/**
* This takes a complicated expression assumed to contain multiple instances of leafA and returns
* the equivalent CSG expression involving just leafA.
*
* @param leafA
* @return equivalent CSG expression involving just leafA
*/
private RrCSG categorise(RrCSG leafA) {
RrHalfPlane a = leafA.plane();
Rr2Point an = a.normal();
Rr2Point x = Rr2Point.add(a.pLine().origin(), an);
if (value(x) <= 0) return leafA.complement();
else return leafA;
}
/**
* This takes a complicated expression assumed to contain multiple instances of leafA and leafB
* and returns the equivalent CSG expression involving at most leafA and leafB once (except for
* non-manifold shapes).
*
* @param leafA
* @param leafB
* @return equivalent CSG expression involving at most leafA and leafB once
*/
private RrCSG crossCategorise(RrCSG leafA, RrCSG leafB) {
RrHalfPlane a = leafA.plane();
RrHalfPlane b = leafB.plane();
Rr2Point an = a.normal();
Rr2Point bn = b.normal();
Rr2Point v02 = Rr2Point.add(an, bn);
Rr2Point v31 = Rr2Point.sub(bn, an);
Rr2Point x, x0, x1, x2, x3;
int category = 0;
try {
x = a.cross_point(b);
v02 = v02.norm();
v31 = v31.norm();
x2 = Rr2Point.add(x, v02);
x0 = Rr2Point.sub(x, v02);
x1 = Rr2Point.add(x, v31);
x3 = Rr2Point.sub(x, v31);
if (value(x0) <= 0) category |= 1;
if (value(x1) <= 0) category |= 2;
if (value(x2) <= 0) category |= 4;
if (value(x3) <= 0) category |= 8;
switch (category) {
case 0:
return nothing();
case 1:
return intersection(leafA, leafB);
case 2:
return intersection(leafA, leafB.complement());
case 3:
return leafA;
case 4:
return intersection(leafA.complement(), leafB.complement());
case 5:
Debug.e("RrCSG crossCategorise: non-manifold shape (case 0101)!");
return union(
intersection(leafA, leafB), intersection(leafA.complement(), leafB.complement()));
case 6:
return leafB.complement();
case 7:
return union(leafA, leafB.complement());
case 8:
return intersection(leafA.complement(), leafB);
case 9:
return leafB;
case 10:
Debug.e("RrCSG crossCategorise: non-manifold shape (case 1010)!");
return union(
RrCSG.intersection(leafA.complement(), leafB),
intersection(leafA, leafB.complement()));
case 11:
return union(leafA, leafB);
case 12:
return leafA.complement();
case 13:
return union(leafA.complement(), leafB);
case 14:
return union(leafA.complement(), leafB.complement());
case 15:
return universe();
default:
Debug.e("RrCSG crossCategorise: bitwise | doesn't seem to work...");
return this;
}
} catch (Exception e) {
// leafA and leafB are parallel
x0 = Rr2Point.mul(Rr2Point.add(a.pLine().origin(), b.pLine().origin()), 0.5);
x1 = Rr2Point.mul(Rr2Point.sub(a.pLine().origin(), b.pLine().origin()), 3);
x2 = Rr2Point.add(x0, x1);
x1 = Rr2Point.sub(x0, x1);
if (value(x0) <= 0) category |= 1;
if (value(x1) <= 0) category |= 2;
if (value(x2) <= 0) category |= 4;
if (leafA.value(x0) <= 0) leafA = leafA.complement();
if (leafB.value(x0) <= 0) leafB = leafB.complement();
switch (category) {
case 0:
return nothing();
case 1:
return intersection(leafA.complement(), leafB.complement());
case 2:
return leafB;
case 3:
return leafA.complement();
case 4:
return leafA;
case 5:
return union(leafA, leafB);
case 6:
return leafB.complement();
case 7:
return universe();
default:
Debug.e("RrCSG crossCategorise: bitwise | doesn't seem to work...");
return this;
}
}
}