| 21 |
|
#include "ambient.h" |
| 22 |
|
#include "random.h" |
| 23 |
|
|
| 24 |
< |
#ifndef OLDAMB |
| 24 |
> |
#ifndef MINADIV |
| 25 |
> |
#define MINADIV 7 /* minimum # divisions in each dimension */ |
| 26 |
> |
#endif |
| 27 |
|
|
| 28 |
|
extern void SDsquare2disk(double ds[2], double seedx, double seedy); |
| 29 |
|
|
| 30 |
|
typedef struct { |
| 31 |
|
COLOR v; /* hemisphere sample value */ |
| 32 |
< |
float d; /* reciprocal distance (1/rt) */ |
| 32 |
> |
float d; /* reciprocal distance */ |
| 33 |
|
FVECT p; /* intersection point */ |
| 34 |
|
} AMBSAMP; /* sample value */ |
| 35 |
|
|
| 53 |
|
|
| 54 |
|
|
| 55 |
|
static int |
| 56 |
+ |
ambcollision( /* proposed direciton collides? */ |
| 57 |
+ |
AMBHEMI *hp, |
| 58 |
+ |
int i, |
| 59 |
+ |
int j, |
| 60 |
+ |
FVECT dv |
| 61 |
+ |
) |
| 62 |
+ |
{ |
| 63 |
+ |
double cos_thresh; |
| 64 |
+ |
int ii, jj; |
| 65 |
+ |
/* min. spacing = 1/4th division */ |
| 66 |
+ |
cos_thresh = (PI/4.)/(double)hp->ns; |
| 67 |
+ |
cos_thresh = 1. - .5*cos_thresh*cos_thresh; |
| 68 |
+ |
/* check existing neighbors */ |
| 69 |
+ |
for (ii = i-1; ii <= i+1; ii++) { |
| 70 |
+ |
if (ii < 0) continue; |
| 71 |
+ |
if (ii >= hp->ns) break; |
| 72 |
+ |
for (jj = j-1; jj <= j+1; jj++) { |
| 73 |
+ |
AMBSAMP *ap; |
| 74 |
+ |
FVECT avec; |
| 75 |
+ |
double dprod; |
| 76 |
+ |
if (jj < 0) continue; |
| 77 |
+ |
if (jj >= hp->ns) break; |
| 78 |
+ |
if ((ii==i) & (jj==j)) continue; |
| 79 |
+ |
ap = &ambsam(hp,ii,jj); |
| 80 |
+ |
if (ap->d <= .5/FHUGE) |
| 81 |
+ |
continue; /* no one home */ |
| 82 |
+ |
VSUB(avec, ap->p, hp->rp->rop); |
| 83 |
+ |
dprod = DOT(avec, dv); |
| 84 |
+ |
if (dprod >= cos_thresh*VLEN(avec)) |
| 85 |
+ |
return(1); /* collision */ |
| 86 |
+ |
} |
| 87 |
+ |
} |
| 88 |
+ |
return(0); /* nothing to worry about */ |
| 89 |
+ |
} |
| 90 |
+ |
|
| 91 |
+ |
|
| 92 |
+ |
static int |
| 93 |
|
ambsample( /* initial ambient division sample */ |
| 94 |
|
AMBHEMI *hp, |
| 95 |
|
int i, |
| 117 |
|
hlist[1] = j; |
| 118 |
|
hlist[2] = i; |
| 119 |
|
multisamp(spt, 2, urand(ilhash(hlist,3)+n)); |
| 120 |
< |
if (!n) { /* avoid border samples for n==0 */ |
| 82 |
< |
if ((spt[0] < 0.1) | (spt[0] >= 0.9)) |
| 83 |
< |
spt[0] = 0.1 + 0.8*frandom(); |
| 84 |
< |
if ((spt[1] < 0.1) | (spt[1] >= 0.9)) |
| 85 |
< |
spt[1] = 0.1 + 0.8*frandom(); |
| 86 |
< |
} |
| 120 |
> |
resample: |
| 121 |
|
SDsquare2disk(spt, (j+spt[1])/hp->ns, (i+spt[0])/hp->ns); |
| 122 |
|
zd = sqrt(1. - spt[0]*spt[0] - spt[1]*spt[1]); |
| 123 |
|
for (ii = 3; ii--; ) |
| 125 |
|
spt[1]*hp->uy[ii] + |
| 126 |
|
zd*hp->rp->ron[ii]; |
| 127 |
|
checknorm(ar.rdir); |
| 128 |
+ |
/* avoid coincident samples */ |
| 129 |
+ |
if (!n && ambcollision(hp, i, j, ar.rdir)) { |
| 130 |
+ |
spt[0] = frandom(); spt[1] = frandom(); |
| 131 |
+ |
goto resample; /* reject this sample */ |
| 132 |
+ |
} |
| 133 |
|
dimlist[ndims++] = AI(hp,i,j) + 90171; |
| 134 |
|
rayvalue(&ar); /* evaluate ray */ |
| 135 |
|
ndims--; |
| 136 |
< |
if (ar.rt <= FTINY) |
| 136 |
> |
zd = raydistance(&ar); |
| 137 |
> |
if (zd <= FTINY) |
| 138 |
|
return(0); /* should never happen */ |
| 139 |
|
multcolor(ar.rcol, ar.rcoef); /* apply coefficient */ |
| 140 |
< |
if (ar.rt*ap->d < 1.0) /* new/closer distance? */ |
| 141 |
< |
ap->d = 1.0/ar.rt; |
| 140 |
> |
if (zd*ap->d < 1.0) /* new/closer distance? */ |
| 141 |
> |
ap->d = 1.0/zd; |
| 142 |
|
if (!n) { /* record first vertex & value */ |
| 143 |
< |
if (ar.rt > 10.0*thescene.cusize) |
| 144 |
< |
ar.rt = 10.0*thescene.cusize; |
| 145 |
< |
VSUM(ap->p, ar.rorg, ar.rdir, ar.rt); |
| 143 |
> |
if (zd > 10.0*thescene.cusize + 1000.) |
| 144 |
> |
zd = 10.0*thescene.cusize + 1000.; |
| 145 |
> |
VSUM(ap->p, ar.rorg, ar.rdir, zd); |
| 146 |
|
copycolor(ap->v, ar.rcol); |
| 147 |
|
} else { /* else update recorded value */ |
| 148 |
|
hp->acol[RED] -= colval(ap->v,RED); |
| 159 |
|
} |
| 160 |
|
|
| 161 |
|
|
| 162 |
< |
/* Estimate errors based on ambient division differences */ |
| 162 |
> |
/* Estimate variance based on ambient division differences */ |
| 163 |
|
static float * |
| 164 |
|
getambdiffs(AMBHEMI *hp) |
| 165 |
|
{ |
| 166 |
+ |
const double normf = 1./bright(hp->acoef); |
| 167 |
|
float *earr = (float *)calloc(hp->ns*hp->ns, sizeof(float)); |
| 168 |
|
float *ep; |
| 169 |
|
AMBSAMP *ap; |
| 170 |
< |
double b, d2; |
| 170 |
> |
double b, b1, d2; |
| 171 |
|
int i, j; |
| 172 |
|
|
| 173 |
|
if (earr == NULL) /* out of memory? */ |
| 174 |
|
return(NULL); |
| 175 |
< |
/* compute squared neighbor diffs */ |
| 175 |
> |
/* sum squared neighbor diffs */ |
| 176 |
|
for (ap = hp->sa, ep = earr, i = 0; i < hp->ns; i++) |
| 177 |
|
for (j = 0; j < hp->ns; j++, ap++, ep++) { |
| 178 |
|
b = bright(ap[0].v); |
| 179 |
|
if (i) { /* from above */ |
| 180 |
< |
d2 = b - bright(ap[-hp->ns].v); |
| 181 |
< |
d2 *= d2; |
| 180 |
> |
b1 = bright(ap[-hp->ns].v); |
| 181 |
> |
d2 = b - b1; |
| 182 |
> |
d2 *= d2*normf/(b + b1); |
| 183 |
|
ep[0] += d2; |
| 184 |
|
ep[-hp->ns] += d2; |
| 185 |
|
} |
| 186 |
|
if (!j) continue; |
| 187 |
|
/* from behind */ |
| 188 |
< |
d2 = b - bright(ap[-1].v); |
| 189 |
< |
d2 *= d2; |
| 188 |
> |
b1 = bright(ap[-1].v); |
| 189 |
> |
d2 = b - b1; |
| 190 |
> |
d2 *= d2*normf/(b + b1); |
| 191 |
|
ep[0] += d2; |
| 192 |
|
ep[-1] += d2; |
| 193 |
|
if (!i) continue; |
| 194 |
|
/* diagonal */ |
| 195 |
< |
d2 = b - bright(ap[-hp->ns-1].v); |
| 196 |
< |
d2 *= d2; |
| 195 |
> |
b1 = bright(ap[-hp->ns-1].v); |
| 196 |
> |
d2 = b - b1; |
| 197 |
> |
d2 *= d2*normf/(b + b1); |
| 198 |
|
ep[0] += d2; |
| 199 |
|
ep[-hp->ns-1] += d2; |
| 200 |
|
} |
| 221 |
|
{ |
| 222 |
|
float *earr = getambdiffs(hp); |
| 223 |
|
double e2rem = 0; |
| 180 |
– |
AMBSAMP *ap; |
| 181 |
– |
RAY ar; |
| 224 |
|
float *ep; |
| 225 |
|
int i, j, n, nss; |
| 226 |
|
|
| 230 |
|
for (ep = earr + hp->ns*hp->ns; ep > earr; ) |
| 231 |
|
e2rem += *--ep; |
| 232 |
|
ep = earr; /* perform super-sampling */ |
| 233 |
< |
for (ap = hp->sa, i = 0; i < hp->ns; i++) |
| 234 |
< |
for (j = 0; j < hp->ns; j++, ap++) { |
| 233 |
> |
for (i = 0; i < hp->ns; i++) |
| 234 |
> |
for (j = 0; j < hp->ns; j++) { |
| 235 |
|
if (e2rem <= FTINY) |
| 236 |
|
goto done; /* nothing left to do */ |
| 237 |
|
nss = *ep/e2rem*cnt + frandom(); |
| 238 |
|
for (n = 1; n <= nss && ambsample(hp,i,j,n); n++) |
| 239 |
< |
--cnt; |
| 239 |
> |
if (!--cnt) goto done; |
| 240 |
|
e2rem -= *ep++; /* update remainder */ |
| 241 |
|
} |
| 242 |
|
done: |
| 254 |
|
AMBHEMI *hp; |
| 255 |
|
double d; |
| 256 |
|
int n, i, j; |
| 257 |
+ |
/* insignificance check */ |
| 258 |
+ |
if (bright(rcol) <= FTINY) |
| 259 |
+ |
return(NULL); |
| 260 |
|
/* set number of divisions */ |
| 261 |
|
if (ambacc <= FTINY && |
| 262 |
|
wt > (d = 0.8*intens(rcol)*r->rweight/(ambdiv*minweight))) |
| 263 |
|
wt = d; /* avoid ray termination */ |
| 264 |
|
n = sqrt(ambdiv * wt) + 0.5; |
| 265 |
< |
i = 1 + 5*(ambacc > FTINY); /* minimum number of samples */ |
| 266 |
< |
if (n < i) |
| 265 |
> |
i = 1 + (MINADIV-1)*(ambacc > FTINY); |
| 266 |
> |
if (n < i) /* use minimum number of samples? */ |
| 267 |
|
n = i; |
| 268 |
|
/* allocate sampling array */ |
| 269 |
|
hp = (AMBHEMI *)malloc(sizeof(AMBHEMI) + sizeof(AMBSAMP)*(n*n - 1)); |
| 279 |
|
d = 1.0/(n*n); |
| 280 |
|
scalecolor(hp->acoef, d); |
| 281 |
|
/* make tangent plane axes */ |
| 282 |
< |
hp->uy[0] = 0.5 - frandom(); |
| 238 |
< |
hp->uy[1] = 0.5 - frandom(); |
| 239 |
< |
hp->uy[2] = 0.5 - frandom(); |
| 240 |
< |
for (i = 3; i--; ) |
| 241 |
< |
if ((-0.6 < r->ron[i]) & (r->ron[i] < 0.6)) |
| 242 |
< |
break; |
| 243 |
< |
if (i < 0) |
| 282 |
> |
if (!getperpendicular(hp->ux, r->ron, 1)) |
| 283 |
|
error(CONSISTENCY, "bad ray direction in samp_hemi"); |
| 245 |
– |
hp->uy[i] = 1.0; |
| 246 |
– |
VCROSS(hp->ux, hp->uy, r->ron); |
| 247 |
– |
normalize(hp->ux); |
| 284 |
|
VCROSS(hp->uy, r->ron, hp->ux); |
| 285 |
|
/* sample divisions */ |
| 286 |
|
for (i = hp->ns; i--; ) |
| 295 |
|
hp->sampOK *= -1; /* soft failure */ |
| 296 |
|
return(hp); |
| 297 |
|
} |
| 298 |
+ |
if (hp->sampOK <= MINADIV*MINADIV) |
| 299 |
+ |
return(hp); /* don't bother super-sampling */ |
| 300 |
|
n = ambssamp*wt + 0.5; |
| 301 |
|
if (n > 8) { /* perform super-sampling? */ |
| 302 |
|
ambsupersamp(hp, n); |
| 646 |
|
ambcorral(AMBHEMI *hp, FVECT uv[2], const double r0, const double r1) |
| 647 |
|
{ |
| 648 |
|
const double max_d = 1.0/(minarad*ambacc + 0.001); |
| 649 |
< |
const double ang_res = 0.5*PI/(hp->ns-1); |
| 650 |
< |
const double ang_step = ang_res/((int)(16/PI*ang_res) + (1+FTINY)); |
| 649 |
> |
const double ang_res = 0.5*PI/hp->ns; |
| 650 |
> |
const double ang_step = ang_res/((int)(16/PI*ang_res) + 1.01); |
| 651 |
|
double avg_d = 0; |
| 652 |
|
uint32 flgs = 0; |
| 653 |
|
FVECT vec; |
| 655 |
|
double ang, a1; |
| 656 |
|
int i, j; |
| 657 |
|
/* don't bother for a few samples */ |
| 658 |
< |
if (hp->ns < 12) |
| 658 |
> |
if (hp->ns < 8) |
| 659 |
|
return(0); |
| 660 |
|
/* check distances overhead */ |
| 661 |
|
for (i = hp->ns*3/4; i-- > hp->ns>>2; ) |
| 678 |
|
if ((r0*r0*u*u + r1*r1*v*v) * ap->d*ap->d <= u*u + v*v) |
| 679 |
|
continue; /* occluder outside ellipse */ |
| 680 |
|
ang = atan2a(v, u); /* else set direction flags */ |
| 681 |
< |
for (a1 = ang-.5*ang_res; a1 <= ang+.5*ang_res; a1 += ang_step) |
| 681 |
> |
for (a1 = ang-ang_res; a1 <= ang+ang_res; a1 += ang_step) |
| 682 |
|
flgs |= 1L<<(int)(16/PI*(a1 + 2.*PI*(a1 < 0))); |
| 683 |
|
} |
| 646 |
– |
/* add low-angle incident (< 20deg) */ |
| 647 |
– |
if (fabs(hp->rp->rod) <= 0.342) { |
| 648 |
– |
u = -DOT(hp->rp->rdir, uv[0]); |
| 649 |
– |
v = -DOT(hp->rp->rdir, uv[1]); |
| 650 |
– |
if ((r0*r0*u*u + r1*r1*v*v) > hp->rp->rot*hp->rp->rot) { |
| 651 |
– |
ang = atan2a(v, u); |
| 652 |
– |
ang += 2.*PI*(ang < 0); |
| 653 |
– |
ang *= 16/PI; |
| 654 |
– |
if ((ang < .5) | (ang >= 31.5)) |
| 655 |
– |
flgs |= 0x80000001; |
| 656 |
– |
else |
| 657 |
– |
flgs |= 3L<<(int)(ang-.5); |
| 658 |
– |
} |
| 659 |
– |
} |
| 684 |
|
return(flgs); |
| 685 |
|
} |
| 686 |
|
|
| 717 |
|
return(0); |
| 718 |
|
|
| 719 |
|
if ((ra == NULL) & (pg == NULL) & (dg == NULL) || |
| 720 |
< |
(hp->sampOK < 0) | (hp->ns < 4)) { |
| 720 |
> |
(hp->sampOK < 0) | (hp->ns < MINADIV)) { |
| 721 |
|
free(hp); /* Hessian not requested/possible */ |
| 722 |
|
return(-1); /* value-only return value */ |
| 723 |
|
} |
| 765 |
|
ra[0] = maxarad; |
| 766 |
|
} |
| 767 |
|
/* flag encroached directions */ |
| 768 |
< |
if ((wt >= 0.89*AVGREFL) & (crlp != NULL)) |
| 768 |
> |
if (crlp != NULL) |
| 769 |
|
*crlp = ambcorral(hp, uv, ra[0]*ambacc, ra[1]*ambacc); |
| 770 |
|
if (pg != NULL) { /* cap gradient if necessary */ |
| 771 |
|
d = pg[0]*pg[0]*ra[0]*ra[0] + pg[1]*pg[1]*ra[1]*ra[1]; |
| 780 |
|
return(1); |
| 781 |
|
} |
| 782 |
|
|
| 759 |
– |
|
| 760 |
– |
#else /* ! NEWAMB */ |
| 761 |
– |
|
| 762 |
– |
|
| 763 |
– |
void |
| 764 |
– |
inithemi( /* initialize sampling hemisphere */ |
| 765 |
– |
AMBHEMI *hp, |
| 766 |
– |
COLOR ac, |
| 767 |
– |
RAY *r, |
| 768 |
– |
double wt |
| 769 |
– |
) |
| 770 |
– |
{ |
| 771 |
– |
double d; |
| 772 |
– |
int i; |
| 773 |
– |
/* set number of divisions */ |
| 774 |
– |
if (ambacc <= FTINY && |
| 775 |
– |
wt > (d = 0.8*intens(ac)*r->rweight/(ambdiv*minweight))) |
| 776 |
– |
wt = d; /* avoid ray termination */ |
| 777 |
– |
hp->nt = sqrt(ambdiv * wt / PI) + 0.5; |
| 778 |
– |
i = ambacc > FTINY ? 3 : 1; /* minimum number of samples */ |
| 779 |
– |
if (hp->nt < i) |
| 780 |
– |
hp->nt = i; |
| 781 |
– |
hp->np = PI * hp->nt + 0.5; |
| 782 |
– |
/* set number of super-samples */ |
| 783 |
– |
hp->ns = ambssamp * wt + 0.5; |
| 784 |
– |
/* assign coefficient */ |
| 785 |
– |
copycolor(hp->acoef, ac); |
| 786 |
– |
d = 1.0/(hp->nt*hp->np); |
| 787 |
– |
scalecolor(hp->acoef, d); |
| 788 |
– |
/* make axes */ |
| 789 |
– |
VCOPY(hp->uz, r->ron); |
| 790 |
– |
hp->uy[0] = hp->uy[1] = hp->uy[2] = 0.0; |
| 791 |
– |
for (i = 0; i < 3; i++) |
| 792 |
– |
if (hp->uz[i] < 0.6 && hp->uz[i] > -0.6) |
| 793 |
– |
break; |
| 794 |
– |
if (i >= 3) |
| 795 |
– |
error(CONSISTENCY, "bad ray direction in inithemi"); |
| 796 |
– |
hp->uy[i] = 1.0; |
| 797 |
– |
fcross(hp->ux, hp->uy, hp->uz); |
| 798 |
– |
normalize(hp->ux); |
| 799 |
– |
fcross(hp->uy, hp->uz, hp->ux); |
| 800 |
– |
} |
| 801 |
– |
|
| 802 |
– |
|
| 803 |
– |
int |
| 804 |
– |
divsample( /* sample a division */ |
| 805 |
– |
AMBSAMP *dp, |
| 806 |
– |
AMBHEMI *h, |
| 807 |
– |
RAY *r |
| 808 |
– |
) |
| 809 |
– |
{ |
| 810 |
– |
RAY ar; |
| 811 |
– |
int hlist[3]; |
| 812 |
– |
double spt[2]; |
| 813 |
– |
double xd, yd, zd; |
| 814 |
– |
double b2; |
| 815 |
– |
double phi; |
| 816 |
– |
int i; |
| 817 |
– |
/* ambient coefficient for weight */ |
| 818 |
– |
if (ambacc > FTINY) |
| 819 |
– |
setcolor(ar.rcoef, AVGREFL, AVGREFL, AVGREFL); |
| 820 |
– |
else |
| 821 |
– |
copycolor(ar.rcoef, h->acoef); |
| 822 |
– |
if (rayorigin(&ar, AMBIENT, r, ar.rcoef) < 0) |
| 823 |
– |
return(-1); |
| 824 |
– |
if (ambacc > FTINY) { |
| 825 |
– |
multcolor(ar.rcoef, h->acoef); |
| 826 |
– |
scalecolor(ar.rcoef, 1./AVGREFL); |
| 827 |
– |
} |
| 828 |
– |
hlist[0] = r->rno; |
| 829 |
– |
hlist[1] = dp->t; |
| 830 |
– |
hlist[2] = dp->p; |
| 831 |
– |
multisamp(spt, 2, urand(ilhash(hlist,3)+dp->n)); |
| 832 |
– |
zd = sqrt((dp->t + spt[0])/h->nt); |
| 833 |
– |
phi = 2.0*PI * (dp->p + spt[1])/h->np; |
| 834 |
– |
xd = tcos(phi) * zd; |
| 835 |
– |
yd = tsin(phi) * zd; |
| 836 |
– |
zd = sqrt(1.0 - zd*zd); |
| 837 |
– |
for (i = 0; i < 3; i++) |
| 838 |
– |
ar.rdir[i] = xd*h->ux[i] + |
| 839 |
– |
yd*h->uy[i] + |
| 840 |
– |
zd*h->uz[i]; |
| 841 |
– |
checknorm(ar.rdir); |
| 842 |
– |
dimlist[ndims++] = dp->t*h->np + dp->p + 90171; |
| 843 |
– |
rayvalue(&ar); |
| 844 |
– |
ndims--; |
| 845 |
– |
multcolor(ar.rcol, ar.rcoef); /* apply coefficient */ |
| 846 |
– |
addcolor(dp->v, ar.rcol); |
| 847 |
– |
/* use rt to improve gradient calc */ |
| 848 |
– |
if (ar.rt > FTINY && ar.rt < FHUGE) |
| 849 |
– |
dp->r += 1.0/ar.rt; |
| 850 |
– |
/* (re)initialize error */ |
| 851 |
– |
if (dp->n++) { |
| 852 |
– |
b2 = bright(dp->v)/dp->n - bright(ar.rcol); |
| 853 |
– |
b2 = b2*b2 + dp->k*((dp->n-1)*(dp->n-1)); |
| 854 |
– |
dp->k = b2/(dp->n*dp->n); |
| 855 |
– |
} else |
| 856 |
– |
dp->k = 0.0; |
| 857 |
– |
return(0); |
| 858 |
– |
} |
| 859 |
– |
|
| 860 |
– |
|
| 861 |
– |
static int |
| 862 |
– |
ambcmp( /* decreasing order */ |
| 863 |
– |
const void *p1, |
| 864 |
– |
const void *p2 |
| 865 |
– |
) |
| 866 |
– |
{ |
| 867 |
– |
const AMBSAMP *d1 = (const AMBSAMP *)p1; |
| 868 |
– |
const AMBSAMP *d2 = (const AMBSAMP *)p2; |
| 869 |
– |
|
| 870 |
– |
if (d1->k < d2->k) |
| 871 |
– |
return(1); |
| 872 |
– |
if (d1->k > d2->k) |
| 873 |
– |
return(-1); |
| 874 |
– |
return(0); |
| 875 |
– |
} |
| 876 |
– |
|
| 877 |
– |
|
| 878 |
– |
static int |
| 879 |
– |
ambnorm( /* standard order */ |
| 880 |
– |
const void *p1, |
| 881 |
– |
const void *p2 |
| 882 |
– |
) |
| 883 |
– |
{ |
| 884 |
– |
const AMBSAMP *d1 = (const AMBSAMP *)p1; |
| 885 |
– |
const AMBSAMP *d2 = (const AMBSAMP *)p2; |
| 886 |
– |
int c; |
| 887 |
– |
|
| 888 |
– |
if ( (c = d1->t - d2->t) ) |
| 889 |
– |
return(c); |
| 890 |
– |
return(d1->p - d2->p); |
| 891 |
– |
} |
| 892 |
– |
|
| 893 |
– |
|
| 894 |
– |
double |
| 895 |
– |
doambient( /* compute ambient component */ |
| 896 |
– |
COLOR rcol, |
| 897 |
– |
RAY *r, |
| 898 |
– |
double wt, |
| 899 |
– |
FVECT pg, |
| 900 |
– |
FVECT dg |
| 901 |
– |
) |
| 902 |
– |
{ |
| 903 |
– |
double b, d=0; |
| 904 |
– |
AMBHEMI hemi; |
| 905 |
– |
AMBSAMP *div; |
| 906 |
– |
AMBSAMP dnew; |
| 907 |
– |
double acol[3]; |
| 908 |
– |
AMBSAMP *dp; |
| 909 |
– |
double arad; |
| 910 |
– |
int divcnt; |
| 911 |
– |
int i, j; |
| 912 |
– |
/* initialize hemisphere */ |
| 913 |
– |
inithemi(&hemi, rcol, r, wt); |
| 914 |
– |
divcnt = hemi.nt * hemi.np; |
| 915 |
– |
/* initialize */ |
| 916 |
– |
if (pg != NULL) |
| 917 |
– |
pg[0] = pg[1] = pg[2] = 0.0; |
| 918 |
– |
if (dg != NULL) |
| 919 |
– |
dg[0] = dg[1] = dg[2] = 0.0; |
| 920 |
– |
setcolor(rcol, 0.0, 0.0, 0.0); |
| 921 |
– |
if (divcnt == 0) |
| 922 |
– |
return(0.0); |
| 923 |
– |
/* allocate super-samples */ |
| 924 |
– |
if (hemi.ns > 0 || pg != NULL || dg != NULL) { |
| 925 |
– |
div = (AMBSAMP *)malloc(divcnt*sizeof(AMBSAMP)); |
| 926 |
– |
if (div == NULL) |
| 927 |
– |
error(SYSTEM, "out of memory in doambient"); |
| 928 |
– |
} else |
| 929 |
– |
div = NULL; |
| 930 |
– |
/* sample the divisions */ |
| 931 |
– |
arad = 0.0; |
| 932 |
– |
acol[0] = acol[1] = acol[2] = 0.0; |
| 933 |
– |
if ((dp = div) == NULL) |
| 934 |
– |
dp = &dnew; |
| 935 |
– |
divcnt = 0; |
| 936 |
– |
for (i = 0; i < hemi.nt; i++) |
| 937 |
– |
for (j = 0; j < hemi.np; j++) { |
| 938 |
– |
dp->t = i; dp->p = j; |
| 939 |
– |
setcolor(dp->v, 0.0, 0.0, 0.0); |
| 940 |
– |
dp->r = 0.0; |
| 941 |
– |
dp->n = 0; |
| 942 |
– |
if (divsample(dp, &hemi, r) < 0) { |
| 943 |
– |
if (div != NULL) |
| 944 |
– |
dp++; |
| 945 |
– |
continue; |
| 946 |
– |
} |
| 947 |
– |
arad += dp->r; |
| 948 |
– |
divcnt++; |
| 949 |
– |
if (div != NULL) |
| 950 |
– |
dp++; |
| 951 |
– |
else |
| 952 |
– |
addcolor(acol, dp->v); |
| 953 |
– |
} |
| 954 |
– |
if (!divcnt) { |
| 955 |
– |
if (div != NULL) |
| 956 |
– |
free((void *)div); |
| 957 |
– |
return(0.0); /* no samples taken */ |
| 958 |
– |
} |
| 959 |
– |
if (divcnt < hemi.nt*hemi.np) { |
| 960 |
– |
pg = dg = NULL; /* incomplete sampling */ |
| 961 |
– |
hemi.ns = 0; |
| 962 |
– |
} else if (arad > FTINY && divcnt/arad < minarad) { |
| 963 |
– |
hemi.ns = 0; /* close enough */ |
| 964 |
– |
} else if (hemi.ns > 0) { /* else perform super-sampling? */ |
| 965 |
– |
comperrs(div, &hemi); /* compute errors */ |
| 966 |
– |
qsort(div, divcnt, sizeof(AMBSAMP), ambcmp); /* sort divs */ |
| 967 |
– |
/* super-sample */ |
| 968 |
– |
for (i = hemi.ns; i > 0; i--) { |
| 969 |
– |
dnew = *div; |
| 970 |
– |
if (divsample(&dnew, &hemi, r) < 0) { |
| 971 |
– |
dp++; |
| 972 |
– |
continue; |
| 973 |
– |
} |
| 974 |
– |
dp = div; /* reinsert */ |
| 975 |
– |
j = divcnt < i ? divcnt : i; |
| 976 |
– |
while (--j > 0 && dnew.k < dp[1].k) { |
| 977 |
– |
*dp = *(dp+1); |
| 978 |
– |
dp++; |
| 979 |
– |
} |
| 980 |
– |
*dp = dnew; |
| 981 |
– |
} |
| 982 |
– |
if (pg != NULL || dg != NULL) /* restore order */ |
| 983 |
– |
qsort(div, divcnt, sizeof(AMBSAMP), ambnorm); |
| 984 |
– |
} |
| 985 |
– |
/* compute returned values */ |
| 986 |
– |
if (div != NULL) { |
| 987 |
– |
arad = 0.0; /* note: divcnt may be < nt*np */ |
| 988 |
– |
for (i = hemi.nt*hemi.np, dp = div; i-- > 0; dp++) { |
| 989 |
– |
arad += dp->r; |
| 990 |
– |
if (dp->n > 1) { |
| 991 |
– |
b = 1.0/dp->n; |
| 992 |
– |
scalecolor(dp->v, b); |
| 993 |
– |
dp->r *= b; |
| 994 |
– |
dp->n = 1; |
| 995 |
– |
} |
| 996 |
– |
addcolor(acol, dp->v); |
| 997 |
– |
} |
| 998 |
– |
b = bright(acol); |
| 999 |
– |
if (b > FTINY) { |
| 1000 |
– |
b = 1.0/b; /* compute & normalize gradient(s) */ |
| 1001 |
– |
if (pg != NULL) { |
| 1002 |
– |
posgradient(pg, div, &hemi); |
| 1003 |
– |
for (i = 0; i < 3; i++) |
| 1004 |
– |
pg[i] *= b; |
| 1005 |
– |
} |
| 1006 |
– |
if (dg != NULL) { |
| 1007 |
– |
dirgradient(dg, div, &hemi); |
| 1008 |
– |
for (i = 0; i < 3; i++) |
| 1009 |
– |
dg[i] *= b; |
| 1010 |
– |
} |
| 1011 |
– |
} |
| 1012 |
– |
free((void *)div); |
| 1013 |
– |
} |
| 1014 |
– |
copycolor(rcol, acol); |
| 1015 |
– |
if (arad <= FTINY) |
| 1016 |
– |
arad = maxarad; |
| 1017 |
– |
else |
| 1018 |
– |
arad = (divcnt+hemi.ns)/arad; |
| 1019 |
– |
if (pg != NULL) { /* reduce radius if gradient large */ |
| 1020 |
– |
d = DOT(pg,pg); |
| 1021 |
– |
if (d*arad*arad > 1.0) |
| 1022 |
– |
arad = 1.0/sqrt(d); |
| 1023 |
– |
} |
| 1024 |
– |
if (arad < minarad) { |
| 1025 |
– |
arad = minarad; |
| 1026 |
– |
if (pg != NULL && d*arad*arad > 1.0) { /* cap gradient */ |
| 1027 |
– |
d = 1.0/arad/sqrt(d); |
| 1028 |
– |
for (i = 0; i < 3; i++) |
| 1029 |
– |
pg[i] *= d; |
| 1030 |
– |
} |
| 1031 |
– |
} |
| 1032 |
– |
if ((arad /= sqrt(wt)) > maxarad) |
| 1033 |
– |
arad = maxarad; |
| 1034 |
– |
return(arad); |
| 1035 |
– |
} |
| 1036 |
– |
|
| 1037 |
– |
|
| 1038 |
– |
void |
| 1039 |
– |
comperrs( /* compute initial error estimates */ |
| 1040 |
– |
AMBSAMP *da, /* assumes standard ordering */ |
| 1041 |
– |
AMBHEMI *hp |
| 1042 |
– |
) |
| 1043 |
– |
{ |
| 1044 |
– |
double b, b2; |
| 1045 |
– |
int i, j; |
| 1046 |
– |
AMBSAMP *dp; |
| 1047 |
– |
/* sum differences from neighbors */ |
| 1048 |
– |
dp = da; |
| 1049 |
– |
for (i = 0; i < hp->nt; i++) |
| 1050 |
– |
for (j = 0; j < hp->np; j++) { |
| 1051 |
– |
#ifdef DEBUG |
| 1052 |
– |
if (dp->t != i || dp->p != j) |
| 1053 |
– |
error(CONSISTENCY, |
| 1054 |
– |
"division order in comperrs"); |
| 1055 |
– |
#endif |
| 1056 |
– |
b = bright(dp[0].v); |
| 1057 |
– |
if (i > 0) { /* from above */ |
| 1058 |
– |
b2 = bright(dp[-hp->np].v) - b; |
| 1059 |
– |
b2 *= b2 * 0.25; |
| 1060 |
– |
dp[0].k += b2; |
| 1061 |
– |
dp[-hp->np].k += b2; |
| 1062 |
– |
} |
| 1063 |
– |
if (j > 0) { /* from behind */ |
| 1064 |
– |
b2 = bright(dp[-1].v) - b; |
| 1065 |
– |
b2 *= b2 * 0.25; |
| 1066 |
– |
dp[0].k += b2; |
| 1067 |
– |
dp[-1].k += b2; |
| 1068 |
– |
} else { /* around */ |
| 1069 |
– |
b2 = bright(dp[hp->np-1].v) - b; |
| 1070 |
– |
b2 *= b2 * 0.25; |
| 1071 |
– |
dp[0].k += b2; |
| 1072 |
– |
dp[hp->np-1].k += b2; |
| 1073 |
– |
} |
| 1074 |
– |
dp++; |
| 1075 |
– |
} |
| 1076 |
– |
/* divide by number of neighbors */ |
| 1077 |
– |
dp = da; |
| 1078 |
– |
for (j = 0; j < hp->np; j++) /* top row */ |
| 1079 |
– |
(dp++)->k *= 1.0/3.0; |
| 1080 |
– |
if (hp->nt < 2) |
| 1081 |
– |
return; |
| 1082 |
– |
for (i = 1; i < hp->nt-1; i++) /* central region */ |
| 1083 |
– |
for (j = 0; j < hp->np; j++) |
| 1084 |
– |
(dp++)->k *= 0.25; |
| 1085 |
– |
for (j = 0; j < hp->np; j++) /* bottom row */ |
| 1086 |
– |
(dp++)->k *= 1.0/3.0; |
| 1087 |
– |
} |
| 1088 |
– |
|
| 1089 |
– |
|
| 1090 |
– |
void |
| 1091 |
– |
posgradient( /* compute position gradient */ |
| 1092 |
– |
FVECT gv, |
| 1093 |
– |
AMBSAMP *da, /* assumes standard ordering */ |
| 1094 |
– |
AMBHEMI *hp |
| 1095 |
– |
) |
| 1096 |
– |
{ |
| 1097 |
– |
int i, j; |
| 1098 |
– |
double nextsine, lastsine, b, d; |
| 1099 |
– |
double mag0, mag1; |
| 1100 |
– |
double phi, cosp, sinp, xd, yd; |
| 1101 |
– |
AMBSAMP *dp; |
| 1102 |
– |
|
| 1103 |
– |
xd = yd = 0.0; |
| 1104 |
– |
for (j = 0; j < hp->np; j++) { |
| 1105 |
– |
dp = da + j; |
| 1106 |
– |
mag0 = mag1 = 0.0; |
| 1107 |
– |
lastsine = 0.0; |
| 1108 |
– |
for (i = 0; i < hp->nt; i++) { |
| 1109 |
– |
#ifdef DEBUG |
| 1110 |
– |
if (dp->t != i || dp->p != j) |
| 1111 |
– |
error(CONSISTENCY, |
| 1112 |
– |
"division order in posgradient"); |
| 1113 |
– |
#endif |
| 1114 |
– |
b = bright(dp->v); |
| 1115 |
– |
if (i > 0) { |
| 1116 |
– |
d = dp[-hp->np].r; |
| 1117 |
– |
if (dp[0].r > d) d = dp[0].r; |
| 1118 |
– |
/* sin(t)*cos(t)^2 */ |
| 1119 |
– |
d *= lastsine * (1.0 - (double)i/hp->nt); |
| 1120 |
– |
mag0 += d*(b - bright(dp[-hp->np].v)); |
| 1121 |
– |
} |
| 1122 |
– |
nextsine = sqrt((double)(i+1)/hp->nt); |
| 1123 |
– |
if (j > 0) { |
| 1124 |
– |
d = dp[-1].r; |
| 1125 |
– |
if (dp[0].r > d) d = dp[0].r; |
| 1126 |
– |
mag1 += d * (nextsine - lastsine) * |
| 1127 |
– |
(b - bright(dp[-1].v)); |
| 1128 |
– |
} else { |
| 1129 |
– |
d = dp[hp->np-1].r; |
| 1130 |
– |
if (dp[0].r > d) d = dp[0].r; |
| 1131 |
– |
mag1 += d * (nextsine - lastsine) * |
| 1132 |
– |
(b - bright(dp[hp->np-1].v)); |
| 1133 |
– |
} |
| 1134 |
– |
dp += hp->np; |
| 1135 |
– |
lastsine = nextsine; |
| 1136 |
– |
} |
| 1137 |
– |
mag0 *= 2.0*PI / hp->np; |
| 1138 |
– |
phi = 2.0*PI * (double)j/hp->np; |
| 1139 |
– |
cosp = tcos(phi); sinp = tsin(phi); |
| 1140 |
– |
xd += mag0*cosp - mag1*sinp; |
| 1141 |
– |
yd += mag0*sinp + mag1*cosp; |
| 1142 |
– |
} |
| 1143 |
– |
for (i = 0; i < 3; i++) |
| 1144 |
– |
gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])*(hp->nt*hp->np)/PI; |
| 1145 |
– |
} |
| 1146 |
– |
|
| 1147 |
– |
|
| 1148 |
– |
void |
| 1149 |
– |
dirgradient( /* compute direction gradient */ |
| 1150 |
– |
FVECT gv, |
| 1151 |
– |
AMBSAMP *da, /* assumes standard ordering */ |
| 1152 |
– |
AMBHEMI *hp |
| 1153 |
– |
) |
| 1154 |
– |
{ |
| 1155 |
– |
int i, j; |
| 1156 |
– |
double mag; |
| 1157 |
– |
double phi, xd, yd; |
| 1158 |
– |
AMBSAMP *dp; |
| 1159 |
– |
|
| 1160 |
– |
xd = yd = 0.0; |
| 1161 |
– |
for (j = 0; j < hp->np; j++) { |
| 1162 |
– |
dp = da + j; |
| 1163 |
– |
mag = 0.0; |
| 1164 |
– |
for (i = 0; i < hp->nt; i++) { |
| 1165 |
– |
#ifdef DEBUG |
| 1166 |
– |
if (dp->t != i || dp->p != j) |
| 1167 |
– |
error(CONSISTENCY, |
| 1168 |
– |
"division order in dirgradient"); |
| 1169 |
– |
#endif |
| 1170 |
– |
/* tan(t) */ |
| 1171 |
– |
mag += bright(dp->v)/sqrt(hp->nt/(i+.5) - 1.0); |
| 1172 |
– |
dp += hp->np; |
| 1173 |
– |
} |
| 1174 |
– |
phi = 2.0*PI * (j+.5)/hp->np + PI/2.0; |
| 1175 |
– |
xd += mag * tcos(phi); |
| 1176 |
– |
yd += mag * tsin(phi); |
| 1177 |
– |
} |
| 1178 |
– |
for (i = 0; i < 3; i++) |
| 1179 |
– |
gv[i] = xd*hp->ux[i] + yd*hp->uy[i]; |
| 1180 |
– |
} |
| 1181 |
– |
|
| 1182 |
– |
#endif /* ! NEWAMB */ |
