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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 1999-2025, 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 "triangulation/dim4.h"
#include "triangulation/isosigtype.h"
#include "triangulation/detail/isosig-impl.h"
#include "triangulation/detail/retriangulate-impl.h"
// NOLINTNEXTLINE(modernize-concat-nested-namespaces)
namespace regina {
namespace detail {
/**
* Provides domain-specific details for the 4-D retriangulation process.
*
* For propagation of 4-D triangulations, we do not make use of the
* options type `Retriangulator::PropagationOptions`.
*/
template <>
struct RetriangulateParams<Triangulation<4>> {
static std::string sig(const Triangulation<4>& tri) {
return tri.isoSig<IsoSigDegrees<4, 2>>();
}
static std::string rigidSig(const Triangulation<4>& tri) {
// Currently rigidity is not supported for triangulations.
return tri.isoSig<IsoSigDegrees<4, 2>>();
}
static constexpr const char* progressStage = "Exploring triangulations";
template <class Retriangulator>
static void propagateFrom(const std::string& sig, size_t maxSize,
Retriangulator* retriang) {
Triangulation<4> t = Triangulation<4>::fromIsoSig(sig);
size_t i;
for (i = 0; i < t.countVertices(); ++i)
if (auto alt = t.withPachner(t.vertex(i)))
if (retriang->candidate(std::move(*alt), sig))
return;
for (i = 0; i < t.countEdges(); ++i)
if (auto alt = t.withPachner(t.edge(i)))
if (retriang->candidate(std::move(*alt), sig))
return;
for (i = 0; i < t.countTriangles(); ++i)
if (auto alt = t.withPachner(t.triangle(i)))
if (retriang->candidate(std::move(*alt), sig))
return;
if (t.size() + 2 <= maxSize)
for (i = 0; i < t.countTetrahedra(); ++i)
if (auto alt = t.withPachner(t.tetrahedron(i)))
if (retriang->candidate(std::move(*alt), sig))
return;
if (t.size() + 4 <= maxSize)
for (i = 0; i < t.size(); ++i) {
// 1-5 moves are always legal.
Triangulation<4> alt(t, false, true);
alt.pachner(alt.pentachoron(i));
if (retriang->candidate(std::move(alt), sig))
return;
}
}
};
} // namespace detail
// Instantiate all necessary retriangulation template functions
// so the full implementation can stay out of the headers.
template bool regina::detail::retriangulateInternal<Triangulation<4>, true>(
const Triangulation<4>&, bool, int, int, ProgressTrackerOpen*,
regina::detail::RetriangulateActionFunc<Triangulation<4>, true>&&);
template bool regina::detail::retriangulateInternal<Triangulation<4>, false>(
const Triangulation<4>&, bool, int, int, ProgressTrackerOpen*,
regina::detail::RetriangulateActionFunc<Triangulation<4>, false>&&);
} // namespace regina
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