| 251 |
|
register CUBE *scene; |
| 252 |
|
{ |
| 253 |
|
FVECT curpos; /* current cube position */ |
| 254 |
< |
int mpos, mneg; /* sign flags */ |
| 254 |
> |
int sflags; /* sign flags */ |
| 255 |
|
double t, dt; |
| 256 |
|
register int i; |
| 257 |
|
|
| 258 |
|
nrays++; /* increment trace counter */ |
| 259 |
|
|
| 260 |
< |
mpos = mneg = 0; |
| 260 |
> |
sflags = 0; |
| 261 |
|
for (i = 0; i < 3; i++) { |
| 262 |
|
curpos[i] = r->rorg[i]; |
| 263 |
|
if (r->rdir[i] > FTINY) |
| 264 |
< |
mpos |= 1 << i; |
| 264 |
> |
sflags |= 1 << i; |
| 265 |
|
else if (r->rdir[i] < -FTINY) |
| 266 |
< |
mneg |= 1 << i; |
| 266 |
> |
sflags |= 0x10 << i; |
| 267 |
|
} |
| 268 |
|
t = 0.0; |
| 269 |
|
if (!incube(scene, curpos)) { |
| 270 |
|
/* find distance to entry */ |
| 271 |
|
for (i = 0; i < 3; i++) { |
| 272 |
|
/* plane in our direction */ |
| 273 |
< |
if (mpos & 1<<i) |
| 273 |
> |
if (sflags & 1<<i) |
| 274 |
|
dt = scene->cuorg[i]; |
| 275 |
< |
else if (mneg & 1<<i) |
| 275 |
> |
else if (sflags & 0x10<<i) |
| 276 |
|
dt = scene->cuorg[i] + scene->cusize; |
| 277 |
|
else |
| 278 |
|
continue; |
| 289 |
|
if (!incube(scene, curpos)) /* non-intersecting ray */ |
| 290 |
|
return(0); |
| 291 |
|
} |
| 292 |
< |
return(raymove(curpos, mpos, mneg, r, scene) == RAYHIT); |
| 292 |
> |
return(raymove(curpos, sflags, r, scene) == RAYHIT); |
| 293 |
|
} |
| 294 |
|
|
| 295 |
|
|
| 296 |
|
static int |
| 297 |
< |
raymove(pos, plus, minus, r, cu) /* check for hit as we move */ |
| 297 |
> |
raymove(pos, dirf, r, cu) /* check for hit as we move */ |
| 298 |
|
FVECT pos; /* modified */ |
| 299 |
< |
int plus, minus; /* direction indicators to speed tests */ |
| 299 |
> |
int dirf; /* direction indicators to speed tests */ |
| 300 |
|
register RAY *r; |
| 301 |
|
register CUBE *cu; |
| 302 |
|
{ |
| 303 |
|
int ax; |
| 304 |
|
double dt, t; |
| 305 |
– |
register int sgn; |
| 305 |
|
|
| 306 |
|
if (istree(cu->cutree)) { /* recurse on subcubes */ |
| 307 |
|
CUBE cukid; |
| 308 |
< |
register int br; |
| 308 |
> |
register int br, sgn; |
| 309 |
|
|
| 310 |
|
cukid.cusize = cu->cusize * 0.5; /* find subcube */ |
| 311 |
|
VCOPY(cukid.cuorg, cu->cuorg); |
| 324 |
|
} |
| 325 |
|
for ( ; ; ) { |
| 326 |
|
cukid.cutree = octkid(cu->cutree, br); |
| 327 |
< |
if ((ax = raymove(pos,plus,minus,r,&cukid)) == RAYHIT) |
| 327 |
> |
if ((ax = raymove(pos,dirf,r,&cukid)) == RAYHIT) |
| 328 |
|
return(RAYHIT); |
| 329 |
|
sgn = 1 << ax; |
| 330 |
< |
if (sgn & minus) /* negative axis? */ |
| 332 |
< |
if (sgn & br) { |
| 333 |
< |
cukid.cuorg[ax] -= cukid.cusize; |
| 334 |
< |
br &= ~sgn; |
| 335 |
< |
} else |
| 336 |
< |
return(ax); /* underflow */ |
| 337 |
< |
else |
| 330 |
> |
if (sgn & dirf) /* positive axis? */ |
| 331 |
|
if (sgn & br) |
| 332 |
|
return(ax); /* overflow */ |
| 333 |
|
else { |
| 334 |
|
cukid.cuorg[ax] += cukid.cusize; |
| 335 |
|
br |= sgn; |
| 336 |
|
} |
| 337 |
+ |
else |
| 338 |
+ |
if (sgn & br) { |
| 339 |
+ |
cukid.cuorg[ax] -= cukid.cusize; |
| 340 |
+ |
br &= ~sgn; |
| 341 |
+ |
} else |
| 342 |
+ |
return(ax); /* underflow */ |
| 343 |
|
} |
| 344 |
|
/*NOTREACHED*/ |
| 345 |
|
} |
| 346 |
|
if (isfull(cu->cutree) && checkhit(r, cu)) |
| 347 |
|
return(RAYHIT); |
| 348 |
|
/* advance to next cube */ |
| 349 |
< |
sgn = plus | minus; |
| 350 |
< |
if (sgn&1) { |
| 352 |
< |
dt = plus&1 ? cu->cuorg[0] + cu->cusize : cu->cuorg[0]; |
| 349 |
> |
if (dirf&0x11) { |
| 350 |
> |
dt = dirf&1 ? cu->cuorg[0] + cu->cusize : cu->cuorg[0]; |
| 351 |
|
t = (dt - pos[0])/r->rdir[0]; |
| 352 |
|
ax = 0; |
| 353 |
|
} else |
| 354 |
|
t = FHUGE; |
| 355 |
< |
if (sgn&2) { |
| 356 |
< |
dt = plus&2 ? cu->cuorg[1] + cu->cusize : cu->cuorg[1]; |
| 355 |
> |
if (dirf&0x22) { |
| 356 |
> |
dt = dirf&2 ? cu->cuorg[1] + cu->cusize : cu->cuorg[1]; |
| 357 |
|
dt = (dt - pos[1])/r->rdir[1]; |
| 358 |
|
if (dt < t) { |
| 359 |
|
t = dt; |
| 360 |
|
ax = 1; |
| 361 |
|
} |
| 362 |
|
} |
| 363 |
< |
if (sgn&4) { |
| 364 |
< |
dt = plus&4 ? cu->cuorg[2] + cu->cusize : cu->cuorg[2]; |
| 363 |
> |
if (dirf&0x44) { |
| 364 |
> |
dt = dirf&4 ? cu->cuorg[2] + cu->cusize : cu->cuorg[2]; |
| 365 |
|
dt = (dt - pos[2])/r->rdir[2]; |
| 366 |
|
if (dt < t) { |
| 367 |
|
t = dt; |
