| 12 |
|
|
| 13 |
|
/* |
| 14 |
|
* Clipping objects permit holes and sections to be taken out |
| 15 |
< |
* of other objects. The method is simple: |
| 15 |
> |
* of other objects. |
| 16 |
|
* |
| 17 |
|
* The argument is the clipped materials; |
| 18 |
|
* the first is used to shade upon exit. |
| 19 |
+ |
* |
| 20 |
+ |
* In the simple case of the first argument being "void", we |
| 21 |
+ |
* just add or subtract (depending on whether we're coming or going) |
| 22 |
+ |
* the list of modifiers to the ray's "newcset", which will then |
| 23 |
+ |
* take over for "clipset" on penetration. Any surface modifier |
| 24 |
+ |
* names found in "clipset" will be treated as invisible in raycont(). |
| 25 |
+ |
* |
| 26 |
+ |
* In the more complicated case of a non-void material as the |
| 27 |
+ |
* first argument, we have to backtrack up the ray tree to count |
| 28 |
+ |
* the number of times we've penetrated the front side of one of |
| 29 |
+ |
* the surfaces we care about. This relies on outward-facing |
| 30 |
+ |
* surface normals and closed objects, so is somewhat error-prone. |
| 31 |
|
*/ |
| 32 |
|
|
| 33 |
|
|
| 34 |
< |
extern int |
| 34 |
> |
int |
| 35 |
|
m_clip( /* clip objects from ray */ |
| 36 |
< |
register OBJREC *m, |
| 37 |
< |
register RAY *r |
| 36 |
> |
OBJREC *m, |
| 37 |
> |
RAY *r |
| 38 |
|
) |
| 39 |
|
{ |
| 40 |
|
OBJECT cset[MAXSET+1], *modset; |
| 41 |
|
OBJECT obj, mod; |
| 42 |
|
int entering; |
| 43 |
< |
register int i; |
| 43 |
> |
int i; |
| 44 |
|
|
| 45 |
|
obj = objndx(m); |
| 46 |
|
if ((modset = (OBJECT *)m->os) == NULL) { |
| 74 |
|
else |
| 75 |
|
cset[0] = 0; |
| 76 |
|
|
| 77 |
< |
entering = r->rod > 0.0; /* entering clipped region? */ |
| 77 |
> |
entering = (r->rod > 0.0); /* entering clipped region? */ |
| 78 |
|
|
| 79 |
< |
for (i = modset[0]; i > 0; i--) { |
| 79 |
> |
for (i = modset[0]; i > 0; i--) |
| 80 |
|
if (entering) { |
| 81 |
|
if (!inset(cset, modset[i])) { |
| 82 |
|
if (cset[0] >= MAXSET) |
| 83 |
|
error(INTERNAL, "set overflow in m_clip"); |
| 84 |
|
insertelem(cset, modset[i]); |
| 85 |
|
} |
| 86 |
< |
} else { |
| 87 |
< |
if (inset(cset, modset[i])) |
| 88 |
< |
deletelem(cset, modset[i]); |
| 77 |
< |
} |
| 78 |
< |
} |
| 86 |
> |
} else if (inset(cset, modset[i])) |
| 87 |
> |
deletelem(cset, modset[i]); |
| 88 |
> |
|
| 89 |
|
/* compute ray value */ |
| 90 |
|
r->newcset = cset; |
| 91 |
|
if (strcmp(m->oargs.sarg[0], VOIDID)) { |
| 92 |
|
int inside = 0; |
| 93 |
< |
register const RAY *rp; |
| 93 |
> |
const RAY *rp; |
| 94 |
|
/* check for penetration */ |
| 95 |
|
for (rp = r; rp->parent != NULL; rp = rp->parent) |
| 96 |
< |
if (!(rp->rtype & RAYREFL) && rp->parent->ro != NULL |
| 96 |
> |
if ((rp->rtype == RAYREFL) & (rp->parent->ro != NULL) |
| 97 |
|
&& inset(modset, rp->parent->ro->omod)) { |
| 98 |
|
if (rp->parent->rod > 0.0) |
| 99 |
|
inside++; |
