| 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 |
* Gather samples and compute glare sources. |
| 9 |
*/ |
| 10 |
|
| 11 |
#include "glare.h" |
| 12 |
|
| 13 |
#define vcont(vd,vu) ((vu)-(vd)<=SEPS) |
| 14 |
#define hcont(s1,s2) ((s1)->r-(s2)->l>=-SEPS&&(s2)->r-(s1)->l>=-SEPS) |
| 15 |
|
| 16 |
struct source *curlist = NULL; /* current source list */ |
| 17 |
struct source *donelist = NULL; /* finished sources */ |
| 18 |
|
| 19 |
|
| 20 |
struct srcspan * |
| 21 |
newspan(l, r, v, sb) /* allocate a new source span */ |
| 22 |
int l, r, v; |
| 23 |
float *sb; |
| 24 |
{ |
| 25 |
register struct srcspan *ss; |
| 26 |
register int i; |
| 27 |
|
| 28 |
ss = (struct srcspan *)malloc(sizeof(struct srcspan)); |
| 29 |
if (ss == NULL) |
| 30 |
memerr("source spans"); |
| 31 |
ss->l = l; |
| 32 |
ss->r = r; |
| 33 |
ss->v = v; |
| 34 |
ss->brsum = 0.0; |
| 35 |
for (i = l; i < r; i++) |
| 36 |
ss->brsum += sb[i+hsize]; |
| 37 |
return(ss); |
| 38 |
} |
| 39 |
|
| 40 |
|
| 41 |
analyze() /* analyze our scene */ |
| 42 |
{ |
| 43 |
int h, v; |
| 44 |
int left; |
| 45 |
float *spanbr; |
| 46 |
|
| 47 |
spanbr = (float *)malloc((2*hsize+1)*sizeof(float)); |
| 48 |
if (spanbr == NULL) |
| 49 |
memerr("view span brightness buffer"); |
| 50 |
for (v = vsize; v >= -vsize; v--) { |
| 51 |
close_sources(v); |
| 52 |
#ifndef DEBUG |
| 53 |
if (verbose) |
| 54 |
fprintf(stderr, "%s: analyzing... %3ld%%\r", |
| 55 |
progname, 100L*(vsize-v)/(2*vsize)); |
| 56 |
#endif |
| 57 |
getviewspan(v, spanbr); |
| 58 |
left = hsize + 1; |
| 59 |
for (h = -hsize; h <= hsize; h++) { |
| 60 |
if (spanbr[h+hsize] < 0.0) { /* off view */ |
| 61 |
if (left < h) { |
| 62 |
addsrcspan(newspan(left,h,v,spanbr)); |
| 63 |
left = hsize + 1; |
| 64 |
} |
| 65 |
continue; |
| 66 |
} |
| 67 |
if (spanbr[h+hsize] > threshold) { /* in source */ |
| 68 |
if (left > h) |
| 69 |
left = h; |
| 70 |
} else { /* out of source */ |
| 71 |
if (left < h) { |
| 72 |
addsrcspan(newspan(left,h,v,spanbr)); |
| 73 |
left = hsize + 1; |
| 74 |
} |
| 75 |
addindirect(h, v, spanbr[h+hsize]); |
| 76 |
} |
| 77 |
} |
| 78 |
if (left < h) |
| 79 |
addsrcspan(newspan(left,h,v,spanbr)); |
| 80 |
} |
| 81 |
free((char *)spanbr); |
| 82 |
close_allsrcs(); |
| 83 |
} |
| 84 |
|
| 85 |
|
| 86 |
addindirect(h, v, br) /* add brightness to indirect illuminances */ |
| 87 |
int h, v; |
| 88 |
double br; |
| 89 |
{ |
| 90 |
double tanb, d; |
| 91 |
int hl; |
| 92 |
register int i; |
| 93 |
|
| 94 |
hl = hlim(v); |
| 95 |
if (h <= -hl) { /* left region */ |
| 96 |
d = (double)(-h-hl)/sampdens; |
| 97 |
if (d >= 1.0-FTINY) |
| 98 |
return; |
| 99 |
tanb = d/sqrt(1.0-d*d); |
| 100 |
for (i = 0; i < nglardirs; i++) { |
| 101 |
d = indirect[i].lcos - tanb*indirect[i].lsin; |
| 102 |
if (d > 0.0) { |
| 103 |
indirect[i].sum += d * br; |
| 104 |
indirect[i].n += d; |
| 105 |
} |
| 106 |
} |
| 107 |
return; |
| 108 |
} |
| 109 |
if (h >= hl) { /* right region */ |
| 110 |
d = (double)(-h+hl)/sampdens; |
| 111 |
if (d <= -1.0+FTINY) |
| 112 |
return; |
| 113 |
tanb = d/sqrt(1.0-d*d); |
| 114 |
for (i = 0; i < nglardirs; i++) { |
| 115 |
d = indirect[i].rcos - tanb*indirect[i].rsin; |
| 116 |
if (d > 0.0) { |
| 117 |
indirect[i].sum += d * br; |
| 118 |
indirect[i].n += d; |
| 119 |
} |
| 120 |
} |
| 121 |
return; |
| 122 |
} |
| 123 |
/* central region */ |
| 124 |
for (i = 0; i < nglardirs; i++) { |
| 125 |
d = cos(h_theta(h,v) - indirect[i].theta); |
| 126 |
if (d > 0.0) { |
| 127 |
indirect[i].sum += d * br; |
| 128 |
indirect[i].n += d; |
| 129 |
} |
| 130 |
} |
| 131 |
} |
| 132 |
|
| 133 |
|
| 134 |
comp_thresh() /* compute glare threshold */ |
| 135 |
{ |
| 136 |
int h, v; |
| 137 |
int nsamps; |
| 138 |
double brsum, br; |
| 139 |
|
| 140 |
if (verbose) |
| 141 |
fprintf(stderr, "%s: computing glare threshold...\n", |
| 142 |
progname); |
| 143 |
brsum = 0.0; |
| 144 |
nsamps = 0; |
| 145 |
for (v = vsize; v >= -vsize; v -= TSAMPSTEP) { |
| 146 |
for (h = -hsize; h <= hsize; h += TSAMPSTEP) { |
| 147 |
if ((br = getviewpix(h, v)) < 0.0) |
| 148 |
continue; |
| 149 |
brsum += br; |
| 150 |
nsamps++; |
| 151 |
} |
| 152 |
} |
| 153 |
if (nsamps == 0) { |
| 154 |
fprintf(stderr, "%s: no viewable scene!\n", progname); |
| 155 |
exit(1); |
| 156 |
} |
| 157 |
threshold = GLAREBR * brsum / nsamps; |
| 158 |
if (threshold <= FTINY) { |
| 159 |
fprintf(stderr, "%s: threshold zero!\n", progname); |
| 160 |
exit(1); |
| 161 |
} |
| 162 |
if (verbose) { |
| 163 |
#ifdef DEBUG |
| 164 |
pict_stats(); |
| 165 |
#endif |
| 166 |
fprintf(stderr, |
| 167 |
"%s: threshold set to %f cd/m2 from %d samples\n", |
| 168 |
progname, threshold, nsamps); |
| 169 |
} |
| 170 |
} |
| 171 |
|
| 172 |
|
| 173 |
addsrcspan(nss) /* add new source span to our list */ |
| 174 |
struct srcspan *nss; |
| 175 |
{ |
| 176 |
struct source *last, *cs, *this; |
| 177 |
register struct srcspan *ss; |
| 178 |
|
| 179 |
cs = NULL; |
| 180 |
for (this = curlist; this != NULL; this = this->next) { |
| 181 |
for (ss = this->first; ss != NULL; ss = ss->next) { |
| 182 |
if (!vcont(nss->v, ss->v)) |
| 183 |
break; |
| 184 |
if (hcont(ss, nss)) { |
| 185 |
if (cs == NULL) |
| 186 |
cs = this; |
| 187 |
else { |
| 188 |
last->next = this->next; |
| 189 |
mergesource(cs, this); |
| 190 |
this = last; |
| 191 |
} |
| 192 |
break; |
| 193 |
} |
| 194 |
} |
| 195 |
last = this; |
| 196 |
} |
| 197 |
if (cs == NULL) { |
| 198 |
cs = (struct source *)malloc(sizeof(struct source)); |
| 199 |
if (cs == NULL) |
| 200 |
memerr("source records"); |
| 201 |
cs->dom = 0.0; |
| 202 |
cs->first = NULL; |
| 203 |
cs->next = curlist; |
| 204 |
curlist = cs; |
| 205 |
} |
| 206 |
nss->next = cs->first; |
| 207 |
cs->first = nss; |
| 208 |
} |
| 209 |
|
| 210 |
|
| 211 |
mergesource(sp, ap) /* merge source ap into source sp */ |
| 212 |
struct source *sp, *ap; |
| 213 |
{ |
| 214 |
struct srcspan head; |
| 215 |
register struct srcspan *alp, *prev, *tp; |
| 216 |
|
| 217 |
head.next = sp->first; |
| 218 |
prev = &head; |
| 219 |
alp = ap->first; |
| 220 |
while (alp != NULL && prev->next != NULL) { |
| 221 |
if (prev->next->v > alp->v) { |
| 222 |
tp = alp->next; |
| 223 |
alp->next = prev->next; |
| 224 |
prev->next = alp; |
| 225 |
alp = tp; |
| 226 |
} |
| 227 |
prev = prev->next; |
| 228 |
} |
| 229 |
if (prev->next == NULL) |
| 230 |
prev->next = alp; |
| 231 |
sp->first = head.next; |
| 232 |
if (ap->dom > 0.0 && sp->dom > 0.0) { /* sources are done */ |
| 233 |
sp->dir[0] *= sp->dom; |
| 234 |
sp->dir[1] *= sp->dom; |
| 235 |
sp->dir[2] *= sp->dom; |
| 236 |
fvsum(sp->dir, sp->dir, ap->dir, ap->dom); |
| 237 |
normalize(sp->dir); |
| 238 |
sp->brt = (sp->brt*sp->dom + ap->brt*ap->dom) |
| 239 |
/ (sp->dom + ap->dom); |
| 240 |
} |
| 241 |
free((char *)ap); |
| 242 |
} |
| 243 |
|
| 244 |
|
| 245 |
close_sources(v) /* close sources above v */ |
| 246 |
int v; |
| 247 |
{ |
| 248 |
struct source head; |
| 249 |
register struct source *last, *this; |
| 250 |
|
| 251 |
head.next = curlist; |
| 252 |
last = &head; |
| 253 |
for (this = curlist; this != NULL; this = this->next) |
| 254 |
if (!vcont(v, this->first->v)) { |
| 255 |
last->next = this->next; |
| 256 |
donesource(this); |
| 257 |
this = last; |
| 258 |
} else |
| 259 |
last = this; |
| 260 |
curlist = head.next; |
| 261 |
} |
| 262 |
|
| 263 |
|
| 264 |
close_allsrcs() /* done with everything */ |
| 265 |
{ |
| 266 |
register struct source *this, *next; |
| 267 |
|
| 268 |
this = curlist; |
| 269 |
while (this != NULL) { |
| 270 |
next = this->next; |
| 271 |
donesource(this); |
| 272 |
this = next; |
| 273 |
} |
| 274 |
curlist = NULL; |
| 275 |
} |
| 276 |
|
| 277 |
|
| 278 |
donesource(sp) /* finished with this source */ |
| 279 |
register struct source *sp; |
| 280 |
{ |
| 281 |
FVECT dthis, dright; |
| 282 |
register struct srcspan *ss; |
| 283 |
int h, n; |
| 284 |
double hsum, vsum, d; |
| 285 |
|
| 286 |
sp->dom = 0.0; |
| 287 |
hsum = vsum = 0.0; |
| 288 |
sp->brt = 0.0; |
| 289 |
n = 0; |
| 290 |
for (ss = sp->first; ss != NULL; ss = ss->next) { |
| 291 |
sp->brt += ss->brsum; |
| 292 |
n += ss->r - ss->l; |
| 293 |
for (h = ss->r-1; h >= ss->l; h--) { |
| 294 |
d = pixsize(h, ss->v); |
| 295 |
hsum += d*h; |
| 296 |
vsum += d*ss->v; |
| 297 |
sp->dom += d; |
| 298 |
} |
| 299 |
free((char *)ss); |
| 300 |
} |
| 301 |
sp->first = NULL; |
| 302 |
sp->brt /= (double)n; |
| 303 |
compdir(sp->dir, (int)(hsum/sp->dom), (int)(vsum/sp->dom)); |
| 304 |
sp->next = donelist; |
| 305 |
donelist = sp; |
| 306 |
if (verbose) |
| 307 |
fprintf(stderr, |
| 308 |
"%s: source at [%.3f,%.3f,%.3f], dw %.5f, br %.1f (%d samps)\n", |
| 309 |
progname, sp->dir[0], sp->dir[1], sp->dir[2], |
| 310 |
sp->dom, sp->brt, n); |
| 311 |
} |
| 312 |
|
| 313 |
|
| 314 |
struct source * |
| 315 |
findbuddy(s, l) /* find close enough source to s in l*/ |
| 316 |
register struct source *s, *l; |
| 317 |
{ |
| 318 |
struct source *bestbuddy = NULL; |
| 319 |
double d, r, mindist = MAXBUDDY; |
| 320 |
|
| 321 |
r = sqrt(s->dom/PI); |
| 322 |
for ( ; l != NULL; l = l->next) { |
| 323 |
d = sqrt(dist2(l->dir, s->dir)) - sqrt(l->dom/PI) - r; |
| 324 |
if (d < mindist) { |
| 325 |
bestbuddy = l; |
| 326 |
mindist = d; |
| 327 |
} |
| 328 |
} |
| 329 |
return(bestbuddy); |
| 330 |
} |
| 331 |
|
| 332 |
|
| 333 |
absorb_specks() /* eliminate too-small sources */ |
| 334 |
{ |
| 335 |
struct source head, *buddy; |
| 336 |
register struct source *last, *this; |
| 337 |
|
| 338 |
if (verbose) |
| 339 |
fprintf(stderr, "%s: absorbing small sources...\n", progname); |
| 340 |
head.next = donelist; |
| 341 |
last = &head; |
| 342 |
for (this = head.next; this != NULL; this = this->next) |
| 343 |
if (TOOSMALL(this)) { |
| 344 |
last->next = this->next; |
| 345 |
buddy = findbuddy(this, head.next); |
| 346 |
if (buddy != NULL) |
| 347 |
mergesource(buddy, this); |
| 348 |
else |
| 349 |
absorb(this); |
| 350 |
this = last; |
| 351 |
} else |
| 352 |
last = this; |
| 353 |
donelist = head.next; |
| 354 |
} |
| 355 |
|
| 356 |
|
| 357 |
absorb(s) /* absorb a source into indirect */ |
| 358 |
register struct source *s; |
| 359 |
{ |
| 360 |
FVECT dir; |
| 361 |
double d; |
| 362 |
register int i; |
| 363 |
|
| 364 |
for (i = 0; i < nglardirs; i++) { |
| 365 |
spinvector(dir, ourview.vdir, ourview.vup, indirect[i].theta); |
| 366 |
d = DOT(dir,s->dir)*s->dom*(sampdens*sampdens); |
| 367 |
if (d <= 0.0) |
| 368 |
continue; |
| 369 |
indirect[i].sum += d * s->brt; |
| 370 |
indirect[i].n += d; |
| 371 |
} |
| 372 |
for ( ; s->first != NULL; s->first = s->first->next) |
| 373 |
free((char *)s->first); |
| 374 |
free((char *)s); |
| 375 |
} |
