| 600 |
|
const double ang_step = ang_res/((int)(16/PI*ang_res) + (1+FTINY)); |
| 601 |
|
double avg_d = 0; |
| 602 |
|
uint32 flgs = 0; |
| 603 |
+ |
FVECT vec; |
| 604 |
+ |
double u, v; |
| 605 |
+ |
double ang, a1; |
| 606 |
|
int i, j; |
| 607 |
|
/* don't bother for a few samples */ |
| 608 |
|
if (hp->ns < 12) |
| 620 |
|
for (i = 0; i < hp->ns; i++) |
| 621 |
|
for (j = 0; j < hp->ns; j += !i|(i==hp->ns-1) ? 1 : hp->ns-1) { |
| 622 |
|
AMBSAMP *ap = &ambsam(hp,i,j); |
| 620 |
– |
FVECT vec; |
| 621 |
– |
double u, v; |
| 622 |
– |
double ang, a1; |
| 623 |
– |
int abp; |
| 623 |
|
if ((ap->d <= FTINY) | (ap->d >= max_d)) |
| 624 |
|
continue; /* too far or too near */ |
| 625 |
|
VSUB(vec, ap->p, hp->rp->rop); |
| 631 |
|
for (a1 = ang-.5*ang_res; a1 <= ang+.5*ang_res; a1 += ang_step) |
| 632 |
|
flgs |= 1L<<(int)(16/PI*(a1 + 2.*PI*(a1 < 0))); |
| 633 |
|
} |
| 634 |
+ |
/* add low-angle incident (< 20deg) */ |
| 635 |
+ |
if (fabs(hp->rp->rod) <= 0.342) { |
| 636 |
+ |
u = -DOT(hp->rp->rdir, uv[0]); |
| 637 |
+ |
v = -DOT(hp->rp->rdir, uv[1]); |
| 638 |
+ |
if ((r0*r0*u*u + r1*r1*v*v) > hp->rp->rot*hp->rp->rot) { |
| 639 |
+ |
ang = atan2a(v, u); |
| 640 |
+ |
ang += 2.*PI*(ang < 0); |
| 641 |
+ |
ang *= 16/PI; |
| 642 |
+ |
if ((ang < .5) | (ang >= 31.5)) |
| 643 |
+ |
flgs |= 0x80000001; |
| 644 |
+ |
else |
| 645 |
+ |
flgs |= 3L<<(int)(ang-.5); |
| 646 |
+ |
} |
| 647 |
+ |
} |
| 648 |
|
return(flgs); |
| 649 |
|
} |
| 650 |
|
|
