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#ifndef lint |
2 |
static const char RCSid[] = "$Id: bsdf_m.c,v 3.2 2011/02/18 00:41:44 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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|
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#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 |
#ifndef FTINY |
23 |
#define FTINY 1e-6 |
24 |
#endif |
25 |
|
26 |
/* Function return codes */ |
27 |
#define RC_GOOD 1 |
28 |
#define RC_FAIL 0 |
29 |
#define RC_FORMERR (-1) |
30 |
#define RC_DATERR (-2) |
31 |
#define RC_UNSUPP (-3) |
32 |
#define RC_INTERR (-4) |
33 |
#define RC_MEMERR (-5) |
34 |
|
35 |
#define MAXLATS 46 /* maximum number of latitudes */ |
36 |
|
37 |
/* BSDF angle specification */ |
38 |
typedef struct { |
39 |
char name[64]; /* basis name */ |
40 |
int nangles; /* total number of directions */ |
41 |
struct { |
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float tmin; /* starting theta */ |
43 |
int nphis; /* number of phis (0 term) */ |
44 |
} lat[MAXLATS+1]; /* latitudes */ |
45 |
} ANGLE_BASIS; |
46 |
|
47 |
#define MAXABASES 7 /* limit on defined bases */ |
48 |
|
49 |
static ANGLE_BASIS abase_list[MAXABASES] = { |
50 |
{ |
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"LBNL/Klems Full", 145, |
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{ {-5., 1}, |
53 |
{5., 8}, |
54 |
{15., 16}, |
55 |
{25., 20}, |
56 |
{35., 24}, |
57 |
{45., 24}, |
58 |
{55., 24}, |
59 |
{65., 16}, |
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{75., 12}, |
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{90., 0} } |
62 |
}, { |
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"LBNL/Klems Half", 73, |
64 |
{ {-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}, |
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{76.5, 4}, |
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{90., 0} } |
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}, { |
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"LBNL/Klems Quarter", 41, |
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{ {-9., 1}, |
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{9., 8}, |
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{27., 12}, |
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{46., 12}, |
78 |
{66., 8}, |
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{90., 0} } |
80 |
} |
81 |
}; |
82 |
|
83 |
static int nabases = 3; /* current number of defined bases */ |
84 |
|
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static int |
86 |
fequal(double a, double b) |
87 |
{ |
88 |
if (b != .0) |
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a = a/b - 1.; |
90 |
return (a <= 1e-6) & (a >= -1e-6); |
91 |
} |
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|
93 |
/* returns the name of the given tag */ |
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#ifdef ezxml_name |
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#undef ezxml_name |
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static char * |
97 |
ezxml_name(ezxml_t xml) |
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{ |
99 |
if (xml == NULL) |
100 |
return NULL; |
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return xml->name; |
102 |
} |
103 |
#endif |
104 |
|
105 |
/* returns the given tag's character content or empty string if none */ |
106 |
#ifdef ezxml_txt |
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#undef ezxml_txt |
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static char * |
109 |
ezxml_txt(ezxml_t xml) |
110 |
{ |
111 |
if (xml == NULL) |
112 |
return ""; |
113 |
return xml->txt; |
114 |
} |
115 |
#endif |
116 |
|
117 |
/* Convert error to standard BSDF code */ |
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static SDError |
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convert_errcode(int ec) |
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{ |
121 |
switch (ec) { |
122 |
case RC_GOOD: |
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return SDEnone; |
124 |
case RC_FORMERR: |
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return SDEformat; |
126 |
case RC_DATERR: |
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return SDEdata; |
128 |
case RC_UNSUPP: |
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return SDEsupport; |
130 |
case RC_INTERR: |
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return SDEinternal; |
132 |
case RC_MEMERR: |
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return SDEmemory; |
134 |
} |
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return SDEunknown; |
136 |
} |
137 |
|
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/* Allocate a BSDF matrix of the given size */ |
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static SDMat * |
140 |
SDnewMatrix(int ni, int no) |
141 |
{ |
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SDMat *sm; |
143 |
|
144 |
if ((ni <= 0) | (no <= 0)) { |
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strcpy(SDerrorDetail, "Empty BSDF matrix request"); |
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return NULL; |
147 |
} |
148 |
sm = (SDMat *)malloc(sizeof(SDMat) + (ni*no - 1)*sizeof(float)); |
149 |
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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} |
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|
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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) |
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{ |
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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)) |
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return RC_FAIL; |
175 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
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ndx -= ab->lat[li].nphis; |
177 |
SDmultiSamp(rx, 2, randX); |
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pol = M_PI/180.*( (1.-rx[0])*ab->lat[li].tmin + |
179 |
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); |
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d = sqrt(1. - d*d); /* sin(pol) */ |
183 |
v[0] = cos(azi)*d; |
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v[1] = sin(azi)*d; |
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return RC_GOOD; |
186 |
} |
187 |
|
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/* get index corresponding to the given vector */ |
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static int |
190 |
ab_getndx(const FVECT v, void *p) |
191 |
{ |
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ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
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int li, ndx; |
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double pol, azi, d; |
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|
196 |
if (v == NULL) |
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return -1; |
198 |
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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} |
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|
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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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|
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if ((ndx < 0) | (ndx >= ab->nangles)) |
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return -1.; |
229 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
230 |
ndx -= ab->lat[li].nphis; |
231 |
if (li == last_li) /* cached latitude? */ |
232 |
return last_ohm; |
233 |
last_li = li; |
234 |
theta1 = M_PI/180. * ab->lat[li+1].tmin; |
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if (ab->lat[li].nphis == 1) /* special case */ |
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return last_ohm = M_PI*(1. - sq(cos(theta1))); |
237 |
theta = M_PI/180. * ab->lat[li].tmin; |
238 |
return last_ohm = M_PI*(sq(cos(theta)) - sq(cos(theta1))) / |
239 |
(double)ab->lat[li].nphis; |
240 |
} |
241 |
|
242 |
/* get reverse vector for this angle basis index */ |
243 |
static int |
244 |
ab_getvecR(FVECT v, int ndx, double randX, void *p) |
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{ |
246 |
int na = (*(ANGLE_BASIS *)p).nangles; |
247 |
|
248 |
if (!ab_getvec(v, ndx, randX, p)) |
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return RC_FAIL; |
250 |
|
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v[0] = -v[0]; |
252 |
v[1] = -v[1]; |
253 |
v[2] = -v[2]; |
254 |
|
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return RC_GOOD; |
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} |
257 |
|
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/* get index corresponding to the reverse vector */ |
259 |
static int |
260 |
ab_getndxR(const FVECT v, void *p) |
261 |
{ |
262 |
FVECT v2; |
263 |
|
264 |
v2[0] = -v[0]; |
265 |
v2[1] = -v[1]; |
266 |
v2[2] = -v[2]; |
267 |
|
268 |
return ab_getndx(v2, p); |
269 |
} |
270 |
|
271 |
/* load custom BSDF angle basis */ |
272 |
static int |
273 |
load_angle_basis(ezxml_t wab) |
274 |
{ |
275 |
char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName")); |
276 |
ezxml_t wbb; |
277 |
int i; |
278 |
|
279 |
if (!abname || !*abname) |
280 |
return RC_FAIL; |
281 |
for (i = nabases; i--; ) |
282 |
if (!strcasecmp(abname, abase_list[i].name)) |
283 |
return RC_GOOD; /* assume it's the same */ |
284 |
if (nabases >= MAXABASES) { |
285 |
sprintf(SDerrorDetail, "Out of angle bases reading '%s'", |
286 |
abname); |
287 |
return RC_INTERR; |
288 |
} |
289 |
strcpy(abase_list[nabases].name, abname); |
290 |
abase_list[nabases].nangles = 0; |
291 |
for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock"); |
292 |
wbb != NULL; i++, wbb = wbb->next) { |
293 |
if (i >= MAXLATS) { |
294 |
sprintf(SDerrorDetail, "Too many latitudes for '%s'", |
295 |
abname); |
296 |
return RC_INTERR; |
297 |
} |
298 |
abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt( |
299 |
ezxml_child(ezxml_child(wbb, |
300 |
"ThetaBounds"), "UpperTheta"))); |
301 |
if (!i) |
302 |
abase_list[nabases].lat[i].tmin = |
303 |
-abase_list[nabases].lat[i+1].tmin; |
304 |
else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb, |
305 |
"ThetaBounds"), "LowerTheta"))), |
306 |
abase_list[nabases].lat[i].tmin)) { |
307 |
sprintf(SDerrorDetail, "Theta values disagree in '%s'", |
308 |
abname); |
309 |
return RC_DATERR; |
310 |
} |
311 |
abase_list[nabases].nangles += |
312 |
abase_list[nabases].lat[i].nphis = |
313 |
atoi(ezxml_txt(ezxml_child(wbb, "nPhis"))); |
314 |
if (abase_list[nabases].lat[i].nphis <= 0 || |
315 |
(abase_list[nabases].lat[i].nphis == 1 && |
316 |
abase_list[nabases].lat[i].tmin > FTINY)) { |
317 |
sprintf(SDerrorDetail, "Illegal phi count in '%s'", |
318 |
abname); |
319 |
return RC_DATERR; |
320 |
} |
321 |
} |
322 |
abase_list[nabases++].lat[i].nphis = 0; |
323 |
return RC_GOOD; |
324 |
} |
325 |
|
326 |
/* compute min. proj. solid angle and max. direct hemispherical scattering */ |
327 |
static int |
328 |
get_extrema(SDSpectralDF *df) |
329 |
{ |
330 |
SDMat *dp = (SDMat *)df->comp[0].dist; |
331 |
double *ohma; |
332 |
int i, o; |
333 |
/* initialize extrema */ |
334 |
df->minProjSA = M_PI; |
335 |
df->maxHemi = .0; |
336 |
ohma = (double *)malloc(dp->nout*sizeof(double)); |
337 |
if (ohma == NULL) |
338 |
return RC_MEMERR; |
339 |
/* get outgoing solid angles */ |
340 |
for (o = dp->nout; o--; ) |
341 |
if ((ohma[o] = mBSDF_outohm(dp,o)) < df->minProjSA) |
342 |
df->minProjSA = ohma[o]; |
343 |
/* compute hemispherical sums */ |
344 |
for (i = dp->ninc; i--; ) { |
345 |
double hemi = .0; |
346 |
for (o = dp->nout; o--; ) |
347 |
hemi += ohma[o] * mBSDF_value(dp, i, o); |
348 |
if (hemi > df->maxHemi) |
349 |
df->maxHemi = hemi; |
350 |
} |
351 |
free(ohma); |
352 |
/* need incoming solid angles, too? */ |
353 |
if (dp->ninc < dp->nout || dp->ib_ohm != dp->ob_ohm || |
354 |
dp->ib_priv != dp->ob_priv) { |
355 |
double ohm; |
356 |
for (i = dp->ninc; i--; ) |
357 |
if ((ohm = mBSDF_incohm(dp,i)) < df->minProjSA) |
358 |
df->minProjSA = ohm; |
359 |
} |
360 |
return (df->maxHemi <= 1.01); |
361 |
} |
362 |
|
363 |
/* load BSDF distribution for this wavelength */ |
364 |
static int |
365 |
load_bsdf_data(SDData *sd, ezxml_t wdb, int rowinc) |
366 |
{ |
367 |
char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis")); |
368 |
char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis")); |
369 |
SDSpectralDF *df; |
370 |
SDMat *dp; |
371 |
char *sdata; |
372 |
int inbi, outbi; |
373 |
int i; |
374 |
|
375 |
if ((!cbasis || !*cbasis) | (!rbasis || !*rbasis)) { |
376 |
sprintf(SDerrorDetail, "Missing column/row basis for BSDF '%s'", |
377 |
sd->name); |
378 |
return RC_FORMERR; |
379 |
} |
380 |
/* allocate BSDF component */ |
381 |
sdata = ezxml_txt(ezxml_child(wdb, "WavelengthDataDirection")); |
382 |
if (!strcasecmp(sdata, "Transmission Front")) { |
383 |
if (sd->tf != NULL) |
384 |
SDfreeSpectralDF(sd->tf); |
385 |
if ((sd->tf = SDnewSpectralDF(1)) == NULL) |
386 |
return RC_MEMERR; |
387 |
df = sd->tf; |
388 |
} else if (!strcasecmp(sdata, "Reflection Front")) { |
389 |
if (sd->rf != NULL) |
390 |
SDfreeSpectralDF(sd->rf); |
391 |
if ((sd->rf = SDnewSpectralDF(1)) == NULL) |
392 |
return RC_MEMERR; |
393 |
df = sd->rf; |
394 |
} else if (!strcasecmp(sdata, "Reflection Back")) { |
395 |
if (sd->rb != NULL) |
396 |
SDfreeSpectralDF(sd->rb); |
397 |
if ((sd->rb = SDnewSpectralDF(1)) == NULL) |
398 |
return RC_MEMERR; |
399 |
df = sd->rb; |
400 |
} else |
401 |
return RC_FAIL; |
402 |
/* get angle bases */ |
403 |
sdata = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis")); |
404 |
if (!sdata || !*sdata) { |
405 |
sprintf(SDerrorDetail, "Missing column basis for BSDF '%s'", |
406 |
sd->name); |
407 |
return RC_FORMERR; |
408 |
} |
409 |
for (inbi = nabases; inbi--; ) |
410 |
if (!strcasecmp(cbasis, abase_list[inbi].name)) |
411 |
break; |
412 |
if (inbi < 0) { |
413 |
sprintf(SDerrorDetail, "Undefined ColumnAngleBasis '%s'", |
414 |
cbasis); |
415 |
return RC_FORMERR; |
416 |
} |
417 |
sdata = ezxml_txt(ezxml_child(wdb,"RowAngleBasis")); |
418 |
if (!sdata || !*sdata) { |
419 |
sprintf(SDerrorDetail, "Missing row basis for BSDF '%s'", |
420 |
sd->name); |
421 |
return RC_FORMERR; |
422 |
} |
423 |
for (outbi = nabases; outbi--; ) |
424 |
if (!strcasecmp(rbasis, abase_list[outbi].name)) |
425 |
break; |
426 |
if (outbi < 0) { |
427 |
sprintf(SDerrorDetail, "Undefined RowAngleBasis '%s'", cbasis); |
428 |
return RC_FORMERR; |
429 |
} |
430 |
/* allocate BSDF matrix */ |
431 |
dp = SDnewMatrix(abase_list[inbi].nangles, abase_list[outbi].nangles); |
432 |
if (dp == NULL) |
433 |
return RC_MEMERR; |
434 |
dp->ib_priv = (void *)&abase_list[inbi]; |
435 |
dp->ob_priv = (void *)&abase_list[outbi]; |
436 |
if (df == sd->tf) { |
437 |
dp->ib_vec = ab_getvecR; |
438 |
dp->ib_ndx = ab_getndxR; |
439 |
dp->ob_vec = ab_getvec; |
440 |
dp->ob_ndx = ab_getndx; |
441 |
} else if (df == sd->rf) { |
442 |
dp->ib_vec = ab_getvec; |
443 |
dp->ib_ndx = ab_getndx; |
444 |
dp->ob_vec = ab_getvec; |
445 |
dp->ob_ndx = ab_getndx; |
446 |
} else /* df == sd->rb */ { |
447 |
dp->ib_vec = ab_getvecR; |
448 |
dp->ib_ndx = ab_getndxR; |
449 |
dp->ob_vec = ab_getvecR; |
450 |
dp->ob_ndx = ab_getndxR; |
451 |
} |
452 |
dp->ib_ohm = ab_getohm; |
453 |
dp->ob_ohm = ab_getohm; |
454 |
df->comp[0].cspec[0] = c_dfcolor; /* XXX monochrome for now */ |
455 |
df->comp[0].dist = dp; |
456 |
df->comp[0].func = &SDhandleMtx; |
457 |
/* read BSDF data */ |
458 |
sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData")); |
459 |
if (!sdata || !*sdata) { |
460 |
sprintf(SDerrorDetail, "Missing BSDF ScatteringData in '%s'", |
461 |
sd->name); |
462 |
return RC_FORMERR; |
463 |
} |
464 |
for (i = 0; i < dp->ninc*dp->nout; i++) { |
465 |
char *sdnext = fskip(sdata); |
466 |
if (sdnext == NULL) { |
467 |
sprintf(SDerrorDetail, |
468 |
"Bad/missing BSDF ScatteringData in '%s'", |
469 |
sd->name); |
470 |
return RC_FORMERR; |
471 |
} |
472 |
while (*sdnext && isspace(*sdnext)) |
473 |
sdnext++; |
474 |
if (*sdnext == ',') sdnext++; |
475 |
if (rowinc) { |
476 |
int r = i/dp->nout; |
477 |
int c = i - c*dp->nout; |
478 |
mBSDF_value(dp,r,c) = atof(sdata); |
479 |
} else |
480 |
dp->bsdf[i] = atof(sdata); |
481 |
sdata = sdnext; |
482 |
} |
483 |
return get_extrema(df); |
484 |
} |
485 |
|
486 |
/* Subtract minimum (diffuse) scattering amount from BSDF */ |
487 |
static double |
488 |
subtract_min(SDMat *sm) |
489 |
{ |
490 |
float minv = sm->bsdf[0]; |
491 |
int n = sm->ninc*sm->nout; |
492 |
int i; |
493 |
|
494 |
for (i = n; --i; ) |
495 |
if (sm->bsdf[i] < minv) |
496 |
minv = sm->bsdf[i]; |
497 |
for (i = n; i--; ) |
498 |
sm->bsdf[i] -= minv; |
499 |
|
500 |
return minv*M_PI; /* be sure to include multiplier */ |
501 |
} |
502 |
|
503 |
/* Extract and separate diffuse portion of BSDF */ |
504 |
static void |
505 |
extract_diffuse(SDValue *dv, SDSpectralDF *df) |
506 |
{ |
507 |
int n; |
508 |
|
509 |
if (df == NULL || df->ncomp <= 0) { |
510 |
dv->spec = c_dfcolor; |
511 |
dv->cieY = .0; |
512 |
return; |
513 |
} |
514 |
dv->spec = df->comp[0].cspec[0]; |
515 |
dv->cieY = subtract_min((SDMat *)df->comp[0].dist); |
516 |
/* in case of multiple components */ |
517 |
for (n = df->ncomp; --n; ) { |
518 |
double ymin = subtract_min((SDMat *)df->comp[n].dist); |
519 |
c_cmix(&dv->spec, dv->cieY, &dv->spec, ymin, &df->comp[n].cspec[0]); |
520 |
dv->cieY += ymin; |
521 |
} |
522 |
df->maxHemi -= dv->cieY; /* correct minimum hemispherical */ |
523 |
dv->spec.clock++; /* make sure everything is set */ |
524 |
c_ccvt(&dv->spec, C_CSXY+C_CSSPEC); |
525 |
} |
526 |
|
527 |
/* Load a BSDF matrix from an open XML file */ |
528 |
SDError |
529 |
SDloadMtx(SDData *sd, ezxml_t fl) |
530 |
{ |
531 |
ezxml_t wtl, wld, wdb; |
532 |
int rowIn; |
533 |
struct BSDF_data *dp; |
534 |
char *txt; |
535 |
int rval; |
536 |
|
537 |
if (strcmp(ezxml_name(fl), "WindowElement")) { |
538 |
sprintf(SDerrorDetail, |
539 |
"BSDF \"%s\": top level node not 'WindowElement'", |
540 |
sd->name); |
541 |
return SDEformat; |
542 |
} |
543 |
wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer"); |
544 |
txt = ezxml_txt(ezxml_child(ezxml_child(wtl, |
545 |
"DataDefinition"), "IncidentDataStructure")); |
546 |
if (!strcasecmp(txt, "Rows")) |
547 |
rowIn = 1; |
548 |
else if (!strcasecmp(txt, "Columns")) |
549 |
rowIn = 0; |
550 |
else { |
551 |
sprintf(SDerrorDetail, |
552 |
"BSDF \"%s\": unsupported IncidentDataStructure", |
553 |
sd->name); |
554 |
return SDEsupport; |
555 |
} |
556 |
/* get angle basis */ |
557 |
rval = load_angle_basis(ezxml_child(ezxml_child(wtl, |
558 |
"DataDefinition"), "AngleBasis")); |
559 |
if (rval < 0) |
560 |
goto err_return; |
561 |
/* load BSDF components */ |
562 |
for (wld = ezxml_child(wtl, "WavelengthData"); |
563 |
wld != NULL; wld = wld->next) { |
564 |
if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")), |
565 |
"Visible")) |
566 |
continue; /* just visible for now */ |
567 |
for (wdb = ezxml_child(wld, "WavelengthDataBlock"); |
568 |
wdb != NULL; wdb = wdb->next) |
569 |
if ((rval = load_bsdf_data(sd, wdb, rowIn)) < 0) |
570 |
goto err_return; |
571 |
} |
572 |
/* separate diffuse components */ |
573 |
extract_diffuse(&sd->rLambFront, sd->rf); |
574 |
extract_diffuse(&sd->rLambBack, sd->rb); |
575 |
extract_diffuse(&sd->tLamb, sd->tf); |
576 |
/* return success */ |
577 |
return SDEnone; |
578 |
err_return: /* jump here on failure */ |
579 |
if (sd->rf != NULL) { |
580 |
SDfreeSpectralDF(sd->rf); |
581 |
sd->rf = NULL; |
582 |
} |
583 |
if (sd->rb != NULL) { |
584 |
SDfreeSpectralDF(sd->rb); |
585 |
sd->rb = NULL; |
586 |
} |
587 |
if (sd->tf != NULL) { |
588 |
SDfreeSpectralDF(sd->tf); |
589 |
sd->tf = NULL; |
590 |
} |
591 |
return convert_errcode(rval); |
592 |
} |
593 |
|
594 |
/* Get Matrix BSDF value */ |
595 |
static int |
596 |
SDgetMtxBSDF(float coef[SDmaxCh], const FVECT outVec, |
597 |
const FVECT inVec, const void *dist) |
598 |
{ |
599 |
const SDMat *dp = (const SDMat *)dist; |
600 |
int i_ndx, o_ndx; |
601 |
/* get angle indices */ |
602 |
i_ndx = mBSDF_incndx(dp, inVec); |
603 |
o_ndx = mBSDF_outndx(dp, outVec); |
604 |
/* try reciprocity if necessary */ |
605 |
if ((i_ndx < 0) & (o_ndx < 0)) { |
606 |
i_ndx = mBSDF_incndx(dp, outVec); |
607 |
o_ndx = mBSDF_outndx(dp, inVec); |
608 |
} |
609 |
if ((i_ndx < 0) | (o_ndx < 0)) |
610 |
return 0; /* nothing from this component */ |
611 |
coef[0] = mBSDF_value(dp, i_ndx, o_ndx); |
612 |
return 1; /* XXX monochrome for now */ |
613 |
} |
614 |
|
615 |
/* Query solid angle for vector */ |
616 |
static SDError |
617 |
SDqueryMtxProjSA(double *psa, const FVECT vec, int qflags, const void *dist) |
618 |
{ |
619 |
const SDMat *dp = (const SDMat *)dist; |
620 |
|
621 |
if (!(qflags & SDqueryInc+SDqueryOut)) |
622 |
return SDEargument; |
623 |
if (qflags & SDqueryInc) { |
624 |
double inc_psa = mBSDF_incohm(dp, mBSDF_incndx(dp, vec)); |
625 |
if (inc_psa < .0) |
626 |
return SDEinternal; |
627 |
switch (qflags & SDqueryMin+SDqueryMax) { |
628 |
case SDqueryMax: |
629 |
if (inc_psa > psa[0]) |
630 |
psa[0] = inc_psa; |
631 |
break; |
632 |
case SDqueryMin+SDqueryMax: |
633 |
if (inc_psa > psa[1]) |
634 |
psa[1] = inc_psa; |
635 |
/* fall through */ |
636 |
case SDqueryMin: |
637 |
if (inc_psa < psa[0]) |
638 |
psa[0] = inc_psa; |
639 |
break; |
640 |
case 0: |
641 |
psa[0] = inc_psa; |
642 |
break; |
643 |
} |
644 |
} |
645 |
if (qflags & SDqueryOut) { |
646 |
double out_psa = mBSDF_outohm(dp, mBSDF_outndx(dp, vec)); |
647 |
if (out_psa < .0) |
648 |
return SDEinternal; |
649 |
switch (qflags & SDqueryMin+SDqueryMax) { |
650 |
case SDqueryMax: |
651 |
if (out_psa > psa[0]) |
652 |
psa[0] = out_psa; |
653 |
break; |
654 |
case SDqueryMin+SDqueryMax: |
655 |
if (out_psa > psa[1]) |
656 |
psa[1] = out_psa; |
657 |
/* fall through */ |
658 |
case SDqueryMin: |
659 |
if (out_psa < psa[0]) |
660 |
psa[0] = out_psa; |
661 |
break; |
662 |
case 0: |
663 |
psa[(qflags&SDqueryInc)!=0] = out_psa; |
664 |
break; |
665 |
} |
666 |
} |
667 |
return SDEnone; |
668 |
} |
669 |
|
670 |
/* Compute new cumulative distribution from BSDF */ |
671 |
static int |
672 |
make_cdist(SDMatCDst *cd, const FVECT inVec, SDMat *dp, int rev) |
673 |
{ |
674 |
const unsigned maxval = ~0; |
675 |
double *cmtab, scale; |
676 |
int o; |
677 |
|
678 |
cmtab = (double *)malloc((cd->calen+1)*sizeof(double)); |
679 |
if (cmtab == NULL) |
680 |
return 0; |
681 |
cmtab[0] = .0; |
682 |
for (o = 0; o < cd->calen; o++) { |
683 |
if (rev) |
684 |
cmtab[o+1] = mBSDF_value(dp, o, cd->indx) * |
685 |
(*dp->ib_ohm)(o, dp->ib_priv); |
686 |
else |
687 |
cmtab[o+1] = mBSDF_value(dp, cd->indx, o) * |
688 |
(*dp->ob_ohm)(o, dp->ob_priv); |
689 |
cmtab[o+1] += cmtab[o]; |
690 |
} |
691 |
cd->cTotal = cmtab[cd->calen]; |
692 |
scale = (double)maxval / cd->cTotal; |
693 |
cd->carr[0] = 0; |
694 |
for (o = 1; o < cd->calen; o++) |
695 |
cd->carr[o] = scale*cmtab[o] + .5; |
696 |
cd->carr[cd->calen] = maxval; |
697 |
free(cmtab); |
698 |
return 1; |
699 |
} |
700 |
|
701 |
/* Get cumulative distribution for matrix BSDF */ |
702 |
static const SDCDst * |
703 |
SDgetMtxCDist(const FVECT inVec, SDComponent *sdc) |
704 |
{ |
705 |
SDMat *dp = (SDMat *)sdc->dist; |
706 |
int reverse; |
707 |
SDMatCDst myCD; |
708 |
SDMatCDst *cd, *cdlast; |
709 |
|
710 |
if (dp == NULL) |
711 |
return NULL; |
712 |
memset(&myCD, 0, sizeof(myCD)); |
713 |
myCD.indx = mBSDF_incndx(dp, inVec); |
714 |
if (myCD.indx >= 0) { |
715 |
myCD.ob_priv = dp->ob_priv; |
716 |
myCD.ob_vec = dp->ob_vec; |
717 |
myCD.calen = dp->nout; |
718 |
reverse = 0; |
719 |
} else { /* try reciprocity */ |
720 |
myCD.indx = mBSDF_outndx(dp, inVec); |
721 |
if (myCD.indx < 0) |
722 |
return NULL; |
723 |
myCD.ob_priv = dp->ib_priv; |
724 |
myCD.ob_vec = dp->ib_vec; |
725 |
myCD.calen = dp->ninc; |
726 |
reverse = 1; |
727 |
} |
728 |
cdlast = NULL; /* check for it in cache list */ |
729 |
for (cd = (SDMatCDst *)sdc->cdList; |
730 |
cd != NULL; cd = (SDMatCDst *)cd->next) { |
731 |
if (cd->indx == myCD.indx && (cd->calen == myCD.calen) & |
732 |
(cd->ob_priv == myCD.ob_priv) & |
733 |
(cd->ob_vec == myCD.ob_vec)) |
734 |
break; |
735 |
cdlast = cd; |
736 |
} |
737 |
if (cd == NULL) { /* need to allocate new entry */ |
738 |
cd = (SDMatCDst *)malloc(sizeof(SDMatCDst) + |
739 |
myCD.calen*sizeof(myCD.carr[0])); |
740 |
if (cd == NULL) |
741 |
return NULL; |
742 |
*cd = myCD; /* compute cumulative distribution */ |
743 |
if (!make_cdist(cd, inVec, dp, reverse)) { |
744 |
free(cd); |
745 |
return NULL; |
746 |
} |
747 |
cdlast = cd; |
748 |
} |
749 |
if (cdlast != NULL) { /* move entry to head of cache list */ |
750 |
cdlast->next = cd->next; |
751 |
cd->next = sdc->cdList; |
752 |
sdc->cdList = (SDCDst *)cd; |
753 |
} |
754 |
return (SDCDst *)cd; /* ready to go */ |
755 |
} |
756 |
|
757 |
/* Sample cumulative distribution */ |
758 |
static SDError |
759 |
SDsampMtxCDist(FVECT outVec, double randX, const SDCDst *cdp) |
760 |
{ |
761 |
const unsigned maxval = ~0; |
762 |
const SDMatCDst *mcd = (const SDMatCDst *)cdp; |
763 |
const unsigned target = randX*maxval; |
764 |
int i, iupper, ilower; |
765 |
/* binary search to find index */ |
766 |
ilower = 0; iupper = mcd->calen; |
767 |
while ((i = (iupper + ilower) >> 1) != ilower) |
768 |
if ((long)target >= (long)mcd->carr[i]) |
769 |
ilower = i; |
770 |
else |
771 |
iupper = i; |
772 |
/* localize random position */ |
773 |
randX = (randX*maxval - mcd->carr[ilower]) / |
774 |
(double)(mcd->carr[iupper] - mcd->carr[ilower]); |
775 |
/* convert index to vector */ |
776 |
if ((*mcd->ob_vec)(outVec, i, randX, mcd->ob_priv)) |
777 |
return SDEnone; |
778 |
strcpy(SDerrorDetail, "BSDF sampling fault"); |
779 |
return SDEinternal; |
780 |
} |
781 |
|
782 |
/* Fixed resolution BSDF methods */ |
783 |
SDFunc SDhandleMtx = { |
784 |
&SDgetMtxBSDF, |
785 |
&SDqueryMtxProjSA, |
786 |
&SDgetMtxCDist, |
787 |
&SDsampMtxCDist, |
788 |
&SDfreeMatrix, |
789 |
}; |