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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 "algebra/nabeliangroup.h"
#include "manifold/nhandlebody.h"
#include "subcomplex/ntrisolidtorus.h"
#include "subcomplex/nlayeredchain.h"
#include "triangulation/ntetrahedron.h"
namespace regina {
NTriSolidTorus* NTriSolidTorus::clone() const {
NTriSolidTorus* ans = new NTriSolidTorus();
for (int i = 0; i < 3; i++) {
ans->tet[i] = tet[i];
ans->vertexRoles[i] = vertexRoles[i];
}
return ans;
}
bool NTriSolidTorus::isAnnulusSelfIdentified(int index, NPerm* roleMap) const {
int lower = (index + 1) % 3;
int upper = (index + 2) % 3;
if (tet[lower]->getAdjacentTetrahedron(vertexRoles[lower][2]) !=
tet[upper])
return false;
if (tet[lower]->getAdjacentFace(vertexRoles[lower][2]) !=
vertexRoles[upper][1])
return false;
// We have a self-identification.
if (roleMap)
*roleMap = vertexRoles[upper].inverse() *
tet[lower]->getAdjacentTetrahedronGluing(vertexRoles[lower][2]) *
vertexRoles[lower];
return true;
}
unsigned long NTriSolidTorus::areAnnuliLinkedMajor(int otherAnnulus) const {
int right = (otherAnnulus + 1) % 3;
int left = (otherAnnulus + 2) % 3;
NTetrahedron* adj = tet[right]->getAdjacentTetrahedron(
vertexRoles[right][1]);
if (adj != tet[left]->getAdjacentTetrahedron(vertexRoles[left][2]))
return 0;
if (adj == tet[0] || adj == tet[1] || adj == tet[2] || adj == 0)
return 0;
NPerm roles = tet[right]->getAdjacentTetrahedronGluing(
vertexRoles[right][1]) * vertexRoles[right] * NPerm(2, 3, 1, 0);
if (roles != tet[left]->getAdjacentTetrahedronGluing(
vertexRoles[left][2]) * vertexRoles[left] * NPerm(3, 2, 0, 1))
return 0;
// We've successfully identified the first tetrahedron of the
// layered chain.
NLayeredChain chain(adj, roles);
chain.extendMaximal();
if (chain.getTop() != tet[otherAnnulus])
return 0;
if (chain.getTopVertexRoles() != vertexRoles[otherAnnulus] *
NPerm(0, 1, 2, 3))
return 0;
// Success!
return chain.getIndex() - 1;
}
unsigned long NTriSolidTorus::areAnnuliLinkedAxis(int otherAnnulus) const {
int right = (otherAnnulus + 1) % 3;
int left = (otherAnnulus + 2) % 3;
NTetrahedron* adj = tet[right]->getAdjacentTetrahedron(
vertexRoles[right][1]);
if (adj != tet[otherAnnulus]->getAdjacentTetrahedron(
vertexRoles[otherAnnulus][2]))
return 0;
if (adj == tet[0] || adj == tet[1] || adj == tet[2] || adj == 0)
return 0;
NPerm roles = tet[right]->getAdjacentTetrahedronGluing(
vertexRoles[right][1]) * vertexRoles[right] * NPerm(2, 1, 0, 3);
if (roles != tet[otherAnnulus]->getAdjacentTetrahedronGluing(
vertexRoles[otherAnnulus][2]) * vertexRoles[otherAnnulus] *
NPerm(0, 3, 2, 1))
return 0;
// We've successfully identified the first tetrahedron of the
// layered chain.
NLayeredChain chain(adj, roles);
chain.extendMaximal();
NTetrahedron* top = chain.getTop();
NPerm topRoles(chain.getTopVertexRoles());
if (top->getAdjacentTetrahedron(topRoles[3]) != tet[left])
return 0;
if (top->getAdjacentTetrahedron(topRoles[0]) != tet[otherAnnulus])
return 0;
if (topRoles != tet[left]->getAdjacentTetrahedronGluing(
vertexRoles[left][2]) * vertexRoles[left] * NPerm(3, 0, 1, 2))
return 0;
if (topRoles != tet[otherAnnulus]->getAdjacentTetrahedronGluing(
vertexRoles[otherAnnulus][1]) * vertexRoles[otherAnnulus] *
NPerm(1, 2, 3, 0))
return 0;
// Success!
return chain.getIndex();
}
NTriSolidTorus* NTriSolidTorus::formsTriSolidTorus(NTetrahedron* tet,
NPerm useVertexRoles) {
NTriSolidTorus* ans = new NTriSolidTorus();
ans->tet[0] = tet;
ans->vertexRoles[0] = useVertexRoles;
// Find the adjacent tetrahedra.
ans->tet[1] = tet->getAdjacentTetrahedron(useVertexRoles[0]);
ans->tet[2] = tet->getAdjacentTetrahedron(useVertexRoles[3]);
// Check that we have three distinct tetrahedra.
if (ans->tet[1] == 0 || ans->tet[2] == 0 || ans->tet[1] == tet ||
ans->tet[2] == tet || ans->tet[1] == ans->tet[2]) {
delete ans;
return 0;
}
// Find the vertex roles for tetrahedra 1 and 2.
ans->vertexRoles[1] = tet->getAdjacentTetrahedronGluing(useVertexRoles[0])
* useVertexRoles * NPerm(1, 2, 3, 0);
ans->vertexRoles[2] = tet->getAdjacentTetrahedronGluing(useVertexRoles[3])
* useVertexRoles * NPerm(3, 0, 1, 2);
// Finally, check that tetrahedra 1 and 2 are glued together
// properly.
NPerm roles1 = ans->vertexRoles[1];
if (ans->tet[1]->getAdjacentTetrahedron(roles1[0]) != ans->tet[2]) {
delete ans;
return 0;
}
if (ans->tet[1]->getAdjacentTetrahedronGluing(roles1[0]) * roles1 *
NPerm(1, 2, 3, 0) != ans->vertexRoles[2]) {
delete ans;
return 0;
}
// We have the desired structure!
return ans;
}
NAbelianGroup* NTriSolidTorus::getHomologyH1() const {
NAbelianGroup* ans = new NAbelianGroup();
ans->addRank();
return ans;
}
NManifold* NTriSolidTorus::getManifold() const {
return new NHandlebody(1, true);
}
} // namespace regina
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