| 27 |
|
short nt, np; /* number of theta and phi directions */ |
| 28 |
|
} AMBHEMI; /* ambient sample hemisphere */ |
| 29 |
|
|
| 30 |
– |
extern double sin(), cos(), sqrt(); |
| 30 |
|
|
| 32 |
– |
|
| 31 |
|
static int |
| 32 |
|
ambcmp(d1, d2) /* decreasing order */ |
| 33 |
|
AMBSAMP *d1, *d2; |
| 84 |
|
rayvalue(&ar); |
| 85 |
|
ndims--; |
| 86 |
|
addcolor(dp->v, ar.rcol); |
| 87 |
< |
if (ar.rt > FTINY && ar.rt < FHUGE) |
| 88 |
< |
dp->r += 1.0/ar.rt; |
| 87 |
> |
/* be conservative and use rot */ |
| 88 |
> |
if (ar.rot > FTINY && ar.rot < FHUGE) |
| 89 |
> |
dp->r += 1.0/ar.rot; |
| 90 |
|
/* (re)initialize error */ |
| 91 |
|
if (dp->n++) { |
| 92 |
|
b2 = bright(dp->v)/dp->n - bright(ar.rcol); |
| 140 |
|
dp->n = 0; |
| 141 |
|
if (divsample(dp, &hemi, r) < 0) |
| 142 |
|
goto oopsy; |
| 143 |
+ |
arad += dp->r; |
| 144 |
|
if (div != NULL) |
| 145 |
|
dp++; |
| 146 |
< |
else { |
| 146 |
> |
else |
| 147 |
|
addcolor(acol, dp->v); |
| 148 |
– |
arad += dp->r; |
| 149 |
– |
} |
| 148 |
|
} |
| 149 |
< |
if (ns > 0) { /* perform super-sampling */ |
| 149 |
> |
if (ns > 0 && arad > FTINY && ndivs/arad < minarad) |
| 150 |
> |
ns = 0; /* close enough */ |
| 151 |
> |
else if (ns > 0) { /* else perform super-sampling */ |
| 152 |
|
comperrs(div, &hemi); /* compute errors */ |
| 153 |
|
qsort(div, ndivs, sizeof(AMBSAMP), ambcmp); /* sort divs */ |
| 154 |
|
/* super-sample */ |
| 170 |
|
} |
| 171 |
|
/* compute returned values */ |
| 172 |
|
if (div != NULL) { |
| 173 |
+ |
arad = 0.0; |
| 174 |
|
for (i = ndivs, dp = div; i-- > 0; dp++) { |
| 175 |
|
arad += dp->r; |
| 176 |
|
if (dp->n > 1) { |
| 207 |
|
b = 1.0/ndivs; |
| 208 |
|
scalecolor(acol, b); |
| 209 |
|
if (arad <= FTINY) |
| 210 |
< |
arad = FHUGE; |
| 210 |
> |
arad = maxarad; |
| 211 |
|
else |
| 212 |
|
arad = (ndivs+ns)/arad; |
| 213 |
< |
if (arad > maxarad) |
| 214 |
< |
arad = maxarad; |
| 215 |
< |
else if (arad < minarad) |
| 213 |
> |
if (pg != NULL) { /* reduce radius if gradient large */ |
| 214 |
> |
d = DOT(pg,pg); |
| 215 |
> |
if (d*arad*arad > 1.0) |
| 216 |
> |
arad = 1.0/sqrt(d); |
| 217 |
> |
} |
| 218 |
> |
if (arad < minarad) { |
| 219 |
|
arad = minarad; |
| 220 |
< |
arad /= sqrt(wt); |
| 221 |
< |
if (pg != NULL) { /* clip pos. gradient if too large */ |
| 218 |
< |
d = 4.0*DOT(pg,pg)*arad*arad; |
| 219 |
< |
if (d > 1.0) { |
| 220 |
< |
d = 1.0/sqrt(d); |
| 220 |
> |
if (pg != NULL && d*arad*arad > 1.0) { /* cap gradient */ |
| 221 |
> |
d = 1.0/arad/sqrt(d); |
| 222 |
|
for (i = 0; i < 3; i++) |
| 223 |
|
pg[i] *= d; |
| 224 |
|
} |
| 225 |
|
} |
| 226 |
+ |
if ((arad /= sqrt(wt)) > maxarad) |
| 227 |
+ |
arad = maxarad; |
| 228 |
|
return(arad); |
| 229 |
|
oopsy: |
| 230 |
|
if (div != NULL) |
| 240 |
|
{ |
| 241 |
|
register int i; |
| 242 |
|
/* set number of divisions */ |
| 243 |
+ |
if (wt < (.25*PI)/ambdiv+FTINY) { |
| 244 |
+ |
hp->nt = hp->np = 0; |
| 245 |
+ |
return; /* zero samples */ |
| 246 |
+ |
} |
| 247 |
|
hp->nt = sqrt(ambdiv * wt / PI) + 0.5; |
| 248 |
< |
hp->np = PI * hp->nt; |
| 248 |
> |
hp->np = PI * hp->nt + 0.5; |
| 249 |
|
/* make axes */ |
| 250 |
|
VCOPY(hp->uz, r->ron); |
| 251 |
|
hp->uy[0] = hp->uy[1] = hp->uy[2] = 0.0; |
| 314 |
|
posgradient(gv, da, hp) /* compute position gradient */ |
| 315 |
|
FVECT gv; |
| 316 |
|
AMBSAMP *da; /* assumes standard ordering */ |
| 317 |
< |
AMBHEMI *hp; |
| 317 |
> |
register AMBHEMI *hp; |
| 318 |
|
{ |
| 319 |
|
register int i, j; |
| 320 |
< |
double b, d; |
| 320 |
> |
double nextsine, lastsine, b, d; |
| 321 |
|
double mag0, mag1; |
| 322 |
|
double phi, cosp, sinp, xd, yd; |
| 323 |
|
register AMBSAMP *dp; |
| 326 |
|
for (j = 0; j < hp->np; j++) { |
| 327 |
|
dp = da + j; |
| 328 |
|
mag0 = mag1 = 0.0; |
| 329 |
+ |
lastsine = 0.0; |
| 330 |
|
for (i = 0; i < hp->nt; i++) { |
| 331 |
|
#ifdef DEBUG |
| 332 |
|
if (dp->t != i || dp->p != j) |
| 337 |
|
if (i > 0) { |
| 338 |
|
d = dp[-hp->np].r; |
| 339 |
|
if (dp[0].r > d) d = dp[0].r; |
| 340 |
< |
d *= 1.0 - sqrt((double)i/hp->nt); |
| 340 |
> |
/* sin(t)*cos(t)^2 */ |
| 341 |
> |
d *= lastsine * (1.0 - (double)i/hp->nt); |
| 342 |
|
mag0 += d*(b - bright(dp[-hp->np].v)); |
| 343 |
|
} |
| 344 |
+ |
nextsine = sqrt((double)(i+1)/hp->nt); |
| 345 |
|
if (j > 0) { |
| 346 |
|
d = dp[-1].r; |
| 347 |
|
if (dp[0].r > d) d = dp[0].r; |
| 348 |
< |
mag1 += d*(b - bright(dp[-1].v)); |
| 348 |
> |
mag1 += d * (nextsine - lastsine) * |
| 349 |
> |
(b - bright(dp[-1].v)); |
| 350 |
|
} else { |
| 351 |
|
d = dp[hp->np-1].r; |
| 352 |
|
if (dp[0].r > d) d = dp[0].r; |
| 353 |
< |
mag1 += d*(b - bright(dp[hp->np-1].v)); |
| 353 |
> |
mag1 += d * (nextsine - lastsine) * |
| 354 |
> |
(b - bright(dp[hp->np-1].v)); |
| 355 |
|
} |
| 356 |
|
dp += hp->np; |
| 357 |
+ |
lastsine = nextsine; |
| 358 |
|
} |
| 359 |
< |
if (hp->nt > 1) { |
| 347 |
< |
mag0 /= (double)hp->np; |
| 348 |
< |
mag1 /= (double)hp->nt; |
| 349 |
< |
} |
| 359 |
> |
mag0 *= 2.0*PI / hp->np; |
| 360 |
|
phi = 2.0*PI * (double)j/hp->np; |
| 361 |
|
cosp = cos(phi); sinp = sin(phi); |
| 362 |
|
xd += mag0*cosp - mag1*sinp; |
| 370 |
|
dirgradient(gv, da, hp) /* compute direction gradient */ |
| 371 |
|
FVECT gv; |
| 372 |
|
AMBSAMP *da; /* assumes standard ordering */ |
| 373 |
< |
AMBHEMI *hp; |
| 373 |
> |
register AMBHEMI *hp; |
| 374 |
|
{ |
| 375 |
|
register int i, j; |
| 376 |
|
double mag; |
| 387 |
|
error(CONSISTENCY, |
| 388 |
|
"division order in dirgradient"); |
| 389 |
|
#endif |
| 390 |
< |
mag += sqrt((i+.5)/hp->nt)*bright(dp->v); |
| 390 |
> |
/* tan(t) */ |
| 391 |
> |
mag += bright(dp->v)/sqrt(hp->nt/(i+.5) - 1.0); |
| 392 |
|
dp += hp->np; |
| 393 |
|
} |
| 394 |
|
phi = 2.0*PI * (j+.5)/hp->np + PI/2.0; |
| 396 |
|
yd += mag * sin(phi); |
| 397 |
|
} |
| 398 |
|
for (i = 0; i < 3; i++) |
| 399 |
< |
gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])*PI/(hp->nt*hp->np); |
| 399 |
> |
gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])/(hp->nt*hp->np); |
| 400 |
|
} |
