| 298 |
|
double |
| 299 |
|
hdinter(gc, r, ed, hp, ro, rd) /* compute ray intersection with section */ |
| 300 |
|
register GCOORD gc[2]; /* returned */ |
| 301 |
< |
BYTE r[2][2]; /* returned */ |
| 301 |
> |
BYTE r[2][2]; /* returned (optional) */ |
| 302 |
|
double *ed; /* returned (optional) */ |
| 303 |
|
register HOLO *hp; |
| 304 |
< |
FVECT ro, rd; /* rd should be normalized */ |
| 304 |
> |
FVECT ro, rd; /* normalization of rd affects distances */ |
| 305 |
|
{ |
| 306 |
|
FVECT p[2], vt; |
| 307 |
|
double d, t0, t1, d0, d1; |
| 353 |
|
d = DOT(vt, v) * hp->wg[wg0[gc[i].w]]; |
| 354 |
|
if (d < 0. || (gc[i].i[0] = d) >= hp->grid[wg0[gc[i].w]]) |
| 355 |
|
return(FHUGE); /* outside wall */ |
| 356 |
< |
r[i][0] = 256. * (d - gc[i].i[0]); |
| 356 |
> |
if (r != NULL) |
| 357 |
> |
r[i][0] = 256. * (d - gc[i].i[0]); |
| 358 |
|
v = hp->wn[wg1[gc[i].w]]; |
| 359 |
|
d = DOT(vt, v) * hp->wg[wg1[gc[i].w]]; |
| 360 |
|
if (d < 0. || (gc[i].i[1] = d) >= hp->grid[wg1[gc[i].w]]) |
| 361 |
|
return(FHUGE); /* outside wall */ |
| 362 |
< |
r[i][1] = 256. * (d - gc[i].i[1]); |
| 362 |
> |
if (r != NULL) |
| 363 |
> |
r[i][1] = 256. * (d - gc[i].i[1]); |
| 364 |
|
} |
| 363 |
– |
|
| 365 |
|
if (ed != NULL) /* assign distance to exit point */ |
| 366 |
|
*ed = t1; |
| 367 |
|
return(t0); /* return distance to entry point */ |
