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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 1999-2008, Ben Burton *
* For further details contact Ben Burton (bab@debian.org). *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License as *
* published by the Free Software Foundation; either version 2 of the *
* License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public *
* License along with this program; if not, write to the Free *
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, *
* MA 02110-1301, USA. *
* *
**************************************************************************/
/* end stub */
#include "triangulation/nface.h"
#include "subcomplex/npillowtwosphere.h"
namespace regina {
NPillowTwoSphere* NPillowTwoSphere::clone() const {
NPillowTwoSphere* ans = new NPillowTwoSphere();
ans->face[0] = face[0];
ans->face[1] = face[1];
ans->faceMapping = faceMapping;
return ans;
}
NPillowTwoSphere* NPillowTwoSphere::formsPillowTwoSphere(
NFace* face1, NFace* face2) {
if (face1 == face2 || face1->isBoundary() || face2->isBoundary())
return 0;
NEdge* edge[2][3];
int i;
for (i = 0; i < 3; i++) {
edge[0][i] = face1->getEdge(i);
edge[1][i] = face2->getEdge(i);
}
if (edge[0][0] == edge[0][1] || edge[0][0] == edge[0][2] ||
edge[0][1] == edge[0][2])
return 0;
// The first face has three distinct edges. See if it matches to the
// second face.
int joinTo0 = -1;
for (i = 0; i < 3; i++)
if (edge[0][0] == edge[1][i]) {
joinTo0 = i;
break;
}
if (joinTo0 == -1)
return 0;
// Now make sure the edges all match up and with the correct
// permutations.
NPerm perm = face2->getEdgeMapping(joinTo0) *
face1->getEdgeMapping(0).inverse();
for (i = 1; i < 3; i++) {
if (edge[0][i] != edge[1][perm[i]])
return 0;
if (! (face2->getEdgeMapping(perm[i]) ==
perm * face1->getEdgeMapping(i)))
return 0;
}
// We have an answer.
NPillowTwoSphere* ans = new NPillowTwoSphere();
ans->face[0] = face1;
ans->face[1] = face2;
ans->faceMapping = perm;
return ans;
}
void NPillowTwoSphere::reduceTriangulation() const {
}
NTriangulation* NPillowTwoSphere::getReducedTriangulation(
const NTriangulation* /* original */) const {
return 0;
}
} // namespace regina
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