
|
637 |
/* Compute new cumulative distribution from BSDF */ |
638 |
static int |
639 |
make_cdist(SDMatCDst *cd, const FVECT inVec, SDMat *dp, int rev) |
640 |
{ |
641 |
const unsigned maxval = ~0; |
642 |
double *cmtab, scale; |
643 |
int o; |
644 |
|
645 |
cmtab = (double *)malloc((cd->calen+1)*sizeof(double)); |
646 |
if (cmtab == NULL) |
647 |
return 0; |
648 |
cmtab[0] = .0; |
649 |
for (o = 0; o < cd->calen; o++) { |
650 |
if (rev) |
651 |
cmtab[o+1] = mBSDF_value(dp, o, cd->indx) * |
652 |
(*dp->ib_ohm)(o, dp->ib_priv); |
653 |
else |
654 |
cmtab[o+1] = mBSDF_value(dp, cd->indx, o) * |
655 |
(*dp->ob_ohm)(o, dp->ob_priv); |
656 |
cmtab[o+1] += cmtab[o]; |
657 |
} |
658 |
cd->cTotal = cmtab[cd->calen]; |
659 |
scale = (double)maxval / cd->cTotal; |
660 |
cd->carr[0] = 0; |
661 |
for (o = 1; o < cd->calen; o++) |
662 |
cd->carr[o] = scale*cmtab[o] + .5; |
663 |
cd->carr[cd->calen] = maxval; |
664 |
free(cmtab); |
665 |
return 1; |
666 |
} |
667 |
|
668 |
/* Get cumulative distribution for matrix BSDF */ |
669 |
static const SDCDst * |
670 |
SDgetMtxCDist(const FVECT inVec, SDComponent *sdc) |
671 |
{ |
672 |
SDMat *dp = (SDMat *)sdc->dist; |
673 |
int reverse; |
674 |
SDMatCDst myCD; |
675 |
SDMatCDst *cd, *cdlast; |
676 |
/* check arguments */ |
677 |
if ((inVec == NULL) | (dp == NULL)) |
678 |
return NULL; |
679 |
memset(&myCD, 0, sizeof(myCD)); |
680 |
myCD.indx = mBSDF_incndx(dp, inVec); |
681 |
if (myCD.indx >= 0) { |
682 |
myCD.ob_priv = dp->ob_priv; |
683 |
myCD.ob_vec = dp->ob_vec; |
684 |
myCD.calen = dp->nout; |
685 |
reverse = 0; |
686 |
} else { /* try reciprocity */ |
687 |
myCD.indx = mBSDF_outndx(dp, inVec); |
688 |
if (myCD.indx < 0) |
689 |
return NULL; |
690 |
myCD.ob_priv = dp->ib_priv; |
691 |
myCD.ob_vec = dp->ib_vec; |
692 |
myCD.calen = dp->ninc; |
693 |
reverse = 1; |
694 |
} |
695 |
cdlast = NULL; /* check for it in cache list */ |
696 |
for (cd = (SDMatCDst *)sdc->cdList; |
697 |
cd != NULL; cd = (SDMatCDst *)cd->next) { |
698 |
if (cd->indx == myCD.indx && (cd->calen == myCD.calen) & |
699 |
(cd->ob_priv == myCD.ob_priv) & |
700 |
(cd->ob_vec == myCD.ob_vec)) |
701 |
break; |
702 |
cdlast = cd; |
703 |
} |
704 |
if (cd == NULL) { /* need to allocate new entry */ |
705 |
cd = (SDMatCDst *)malloc(sizeof(SDMatCDst) + |
706 |
myCD.calen*sizeof(myCD.carr[0])); |
707 |
if (cd == NULL) |
708 |
return NULL; |
709 |
*cd = myCD; /* compute cumulative distribution */ |
710 |
if (!make_cdist(cd, inVec, dp, reverse)) { |
711 |
free(cd); |
712 |
return NULL; |
713 |
} |
714 |
cdlast = cd; |
715 |
} |
716 |
if (cdlast != NULL) { /* move entry to head of cache list */ |
717 |
cdlast->next = cd->next; |
718 |
cd->next = sdc->cdList; |
719 |
sdc->cdList = (SDCDst *)cd; |
720 |
} |
721 |
return (SDCDst *)cd; /* ready to go */ |
722 |
} |
723 |
|
724 |
/* Sample cumulative distribution */ |
725 |
static SDError |
726 |
SDsampMtxCDist(FVECT outVec, double randX, const SDCDst *cdp) |
727 |
{ |
728 |
const unsigned maxval = ~0; |
729 |
const SDMatCDst *mcd = (const SDMatCDst *)cdp; |
730 |
const unsigned target = randX*maxval; |
731 |
int i, iupper, ilower; |
732 |
/* check arguments */ |
733 |
if ((outVec == NULL) | (mcd == NULL)) |
734 |
return SDEargument; |
735 |
/* binary search to find index */ |
736 |
ilower = 0; iupper = mcd->calen; |
737 |
while ((i = (iupper + ilower) >> 1) != ilower) |
738 |
if ((long)target >= (long)mcd->carr[i]) |
739 |
ilower = i; |
740 |
else |
741 |
iupper = i; |
742 |
/* localize random position */ |
743 |
randX = (randX*maxval - mcd->carr[ilower]) / |
744 |
(double)(mcd->carr[iupper] - mcd->carr[ilower]); |
745 |
/* convert index to vector */ |
746 |
if ((*mcd->ob_vec)(outVec, i, randX, mcd->ob_priv)) |
747 |
return SDEnone; |
748 |
strcpy(SDerrorDetail, "BSDF sampling fault"); |
749 |
return SDEinternal; |
750 |
} |
751 |
|
752 |
/* Fixed resolution BSDF methods */ |
753 |
SDFunc SDhandleMtx = { |
754 |
&SDgetMtxBSDF, |
755 |
&SDqueryMtxProjSA, |
756 |
&SDgetMtxCDist, |
757 |
&SDsampMtxCDist, |
758 |
&SDfreeMatrix, |
759 |
}; |