| 1 |
/* Copyright (c) 1991 Regents of the University of California */ |
| 2 |
|
| 3 |
#ifndef lint |
| 4 |
static char SCCSid[] = "$SunId$ LBL"; |
| 5 |
#endif |
| 6 |
|
| 7 |
/* |
| 8 |
* source.c - routines dealing with illumination sources. |
| 9 |
* |
| 10 |
* 8/20/85 |
| 11 |
*/ |
| 12 |
|
| 13 |
#include "ray.h" |
| 14 |
|
| 15 |
#include "octree.h" |
| 16 |
|
| 17 |
#include "otypes.h" |
| 18 |
|
| 19 |
#include "source.h" |
| 20 |
|
| 21 |
/* |
| 22 |
* Structures used by direct() |
| 23 |
*/ |
| 24 |
|
| 25 |
typedef struct { |
| 26 |
int sno; /* source number */ |
| 27 |
FVECT dir; /* source direction */ |
| 28 |
COLOR coef; /* material coefficient */ |
| 29 |
COLOR val; /* contribution */ |
| 30 |
} CONTRIB; /* direct contribution */ |
| 31 |
|
| 32 |
typedef struct { |
| 33 |
int sndx; /* source index (to CONTRIB array) */ |
| 34 |
float brt; /* brightness (for comparison) */ |
| 35 |
} CNTPTR; /* contribution pointer */ |
| 36 |
|
| 37 |
static CONTRIB *srccnt; /* source contributions in direct() */ |
| 38 |
static CNTPTR *cntord; /* source ordering in direct() */ |
| 39 |
static int maxcntr = 0; /* size of contribution arrays */ |
| 40 |
|
| 41 |
|
| 42 |
marksources() /* find and mark source objects */ |
| 43 |
{ |
| 44 |
int foundsource = 0; |
| 45 |
int i; |
| 46 |
register OBJREC *o, *m; |
| 47 |
register int ns; |
| 48 |
/* initialize dispatch table */ |
| 49 |
initstypes(); |
| 50 |
/* find direct sources */ |
| 51 |
for (i = 0; i < nobjects; i++) { |
| 52 |
|
| 53 |
o = objptr(i); |
| 54 |
|
| 55 |
if (!issurface(o->otype) || o->omod == OVOID) |
| 56 |
continue; |
| 57 |
|
| 58 |
m = objptr(o->omod); |
| 59 |
|
| 60 |
if (!islight(m->otype)) |
| 61 |
continue; |
| 62 |
|
| 63 |
if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 : |
| 64 |
m->otype == MAT_SPOT ? 7 : 3)) |
| 65 |
objerror(m, USER, "bad # arguments"); |
| 66 |
|
| 67 |
if (m->otype == MAT_GLOW && |
| 68 |
o->otype != OBJ_SOURCE && |
| 69 |
m->oargs.farg[3] <= FTINY) |
| 70 |
continue; /* don't bother */ |
| 71 |
|
| 72 |
if (sfun[o->otype].of == NULL || |
| 73 |
sfun[o->otype].of->setsrc == NULL) |
| 74 |
objerror(o, USER, "illegal material"); |
| 75 |
|
| 76 |
if ((ns = newsource()) < 0) |
| 77 |
goto memerr; |
| 78 |
|
| 79 |
setsource(&source[ns], o); |
| 80 |
|
| 81 |
if (m->otype == MAT_GLOW) { |
| 82 |
source[ns].sflags |= SPROX; |
| 83 |
source[ns].sl.prox = m->oargs.farg[3]; |
| 84 |
if (o->otype == OBJ_SOURCE) |
| 85 |
source[ns].sflags |= SSKIP; |
| 86 |
} else if (m->otype == MAT_SPOT) { |
| 87 |
source[ns].sflags |= SSPOT; |
| 88 |
if ((source[ns].sl.s = makespot(m)) == NULL) |
| 89 |
goto memerr; |
| 90 |
if (source[ns].sflags & SFLAT && |
| 91 |
!checkspot(source[ns].sl.s,source[ns].snorm)) { |
| 92 |
objerror(o, WARNING, |
| 93 |
"invalid spotlight direction"); |
| 94 |
source[ns].sflags |= SSKIP; |
| 95 |
} |
| 96 |
} |
| 97 |
if (!(source[ns].sflags & SSKIP)) |
| 98 |
foundsource++; |
| 99 |
} |
| 100 |
if (!foundsource) { |
| 101 |
error(WARNING, "no light sources found"); |
| 102 |
return; |
| 103 |
} |
| 104 |
markvirtuals(); /* find and add virtual sources */ |
| 105 |
/* allocate our contribution arrays */ |
| 106 |
maxcntr = nsources + MAXSPART; /* start with this many */ |
| 107 |
srccnt = (CONTRIB *)malloc(maxcntr*sizeof(CONTRIB)); |
| 108 |
cntord = (CNTPTR *)malloc(maxcntr*sizeof(CNTPTR)); |
| 109 |
if (srccnt == NULL | cntord == NULL) |
| 110 |
goto memerr; |
| 111 |
return; |
| 112 |
memerr: |
| 113 |
error(SYSTEM, "out of memory in marksources"); |
| 114 |
} |
| 115 |
|
| 116 |
|
| 117 |
srcray(sr, r, si) /* send a ray to a source, return domega */ |
| 118 |
register RAY *sr; /* returned source ray */ |
| 119 |
RAY *r; /* ray which hit object */ |
| 120 |
SRCINDEX *si; /* source sample index */ |
| 121 |
{ |
| 122 |
double d; /* distance to source */ |
| 123 |
FVECT vd; |
| 124 |
register SRCREC *srcp; |
| 125 |
register int i; |
| 126 |
|
| 127 |
rayorigin(sr, r, SHADOW, 1.0); /* ignore limits */ |
| 128 |
|
| 129 |
while ((d = nextssamp(sr, si)) != 0.0) { |
| 130 |
sr->rsrc = si->sn; /* remember source */ |
| 131 |
srcp = source + si->sn; |
| 132 |
if (srcp->sflags & SDISTANT) { |
| 133 |
if (srcp->sflags & SSPOT) { /* check location */ |
| 134 |
for (i = 0; i < 3; i++) |
| 135 |
vd[i] = srcp->sl.s->aim[i] - sr->rorg[i]; |
| 136 |
d = DOT(sr->rdir,vd); |
| 137 |
if (d <= FTINY) |
| 138 |
continue; |
| 139 |
d = DOT(vd,vd) - d*d; |
| 140 |
if (PI*d > srcp->sl.s->siz) |
| 141 |
continue; |
| 142 |
} |
| 143 |
return(1); /* sample OK */ |
| 144 |
} |
| 145 |
/* local source */ |
| 146 |
/* check proximity */ |
| 147 |
if (srcp->sflags & SPROX && d > srcp->sl.prox) |
| 148 |
continue; |
| 149 |
/* check angle */ |
| 150 |
if (srcp->sflags & SSPOT) { |
| 151 |
if (srcp->sl.s->siz < 2.0*PI * |
| 152 |
(1.0 + DOT(srcp->sl.s->aim,sr->rdir))) |
| 153 |
continue; |
| 154 |
/* adjust solid angle */ |
| 155 |
si->dom *= d*d; |
| 156 |
d += srcp->sl.s->flen; |
| 157 |
si->dom /= d*d; |
| 158 |
} |
| 159 |
return(1); /* sample OK */ |
| 160 |
} |
| 161 |
return(0); /* no more samples */ |
| 162 |
} |
| 163 |
|
| 164 |
|
| 165 |
srcvalue(r) /* punch ray to source and compute value */ |
| 166 |
RAY *r; |
| 167 |
{ |
| 168 |
register SRCREC *sp; |
| 169 |
|
| 170 |
sp = &source[r->rsrc]; |
| 171 |
if (sp->sflags & SVIRTUAL) { /* virtual source */ |
| 172 |
/* check intersection */ |
| 173 |
if (!(*ofun[sp->so->otype].funp)(sp->so, r)) |
| 174 |
return; |
| 175 |
raycont(r); /* compute contribution */ |
| 176 |
return; |
| 177 |
} |
| 178 |
/* compute intersection */ |
| 179 |
if (sp->sflags & SDISTANT ? sourcehit(r) : |
| 180 |
(*ofun[sp->so->otype].funp)(sp->so, r)) { |
| 181 |
if (sp->sa.success >= 0) |
| 182 |
sp->sa.success++; |
| 183 |
raycont(r); /* compute contribution */ |
| 184 |
return; |
| 185 |
} |
| 186 |
if (sp->sa.success < 0) |
| 187 |
return; /* bitched already */ |
| 188 |
sp->sa.success -= AIMREQT; |
| 189 |
if (sp->sa.success >= 0) |
| 190 |
return; /* leniency */ |
| 191 |
sprintf(errmsg, "aiming failure for light source \"%s\"", |
| 192 |
sp->so->oname); |
| 193 |
error(WARNING, errmsg); /* issue warning */ |
| 194 |
} |
| 195 |
|
| 196 |
|
| 197 |
static int |
| 198 |
cntcmp(sc1, sc2) /* contribution compare (descending) */ |
| 199 |
register CNTPTR *sc1, *sc2; |
| 200 |
{ |
| 201 |
if (sc1->brt > sc2->brt) |
| 202 |
return(-1); |
| 203 |
if (sc1->brt < sc2->brt) |
| 204 |
return(1); |
| 205 |
return(0); |
| 206 |
} |
| 207 |
|
| 208 |
|
| 209 |
direct(r, f, p) /* add direct component */ |
| 210 |
RAY *r; /* ray that hit surface */ |
| 211 |
int (*f)(); /* direct component coefficient function */ |
| 212 |
char *p; /* data for f */ |
| 213 |
{ |
| 214 |
extern int (*trace)(); |
| 215 |
extern double pow(); |
| 216 |
register int sn; |
| 217 |
SRCINDEX si; |
| 218 |
int nshadcheck, ncnts; |
| 219 |
int nhits; |
| 220 |
double prob, ourthresh, hwt; |
| 221 |
RAY sr; |
| 222 |
/* NOTE: srccnt and cntord global so no recursion */ |
| 223 |
if (nsources <= 0) |
| 224 |
return; /* no sources?! */ |
| 225 |
/* potential contributions */ |
| 226 |
initsrcindex(&si); |
| 227 |
for (sn = 0; srcray(&sr, r, &si); sn++) { |
| 228 |
if (sn >= maxcntr) { |
| 229 |
maxcntr = sn + MAXSPART; |
| 230 |
srccnt = (CONTRIB *)realloc((char *)srccnt, |
| 231 |
maxcntr*sizeof(CONTRIB)); |
| 232 |
cntord = (CNTPTR *)realloc((char *)cntord, |
| 233 |
maxcntr*sizeof(CNTPTR)); |
| 234 |
if (srccnt == NULL | cntord == NULL) |
| 235 |
error(SYSTEM, "out of memory in direct"); |
| 236 |
} |
| 237 |
cntord[sn].sndx = sn; |
| 238 |
srccnt[sn].sno = sr.rsrc; |
| 239 |
/* compute coefficient */ |
| 240 |
(*f)(srccnt[sn].coef, p, sr.rdir, si.dom); |
| 241 |
cntord[sn].brt = bright(srccnt[sn].coef); |
| 242 |
if (cntord[sn].brt <= 0.0) |
| 243 |
continue; |
| 244 |
VCOPY(srccnt[sn].dir, sr.rdir); |
| 245 |
/* compute potential */ |
| 246 |
sr.revf = srcvalue; |
| 247 |
rayvalue(&sr); |
| 248 |
copycolor(srccnt[sn].val, sr.rcol); |
| 249 |
multcolor(srccnt[sn].val, srccnt[sn].coef); |
| 250 |
cntord[sn].brt = bright(srccnt[sn].val); |
| 251 |
} |
| 252 |
/* sort contributions */ |
| 253 |
qsort(cntord, sn, sizeof(CNTPTR), cntcmp); |
| 254 |
{ /* find last */ |
| 255 |
register int l, m; |
| 256 |
|
| 257 |
ncnts = l = sn; |
| 258 |
sn = 0; |
| 259 |
while ((m = (sn + ncnts) >> 1) != l) { |
| 260 |
if (cntord[m].brt > 0.0) |
| 261 |
sn = m; |
| 262 |
else |
| 263 |
ncnts = m; |
| 264 |
l = m; |
| 265 |
} |
| 266 |
} |
| 267 |
if (ncnts == 0) |
| 268 |
return; /* no contributions! */ |
| 269 |
/* accumulate tail */ |
| 270 |
for (sn = ncnts-1; sn > 0; sn--) |
| 271 |
cntord[sn-1].brt += cntord[sn].brt; |
| 272 |
/* compute number to check */ |
| 273 |
nshadcheck = pow((double)ncnts, shadcert) + .5; |
| 274 |
/* modify threshold */ |
| 275 |
ourthresh = shadthresh / r->rweight; |
| 276 |
/* test for shadows */ |
| 277 |
nhits = 0; |
| 278 |
for (sn = 0; sn < ncnts; sn++) { |
| 279 |
/* check threshold */ |
| 280 |
if ((sn+nshadcheck>=ncnts ? cntord[sn].brt : |
| 281 |
cntord[sn].brt-cntord[sn+nshadcheck].brt) |
| 282 |
< ourthresh*bright(r->rcol)) |
| 283 |
break; |
| 284 |
/* test for hit */ |
| 285 |
rayorigin(&sr, r, SHADOW, 1.0); |
| 286 |
VCOPY(sr.rdir, srccnt[cntord[sn].sndx].dir); |
| 287 |
sr.rsrc = srccnt[cntord[sn].sndx].sno; |
| 288 |
source[sr.rsrc].ntests++; /* keep statistics */ |
| 289 |
if (localhit(&sr, &thescene) && |
| 290 |
( sr.ro != source[sr.rsrc].so || |
| 291 |
source[sr.rsrc].sflags & SFOLLOW )) { |
| 292 |
/* follow entire path */ |
| 293 |
raycont(&sr); |
| 294 |
if (trace != NULL) |
| 295 |
(*trace)(&sr); /* trace execution */ |
| 296 |
if (bright(sr.rcol) <= FTINY) |
| 297 |
continue; /* missed! */ |
| 298 |
copycolor(srccnt[cntord[sn].sndx].val, sr.rcol); |
| 299 |
multcolor(srccnt[cntord[sn].sndx].val, |
| 300 |
srccnt[cntord[sn].sndx].coef); |
| 301 |
} |
| 302 |
/* add contribution if hit */ |
| 303 |
addcolor(r->rcol, srccnt[cntord[sn].sndx].val); |
| 304 |
nhits++; |
| 305 |
source[sr.rsrc].nhits++; |
| 306 |
} |
| 307 |
/* surface hit rate */ |
| 308 |
if (sn > 0) |
| 309 |
hwt = (double)nhits / (double)sn; |
| 310 |
else |
| 311 |
hwt = 0.5; |
| 312 |
#ifdef DEBUG |
| 313 |
sprintf(errmsg, "%d tested, %d untested, %f hit rate\n", |
| 314 |
sn, ncnts-sn, hwt); |
| 315 |
eputs(errmsg); |
| 316 |
#endif |
| 317 |
/* add in untested sources */ |
| 318 |
for ( ; sn < ncnts; sn++) { |
| 319 |
sr.rsrc = srccnt[cntord[sn].sndx].sno; |
| 320 |
prob = hwt * (double)source[sr.rsrc].nhits / |
| 321 |
(double)source[sr.rsrc].ntests; |
| 322 |
scalecolor(srccnt[cntord[sn].sndx].val, prob); |
| 323 |
addcolor(r->rcol, srccnt[cntord[sn].sndx].val); |
| 324 |
} |
| 325 |
} |
