| 1 |
– |
/* Copyright (c) 1991 Regents of the University of California */ |
| 2 |
– |
|
| 1 |
|
#ifndef lint |
| 2 |
< |
static char SCCSid[] = "$SunId$ LBL"; |
| 2 |
> |
static const char RCSid[] = "$Id$"; |
| 3 |
|
#endif |
| 6 |
– |
|
| 4 |
|
/* |
| 5 |
|
* Routines to compute "ambient" values using Monte Carlo |
| 6 |
+ |
* |
| 7 |
+ |
* Declarations of external symbols in ambient.h |
| 8 |
|
*/ |
| 9 |
|
|
| 10 |
+ |
#include "copyright.h" |
| 11 |
+ |
|
| 12 |
|
#include "ray.h" |
| 13 |
|
|
| 14 |
|
#include "ambient.h" |
| 15 |
|
|
| 16 |
|
#include "random.h" |
| 17 |
|
|
| 17 |
– |
typedef struct { |
| 18 |
– |
short t, p; /* theta, phi indices */ |
| 19 |
– |
COLOR v; /* value sum */ |
| 20 |
– |
float r; /* 1/distance sum */ |
| 21 |
– |
float k; /* variance for this division */ |
| 22 |
– |
int n; /* number of subsamples */ |
| 23 |
– |
} AMBSAMP; /* ambient sample division */ |
| 18 |
|
|
| 25 |
– |
typedef struct { |
| 26 |
– |
FVECT ux, uy, uz; /* x, y and z axis directions */ |
| 27 |
– |
short nt, np; /* number of theta and phi directions */ |
| 28 |
– |
} AMBHEMI; /* ambient sample hemisphere */ |
| 29 |
– |
|
| 30 |
– |
extern double sin(), cos(), sqrt(); |
| 31 |
– |
|
| 32 |
– |
|
| 19 |
|
static int |
| 20 |
|
ambcmp(d1, d2) /* decreasing order */ |
| 21 |
|
AMBSAMP *d1, *d2; |
| 40 |
|
} |
| 41 |
|
|
| 42 |
|
|
| 43 |
+ |
int |
| 44 |
|
divsample(dp, h, r) /* sample a division */ |
| 45 |
|
register AMBSAMP *dp; |
| 46 |
|
AMBHEMI *h; |
| 62 |
|
multisamp(spt, 2, urand(ilhash(hlist,3)+dp->n)); |
| 63 |
|
zd = sqrt((dp->t + spt[0])/h->nt); |
| 64 |
|
phi = 2.0*PI * (dp->p + spt[1])/h->np; |
| 65 |
< |
xd = cos(phi) * zd; |
| 66 |
< |
yd = sin(phi) * zd; |
| 65 |
> |
xd = tcos(phi) * zd; |
| 66 |
> |
yd = tsin(phi) * zd; |
| 67 |
|
zd = sqrt(1.0 - zd*zd); |
| 68 |
|
for (i = 0; i < 3; i++) |
| 69 |
|
ar.rdir[i] = xd*h->ux[i] + |
| 73 |
|
rayvalue(&ar); |
| 74 |
|
ndims--; |
| 75 |
|
addcolor(dp->v, ar.rcol); |
| 76 |
+ |
/* use rt to improve gradient calc */ |
| 77 |
|
if (ar.rt > FTINY && ar.rt < FHUGE) |
| 78 |
|
dp->r += 1.0/ar.rt; |
| 79 |
|
/* (re)initialize error */ |
| 129 |
|
dp->n = 0; |
| 130 |
|
if (divsample(dp, &hemi, r) < 0) |
| 131 |
|
goto oopsy; |
| 132 |
+ |
arad += dp->r; |
| 133 |
|
if (div != NULL) |
| 134 |
|
dp++; |
| 135 |
< |
else { |
| 135 |
> |
else |
| 136 |
|
addcolor(acol, dp->v); |
| 148 |
– |
arad += dp->r; |
| 149 |
– |
} |
| 137 |
|
} |
| 138 |
< |
if (ns > 0) { /* perform super-sampling */ |
| 138 |
> |
if (ns > 0 && arad > FTINY && ndivs/arad < minarad) |
| 139 |
> |
ns = 0; /* close enough */ |
| 140 |
> |
else if (ns > 0) { /* else perform super-sampling */ |
| 141 |
|
comperrs(div, &hemi); /* compute errors */ |
| 142 |
|
qsort(div, ndivs, sizeof(AMBSAMP), ambcmp); /* sort divs */ |
| 143 |
|
/* super-sample */ |
| 159 |
|
} |
| 160 |
|
/* compute returned values */ |
| 161 |
|
if (div != NULL) { |
| 162 |
+ |
arad = 0.0; |
| 163 |
|
for (i = ndivs, dp = div; i-- > 0; dp++) { |
| 164 |
|
arad += dp->r; |
| 165 |
|
if (dp->n > 1) { |
| 191 |
|
for (i = 0; i < 3; i++) |
| 192 |
|
dg[i] = 0.0; |
| 193 |
|
} |
| 194 |
< |
free((char *)div); |
| 194 |
> |
free((void *)div); |
| 195 |
|
} |
| 196 |
|
b = 1.0/ndivs; |
| 197 |
|
scalecolor(acol, b); |
| 198 |
|
if (arad <= FTINY) |
| 199 |
|
arad = maxarad; |
| 200 |
< |
else { |
| 200 |
> |
else |
| 201 |
|
arad = (ndivs+ns)/arad; |
| 212 |
– |
if (arad > maxarad) |
| 213 |
– |
arad = maxarad; |
| 214 |
– |
} |
| 202 |
|
if (pg != NULL) { /* reduce radius if gradient large */ |
| 203 |
|
d = DOT(pg,pg); |
| 204 |
|
if (d*arad*arad > 1.0) |
| 212 |
|
pg[i] *= d; |
| 213 |
|
} |
| 214 |
|
} |
| 215 |
< |
return(arad/sqrt(wt)); |
| 215 |
> |
if ((arad /= sqrt(wt)) > maxarad) |
| 216 |
> |
arad = maxarad; |
| 217 |
> |
return(arad); |
| 218 |
|
oopsy: |
| 219 |
|
if (div != NULL) |
| 220 |
< |
free((char *)div); |
| 220 |
> |
free((void *)div); |
| 221 |
|
return(0.0); |
| 222 |
|
} |
| 223 |
|
|
| 224 |
|
|
| 225 |
+ |
void |
| 226 |
|
inithemi(hp, r, wt) /* initialize sampling hemisphere */ |
| 227 |
|
register AMBHEMI *hp; |
| 228 |
|
RAY *r; |
| 251 |
|
} |
| 252 |
|
|
| 253 |
|
|
| 254 |
+ |
void |
| 255 |
|
comperrs(da, hp) /* compute initial error estimates */ |
| 256 |
|
AMBSAMP *da; /* assumes standard ordering */ |
| 257 |
|
register AMBHEMI *hp; |
| 302 |
|
} |
| 303 |
|
|
| 304 |
|
|
| 305 |
+ |
void |
| 306 |
|
posgradient(gv, da, hp) /* compute position gradient */ |
| 307 |
|
FVECT gv; |
| 308 |
|
AMBSAMP *da; /* assumes standard ordering */ |
| 350 |
|
} |
| 351 |
|
mag0 *= 2.0*PI / hp->np; |
| 352 |
|
phi = 2.0*PI * (double)j/hp->np; |
| 353 |
< |
cosp = cos(phi); sinp = sin(phi); |
| 353 |
> |
cosp = tcos(phi); sinp = tsin(phi); |
| 354 |
|
xd += mag0*cosp - mag1*sinp; |
| 355 |
|
yd += mag0*sinp + mag1*cosp; |
| 356 |
|
} |
| 359 |
|
} |
| 360 |
|
|
| 361 |
|
|
| 362 |
+ |
void |
| 363 |
|
dirgradient(gv, da, hp) /* compute direction gradient */ |
| 364 |
|
FVECT gv; |
| 365 |
|
AMBSAMP *da; /* assumes standard ordering */ |
| 385 |
|
dp += hp->np; |
| 386 |
|
} |
| 387 |
|
phi = 2.0*PI * (j+.5)/hp->np + PI/2.0; |
| 388 |
< |
xd += mag * cos(phi); |
| 389 |
< |
yd += mag * sin(phi); |
| 388 |
> |
xd += mag * tcos(phi); |
| 389 |
> |
yd += mag * tsin(phi); |
| 390 |
|
} |
| 391 |
|
for (i = 0; i < 3; i++) |
| 392 |
|
gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])/(hp->nt*hp->np); |
