| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id$"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Support BSDF representation as radial basis functions. |
| 6 |
* |
| 7 |
* G. Ward |
| 8 |
*/ |
| 9 |
|
| 10 |
#define _USE_MATH_DEFINES |
| 11 |
#include <stdlib.h> |
| 12 |
#include <math.h> |
| 13 |
#include "rtio.h" |
| 14 |
#include "resolu.h" |
| 15 |
#include "bsdfrep.h" |
| 16 |
/* which quadrants are represented */ |
| 17 |
int inp_coverage = 0; |
| 18 |
/* all incident angles in-plane so far? */ |
| 19 |
int single_plane_incident = -1; |
| 20 |
|
| 21 |
/* input/output orientations */ |
| 22 |
int input_orient = 0; |
| 23 |
int output_orient = 0; |
| 24 |
|
| 25 |
/* processed incident DSF measurements */ |
| 26 |
RBFNODE *dsf_list = NULL; |
| 27 |
|
| 28 |
/* RBF-linking matrices (edges) */ |
| 29 |
MIGRATION *mig_list = NULL; |
| 30 |
|
| 31 |
/* current input direction */ |
| 32 |
double theta_in_deg, phi_in_deg; |
| 33 |
|
| 34 |
/* Register new input direction */ |
| 35 |
int |
| 36 |
new_input_direction(double new_theta, double new_phi) |
| 37 |
{ |
| 38 |
if (!input_orient) /* check input orientation */ |
| 39 |
input_orient = 1 - 2*(new_theta > 90.); |
| 40 |
else if (input_orient > 0 ^ new_theta < 90.) { |
| 41 |
fprintf(stderr, |
| 42 |
"%s: Cannot handle input angles on both sides of surface\n", |
| 43 |
progname); |
| 44 |
return(0); |
| 45 |
} |
| 46 |
/* normalize angle ranges */ |
| 47 |
while (new_theta < -180.) |
| 48 |
new_theta += 360.; |
| 49 |
while (new_theta > 180.) |
| 50 |
new_theta -= 360.; |
| 51 |
if (new_theta < 0) { |
| 52 |
new_theta = -new_theta; |
| 53 |
new_phi += 180.; |
| 54 |
} |
| 55 |
while (new_phi < 0) |
| 56 |
new_phi += 360.; |
| 57 |
while (new_phi >= 360.) |
| 58 |
new_phi -= 360.; |
| 59 |
if (single_plane_incident > 0) /* check input coverage */ |
| 60 |
single_plane_incident = (round(new_phi) == round(phi_in_deg)); |
| 61 |
else if (single_plane_incident < 0) |
| 62 |
single_plane_incident = 1; |
| 63 |
theta_in_deg = new_theta; /* assume it's OK */ |
| 64 |
phi_in_deg = new_phi; |
| 65 |
if ((1. < new_phi) & (new_phi < 89.)) |
| 66 |
inp_coverage |= INP_QUAD1; |
| 67 |
else if ((91. < new_phi) & (new_phi < 179.)) |
| 68 |
inp_coverage |= INP_QUAD2; |
| 69 |
else if ((181. < new_phi) & (new_phi < 269.)) |
| 70 |
inp_coverage |= INP_QUAD3; |
| 71 |
else if ((271. < new_phi) & (new_phi < 359.)) |
| 72 |
inp_coverage |= INP_QUAD4; |
| 73 |
return(1); |
| 74 |
} |
| 75 |
|
| 76 |
/* Apply symmetry to the given vector based on distribution */ |
| 77 |
int |
| 78 |
use_symmetry(FVECT vec) |
| 79 |
{ |
| 80 |
double phi = get_phi360(vec); |
| 81 |
|
| 82 |
switch (inp_coverage) { |
| 83 |
case INP_QUAD1|INP_QUAD2|INP_QUAD3|INP_QUAD4: |
| 84 |
break; |
| 85 |
case INP_QUAD1|INP_QUAD2: |
| 86 |
if ((-FTINY > phi) | (phi > 180.+FTINY)) |
| 87 |
goto mir_y; |
| 88 |
break; |
| 89 |
case INP_QUAD2|INP_QUAD3: |
| 90 |
if ((90.-FTINY > phi) | (phi > 270.+FTINY)) |
| 91 |
goto mir_x; |
| 92 |
break; |
| 93 |
case INP_QUAD3|INP_QUAD4: |
| 94 |
if ((180.-FTINY > phi) | (phi > 360.+FTINY)) |
| 95 |
goto mir_y; |
| 96 |
break; |
| 97 |
case INP_QUAD4|INP_QUAD1: |
| 98 |
if ((270.-FTINY > phi) & (phi > 90.+FTINY)) |
| 99 |
goto mir_x; |
| 100 |
break; |
| 101 |
case INP_QUAD1: |
| 102 |
if ((-FTINY > phi) | (phi > 90.+FTINY)) |
| 103 |
switch ((int)(phi*(1./90.))) { |
| 104 |
case 1: goto mir_x; |
| 105 |
case 2: goto mir_xy; |
| 106 |
case 3: goto mir_y; |
| 107 |
} |
| 108 |
break; |
| 109 |
case INP_QUAD2: |
| 110 |
if ((90.-FTINY > phi) | (phi > 180.+FTINY)) |
| 111 |
switch ((int)(phi*(1./90.))) { |
| 112 |
case 0: goto mir_x; |
| 113 |
case 2: goto mir_y; |
| 114 |
case 3: goto mir_xy; |
| 115 |
} |
| 116 |
break; |
| 117 |
case INP_QUAD3: |
| 118 |
if ((180.-FTINY > phi) | (phi > 270.+FTINY)) |
| 119 |
switch ((int)(phi*(1./90.))) { |
| 120 |
case 0: goto mir_xy; |
| 121 |
case 1: goto mir_y; |
| 122 |
case 3: goto mir_x; |
| 123 |
} |
| 124 |
break; |
| 125 |
case INP_QUAD4: |
| 126 |
if ((270.-FTINY > phi) | (phi > 360.+FTINY)) |
| 127 |
switch ((int)(phi*(1./90.))) { |
| 128 |
case 0: goto mir_y; |
| 129 |
case 1: goto mir_xy; |
| 130 |
case 2: goto mir_x; |
| 131 |
} |
| 132 |
break; |
| 133 |
default: |
| 134 |
fprintf(stderr, "%s: Illegal input coverage (%d)\n", |
| 135 |
progname, inp_coverage); |
| 136 |
exit(1); |
| 137 |
} |
| 138 |
return(0); /* in range */ |
| 139 |
mir_x: |
| 140 |
vec[0] = -vec[0]; |
| 141 |
return(MIRROR_X); |
| 142 |
mir_y: |
| 143 |
vec[1] = -vec[1]; |
| 144 |
return(MIRROR_Y); |
| 145 |
mir_xy: |
| 146 |
vec[0] = -vec[0]; |
| 147 |
vec[1] = -vec[1]; |
| 148 |
return(MIRROR_X|MIRROR_Y); |
| 149 |
} |
| 150 |
|
| 151 |
/* Reverse symmetry based on what was done before */ |
| 152 |
void |
| 153 |
rev_symmetry(FVECT vec, int sym) |
| 154 |
{ |
| 155 |
if (sym & MIRROR_X) |
| 156 |
vec[0] = -vec[0]; |
| 157 |
if (sym & MIRROR_Y) |
| 158 |
vec[1] = -vec[1]; |
| 159 |
} |
| 160 |
|
| 161 |
/* Reverse symmetry for an RBF distribution */ |
| 162 |
void |
| 163 |
rev_rbf_symmetry(RBFNODE *rbf, int sym) |
| 164 |
{ |
| 165 |
int n; |
| 166 |
|
| 167 |
rev_symmetry(rbf->invec, sym); |
| 168 |
if (sym & MIRROR_X) |
| 169 |
for (n = rbf->nrbf; n-- > 0; ) |
| 170 |
rbf->rbfa[n].gx = GRIDRES-1 - rbf->rbfa[n].gx; |
| 171 |
if (sym & MIRROR_Y) |
| 172 |
for (n = rbf->nrbf; n-- > 0; ) |
| 173 |
rbf->rbfa[n].gy = GRIDRES-1 - rbf->rbfa[n].gy; |
| 174 |
} |
| 175 |
|
| 176 |
/* Compute volume associated with Gaussian lobe */ |
| 177 |
double |
| 178 |
rbf_volume(const RBFVAL *rbfp) |
| 179 |
{ |
| 180 |
double rad = R2ANG(rbfp->crad); |
| 181 |
|
| 182 |
return((2.*M_PI) * rbfp->peak * rad*rad); |
| 183 |
} |
| 184 |
|
| 185 |
/* Compute outgoing vector from grid position */ |
| 186 |
void |
| 187 |
ovec_from_pos(FVECT vec, int xpos, int ypos) |
| 188 |
{ |
| 189 |
double uv[2]; |
| 190 |
double r2; |
| 191 |
|
| 192 |
SDsquare2disk(uv, (1./GRIDRES)*(xpos+.5), (1./GRIDRES)*(ypos+.5)); |
| 193 |
/* uniform hemispherical projection */ |
| 194 |
r2 = uv[0]*uv[0] + uv[1]*uv[1]; |
| 195 |
vec[0] = vec[1] = sqrt(2. - r2); |
| 196 |
vec[0] *= uv[0]; |
| 197 |
vec[1] *= uv[1]; |
| 198 |
vec[2] = output_orient*(1. - r2); |
| 199 |
} |
| 200 |
|
| 201 |
/* Compute grid position from normalized input/output vector */ |
| 202 |
void |
| 203 |
pos_from_vec(int pos[2], const FVECT vec) |
| 204 |
{ |
| 205 |
double sq[2]; /* uniform hemispherical projection */ |
| 206 |
double norm = 1./sqrt(1. + fabs(vec[2])); |
| 207 |
|
| 208 |
SDdisk2square(sq, vec[0]*norm, vec[1]*norm); |
| 209 |
|
| 210 |
pos[0] = (int)(sq[0]*GRIDRES); |
| 211 |
pos[1] = (int)(sq[1]*GRIDRES); |
| 212 |
} |
| 213 |
|
| 214 |
/* Evaluate RBF for DSF at the given normalized outgoing direction */ |
| 215 |
double |
| 216 |
eval_rbfrep(const RBFNODE *rp, const FVECT outvec) |
| 217 |
{ |
| 218 |
double res = .0; |
| 219 |
const RBFVAL *rbfp; |
| 220 |
FVECT odir; |
| 221 |
double sig2; |
| 222 |
int n; |
| 223 |
|
| 224 |
if (rp == NULL) |
| 225 |
return(.0); |
| 226 |
rbfp = rp->rbfa; |
| 227 |
for (n = rp->nrbf; n--; rbfp++) { |
| 228 |
ovec_from_pos(odir, rbfp->gx, rbfp->gy); |
| 229 |
sig2 = R2ANG(rbfp->crad); |
| 230 |
sig2 = (DOT(odir,outvec) - 1.) / (sig2*sig2); |
| 231 |
if (sig2 > -19.) |
| 232 |
res += rbfp->peak * exp(sig2); |
| 233 |
} |
| 234 |
return(res); |
| 235 |
} |
| 236 |
|
| 237 |
/* Insert a new directional scattering function in our global list */ |
| 238 |
int |
| 239 |
insert_dsf(RBFNODE *newrbf) |
| 240 |
{ |
| 241 |
RBFNODE *rbf, *rbf_last; |
| 242 |
int pos; |
| 243 |
/* check for redundant meas. */ |
| 244 |
for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) |
| 245 |
if (DOT(rbf->invec, newrbf->invec) >= 1.-FTINY) { |
| 246 |
fprintf(stderr, |
| 247 |
"%s: Duplicate incident measurement (ignored)\n", |
| 248 |
progname); |
| 249 |
free(newrbf); |
| 250 |
return(-1); |
| 251 |
} |
| 252 |
/* keep in ascending theta order */ |
| 253 |
for (rbf_last = NULL, rbf = dsf_list; rbf != NULL; |
| 254 |
rbf_last = rbf, rbf = rbf->next) |
| 255 |
if (single_plane_incident && input_orient*rbf->invec[2] < |
| 256 |
input_orient*newrbf->invec[2]) |
| 257 |
break; |
| 258 |
if (rbf_last == NULL) { /* insert new node in list */ |
| 259 |
newrbf->ord = 0; |
| 260 |
newrbf->next = dsf_list; |
| 261 |
dsf_list = newrbf; |
| 262 |
} else { |
| 263 |
newrbf->ord = rbf_last->ord + 1; |
| 264 |
newrbf->next = rbf; |
| 265 |
rbf_last->next = newrbf; |
| 266 |
} |
| 267 |
rbf_last = newrbf; |
| 268 |
while (rbf != NULL) { /* update ordinal positions */ |
| 269 |
rbf->ord = rbf_last->ord + 1; |
| 270 |
rbf_last = rbf; |
| 271 |
rbf = rbf->next; |
| 272 |
} |
| 273 |
return(newrbf->ord); |
| 274 |
} |
| 275 |
|
| 276 |
/* Get the DSF indicated by its ordinal position */ |
| 277 |
RBFNODE * |
| 278 |
get_dsf(int ord) |
| 279 |
{ |
| 280 |
RBFNODE *rbf; |
| 281 |
|
| 282 |
for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) |
| 283 |
if (rbf->ord == ord); |
| 284 |
return(rbf); |
| 285 |
return(NULL); |
| 286 |
} |
| 287 |
|
| 288 |
/* Get triangle surface orientation (unnormalized) */ |
| 289 |
void |
| 290 |
tri_orient(FVECT vres, const FVECT v1, const FVECT v2, const FVECT v3) |
| 291 |
{ |
| 292 |
FVECT v2minus1, v3minus2; |
| 293 |
|
| 294 |
VSUB(v2minus1, v2, v1); |
| 295 |
VSUB(v3minus2, v3, v2); |
| 296 |
VCROSS(vres, v2minus1, v3minus2); |
| 297 |
} |
| 298 |
|
| 299 |
/* Determine if vertex order is reversed (inward normal) */ |
| 300 |
int |
| 301 |
is_rev_tri(const FVECT v1, const FVECT v2, const FVECT v3) |
| 302 |
{ |
| 303 |
FVECT tor; |
| 304 |
|
| 305 |
tri_orient(tor, v1, v2, v3); |
| 306 |
|
| 307 |
return(DOT(tor, v2) < 0.); |
| 308 |
} |
| 309 |
|
| 310 |
/* Find vertices completing triangles on either side of the given edge */ |
| 311 |
int |
| 312 |
get_triangles(RBFNODE *rbfv[2], const MIGRATION *mig) |
| 313 |
{ |
| 314 |
const MIGRATION *ej, *ej2; |
| 315 |
RBFNODE *tv; |
| 316 |
|
| 317 |
rbfv[0] = rbfv[1] = NULL; |
| 318 |
if (mig == NULL) |
| 319 |
return(0); |
| 320 |
for (ej = mig->rbfv[0]->ejl; ej != NULL; |
| 321 |
ej = nextedge(mig->rbfv[0],ej)) { |
| 322 |
if (ej == mig) |
| 323 |
continue; |
| 324 |
tv = opp_rbf(mig->rbfv[0],ej); |
| 325 |
for (ej2 = tv->ejl; ej2 != NULL; ej2 = nextedge(tv,ej2)) |
| 326 |
if (opp_rbf(tv,ej2) == mig->rbfv[1]) { |
| 327 |
rbfv[is_rev_tri(mig->rbfv[0]->invec, |
| 328 |
mig->rbfv[1]->invec, |
| 329 |
tv->invec)] = tv; |
| 330 |
break; |
| 331 |
} |
| 332 |
} |
| 333 |
return((rbfv[0] != NULL) + (rbfv[1] != NULL)); |
| 334 |
} |
| 335 |
|
| 336 |
/* Write our BSDF mesh interpolant out to the given binary stream */ |
| 337 |
void |
| 338 |
save_bsdf_rep(FILE *ofp) |
| 339 |
{ |
| 340 |
RBFNODE *rbf; |
| 341 |
MIGRATION *mig; |
| 342 |
int i, n; |
| 343 |
/* finish header */ |
| 344 |
fputformat(BSDFREP_FMT, ofp); |
| 345 |
fputc('\n', ofp); |
| 346 |
/* write each DSF */ |
| 347 |
for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) { |
| 348 |
putint(rbf->ord, 4, ofp); |
| 349 |
putflt(rbf->invec[0], ofp); |
| 350 |
putflt(rbf->invec[1], ofp); |
| 351 |
putflt(rbf->invec[2], ofp); |
| 352 |
putflt(rbf->vtotal, ofp); |
| 353 |
putint(rbf->nrbf, 4, ofp); |
| 354 |
for (i = 0; i < rbf->nrbf; i++) { |
| 355 |
putflt(rbf->rbfa[i].peak, ofp); |
| 356 |
putint(rbf->rbfa[i].crad, 2, ofp); |
| 357 |
putint(rbf->rbfa[i].gx, 1, ofp); |
| 358 |
putint(rbf->rbfa[i].gy, 1, ofp); |
| 359 |
} |
| 360 |
} |
| 361 |
putint(-1, 4, ofp); /* terminator */ |
| 362 |
/* write each migration matrix */ |
| 363 |
for (mig = mig_list; mig != NULL; mig = mig_list->next) { |
| 364 |
putint(mig->rbfv[0]->ord, 4, ofp); |
| 365 |
putint(mig->rbfv[1]->ord, 4, ofp); |
| 366 |
n = mtx_nrows(mig) * mtx_ncols(mig); |
| 367 |
for (i = 0; i < n; i++) |
| 368 |
putflt(mig->mtx[i], ofp); |
| 369 |
} |
| 370 |
putint(-1, 4, ofp); /* terminator */ |
| 371 |
putint(-1, 4, ofp); |
| 372 |
if (fflush(ofp) == EOF) { |
| 373 |
fprintf(stderr, "%s: error writing BSDF interpolant\n", |
| 374 |
progname); |
| 375 |
exit(1); |
| 376 |
} |
| 377 |
} |
| 378 |
|
| 379 |
/* Read a BSDF mesh interpolant from the given binary stream */ |
| 380 |
int |
| 381 |
load_bsdf_rep(FILE *ifp) |
| 382 |
{ |
| 383 |
RBFNODE rbfh; |
| 384 |
int from_ord, to_ord; |
| 385 |
int i; |
| 386 |
#ifdef DEBUG |
| 387 |
if ((dsf_list != NULL) | (mig_list != NULL)) { |
| 388 |
fprintf(stderr, |
| 389 |
"%s: attempt to load BSDF interpolant over existing\n", |
| 390 |
progname); |
| 391 |
return(0); |
| 392 |
} |
| 393 |
#endif |
| 394 |
if (checkheader(ifp, BSDFREP_FMT, NULL) <= 0) { |
| 395 |
fprintf(stderr, "%s: missing/bad format for BSDF interpolant\n", |
| 396 |
progname); |
| 397 |
return(0); |
| 398 |
} |
| 399 |
rbfh.next = NULL; /* read each DSF */ |
| 400 |
rbfh.ejl = NULL; |
| 401 |
while ((rbfh.ord = getint(4, ifp)) >= 0) { |
| 402 |
RBFNODE *newrbf; |
| 403 |
|
| 404 |
rbfh.invec[0] = getflt(ifp); |
| 405 |
rbfh.invec[1] = getflt(ifp); |
| 406 |
rbfh.invec[2] = getflt(ifp); |
| 407 |
rbfh.nrbf = getint(4, ifp); |
| 408 |
if (!new_input_vector(rbfh.invec)) |
| 409 |
return(0); |
| 410 |
newrbf = (RBFNODE *)malloc(sizeof(RBFNODE) + |
| 411 |
sizeof(RBFVAL)*(rbfh.nrbf-1)); |
| 412 |
if (newrbf == NULL) |
| 413 |
goto memerr; |
| 414 |
memcpy(newrbf, &rbfh, sizeof(RBFNODE)); |
| 415 |
for (i = 0; i < rbfh.nrbf; i++) { |
| 416 |
newrbf->rbfa[i].peak = getflt(ifp); |
| 417 |
newrbf->rbfa[i].crad = getint(2, ifp) & 0xffff; |
| 418 |
newrbf->rbfa[i].gx = getint(1, ifp) & 0xff; |
| 419 |
newrbf->rbfa[i].gy = getint(1, ifp) & 0xff; |
| 420 |
} |
| 421 |
if (feof(ifp)) |
| 422 |
goto badEOF; |
| 423 |
/* insert in global list */ |
| 424 |
if (insert_dsf(newrbf) != rbfh.ord) { |
| 425 |
fprintf(stderr, "%s: error adding DSF\n", progname); |
| 426 |
return(0); |
| 427 |
} |
| 428 |
} |
| 429 |
/* read each migration matrix */ |
| 430 |
while ((from_ord = getint(4, ifp)) >= 0 && |
| 431 |
(to_ord = getint(4, ifp)) >= 0) { |
| 432 |
RBFNODE *from_rbf = get_dsf(from_ord); |
| 433 |
RBFNODE *to_rbf = get_dsf(to_ord); |
| 434 |
MIGRATION *newmig; |
| 435 |
int n; |
| 436 |
|
| 437 |
if ((from_rbf == NULL) | (to_rbf == NULL)) { |
| 438 |
fprintf(stderr, |
| 439 |
"%s: bad DSF reference in migration edge\n", |
| 440 |
progname); |
| 441 |
return(0); |
| 442 |
} |
| 443 |
n = from_rbf->nrbf * to_rbf->nrbf; |
| 444 |
newmig = (MIGRATION *)malloc(sizeof(MIGRATION) + |
| 445 |
sizeof(float)*(n-1)); |
| 446 |
if (newmig == NULL) |
| 447 |
goto memerr; |
| 448 |
newmig->rbfv[0] = from_rbf; |
| 449 |
newmig->rbfv[1] = to_rbf; |
| 450 |
/* read matrix coefficients */ |
| 451 |
for (i = 0; i < n; i++) |
| 452 |
newmig->mtx[i] = getflt(ifp); |
| 453 |
if (feof(ifp)) |
| 454 |
goto badEOF; |
| 455 |
/* insert in edge lists */ |
| 456 |
newmig->enxt[0] = from_rbf->ejl; |
| 457 |
from_rbf->ejl = newmig; |
| 458 |
newmig->enxt[1] = to_rbf->ejl; |
| 459 |
to_rbf->ejl = newmig; |
| 460 |
/* push onto global list */ |
| 461 |
newmig->next = mig_list; |
| 462 |
mig_list = newmig; |
| 463 |
} |
| 464 |
return(1); /* success! */ |
| 465 |
memerr: |
| 466 |
fprintf(stderr, "%s: Out of memory in load_bsdf_rep()\n", progname); |
| 467 |
exit(1); |
| 468 |
badEOF: |
| 469 |
fprintf(stderr, "%s: Unexpected EOF in load_bsdf_rep()\n", progname); |
| 470 |
return(0); |
| 471 |
} |
