TQMesh by Florian Setzwein, a header-only two-dimensional mesh generator for triangular and
quadrilateral elements, is used by pyoomph but is NOT part of this repository: it is downloaded at
build time by cmake/ThirdPartyTQMesh.cmake, which pins the exact revision, and prepared by
citools/patches/patch_tqmesh.cmake. It is compiled into the extension module, i.e. it is contained
in the python wheels, which is why its licence is reproduced below.

TQMesh is hosted at https://github.com/FloSewn/TQMesh

pyoomph exposes it to python in src/nanobind/tqmesh/, and pyoomph/meshes/tqmesh.py builds on that
with the TQMeshTemplate. Both are dropped from the build - and the download skipped - by
-DPYOOMPH_HAS_TQMESH=OFF.

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Following changes are made to the downloaded TQMesh sources:
These changes are indicated by a comment starting with "//FOR PYOOMPH"
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Two passages in src/utils/, applied by citools/patches/patch_tqmesh.cmake, where they are also
explained in full: ASSERT/assert_msg and TERMINATE throw instead of calling assert(), doing nothing
at all in a release build, or exiting the process - none of which is acceptable inside a python
session - and the ASSERT in ~QuadTree() becomes a plain null check, since throwing from a destructor
would call std::terminate. Nothing else is touched.

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Original licence of TQMesh
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MIT License

Copyright (c) 2022 Florian Setzwein

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
