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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 <cassert>
#include <iomanip>
#include <iostream>
#include <sstream>
#include "triangulation/dim2.h"
#include "utilities/xmlutils.h"
namespace regina {
Triangulation<2>::Triangulation(const std::string& description) {
try {
*this = fromIsoSig(description);
return;
} catch (const InvalidArgument&) {
}
throw InvalidArgument("The given string could not be interpreted "
"as representing a 2-dimensional triangulation");
}
void Triangulation<2>::swap(Triangulation<2>& other) {
if (&other == this)
return;
// We use a basic PacketChangeSpan here, not a richer ChangeAndClearSpan,
// since we do not want to touch computed properties. Our intention here
// is to swap them, not clear them.
PacketChangeSpan span1(*this);
PacketChangeSpan span2(other);
// Note: swapBaseData() calls Snapshottable::swap().
swapBaseData(other);
}
bool Triangulation<2>::isMinimal() const {
// 2-sphere:
if (eulerChar() == 2)
return (simplices_.size() == 2);
// Projective plane and disc:
if (eulerChar() == 1)
return (simplices_.size() == (isClosed() ? 2 : 1));
// All other closed manifolds:
if (isClosed())
return (countVertices() == 1);
// All other bounded manifolds:
return (countVertices() == countBoundaryComponents());
}
} // namespace regina
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