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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 2011-2025, 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. *
* *
* As an exception, when this program is distributed through (i) the *
* App Store by Apple Inc.; (ii) the Mac App Store by Apple Inc.; or *
* (iii) Google Play by Google Inc., then that store may impose any *
* digital rights management, device limits and/or redistribution *
* restrictions that are required by its terms of service. *
* *
* 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, see <https://www.gnu.org/licenses/>. *
* *
**************************************************************************/
#include "enumerate/treeconstraint-impl.h"
#include "snappea/snappeatriangulation.h"
namespace regina {
// Instantiate all templates that we might need:
template BanBoundary::BanBoundary(const LPInitialTableaux<LPConstraintNone>&);
template BanBoundary::BanBoundary(
const LPInitialTableaux<LPConstraintEulerPositive>&);
template BanBoundary::BanBoundary(
const LPInitialTableaux<LPConstraintEulerZero>&);
template BanBoundary::BanBoundary(
const LPInitialTableaux<LPConstraintNonSpun>&);
template BanEdge::BanEdge(const LPInitialTableaux<LPConstraintNone>&, Edge<3>*);
template BanEdge::BanEdge(const LPInitialTableaux<LPConstraintEulerPositive>&,
Edge<3>*);
template BanEdge::BanEdge(const LPInitialTableaux<LPConstraintEulerZero>&,
Edge<3>*);
template BanEdge::BanEdge(const LPInitialTableaux<LPConstraintNonSpun>&,
Edge<3>*);
template BanTorusBoundary::BanTorusBoundary(
const LPInitialTableaux<LPConstraintNone>&);
template BanTorusBoundary::BanTorusBoundary(
const LPInitialTableaux<LPConstraintEulerPositive>&);
template BanTorusBoundary::BanTorusBoundary(
const LPInitialTableaux<LPConstraintEulerZero>&);
template BanTorusBoundary::BanTorusBoundary(
const LPInitialTableaux<LPConstraintNonSpun>&);
void LPConstraintEulerPositive::addRows(
LPCol<regina::LPConstraintEulerPositive>* col,
const LPInitialTableaux<LPConstraintEulerPositive>& init) {
const Triangulation<3>& tri = init.tri();
int* obj = new int[7 * tri.size()];
size_t tet, i;
Perm<4> p;
for (i = 0; i < 7 * tri.size(); ++i)
obj[i] = 1;
for (i = 0; i < tri.countTriangles(); ++i) {
tet = tri.triangle(i)->front().tetrahedron()->index();
p = tri.triangle(i)->front().vertices();
--obj[7 * tet + p[0]];
--obj[7 * tet + p[1]];
--obj[7 * tet + p[2]];
--obj[7 * tet + 4];
--obj[7 * tet + 5];
--obj[7 * tet + 6];
}
for (i = 0; i < tri.countEdges(); ++i) {
tet = tri.edge(i)->front().tetrahedron()->index();
p = tri.edge(i)->front().vertices();
++obj[7 * tet + p[0]];
++obj[7 * tet + p[1]];
++obj[7 * tet + 4 + quadMeeting[p[0]][p[1]][0]];
++obj[7 * tet + 4 + quadMeeting[p[0]][p[1]][1]];
}
for (i = 0; i < 7 * tri.size(); ++i)
col[i].extra[0] = obj[init.columnPerm()[i]];
col[7 * tri.size()].extra[0] = -1;
delete[] obj;
}
void LPConstraintEulerZero::addRows(
LPCol<regina::LPConstraintEulerZero>* col,
const LPInitialTableaux<LPConstraintEulerZero>& init) {
const Triangulation<3>& tri = init.tri();
int* obj = new int[7 * tri.size()];
size_t tet, i;
Perm<4> p;
for (i = 0; i < 7 * tri.size(); ++i)
obj[i] = 1;
for (i = 0; i < tri.countTriangles(); ++i) {
tet = tri.triangle(i)->front().tetrahedron()->index();
p = tri.triangle(i)->front().vertices();
--obj[7 * tet + p[0]];
--obj[7 * tet + p[1]];
--obj[7 * tet + p[2]];
--obj[7 * tet + 4];
--obj[7 * tet + 5];
--obj[7 * tet + 6];
}
for (i = 0; i < tri.countEdges(); ++i) {
tet = tri.edge(i)->front().tetrahedron()->index();
p = tri.edge(i)->front().vertices();
++obj[7 * tet + p[0]];
++obj[7 * tet + p[1]];
++obj[7 * tet + 4 + quadMeeting[p[0]][p[1]][0]];
++obj[7 * tet + 4 + quadMeeting[p[0]][p[1]][1]];
}
for (i = 0; i < 7 * tri.size(); ++i)
col[i].extra[0] = obj[init.columnPerm()[i]];
col[7 * tri.size()].extra[0] = -1;
delete[] obj;
}
void LPConstraintNonSpun::addRows(
LPCol<regina::LPConstraintNonSpun>* col,
const LPInitialTableaux<LPConstraintNonSpun>& init) {
const Triangulation<3>& tri = init.tri();
// Add the coefficients for the two new variables now.
col[3 * tri.size()].extra[0] = -1;
col[3 * tri.size() + 1].extra[1] = -1;
// For the time being we insist on one vertex, which must be
// ideal with torus link.
if (tri.countVertices() != 1 ||
(! tri.vertex(0)->isIdeal()) ||
(! tri.vertex(0)->isLinkOrientable()) ||
tri.vertex(0)->linkEulerChar() != 0)
throw InvalidArgument(
"LPConstraintNonSpun requires an oriented ideal triangulation "
"with precisely one torus cusp and no other vertices");
// Compute the two slope equations for the torus cusp, if we can.
SnapPeaTriangulation snapPea(tri, false);
if (snapPea.isNull())
throw UnsolvedCase("SnapPea produced a null triangulation "
"when attempting to use LPConstraintNonSpun");
MatrixInt coeffs = snapPea.slopeEquations();
// Use a static_cast to ensure we are using the Triangulation<3>
// equality test. Otherwise C++20 complains about ambiguity.
if (static_cast<const Triangulation<3>&>(snapPea) != tri)
throw UnsolvedCase("SnapPea retriangulated "
"when attempting to use LPConstraintNonSpun");
// All good! Add the two slope equations as extra rows to
// our constraint matrix.
//
// The coefficients here are differences of terms from
// SnapPy's get_cusp_equation(), which works in native
// integers; therefore we *should* be able to happily convert them
// back to native integers now. However, just in case:
try {
for (size_t i = 0; i < 3 * tri.size(); ++i) {
col[i].extra[0] =
coeffs.entry(0, init.columnPerm()[i]).safeLongValue();
col[i].extra[1] =
coeffs.entry(1, init.columnPerm()[i]).safeLongValue();
}
} catch (const NoSolution&) {
throw UnsolvedCase("The coefficients of the slope equations "
"do not fit into a native long integer");
}
}
void BanConstraintBase::writeTextShort(std::ostream& out) const {
const size_t nCols = system_.coords(tri_.size());
bool foundBanned = false, foundMarked = false;
for (size_t i = 0; i < nCols; ++i)
if (banned_[i]) {
if (! foundBanned) {
out << "Banned:";
foundBanned = true;
}
out << ' ' << i;
}
if (! foundBanned)
out << "Nothing banned";
out << ", ";
for (size_t i = 0; i < nCols; ++i)
if (marked_[i]) {
if (! foundMarked) {
out << "marked:";
foundMarked = true;
}
out << ' ' << i;
}
if (! foundMarked)
out << "nothing marked";
}
} // namespace regina
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