| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: virtuals.c,v 2.25 2021/02/12 00:41:19 greg Exp $"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Routines for simulating virtual light sources |
| 6 |
* Thus far, we only support planar mirrors. |
| 7 |
* |
| 8 |
* External symbols declared in source.h |
| 9 |
*/ |
| 10 |
|
| 11 |
#include "copyright.h" |
| 12 |
|
| 13 |
#include "ray.h" |
| 14 |
#include "otypes.h" |
| 15 |
#include "otspecial.h" |
| 16 |
#include "source.h" |
| 17 |
#include "random.h" |
| 18 |
|
| 19 |
#define MINSAMPLES 16 /* minimum number of pretest samples */ |
| 20 |
#define STESTMAX 32 /* maximum seeks per sample */ |
| 21 |
|
| 22 |
|
| 23 |
static OBJECT *vobject; /* virtual source objects */ |
| 24 |
static int nvobjects = 0; /* number of virtual source objects */ |
| 25 |
|
| 26 |
|
| 27 |
static int |
| 28 |
isident4(MAT4 m) |
| 29 |
{ |
| 30 |
int i, j; |
| 31 |
|
| 32 |
for (i = 4; i--; ) |
| 33 |
for (j = 4; j--; ) |
| 34 |
if (!FABSEQ(m[i][j], i==j)) |
| 35 |
return(0); |
| 36 |
return(1); |
| 37 |
} |
| 38 |
|
| 39 |
|
| 40 |
void |
| 41 |
markvirtuals(void) /* find and mark virtual sources */ |
| 42 |
{ |
| 43 |
OBJREC *o; |
| 44 |
int i; |
| 45 |
/* check number of direct relays */ |
| 46 |
if (directrelay <= 0) |
| 47 |
return; |
| 48 |
/* find virtual source objects */ |
| 49 |
for (i = 0; i < nsceneobjs; i++) { |
| 50 |
o = objptr(i); |
| 51 |
if (!issurface(o->otype) || o->omod == OVOID) |
| 52 |
continue; |
| 53 |
if (!isvlight(vsmaterial(o)->otype)) |
| 54 |
continue; |
| 55 |
if (sfun[o->otype].of == NULL || |
| 56 |
sfun[o->otype].of->getpleq == NULL) { |
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objerror(o,WARNING,"secondary sources not supported"); |
| 58 |
continue; |
| 59 |
} |
| 60 |
if (nvobjects == 0) |
| 61 |
vobject = (OBJECT *)malloc(sizeof(OBJECT)); |
| 62 |
else |
| 63 |
vobject = (OBJECT *)realloc((void *)vobject, |
| 64 |
(unsigned)(nvobjects+1)*sizeof(OBJECT)); |
| 65 |
if (vobject == NULL) |
| 66 |
error(SYSTEM, "out of memory in addvirtuals"); |
| 67 |
vobject[nvobjects++] = i; |
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} |
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if (nvobjects == 0) |
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return; |
| 71 |
#ifdef DEBUG |
| 72 |
fprintf(stderr, "found %d virtual source objects\n", nvobjects); |
| 73 |
#endif |
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/* append virtual sources */ |
| 75 |
for (i = nsources; i-- > 0; ) |
| 76 |
addvirtuals(i, directrelay); |
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/* done with our object list */ |
| 78 |
free((void *)vobject); |
| 79 |
nvobjects = 0; |
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} |
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|
| 82 |
|
| 83 |
void |
| 84 |
addvirtuals( /* add virtuals associated with source */ |
| 85 |
int sn, |
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int nr |
| 87 |
) |
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{ |
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int i; |
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/* check relay limit first */ |
| 91 |
if (nr <= 0) |
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return; |
| 93 |
if (source[sn].sflags & SSKIP) |
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return; |
| 95 |
/* check each virtual object for projection */ |
| 96 |
for (i = 0; i < nvobjects; i++) |
| 97 |
/* vproject() calls us recursively */ |
| 98 |
vproject(objptr(vobject[i]), sn, nr-1); |
| 99 |
} |
| 100 |
|
| 101 |
|
| 102 |
void |
| 103 |
vproject( /* create projected source(s) if they exist */ |
| 104 |
OBJREC *o, |
| 105 |
int sn, |
| 106 |
int n |
| 107 |
) |
| 108 |
{ |
| 109 |
int i; |
| 110 |
VSMATERIAL *vsmat; |
| 111 |
MAT4 proj; |
| 112 |
int ns; |
| 113 |
|
| 114 |
if (o == source[sn].so) /* objects cannot project themselves */ |
| 115 |
return; |
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/* get virtual source material */ |
| 117 |
vsmat = sfun[vsmaterial(o)->otype].mf; |
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/* project virtual sources */ |
| 119 |
for (i = 0; i < vsmat->nproj; i++) |
| 120 |
if ((*vsmat->vproj)(proj, o, &source[sn], i)) |
| 121 |
if ((ns = makevsrc(o, sn, proj)) >= 0) { |
| 122 |
source[ns].sa.sv.pn = i; |
| 123 |
#ifdef DEBUG |
| 124 |
virtverb(ns, stderr); |
| 125 |
#endif |
| 126 |
addvirtuals(ns, n); |
| 127 |
} |
| 128 |
} |
| 129 |
|
| 130 |
|
| 131 |
OBJREC * |
| 132 |
vsmaterial( /* get virtual source material pointer */ |
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OBJREC *o |
| 134 |
) |
| 135 |
{ |
| 136 |
int i; |
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OBJREC *m; |
| 138 |
|
| 139 |
i = o->omod; |
| 140 |
m = findmaterial(o); |
| 141 |
if (m == NULL) |
| 142 |
return(objptr(i)); |
| 143 |
if (m->otype != MAT_ILLUM || m->oargs.nsargs < 1 || |
| 144 |
!strcmp(m->oargs.sarg[0], VOIDID) || |
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(i = lastmod(objndx(m), m->oargs.sarg[0])) == OVOID) |
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return(m); /* direct modifier */ |
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return(objptr(i)); /* illum alternate */ |
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} |
| 149 |
|
| 150 |
|
| 151 |
int |
| 152 |
makevsrc( /* make virtual source if reasonable */ |
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OBJREC *op, |
| 154 |
int sn, |
| 155 |
MAT4 pm |
| 156 |
) |
| 157 |
{ |
| 158 |
FVECT nsloc, nsnorm, ocent, v; |
| 159 |
double maxrad2, d; |
| 160 |
int nsflags; |
| 161 |
SPOT theirspot, ourspot; |
| 162 |
int i; |
| 163 |
/* check for no-op */ |
| 164 |
if (isident4(pm)) |
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return(0); |
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nsflags = source[sn].sflags | (SVIRTUAL|SSPOT|SFOLLOW); |
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/* get object center and max. radius */ |
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maxrad2 = getdisk(ocent, op, sn); |
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if (maxrad2 <= FTINY) /* too small? */ |
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return(-1); |
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/* get location and spot */ |
| 172 |
if (source[sn].sflags & SDISTANT) { /* distant source */ |
| 173 |
if (source[sn].sflags & SPROX) |
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return(-1); /* should never get here! */ |
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multv3(nsloc, source[sn].sloc, pm); |
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normalize(nsloc); |
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VCOPY(ourspot.aim, ocent); |
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ourspot.siz = PI*maxrad2; |
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ourspot.flen = -1.; |
| 180 |
if (source[sn].sflags & SSPOT) { |
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multp3(theirspot.aim, source[sn].sl.s->aim, pm); |
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/* adjust for source size */ |
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d = sqrt(dist2(ourspot.aim, theirspot.aim)); |
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d = sqrt(source[sn].sl.s->siz/PI) + d*source[sn].srad; |
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theirspot.siz = PI*d*d; |
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ourspot.flen = theirspot.flen = source[sn].sl.s->flen; |
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d = ourspot.siz; |
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if (!commonbeam(&ourspot, &theirspot, nsloc)) |
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return(-1); /* no overlap */ |
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if (ourspot.siz < d-FTINY) { /* it shrunk */ |
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d = beamdisk(v, op, &ourspot, nsloc); |
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if (d <= FTINY) |
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return(-1); |
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if (d < maxrad2) { |
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maxrad2 = d; |
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VCOPY(ocent, v); |
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} |
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} |
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} |
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} else { /* local source */ |
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multp3(nsloc, source[sn].sloc, pm); |
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for (i = 0; i < 3; i++) |
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ourspot.aim[i] = ocent[i] - nsloc[i]; |
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if ((d = normalize(ourspot.aim)) == 0.) |
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return(-1); /* at source!! */ |
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if (source[sn].sflags & SPROX && d > source[sn].sl.prox) |
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return(-1); /* too far away */ |
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ourspot.flen = 0.; |
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/* adjust for source size */ |
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d = (sqrt(maxrad2) + source[sn].srad) / d; |
| 211 |
if (d < 1.-FTINY) |
| 212 |
ourspot.siz = 2.*PI*(1. - sqrt(1.-d*d)); |
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else |
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nsflags &= ~SSPOT; |
| 215 |
if (source[sn].sflags & SSPOT) { |
| 216 |
theirspot = *(source[sn].sl.s); |
| 217 |
multv3(theirspot.aim, source[sn].sl.s->aim, pm); |
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normalize(theirspot.aim); |
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if (nsflags & SSPOT) { |
| 220 |
ourspot.flen = theirspot.flen; |
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d = ourspot.siz; |
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if (!commonspot(&ourspot, &theirspot, nsloc)) |
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return(-1); /* no overlap */ |
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} else { |
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nsflags |= SSPOT; |
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ourspot = theirspot; |
| 227 |
d = 2.*ourspot.siz; |
| 228 |
} |
| 229 |
if (ourspot.siz < d-FTINY) { /* it shrunk */ |
| 230 |
d = spotdisk(v, op, &ourspot, nsloc); |
| 231 |
if (d <= FTINY) |
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return(-1); |
| 233 |
if (d < maxrad2) { |
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maxrad2 = d; |
| 235 |
VCOPY(ocent, v); |
| 236 |
} |
| 237 |
} |
| 238 |
} |
| 239 |
if (source[sn].sflags & SFLAT) { /* behind source? */ |
| 240 |
multv3(nsnorm, source[sn].snorm, pm); |
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normalize(nsnorm); |
| 242 |
if (nsflags & SSPOT && !checkspot(&ourspot, nsnorm)) |
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return(-1); |
| 244 |
} |
| 245 |
} |
| 246 |
/* pretest visibility */ |
| 247 |
nsflags = vstestvis(nsflags, op, ocent, maxrad2, sn); |
| 248 |
if (nsflags & SSKIP) |
| 249 |
return(-1); /* obstructed */ |
| 250 |
/* it all checks out, so make it */ |
| 251 |
if ((i = newsource()) < 0) |
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goto memerr; |
| 253 |
source[i].sflags = nsflags; |
| 254 |
VCOPY(source[i].sloc, nsloc); |
| 255 |
multv3(source[i].ss[SU], source[sn].ss[SU], pm); |
| 256 |
multv3(source[i].ss[SV], source[sn].ss[SV], pm); |
| 257 |
if (nsflags & SFLAT) |
| 258 |
VCOPY(source[i].snorm, nsnorm); |
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else |
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multv3(source[i].ss[SW], source[sn].ss[SW], pm); |
| 261 |
source[i].srad = source[sn].srad; |
| 262 |
source[i].ss2 = source[sn].ss2; |
| 263 |
if (nsflags & SSPOT) { |
| 264 |
if ((source[i].sl.s = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
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goto memerr; |
| 266 |
*(source[i].sl.s) = ourspot; |
| 267 |
} |
| 268 |
if (nsflags & SPROX) |
| 269 |
source[i].sl.prox = source[sn].sl.prox; |
| 270 |
source[i].sa.sv.sn = sn; |
| 271 |
source[i].so = op; |
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return(i); |
| 273 |
memerr: |
| 274 |
error(SYSTEM, "out of memory in makevsrc"); |
| 275 |
return -1; /* pro forma return */ |
| 276 |
} |
| 277 |
|
| 278 |
|
| 279 |
double |
| 280 |
getdisk( /* get visible object disk */ |
| 281 |
FVECT oc, |
| 282 |
OBJREC *op, |
| 283 |
int sn |
| 284 |
) |
| 285 |
{ |
| 286 |
double rad2, roffs, offs, d, rd, rdoto; |
| 287 |
FVECT rnrm, nrm; |
| 288 |
/* first, use object getdisk function */ |
| 289 |
rad2 = getmaxdisk(oc, op); |
| 290 |
if (!(source[sn].sflags & SVIRTUAL)) |
| 291 |
return(rad2); /* all done for normal source */ |
| 292 |
/* check for correct side of relay surface */ |
| 293 |
roffs = getplaneq(rnrm, source[sn].so); |
| 294 |
rd = DOT(rnrm, source[sn].sloc); /* source projection */ |
| 295 |
if (!(source[sn].sflags & SDISTANT)) |
| 296 |
rd -= roffs; |
| 297 |
d = DOT(rnrm, oc) - roffs; /* disk distance to relay plane */ |
| 298 |
if ((d > 0.) ^ (rd > 0.)) |
| 299 |
return(rad2); /* OK if opposite sides */ |
| 300 |
if (d*d >= rad2) |
| 301 |
return(0.); /* no relay is possible */ |
| 302 |
/* we need a closer look */ |
| 303 |
offs = getplaneq(nrm, op); |
| 304 |
rdoto = DOT(rnrm, nrm); |
| 305 |
if (d*d >= rad2*(1.-rdoto*rdoto)) |
| 306 |
return(0.); /* disk entirely on projection side */ |
| 307 |
/* should shrink disk but I'm lazy */ |
| 308 |
return(rad2); |
| 309 |
} |
| 310 |
|
| 311 |
|
| 312 |
int |
| 313 |
vstestvis( /* pretest source visibility */ |
| 314 |
int f, /* virtual source flags */ |
| 315 |
OBJREC *o, /* relay object */ |
| 316 |
FVECT oc, /* relay object center */ |
| 317 |
double or2, /* relay object radius squared */ |
| 318 |
int sn /* target source number */ |
| 319 |
) |
| 320 |
{ |
| 321 |
RAY sr; |
| 322 |
FVECT onorm; |
| 323 |
double offsdir[3]; |
| 324 |
SRCINDEX si; |
| 325 |
double or, d, d1; |
| 326 |
int stestlim, ssn; |
| 327 |
int nhit, nok; |
| 328 |
int i, n; |
| 329 |
/* return if pretesting disabled */ |
| 330 |
if (vspretest <= 0) |
| 331 |
return(f); |
| 332 |
/* get surface normal */ |
| 333 |
getplaneq(onorm, o); |
| 334 |
/* set number of rays to sample */ |
| 335 |
if (source[sn].sflags & SDISTANT) { |
| 336 |
/* 32. == heuristic constant */ |
| 337 |
n = 32.*or2/(thescene.cusize*thescene.cusize)*vspretest + .5; |
| 338 |
} else { |
| 339 |
VSUB(offsdir, source[sn].sloc, oc); |
| 340 |
d = DOT(offsdir,offsdir); |
| 341 |
if (d <= FTINY) |
| 342 |
n = 2.*PI * vspretest + .5; |
| 343 |
else |
| 344 |
n = 2.*PI * (1.-sqrt(1./(1.+or2/d)))*vspretest + .5; |
| 345 |
} |
| 346 |
if (n < MINSAMPLES) n = MINSAMPLES; |
| 347 |
#ifdef DEBUG |
| 348 |
fprintf(stderr, "pretesting source %d in object %s with %d rays\n", |
| 349 |
sn, o->oname, n); |
| 350 |
#endif |
| 351 |
/* sample */ |
| 352 |
or = sqrt(or2); |
| 353 |
stestlim = n*STESTMAX; |
| 354 |
ssn = 0; |
| 355 |
nhit = nok = 0; |
| 356 |
initsrcindex(&si); |
| 357 |
while (n-- > 0) { |
| 358 |
/* get sample point */ |
| 359 |
do { |
| 360 |
if (ssn >= stestlim) { |
| 361 |
#ifdef DEBUG |
| 362 |
fprintf(stderr, "\ttoo hard to hit\n"); |
| 363 |
#endif |
| 364 |
return(f); /* too small a target! */ |
| 365 |
} |
| 366 |
multisamp(offsdir, 3, urand(sn*931+5827+ssn)); |
| 367 |
for (i = 0; i < 3; i++) |
| 368 |
offsdir[i] = or*(1. - 2.*offsdir[i]); |
| 369 |
ssn++; |
| 370 |
d = 1. - DOT(offsdir, onorm); |
| 371 |
for (i = 0; i < 3; i++) { |
| 372 |
sr.rorg[i] = oc[i] + offsdir[i] + d*onorm[i]; |
| 373 |
sr.rdir[i] = -onorm[i]; |
| 374 |
} |
| 375 |
sr.rmax = 0.0; |
| 376 |
rayorigin(&sr, PRIMARY, NULL, NULL); |
| 377 |
} while (!(*ofun[o->otype].funp)(o, &sr)); |
| 378 |
/* check against source */ |
| 379 |
VCOPY(sr.rorg, sr.rop); /* starting from intersection */ |
| 380 |
samplendx++; |
| 381 |
if (si.sp >= si.np-1 || |
| 382 |
!srcray(&sr, NULL, &si) || sr.rsrc != sn) { |
| 383 |
si.sn = sn-1; /* reset index to our source */ |
| 384 |
si.np = 0; |
| 385 |
if (!srcray(&sr, NULL, &si) || sr.rsrc != sn) |
| 386 |
continue; /* can't get there from here */ |
| 387 |
} |
| 388 |
sr.revf = srcvalue; |
| 389 |
rayvalue(&sr); /* check sample validity */ |
| 390 |
if ((d = scolor_mean(sr.rcol)) <= FTINY) |
| 391 |
continue; |
| 392 |
nok++; /* got sample; check obstructions */ |
| 393 |
rayclear(&sr); |
| 394 |
sr.revf = raytrace; |
| 395 |
rayvalue(&sr); |
| 396 |
if ((d1 = scolor_mean(sr.rcol)) > FTINY) { |
| 397 |
if (d - d1 > FTINY) { |
| 398 |
#ifdef DEBUG |
| 399 |
fprintf(stderr, "\tpartially shadowed\n"); |
| 400 |
#endif |
| 401 |
return(f); /* intervening transmitter */ |
| 402 |
} |
| 403 |
nhit++; |
| 404 |
} |
| 405 |
if (nhit > 0 && nhit < nok) { |
| 406 |
#ifdef DEBUG |
| 407 |
fprintf(stderr, "\tpartially occluded\n"); |
| 408 |
#endif |
| 409 |
return(f); /* need to shadow test */ |
| 410 |
} |
| 411 |
} |
| 412 |
if (nhit == 0) { |
| 413 |
#ifdef DEBUG |
| 414 |
fprintf(stderr, "\t0%% hit rate\n"); |
| 415 |
#endif |
| 416 |
return(f | SSKIP); /* 0% hit rate: totally occluded */ |
| 417 |
} |
| 418 |
#ifdef DEBUG |
| 419 |
fprintf(stderr, "\t100%% hit rate\n"); |
| 420 |
#endif |
| 421 |
return(f & ~SFOLLOW); /* 100% hit rate: no occlusion */ |
| 422 |
} |
| 423 |
|
| 424 |
|
| 425 |
#ifdef DEBUG |
| 426 |
void |
| 427 |
virtverb( /* print verbose description of virtual source */ |
| 428 |
int sn, |
| 429 |
FILE *fp |
| 430 |
) |
| 431 |
{ |
| 432 |
fprintf(fp, "%s virtual source %d in %s %s\n", |
| 433 |
source[sn].sflags & SDISTANT ? "distant" : "local", |
| 434 |
sn, ofun[source[sn].so->otype].funame, |
| 435 |
source[sn].so->oname); |
| 436 |
fprintf(fp, "\tat (%f,%f,%f)\n", |
| 437 |
source[sn].sloc[0], source[sn].sloc[1], source[sn].sloc[2]); |
| 438 |
fprintf(fp, "\tlinked to source %d (%s)\n", |
| 439 |
source[sn].sa.sv.sn, source[source[sn].sa.sv.sn].so->oname); |
| 440 |
if (source[sn].sflags & SFOLLOW) |
| 441 |
fprintf(fp, "\talways followed\n"); |
| 442 |
else |
| 443 |
fprintf(fp, "\tnever followed\n"); |
| 444 |
if (!(source[sn].sflags & SSPOT)) |
| 445 |
return; |
| 446 |
fprintf(fp, "\twith spot aim (%f,%f,%f) and size %f\n", |
| 447 |
source[sn].sl.s->aim[0], source[sn].sl.s->aim[1], |
| 448 |
source[sn].sl.s->aim[2], source[sn].sl.s->siz); |
| 449 |
} |
| 450 |
#endif |
