| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: bsdf_t.c,v 3.11 2011/04/28 17:46:25 greg Exp $"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* bsdf_t.c |
| 6 |
* |
| 7 |
* Definitions for variable-resolution BSDF trees |
| 8 |
* |
| 9 |
* Created by Greg Ward on 2/2/11. |
| 10 |
* |
| 11 |
*/ |
| 12 |
|
| 13 |
#include "rtio.h" |
| 14 |
#include <stdlib.h> |
| 15 |
#include <math.h> |
| 16 |
#include <ctype.h> |
| 17 |
#include "ezxml.h" |
| 18 |
#include "bsdf.h" |
| 19 |
#include "bsdf_t.h" |
| 20 |
#include "hilbert.h" |
| 21 |
|
| 22 |
/* Callback function type for SDtraverseTre() */ |
| 23 |
typedef int SDtreCallback(float val, const double *cmin, |
| 24 |
double csiz, void *cptr); |
| 25 |
|
| 26 |
/* reference width maximum (1.0) */ |
| 27 |
static const unsigned iwbits = sizeof(unsigned)*4; |
| 28 |
static const unsigned iwmax = (1<<(sizeof(unsigned)*4))-1; |
| 29 |
/* maximum cumulative value */ |
| 30 |
static const unsigned cumlmax = ~0; |
| 31 |
|
| 32 |
/* Struct used for our distribution-building callback */ |
| 33 |
typedef struct { |
| 34 |
int nic; /* number of input coordinates */ |
| 35 |
unsigned alen; /* current array length */ |
| 36 |
unsigned nall; /* number of allocated entries */ |
| 37 |
unsigned wmin; /* minimum square size so far */ |
| 38 |
unsigned wmax; /* maximum square size */ |
| 39 |
struct outdir_s { |
| 40 |
unsigned hent; /* entering Hilbert index */ |
| 41 |
int wid; /* this square size */ |
| 42 |
float bsdf; /* BSDF for this square */ |
| 43 |
} *darr; /* output direction array */ |
| 44 |
} SDdistScaffold; |
| 45 |
|
| 46 |
/* Allocate a new scattering distribution node */ |
| 47 |
static SDNode * |
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SDnewNode(int nd, int lg) |
| 49 |
{ |
| 50 |
SDNode *st; |
| 51 |
|
| 52 |
if (nd <= 0) { |
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strcpy(SDerrorDetail, "Zero dimension BSDF node request"); |
| 54 |
return NULL; |
| 55 |
} |
| 56 |
if (nd > SD_MAXDIM) { |
| 57 |
sprintf(SDerrorDetail, "Illegal BSDF dimension (%d > %d)", |
| 58 |
nd, SD_MAXDIM); |
| 59 |
return NULL; |
| 60 |
} |
| 61 |
if (lg < 0) { |
| 62 |
st = (SDNode *)malloc(sizeof(SDNode) + |
| 63 |
sizeof(st->u.t[0])*((1<<nd) - 1)); |
| 64 |
if (st == NULL) { |
| 65 |
sprintf(SDerrorDetail, |
| 66 |
"Cannot allocate %d branch BSDF tree", 1<<nd); |
| 67 |
return NULL; |
| 68 |
} |
| 69 |
memset(st->u.t, 0, sizeof(st->u.t[0])<<nd); |
| 70 |
} else { |
| 71 |
st = (SDNode *)malloc(sizeof(SDNode) + |
| 72 |
sizeof(st->u.v[0])*((1 << nd*lg) - 1)); |
| 73 |
if (st == NULL) { |
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sprintf(SDerrorDetail, |
| 75 |
"Cannot allocate %d BSDF leaves", 1 << nd*lg); |
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return NULL; |
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} |
| 78 |
} |
| 79 |
st->ndim = nd; |
| 80 |
st->log2GR = lg; |
| 81 |
return st; |
| 82 |
} |
| 83 |
|
| 84 |
/* Free an SD tree */ |
| 85 |
static void |
| 86 |
SDfreeTre(SDNode *st) |
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{ |
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int n; |
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|
| 90 |
if (st == NULL) |
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return; |
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for (n = (st->log2GR < 0) << st->ndim; n--; ) |
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SDfreeTre(st->u.t[n]); |
| 94 |
free((void *)st); |
| 95 |
} |
| 96 |
|
| 97 |
/* Free a variable-resolution BSDF */ |
| 98 |
static void |
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SDFreeBTre(void *p) |
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{ |
| 101 |
SDTre *sdt = (SDTre *)p; |
| 102 |
|
| 103 |
if (sdt == NULL) |
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return; |
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SDfreeTre(sdt->st); |
| 106 |
free(sdt); |
| 107 |
} |
| 108 |
|
| 109 |
/* Fill branch's worth of grid values from subtree */ |
| 110 |
static void |
| 111 |
fill_grid_branch(float *dptr, const float *sptr, int nd, int shft) |
| 112 |
{ |
| 113 |
unsigned n = 1 << (shft-1); |
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|
| 115 |
if (!--nd) { /* end on the line */ |
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memcpy(dptr, sptr, sizeof(*dptr)*n); |
| 117 |
return; |
| 118 |
} |
| 119 |
while (n--) /* recurse on each slice */ |
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fill_grid_branch(dptr + (n << shft*nd), |
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sptr + (n << (shft-1)*nd), nd, shft); |
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} |
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|
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/* Get pointer at appropriate offset for the given branch */ |
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static float * |
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grid_branch_start(SDNode *st, int n) |
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{ |
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unsigned skipsiz = 1 << st->log2GR; |
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float *vptr = st->u.v; |
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int i; |
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|
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for (i = 0; i < st->ndim; skipsiz <<= st->log2GR) |
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if (1<<i++ & n) |
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vptr += skipsiz >> 1; |
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return vptr; |
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} |
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|
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/* Simplify (consolidate) a tree by flattening uniform depth regions */ |
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static SDNode * |
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SDsimplifyTre(SDNode *st) |
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{ |
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int match, n; |
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|
| 144 |
if (st == NULL) /* check for invalid tree */ |
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return NULL; |
| 146 |
if (st->log2GR >= 0) /* grid just returns unaltered */ |
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return st; |
| 148 |
match = 1; /* check if grids below match */ |
| 149 |
for (n = 0; n < 1<<st->ndim; n++) { |
| 150 |
if ((st->u.t[n] = SDsimplifyTre(st->u.t[n])) == NULL) |
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return NULL; /* propogate error up call stack */ |
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match &= (st->u.t[n]->log2GR == st->u.t[0]->log2GR); |
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} |
| 154 |
if (match && (match = st->u.t[0]->log2GR) >= 0) { |
| 155 |
SDNode *stn = SDnewNode(st->ndim, match + 1); |
| 156 |
if (stn == NULL) /* out of memory? */ |
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return st; |
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/* transfer values to new grid */ |
| 159 |
for (n = 1 << st->ndim; n--; ) |
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fill_grid_branch(grid_branch_start(stn, n), |
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st->u.t[n]->u.v, stn->ndim, stn->log2GR); |
| 162 |
SDfreeTre(st); /* free old tree */ |
| 163 |
st = stn; /* return new one */ |
| 164 |
} |
| 165 |
return st; |
| 166 |
} |
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|
| 168 |
/* Find smallest leaf in tree */ |
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static double |
| 170 |
SDsmallestLeaf(const SDNode *st) |
| 171 |
{ |
| 172 |
if (st->log2GR < 0) { /* tree branches */ |
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double lmin = 1.; |
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int n; |
| 175 |
for (n = 1<<st->ndim; n--; ) { |
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double lsiz = SDsmallestLeaf(st->u.t[n]); |
| 177 |
if (lsiz < lmin) |
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lmin = lsiz; |
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} |
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return .5*lmin; |
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} |
| 182 |
/* leaf grid width */ |
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return 1. / (double)(1 << st->log2GR); |
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} |
| 185 |
|
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/* Add up N-dimensional hypercube array values over the given box */ |
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static double |
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SDiterSum(const float *va, int nd, int shft, const int *imin, const int *imax) |
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{ |
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const unsigned skipsiz = 1 << --nd*shft; |
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double sum = .0; |
| 192 |
int i; |
| 193 |
|
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if (skipsiz == 1) |
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for (i = *imin; i < *imax; i++) |
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sum += va[i]; |
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else |
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for (i = *imin; i < *imax; i++) |
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sum += SDiterSum(va + i*skipsiz, nd, shft, imin+1, imax+1); |
| 200 |
return sum; |
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} |
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|
| 203 |
/* Average BSDF leaves over an orthotope defined by the unit hypercube */ |
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static double |
| 205 |
SDavgTreBox(const SDNode *st, const double *bmin, const double *bmax) |
| 206 |
{ |
| 207 |
int imin[SD_MAXDIM], imax[SD_MAXDIM]; |
| 208 |
unsigned n; |
| 209 |
int i; |
| 210 |
|
| 211 |
if (!st) |
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return .0; |
| 213 |
/* check box limits */ |
| 214 |
for (i = st->ndim; i--; ) { |
| 215 |
if (bmin[i] >= 1.) |
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return .0; |
| 217 |
if (bmax[i] <= .0) |
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return .0; |
| 219 |
if (bmin[i] >= bmax[i]) |
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return .0; |
| 221 |
} |
| 222 |
if (st->log2GR < 0) { /* iterate on subtree */ |
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double sum = .0, wsum = 1e-20; |
| 224 |
double sbmin[SD_MAXDIM], sbmax[SD_MAXDIM], w; |
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|
| 226 |
for (n = 1 << st->ndim; n--; ) { |
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w = 1.; |
| 228 |
for (i = st->ndim; i--; ) { |
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sbmin[i] = 2.*bmin[i]; |
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sbmax[i] = 2.*bmax[i]; |
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if (n & 1<<i) { |
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sbmin[i] -= 1.; |
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sbmax[i] -= 1.; |
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} |
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if (sbmin[i] < .0) sbmin[i] = .0; |
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if (sbmax[i] > 1.) sbmax[i] = 1.; |
| 237 |
w *= sbmax[i] - sbmin[i]; |
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} |
| 239 |
if (w > 1e-10) { |
| 240 |
sum += w * SDavgTreBox(st->u.t[n], sbmin, sbmax); |
| 241 |
wsum += w; |
| 242 |
} |
| 243 |
} |
| 244 |
return sum / wsum; |
| 245 |
} |
| 246 |
n = 1; /* iterate over leaves */ |
| 247 |
for (i = st->ndim; i--; ) { |
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imin[i] = (bmin[i] <= 0) ? 0 |
| 249 |
: (int)((1 << st->log2GR)*bmin[i]); |
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imax[i] = (bmax[i] >= 1.) ? (1 << st->log2GR) |
| 251 |
: (int)((1 << st->log2GR)*bmax[i] + .999999); |
| 252 |
n *= imax[i] - imin[i]; |
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} |
| 254 |
if (!n) |
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return .0; |
| 256 |
|
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return SDiterSum(st->u.v, st->ndim, st->log2GR, imin, imax) / (double)n; |
| 258 |
} |
| 259 |
|
| 260 |
/* Recursive call for SDtraverseTre() */ |
| 261 |
static int |
| 262 |
SDdotravTre(const SDNode *st, const double *pos, int cmask, |
| 263 |
SDtreCallback *cf, void *cptr, |
| 264 |
const double *cmin, double csiz) |
| 265 |
{ |
| 266 |
int rv, rval = 0; |
| 267 |
double bmin[SD_MAXDIM]; |
| 268 |
int i, n; |
| 269 |
/* in branches? */ |
| 270 |
if (st->log2GR < 0) { |
| 271 |
unsigned skipmask = 0; |
| 272 |
|
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csiz *= .5; |
| 274 |
for (i = st->ndim; i--; ) |
| 275 |
if (1<<i & cmask) |
| 276 |
if (pos[i] < cmin[i] + csiz) |
| 277 |
for (n = 1 << st->ndim; n--; ) |
| 278 |
if (n & 1<<i) |
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skipmask |= 1<<n; |
| 280 |
else |
| 281 |
for (n = 1 << st->ndim; n--; ) |
| 282 |
if (!(n & 1<<i)) |
| 283 |
skipmask |= 1<<n; |
| 284 |
for (n = 1 << st->ndim; n--; ) { |
| 285 |
if (1<<n & skipmask) |
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continue; |
| 287 |
for (i = st->ndim; i--; ) |
| 288 |
if (1<<i & n) |
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bmin[i] = cmin[i] + csiz; |
| 290 |
else |
| 291 |
bmin[i] = cmin[i]; |
| 292 |
|
| 293 |
rval += rv = SDdotravTre(st->u.t[n], pos, cmask, |
| 294 |
cf, cptr, bmin, csiz); |
| 295 |
if (rv < 0) |
| 296 |
return rv; |
| 297 |
} |
| 298 |
} else { /* else traverse leaves */ |
| 299 |
int clim[SD_MAXDIM][2]; |
| 300 |
int cpos[SD_MAXDIM]; |
| 301 |
|
| 302 |
if (st->log2GR == 0) /* short cut */ |
| 303 |
return (*cf)(st->u.v[0], cmin, csiz, cptr); |
| 304 |
|
| 305 |
csiz /= (double)(1 << st->log2GR); |
| 306 |
/* assign coord. ranges */ |
| 307 |
for (i = st->ndim; i--; ) |
| 308 |
if (1<<i & cmask) { |
| 309 |
clim[i][0] = (pos[i] - cmin[i])/csiz; |
| 310 |
/* check overflow from f.p. error */ |
| 311 |
clim[i][0] -= clim[i][0] >> st->log2GR; |
| 312 |
clim[i][1] = clim[i][0] + 1; |
| 313 |
} else { |
| 314 |
clim[i][0] = 0; |
| 315 |
clim[i][1] = 1 << st->log2GR; |
| 316 |
} |
| 317 |
/* fill in unused dimensions */ |
| 318 |
for (i = SD_MAXDIM; i-- > st->ndim; ) { |
| 319 |
clim[i][0] = 0; clim[i][1] = 1; |
| 320 |
} |
| 321 |
#if (SD_MAXDIM == 4) |
| 322 |
bmin[0] = cmin[0] + csiz*clim[0][0]; |
| 323 |
for (cpos[0] = clim[0][0]; cpos[0] < clim[0][1]; cpos[0]++) { |
| 324 |
bmin[1] = cmin[1] + csiz*clim[1][0]; |
| 325 |
for (cpos[1] = clim[1][0]; cpos[1] < clim[1][1]; cpos[1]++) { |
| 326 |
bmin[2] = cmin[2] + csiz*clim[2][0]; |
| 327 |
for (cpos[2] = clim[2][0]; cpos[2] < clim[2][1]; cpos[2]++) { |
| 328 |
bmin[3] = cmin[3] + csiz*(cpos[3] = clim[3][0]); |
| 329 |
n = cpos[0]; |
| 330 |
for (i = 1; i < st->ndim; i++) |
| 331 |
n = (n << st->log2GR) + cpos[i]; |
| 332 |
for ( ; cpos[3] < clim[3][1]; cpos[3]++) { |
| 333 |
rval += rv = (*cf)(st->u.v[n++], bmin, csiz, cptr); |
| 334 |
if (rv < 0) |
| 335 |
return rv; |
| 336 |
bmin[3] += csiz; |
| 337 |
} |
| 338 |
bmin[2] += csiz; |
| 339 |
} |
| 340 |
bmin[1] += csiz; |
| 341 |
} |
| 342 |
bmin[0] += csiz; |
| 343 |
} |
| 344 |
#else |
| 345 |
_!_ "broken code segment!" |
| 346 |
#endif |
| 347 |
} |
| 348 |
return rval; |
| 349 |
} |
| 350 |
|
| 351 |
/* Traverse a tree, visiting nodes in a slice that fits partial position */ |
| 352 |
static int |
| 353 |
SDtraverseTre(const SDNode *st, const double *pos, int cmask, |
| 354 |
SDtreCallback *cf, void *cptr) |
| 355 |
{ |
| 356 |
static double czero[SD_MAXDIM]; |
| 357 |
int i; |
| 358 |
/* check arguments */ |
| 359 |
if ((st == NULL) | (cf == NULL)) |
| 360 |
return -1; |
| 361 |
for (i = st->ndim; i--; ) |
| 362 |
if (1<<i & cmask && (pos[i] < 0) | (pos[i] >= 1.)) |
| 363 |
return -1; |
| 364 |
|
| 365 |
return SDdotravTre(st, pos, cmask, cf, cptr, czero, 1.); |
| 366 |
} |
| 367 |
|
| 368 |
/* Look up tree value at the given grid position */ |
| 369 |
static float |
| 370 |
SDlookupTre(const SDNode *st, const double *pos, double *hcube) |
| 371 |
{ |
| 372 |
double spos[SD_MAXDIM]; |
| 373 |
int i, n, t; |
| 374 |
/* initialize voxel return */ |
| 375 |
if (hcube) { |
| 376 |
hcube[i = st->ndim] = 1.; |
| 377 |
while (i--) |
| 378 |
hcube[i] = .0; |
| 379 |
} |
| 380 |
/* climb the tree */ |
| 381 |
while (st->log2GR < 0) { |
| 382 |
n = 0; /* move to appropriate branch */ |
| 383 |
if (hcube) hcube[st->ndim] *= .5; |
| 384 |
for (i = st->ndim; i--; ) { |
| 385 |
spos[i] = 2.*pos[i]; |
| 386 |
t = (spos[i] >= 1.); |
| 387 |
n |= t<<i; |
| 388 |
spos[i] -= (double)t; |
| 389 |
if (hcube) hcube[i] += (double)t * hcube[st->ndim]; |
| 390 |
} |
| 391 |
st = st->u.t[n]; /* avoids tail recursion */ |
| 392 |
pos = spos; |
| 393 |
} |
| 394 |
if (st->log2GR == 0) /* short cut */ |
| 395 |
return st->u.v[0]; |
| 396 |
n = t = 0; /* find grid array index */ |
| 397 |
for (i = st->ndim; i--; ) { |
| 398 |
n += (int)((1<<st->log2GR)*pos[i]) << t; |
| 399 |
t += st->log2GR; |
| 400 |
} |
| 401 |
if (hcube) { /* compute final hypercube */ |
| 402 |
hcube[st->ndim] /= (double)(1<<st->log2GR); |
| 403 |
for (i = st->ndim; i--; ) |
| 404 |
hcube[i] += floor((1<<st->log2GR)*pos[i])*hcube[st->ndim]; |
| 405 |
} |
| 406 |
return st->u.v[n]; /* no interpolation */ |
| 407 |
} |
| 408 |
|
| 409 |
/* Query BSDF value and sample hypercube for the given vectors */ |
| 410 |
static float |
| 411 |
SDqueryTre(const SDTre *sdt, const FVECT outVec, const FVECT inVec, double *hc) |
| 412 |
{ |
| 413 |
static const FVECT zvec = {.0, .0, 1.}; |
| 414 |
FVECT rOutVec; |
| 415 |
double gridPos[4]; |
| 416 |
|
| 417 |
switch (sdt->sidef) { /* whose side are you on? */ |
| 418 |
case SD_UFRONT: |
| 419 |
if ((outVec[2] < 0) | (inVec[2] < 0)) |
| 420 |
return -1.; |
| 421 |
break; |
| 422 |
case SD_UBACK: |
| 423 |
if ((outVec[2] > 0) | (inVec[2] > 0)) |
| 424 |
return -1.; |
| 425 |
break; |
| 426 |
case SD_XMIT: |
| 427 |
if ((outVec[2] > 0) == (inVec[2] > 0)) |
| 428 |
return -1.; |
| 429 |
break; |
| 430 |
default: |
| 431 |
return -1.; |
| 432 |
} |
| 433 |
/* convert vector coordinates */ |
| 434 |
if (sdt->st->ndim == 3) { |
| 435 |
spinvector(rOutVec, outVec, zvec, -atan2(inVec[1],inVec[0])); |
| 436 |
gridPos[0] = .5 - .5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]); |
| 437 |
SDdisk2square(gridPos+1, rOutVec[0], rOutVec[1]); |
| 438 |
} else if (sdt->st->ndim == 4) { |
| 439 |
SDdisk2square(gridPos, -inVec[0], -inVec[1]); |
| 440 |
SDdisk2square(gridPos+2, outVec[0], outVec[1]); |
| 441 |
} else |
| 442 |
return -1.; /* should be internal error */ |
| 443 |
|
| 444 |
return SDlookupTre(sdt->st, gridPos, hc); |
| 445 |
} |
| 446 |
|
| 447 |
/* Compute non-diffuse component for variable-resolution BSDF */ |
| 448 |
static int |
| 449 |
SDgetTreBSDF(float coef[SDmaxCh], const FVECT outVec, |
| 450 |
const FVECT inVec, SDComponent *sdc) |
| 451 |
{ |
| 452 |
/* check arguments */ |
| 453 |
if ((coef == NULL) | (outVec == NULL) | (inVec == NULL) | (sdc == NULL) |
| 454 |
|| sdc->dist == NULL) |
| 455 |
return 0; |
| 456 |
/* get nearest BSDF value */ |
| 457 |
coef[0] = SDqueryTre((SDTre *)sdc->dist, outVec, inVec, NULL); |
| 458 |
return (coef[0] >= 0); /* monochromatic for now */ |
| 459 |
} |
| 460 |
|
| 461 |
/* Callback to build cumulative distribution using SDtraverseTre() */ |
| 462 |
static int |
| 463 |
build_scaffold(float val, const double *cmin, double csiz, void *cptr) |
| 464 |
{ |
| 465 |
SDdistScaffold *sp = (SDdistScaffold *)cptr; |
| 466 |
int wid = csiz*(double)iwmax + .5; |
| 467 |
bitmask_t bmin[2], bmax[2]; |
| 468 |
|
| 469 |
cmin += sp->nic; /* skip to output coords */ |
| 470 |
if (wid < sp->wmin) /* new minimum width? */ |
| 471 |
sp->wmin = wid; |
| 472 |
if (wid > sp->wmax) /* new maximum? */ |
| 473 |
sp->wmax = wid; |
| 474 |
if (sp->alen >= sp->nall) { /* need more space? */ |
| 475 |
struct outdir_s *ndarr; |
| 476 |
sp->nall += 1024; |
| 477 |
ndarr = (struct outdir_s *)realloc(sp->darr, |
| 478 |
sizeof(struct outdir_s)*sp->nall); |
| 479 |
if (ndarr == NULL) { |
| 480 |
sprintf(SDerrorDetail, |
| 481 |
"Cannot grow scaffold to %u entries", sp->nall); |
| 482 |
return -1; /* abort build */ |
| 483 |
} |
| 484 |
sp->darr = ndarr; |
| 485 |
} |
| 486 |
/* find Hilbert entry index */ |
| 487 |
bmin[0] = cmin[0]*(double)iwmax + .5; |
| 488 |
bmin[1] = cmin[1]*(double)iwmax + .5; |
| 489 |
bmax[0] = bmin[0] + wid-1; |
| 490 |
bmax[1] = bmin[1] + wid-1; |
| 491 |
hilbert_box_vtx(2, sizeof(bitmask_t), iwbits, 1, bmin, bmax); |
| 492 |
sp->darr[sp->alen].hent = hilbert_c2i(2, iwbits, bmin); |
| 493 |
sp->darr[sp->alen].wid = wid; |
| 494 |
sp->darr[sp->alen].bsdf = val; |
| 495 |
sp->alen++; /* on to the next entry */ |
| 496 |
return 0; |
| 497 |
} |
| 498 |
|
| 499 |
/* Scaffold comparison function for qsort -- ascending Hilbert index */ |
| 500 |
static int |
| 501 |
sscmp(const void *p1, const void *p2) |
| 502 |
{ |
| 503 |
unsigned h1 = (*(const struct outdir_s *)p1).hent; |
| 504 |
unsigned h2 = (*(const struct outdir_s *)p2).hent; |
| 505 |
|
| 506 |
if (h1 > h2) |
| 507 |
return 1; |
| 508 |
if (h1 < h2) |
| 509 |
return -1; |
| 510 |
return 0; |
| 511 |
} |
| 512 |
|
| 513 |
/* Create a new cumulative distribution for the given input direction */ |
| 514 |
static SDTreCDst * |
| 515 |
make_cdist(const SDTre *sdt, const double *pos) |
| 516 |
{ |
| 517 |
SDdistScaffold myScaffold; |
| 518 |
SDTreCDst *cd; |
| 519 |
struct outdir_s *sp; |
| 520 |
double scale, cursum; |
| 521 |
int i; |
| 522 |
/* initialize scaffold */ |
| 523 |
myScaffold.wmin = iwmax; |
| 524 |
myScaffold.wmax = 0; |
| 525 |
myScaffold.nic = sdt->st->ndim - 2; |
| 526 |
myScaffold.alen = 0; |
| 527 |
myScaffold.nall = 512; |
| 528 |
myScaffold.darr = (struct outdir_s *)malloc(sizeof(struct outdir_s) * |
| 529 |
myScaffold.nall); |
| 530 |
if (myScaffold.darr == NULL) |
| 531 |
return NULL; |
| 532 |
/* grow the distribution */ |
| 533 |
if (SDtraverseTre(sdt->st, pos, (1<<myScaffold.nic)-1, |
| 534 |
&build_scaffold, &myScaffold) < 0) { |
| 535 |
free(myScaffold.darr); |
| 536 |
return NULL; |
| 537 |
} |
| 538 |
/* allocate result holder */ |
| 539 |
cd = (SDTreCDst *)malloc(sizeof(SDTreCDst) + |
| 540 |
sizeof(cd->carr[0])*myScaffold.alen); |
| 541 |
if (cd == NULL) { |
| 542 |
sprintf(SDerrorDetail, |
| 543 |
"Cannot allocate %u entry cumulative distribution", |
| 544 |
myScaffold.alen); |
| 545 |
free(myScaffold.darr); |
| 546 |
return NULL; |
| 547 |
} |
| 548 |
/* sort the distribution */ |
| 549 |
qsort(myScaffold.darr, cd->calen = myScaffold.alen, |
| 550 |
sizeof(struct outdir_s), &sscmp); |
| 551 |
|
| 552 |
/* record input range */ |
| 553 |
scale = myScaffold.wmin / (double)iwmax; |
| 554 |
for (i = myScaffold.nic; i--; ) { |
| 555 |
cd->clim[i][0] = floor(pos[i]/scale) * scale; |
| 556 |
cd->clim[i][1] = cd->clim[i][0] + scale; |
| 557 |
} |
| 558 |
cd->max_psa = myScaffold.wmax / (double)iwmax; |
| 559 |
cd->max_psa *= cd->max_psa * M_PI; |
| 560 |
cd->sidef = sdt->sidef; |
| 561 |
cd->cTotal = 1e-20; /* compute directional total */ |
| 562 |
sp = myScaffold.darr; |
| 563 |
for (i = myScaffold.alen; i--; sp++) |
| 564 |
cd->cTotal += sp->bsdf * (double)sp->wid * sp->wid; |
| 565 |
cursum = .0; /* go back and get cumulative values */ |
| 566 |
scale = (double)cumlmax / cd->cTotal; |
| 567 |
sp = myScaffold.darr; |
| 568 |
for (i = 0; i < cd->calen; i++, sp++) { |
| 569 |
cd->carr[i].hndx = sp->hent; |
| 570 |
cd->carr[i].cuml = scale*cursum + .5; |
| 571 |
cursum += sp->bsdf * (double)sp->wid * sp->wid; |
| 572 |
} |
| 573 |
cd->carr[i].hndx = ~0; /* make final entry */ |
| 574 |
cd->carr[i].cuml = cumlmax; |
| 575 |
cd->cTotal *= M_PI/(double)iwmax/iwmax; |
| 576 |
/* all done, clean up and return */ |
| 577 |
free(myScaffold.darr); |
| 578 |
return cd; |
| 579 |
} |
| 580 |
|
| 581 |
/* Find or allocate a cumulative distribution for the given incoming vector */ |
| 582 |
const SDCDst * |
| 583 |
SDgetTreCDist(const FVECT inVec, SDComponent *sdc) |
| 584 |
{ |
| 585 |
const SDTre *sdt; |
| 586 |
double inCoord[2]; |
| 587 |
int vflags; |
| 588 |
int i; |
| 589 |
SDTreCDst *cd, *cdlast; |
| 590 |
/* check arguments */ |
| 591 |
if ((inVec == NULL) | (sdc == NULL) || |
| 592 |
(sdt = (SDTre *)sdc->dist) == NULL) |
| 593 |
return NULL; |
| 594 |
if (sdt->st->ndim == 3) /* isotropic BSDF? */ |
| 595 |
inCoord[0] = .5 - .5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]); |
| 596 |
else if (sdt->st->ndim == 4) |
| 597 |
SDdisk2square(inCoord, -inVec[0], -inVec[1]); |
| 598 |
else |
| 599 |
return NULL; /* should be internal error */ |
| 600 |
cdlast = NULL; /* check for direction in cache list */ |
| 601 |
for (cd = (SDTreCDst *)sdc->cdList; cd != NULL; |
| 602 |
cdlast = cd, cd = (SDTreCDst *)cd->next) { |
| 603 |
for (i = sdt->st->ndim - 2; i--; ) |
| 604 |
if ((cd->clim[i][0] > inCoord[i]) | |
| 605 |
(inCoord[i] >= cd->clim[i][1])) |
| 606 |
break; |
| 607 |
if (i < 0) |
| 608 |
break; /* means we have a match */ |
| 609 |
} |
| 610 |
if (cd == NULL) /* need to create new entry? */ |
| 611 |
cdlast = cd = make_cdist(sdt, inCoord); |
| 612 |
if (cdlast != NULL) { /* move entry to head of cache list */ |
| 613 |
cdlast->next = cd->next; |
| 614 |
cd->next = sdc->cdList; |
| 615 |
sdc->cdList = (SDCDst *)cd; |
| 616 |
} |
| 617 |
return (SDCDst *)cd; /* ready to go */ |
| 618 |
} |
| 619 |
|
| 620 |
/* Query solid angle for vector(s) */ |
| 621 |
static SDError |
| 622 |
SDqueryTreProjSA(double *psa, const FVECT v1, const RREAL *v2, |
| 623 |
int qflags, SDComponent *sdc) |
| 624 |
{ |
| 625 |
double myPSA[2]; |
| 626 |
/* check arguments */ |
| 627 |
if ((psa == NULL) | (v1 == NULL) | (sdc == NULL) || |
| 628 |
sdc->dist == NULL) |
| 629 |
return SDEargument; |
| 630 |
/* get projected solid angle(s) */ |
| 631 |
if (v2 != NULL) { |
| 632 |
const SDTre *sdt = (SDTre *)sdc->dist; |
| 633 |
double hcube[SD_MAXDIM]; |
| 634 |
if (SDqueryTre(sdt, v1, v2, hcube) < 0) { |
| 635 |
strcpy(SDerrorDetail, "Bad call to SDqueryTreProjSA"); |
| 636 |
return SDEinternal; |
| 637 |
} |
| 638 |
myPSA[0] = hcube[sdt->st->ndim]; |
| 639 |
myPSA[1] = myPSA[0] *= myPSA[0] * M_PI; |
| 640 |
} else { |
| 641 |
const SDTreCDst *cd = (const SDTreCDst *)SDgetTreCDist(v1, sdc); |
| 642 |
if (cd == NULL) |
| 643 |
return SDEmemory; |
| 644 |
myPSA[0] = M_PI * (cd->clim[0][1] - cd->clim[0][0]) * |
| 645 |
(cd->clim[1][1] - cd->clim[1][0]); |
| 646 |
myPSA[1] = cd->max_psa; |
| 647 |
} |
| 648 |
switch (qflags) { /* record based on flag settings */ |
| 649 |
case SDqueryVal: |
| 650 |
*psa = myPSA[0]; |
| 651 |
break; |
| 652 |
case SDqueryMax: |
| 653 |
if (myPSA[1] > *psa) |
| 654 |
*psa = myPSA[1]; |
| 655 |
break; |
| 656 |
case SDqueryMin+SDqueryMax: |
| 657 |
if (myPSA[1] > psa[1]) |
| 658 |
psa[1] = myPSA[1]; |
| 659 |
/* fall through */ |
| 660 |
case SDqueryMin: |
| 661 |
if (myPSA[0] < psa[0]) |
| 662 |
psa[0] = myPSA[0]; |
| 663 |
break; |
| 664 |
} |
| 665 |
return SDEnone; |
| 666 |
} |
| 667 |
|
| 668 |
/* Sample cumulative distribution */ |
| 669 |
static SDError |
| 670 |
SDsampTreCDist(FVECT ioVec, double randX, const SDCDst *cdp) |
| 671 |
{ |
| 672 |
const unsigned nBitsC = 4*sizeof(bitmask_t); |
| 673 |
const unsigned nExtraBits = 8*(sizeof(bitmask_t)-sizeof(unsigned)); |
| 674 |
const SDTreCDst *cd = (const SDTreCDst *)cdp; |
| 675 |
const unsigned target = randX*cumlmax; |
| 676 |
bitmask_t hndx, hcoord[2]; |
| 677 |
double gpos[3]; |
| 678 |
int i, iupper, ilower; |
| 679 |
/* check arguments */ |
| 680 |
if ((ioVec == NULL) | (cd == NULL)) |
| 681 |
return SDEargument; |
| 682 |
if (ioVec[2] > 0) { |
| 683 |
if (!(cd->sidef & SD_UFRONT)) |
| 684 |
return SDEargument; |
| 685 |
} else if (!(cd->sidef & SD_UBACK)) |
| 686 |
return SDEargument; |
| 687 |
/* binary search to find position */ |
| 688 |
ilower = 0; iupper = cd->calen; |
| 689 |
while ((i = (iupper + ilower) >> 1) != ilower) |
| 690 |
if ((long)target >= (long)cd->carr[i].cuml) |
| 691 |
ilower = i; |
| 692 |
else |
| 693 |
iupper = i; |
| 694 |
/* localize random position */ |
| 695 |
randX = (randX*cumlmax - cd->carr[ilower].cuml) / |
| 696 |
(double)(cd->carr[iupper].cuml - cd->carr[ilower].cuml); |
| 697 |
/* index in longer Hilbert curve */ |
| 698 |
hndx = (randX*cd->carr[iupper].hndx + (1.-randX)*cd->carr[ilower].hndx) |
| 699 |
* (double)((bitmask_t)1 << nExtraBits); |
| 700 |
/* convert Hilbert index to vector */ |
| 701 |
hilbert_i2c(2, nBitsC, hndx, hcoord); |
| 702 |
for (i = 2; i--; ) |
| 703 |
gpos[i] = ((double)hcoord[i] + rand()*(1./(RAND_MAX+.5))) / |
| 704 |
(double)((bitmask_t)1 << nBitsC); |
| 705 |
SDsquare2disk(gpos, gpos[0], gpos[1]); |
| 706 |
/* compute Z-coordinate */ |
| 707 |
gpos[2] = 1. - gpos[0]*gpos[0] - gpos[1]*gpos[1]; |
| 708 |
if (gpos[2] > 0) /* paranoia, I hope */ |
| 709 |
gpos[2] = sqrt(gpos[2]); |
| 710 |
/* emit from back? */ |
| 711 |
if (ioVec[2] > 0 ^ cd->sidef != SD_XMIT) |
| 712 |
gpos[2] = -gpos[2]; |
| 713 |
VCOPY(ioVec, gpos); |
| 714 |
return SDEnone; |
| 715 |
} |
| 716 |
|
| 717 |
/* Advance pointer to the next non-white character in the string (or nul) */ |
| 718 |
static int |
| 719 |
next_token(char **spp) |
| 720 |
{ |
| 721 |
while (isspace(**spp)) |
| 722 |
++*spp; |
| 723 |
return **spp; |
| 724 |
} |
| 725 |
|
| 726 |
/* Advance pointer past matching token (or any token if c==0) */ |
| 727 |
#define eat_token(spp,c) (next_token(spp)==(c) ^ !(c) ? *(*(spp))++ : 0) |
| 728 |
|
| 729 |
/* Count words from this point in string to '}' */ |
| 730 |
static int |
| 731 |
count_values(char *cp) |
| 732 |
{ |
| 733 |
int n = 0; |
| 734 |
|
| 735 |
while (next_token(&cp) != '}' && *cp) { |
| 736 |
while (!isspace(*cp) & (*cp != ',') & (*cp != '}')) |
| 737 |
if (!*++cp) |
| 738 |
break; |
| 739 |
++n; |
| 740 |
eat_token(&cp, ','); |
| 741 |
} |
| 742 |
return n; |
| 743 |
} |
| 744 |
|
| 745 |
/* Load an array of real numbers, returning total */ |
| 746 |
static int |
| 747 |
load_values(char **spp, float *va, int n) |
| 748 |
{ |
| 749 |
float *v = va; |
| 750 |
char *svnext; |
| 751 |
|
| 752 |
while (n-- > 0 && (svnext = fskip(*spp)) != NULL) { |
| 753 |
*v++ = atof(*spp); |
| 754 |
*spp = svnext; |
| 755 |
eat_token(spp, ','); |
| 756 |
} |
| 757 |
return v - va; |
| 758 |
} |
| 759 |
|
| 760 |
/* Load BSDF tree data */ |
| 761 |
static SDNode * |
| 762 |
load_tree_data(char **spp, int nd) |
| 763 |
{ |
| 764 |
SDNode *st; |
| 765 |
int n; |
| 766 |
|
| 767 |
if (!eat_token(spp, '{')) { |
| 768 |
strcpy(SDerrorDetail, "Missing '{' in tensor tree"); |
| 769 |
return NULL; |
| 770 |
} |
| 771 |
if (next_token(spp) == '{') { /* tree branches */ |
| 772 |
st = SDnewNode(nd, -1); |
| 773 |
if (st == NULL) |
| 774 |
return NULL; |
| 775 |
for (n = 0; n < 1<<nd; n++) |
| 776 |
if ((st->u.t[n] = load_tree_data(spp, nd)) == NULL) { |
| 777 |
SDfreeTre(st); |
| 778 |
return NULL; |
| 779 |
} |
| 780 |
} else { /* else load value grid */ |
| 781 |
int bsiz; |
| 782 |
n = count_values(*spp); /* see how big the grid is */ |
| 783 |
for (bsiz = 0; bsiz < 8*sizeof(size_t)-1; bsiz += nd) |
| 784 |
if (1<<bsiz == n) |
| 785 |
break; |
| 786 |
if (bsiz >= 8*sizeof(size_t)) { |
| 787 |
strcpy(SDerrorDetail, "Illegal value count in tensor tree"); |
| 788 |
return NULL; |
| 789 |
} |
| 790 |
st = SDnewNode(nd, bsiz/nd); |
| 791 |
if (st == NULL) |
| 792 |
return NULL; |
| 793 |
if (load_values(spp, st->u.v, n) != n) { |
| 794 |
strcpy(SDerrorDetail, "Real format error in tensor tree"); |
| 795 |
SDfreeTre(st); |
| 796 |
return NULL; |
| 797 |
} |
| 798 |
} |
| 799 |
if (!eat_token(spp, '}')) { |
| 800 |
strcpy(SDerrorDetail, "Missing '}' in tensor tree"); |
| 801 |
SDfreeTre(st); |
| 802 |
return NULL; |
| 803 |
} |
| 804 |
eat_token(spp, ','); |
| 805 |
return st; |
| 806 |
} |
| 807 |
|
| 808 |
/* Compute min. proj. solid angle and max. direct hemispherical scattering */ |
| 809 |
static SDError |
| 810 |
get_extrema(SDSpectralDF *df) |
| 811 |
{ |
| 812 |
SDNode *st = (*(SDTre *)df->comp[0].dist).st; |
| 813 |
double stepWidth, dhemi, bmin[4], bmax[4]; |
| 814 |
|
| 815 |
stepWidth = SDsmallestLeaf(st); |
| 816 |
df->minProjSA = M_PI*stepWidth*stepWidth; |
| 817 |
if (stepWidth < .03125) |
| 818 |
stepWidth = .03125; /* 1/32 resolution good enough */ |
| 819 |
df->maxHemi = .0; |
| 820 |
if (st->ndim == 3) { /* isotropic BSDF */ |
| 821 |
bmin[1] = bmin[2] = .0; |
| 822 |
bmax[1] = bmax[2] = 1.; |
| 823 |
for (bmin[0] = .0; bmin[0] < .5-FTINY; bmin[0] += stepWidth) { |
| 824 |
bmax[0] = bmin[0] + stepWidth; |
| 825 |
dhemi = SDavgTreBox(st, bmin, bmax); |
| 826 |
if (dhemi > df->maxHemi) |
| 827 |
df->maxHemi = dhemi; |
| 828 |
} |
| 829 |
} else if (st->ndim == 4) { /* anisotropic BSDF */ |
| 830 |
bmin[2] = bmin[3] = .0; |
| 831 |
bmax[2] = bmax[3] = 1.; |
| 832 |
for (bmin[0] = .0; bmin[0] < 1.-FTINY; bmin[0] += stepWidth) { |
| 833 |
bmax[0] = bmin[0] + stepWidth; |
| 834 |
for (bmin[1] = .0; bmin[1] < 1.-FTINY; bmin[1] += stepWidth) { |
| 835 |
bmax[1] = bmin[1] + stepWidth; |
| 836 |
dhemi = SDavgTreBox(st, bmin, bmax); |
| 837 |
if (dhemi > df->maxHemi) |
| 838 |
df->maxHemi = dhemi; |
| 839 |
} |
| 840 |
} |
| 841 |
} else |
| 842 |
return SDEinternal; |
| 843 |
/* correct hemispherical value */ |
| 844 |
df->maxHemi *= M_PI; |
| 845 |
return SDEnone; |
| 846 |
} |
| 847 |
|
| 848 |
/* Load BSDF distribution for this wavelength */ |
| 849 |
static SDError |
| 850 |
load_bsdf_data(SDData *sd, ezxml_t wdb, int ndim) |
| 851 |
{ |
| 852 |
SDSpectralDF *df; |
| 853 |
SDTre *sdt; |
| 854 |
char *sdata; |
| 855 |
int i; |
| 856 |
/* allocate BSDF component */ |
| 857 |
sdata = ezxml_txt(ezxml_child(wdb, "WavelengthDataDirection")); |
| 858 |
if (!sdata) |
| 859 |
return SDEnone; |
| 860 |
/* |
| 861 |
* Remember that front and back are reversed from WINDOW 6 orientations |
| 862 |
*/ |
| 863 |
if (!strcasecmp(sdata, "Transmission")) { |
| 864 |
if (sd->tf != NULL) |
| 865 |
SDfreeSpectralDF(sd->tf); |
| 866 |
if ((sd->tf = SDnewSpectralDF(1)) == NULL) |
| 867 |
return SDEmemory; |
| 868 |
df = sd->tf; |
| 869 |
} else if (!strcasecmp(sdata, "Reflection Front")) { |
| 870 |
if (sd->rb != NULL) /* note back-front reversal */ |
| 871 |
SDfreeSpectralDF(sd->rb); |
| 872 |
if ((sd->rb = SDnewSpectralDF(1)) == NULL) |
| 873 |
return SDEmemory; |
| 874 |
df = sd->rb; |
| 875 |
} else if (!strcasecmp(sdata, "Reflection Back")) { |
| 876 |
if (sd->rf != NULL) /* note front-back reversal */ |
| 877 |
SDfreeSpectralDF(sd->rf); |
| 878 |
if ((sd->rf = SDnewSpectralDF(1)) == NULL) |
| 879 |
return SDEmemory; |
| 880 |
df = sd->rf; |
| 881 |
} else |
| 882 |
return SDEnone; |
| 883 |
/* XXX should also check "ScatteringDataType" for consistency? */ |
| 884 |
/* get angle bases */ |
| 885 |
sdata = ezxml_txt(ezxml_child(wdb,"AngleBasis")); |
| 886 |
if (!sdata || strcasecmp(sdata, "LBNL/Shirley-Chiu")) { |
| 887 |
sprintf(SDerrorDetail, "%s angle basis for BSDF '%s'", |
| 888 |
!sdata ? "Missing" : "Unsupported", sd->name); |
| 889 |
return !sdata ? SDEformat : SDEsupport; |
| 890 |
} |
| 891 |
/* allocate BSDF tree */ |
| 892 |
sdt = (SDTre *)malloc(sizeof(SDTre)); |
| 893 |
if (sdt == NULL) |
| 894 |
return SDEmemory; |
| 895 |
if (df == sd->rf) |
| 896 |
sdt->sidef = SD_UFRONT; |
| 897 |
else if (df == sd->rb) |
| 898 |
sdt->sidef = SD_UBACK; |
| 899 |
else |
| 900 |
sdt->sidef = SD_XMIT; |
| 901 |
sdt->st = NULL; |
| 902 |
df->comp[0].cspec[0] = c_dfcolor; /* XXX monochrome for now */ |
| 903 |
df->comp[0].dist = sdt; |
| 904 |
df->comp[0].func = &SDhandleTre; |
| 905 |
/* read BSDF data */ |
| 906 |
sdata = ezxml_txt(ezxml_child(wdb, "ScatteringData")); |
| 907 |
if (!sdata || !next_token(&sdata)) { |
| 908 |
sprintf(SDerrorDetail, "Missing BSDF ScatteringData in '%s'", |
| 909 |
sd->name); |
| 910 |
return SDEformat; |
| 911 |
} |
| 912 |
sdt->st = load_tree_data(&sdata, ndim); |
| 913 |
if (sdt->st == NULL) |
| 914 |
return SDEformat; |
| 915 |
if (next_token(&sdata)) { /* check for unconsumed characters */ |
| 916 |
sprintf(SDerrorDetail, |
| 917 |
"Extra characters at end of ScatteringData in '%s'", |
| 918 |
sd->name); |
| 919 |
return SDEformat; |
| 920 |
} |
| 921 |
/* flatten branches where possible */ |
| 922 |
sdt->st = SDsimplifyTre(sdt->st); |
| 923 |
if (sdt->st == NULL) |
| 924 |
return SDEinternal; |
| 925 |
return get_extrema(df); /* compute global quantities */ |
| 926 |
} |
| 927 |
|
| 928 |
/* Find minimum value in tree */ |
| 929 |
static float |
| 930 |
SDgetTreMin(const SDNode *st) |
| 931 |
{ |
| 932 |
float vmin = FHUGE; |
| 933 |
int n; |
| 934 |
|
| 935 |
if (st->log2GR < 0) { |
| 936 |
for (n = 1<<st->ndim; n--; ) { |
| 937 |
float v = SDgetTreMin(st->u.t[n]); |
| 938 |
if (v < vmin) |
| 939 |
vmin = v; |
| 940 |
} |
| 941 |
} else { |
| 942 |
for (n = 1<<(st->ndim*st->log2GR); n--; ) |
| 943 |
if (st->u.v[n] < vmin) |
| 944 |
vmin = st->u.v[n]; |
| 945 |
} |
| 946 |
return vmin; |
| 947 |
} |
| 948 |
|
| 949 |
/* Subtract the given value from all tree nodes */ |
| 950 |
static void |
| 951 |
SDsubtractTreVal(SDNode *st, float val) |
| 952 |
{ |
| 953 |
int n; |
| 954 |
|
| 955 |
if (st->log2GR < 0) { |
| 956 |
for (n = 1<<st->ndim; n--; ) |
| 957 |
SDsubtractTreVal(st->u.t[n], val); |
| 958 |
} else { |
| 959 |
for (n = 1<<(st->ndim*st->log2GR); n--; ) |
| 960 |
st->u.v[n] -= val; |
| 961 |
} |
| 962 |
} |
| 963 |
|
| 964 |
/* Subtract minimum value from BSDF */ |
| 965 |
static double |
| 966 |
subtract_min(SDNode *st) |
| 967 |
{ |
| 968 |
float vmin; |
| 969 |
/* be sure to skip unused portion */ |
| 970 |
if (st->ndim == 3) { |
| 971 |
int n; |
| 972 |
vmin = 1./M_PI; |
| 973 |
if (st->log2GR < 0) { |
| 974 |
for (n = 0; n < 4; n++) { |
| 975 |
float v = SDgetTreMin(st->u.t[n]); |
| 976 |
if (v < vmin) |
| 977 |
vmin = v; |
| 978 |
} |
| 979 |
} else if (st->log2GR) { |
| 980 |
for (n = 1 << (3*st->log2GR - 1); n--; ) |
| 981 |
if (st->u.v[n] < vmin) |
| 982 |
vmin = st->u.v[n]; |
| 983 |
} else |
| 984 |
vmin = st->u.v[0]; |
| 985 |
} else /* anisotropic covers entire tree */ |
| 986 |
vmin = SDgetTreMin(st); |
| 987 |
|
| 988 |
if (vmin <= FTINY) |
| 989 |
return .0; |
| 990 |
|
| 991 |
SDsubtractTreVal(st, vmin); |
| 992 |
|
| 993 |
return M_PI * vmin; /* return hemispherical value */ |
| 994 |
} |
| 995 |
|
| 996 |
/* Extract and separate diffuse portion of BSDF */ |
| 997 |
static void |
| 998 |
extract_diffuse(SDValue *dv, SDSpectralDF *df) |
| 999 |
{ |
| 1000 |
int n; |
| 1001 |
|
| 1002 |
if (df == NULL || df->ncomp <= 0) { |
| 1003 |
dv->spec = c_dfcolor; |
| 1004 |
dv->cieY = .0; |
| 1005 |
return; |
| 1006 |
} |
| 1007 |
dv->spec = df->comp[0].cspec[0]; |
| 1008 |
dv->cieY = subtract_min((*(SDTre *)df->comp[0].dist).st); |
| 1009 |
/* in case of multiple components */ |
| 1010 |
for (n = df->ncomp; --n; ) { |
| 1011 |
double ymin = subtract_min((*(SDTre *)df->comp[n].dist).st); |
| 1012 |
c_cmix(&dv->spec, dv->cieY, &dv->spec, ymin, &df->comp[n].cspec[0]); |
| 1013 |
dv->cieY += ymin; |
| 1014 |
} |
| 1015 |
df->maxHemi -= dv->cieY; /* adjust maximum hemispherical */ |
| 1016 |
/* make sure everything is set */ |
| 1017 |
c_ccvt(&dv->spec, C_CSXY+C_CSSPEC); |
| 1018 |
} |
| 1019 |
|
| 1020 |
/* Load a variable-resolution BSDF tree from an open XML file */ |
| 1021 |
SDError |
| 1022 |
SDloadTre(SDData *sd, ezxml_t wtl) |
| 1023 |
{ |
| 1024 |
SDError ec; |
| 1025 |
ezxml_t wld, wdb; |
| 1026 |
int rank; |
| 1027 |
char *txt; |
| 1028 |
/* basic checks and tensor rank */ |
| 1029 |
txt = ezxml_txt(ezxml_child(ezxml_child(wtl, |
| 1030 |
"DataDefinition"), "IncidentDataStructure")); |
| 1031 |
if (txt == NULL || !*txt) { |
| 1032 |
sprintf(SDerrorDetail, |
| 1033 |
"BSDF \"%s\": missing IncidentDataStructure", |
| 1034 |
sd->name); |
| 1035 |
return SDEformat; |
| 1036 |
} |
| 1037 |
if (!strcasecmp(txt, "TensorTree3")) |
| 1038 |
rank = 3; |
| 1039 |
else if (!strcasecmp(txt, "TensorTree4")) |
| 1040 |
rank = 4; |
| 1041 |
else { |
| 1042 |
sprintf(SDerrorDetail, |
| 1043 |
"BSDF \"%s\": unsupported IncidentDataStructure", |
| 1044 |
sd->name); |
| 1045 |
return SDEsupport; |
| 1046 |
} |
| 1047 |
/* load BSDF components */ |
| 1048 |
for (wld = ezxml_child(wtl, "WavelengthData"); |
| 1049 |
wld != NULL; wld = wld->next) { |
| 1050 |
if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")), |
| 1051 |
"Visible")) |
| 1052 |
continue; /* just visible for now */ |
| 1053 |
for (wdb = ezxml_child(wld, "WavelengthDataBlock"); |
| 1054 |
wdb != NULL; wdb = wdb->next) |
| 1055 |
if ((ec = load_bsdf_data(sd, wdb, rank)) != SDEnone) |
| 1056 |
return ec; |
| 1057 |
} |
| 1058 |
/* separate diffuse components */ |
| 1059 |
extract_diffuse(&sd->rLambFront, sd->rf); |
| 1060 |
extract_diffuse(&sd->rLambBack, sd->rb); |
| 1061 |
extract_diffuse(&sd->tLamb, sd->tf); |
| 1062 |
/* return success */ |
| 1063 |
return SDEnone; |
| 1064 |
} |
| 1065 |
|
| 1066 |
/* Variable resolution BSDF methods */ |
| 1067 |
SDFunc SDhandleTre = { |
| 1068 |
&SDgetTreBSDF, |
| 1069 |
&SDqueryTreProjSA, |
| 1070 |
&SDgetTreCDist, |
| 1071 |
&SDsampTreCDist, |
| 1072 |
&SDFreeBTre, |
| 1073 |
}; |
