From fd467d48a2585af80bf242daa7c06b78908d7417 Mon Sep 17 00:00:00 2001
From: Bruno Turcksin <bruno.turcksin@gmail.com>
Date: Wed, 3 Apr 2024 09:09:37 -0400
Subject: [PATCH] Add GridGenerator::cylinder to the python wrappers

---
 .../include/triangulation_wrapper.h           |  5 ++++
 .../source/export_triangulation.cc            | 22 ++++++++++++++
 .../source/triangulation_wrapper.cc           | 30 +++++++++++++++++++
 .../tests/triangulation_wrapper.py            | 11 +++++++
 4 files changed, 68 insertions(+)

diff --git a/contrib/python-bindings/include/triangulation_wrapper.h b/contrib/python-bindings/include/triangulation_wrapper.h
index 0a617ab24c..7422c11ac6 100644
--- a/contrib/python-bindings/include/triangulation_wrapper.h
+++ b/contrib/python-bindings/include/triangulation_wrapper.h
@@ -286,6 +286,11 @@ namespace python
     void
     generate_half_hyper_ball(PointWrapper &center, const double radius = 1.);
 
+    /*! @copydoc GridGenerator::cylinder
+     */
+    void
+    generate_cylinder(const double radius = 1., const double half_length = 1.);
+
     /*! @copydoc GridGenerator::hyper_shell
      */
     void
diff --git a/contrib/python-bindings/source/export_triangulation.cc b/contrib/python-bindings/source/export_triangulation.cc
index 5a9b28e6e4..65b1bbdac0 100644
--- a/contrib/python-bindings/source/export_triangulation.cc
+++ b/contrib/python-bindings/source/export_triangulation.cc
@@ -110,6 +110,10 @@ namespace python
                                          generate_half_hyper_ball,
                                          1,
                                          2)
+  BOOST_PYTHON_MEMBER_FUNCTION_OVERLOADS(generate_cylinder_overloads,
+                                         generate_cylinder,
+                                         0,
+                                         2)
   BOOST_PYTHON_MEMBER_FUNCTION_OVERLOADS(generate_hyper_shell_overloads,
                                          generate_hyper_shell,
                                          3,
@@ -330,6 +334,19 @@ namespace python
 
 
 
+  const char generate_cylinder_docstring[] =
+    "Create a dim dimensional cylinder where the x-axis serves as the axis \n"
+    "of the cylinder. For the purposes of this function, a cylinder is     \n"
+    "defined as a (dim - 1) dimensional disk of given radius, extruded     \n"
+    "along the axis of the cylinder (which is the first coordinate         \n"
+    "direction). Consequently, in three dimensions, the cylinder extends   \n"
+    "from x=-half_length to x=+half_length and its projection into the     \n"
+    "yz-plane is a circle of radius radius. In two dimensions, the         \n"
+    "cylinder is a rectangle from x=-half_length to x=+half_length and     \n"
+    "from y=-radius to y=radius.                                           \n";
+
+
+
   const char generate_hyper_cube_with_cylindrical_hole_docstring[] =
     "This function produces a square in the xy-plane with a cylindrical     \n"
     "hole in the middle. In 3d, this geometry is extruded in z direction    \n"
@@ -711,6 +728,11 @@ namespace python
            generate_half_hyper_ball_overloads(
              boost::python::args("self", "center", "radius"),
              generate_half_hyper_ball_docstring))
+      .def("generate_cylinder",
+           &TriangulationWrapper::generate_cylinder,
+           generate_cylinder_overloads(
+             boost::python::args("self", "radius", "half_length"),
+             generate_cylinder_docstring))
       .def("generate_hyper_shell",
            &TriangulationWrapper::generate_hyper_shell,
            generate_hyper_shell_overloads(boost::python::args("self",
diff --git a/contrib/python-bindings/source/triangulation_wrapper.cc b/contrib/python-bindings/source/triangulation_wrapper.cc
index 69ead0d4e6..1f131c00d2 100644
--- a/contrib/python-bindings/source/triangulation_wrapper.cc
+++ b/contrib/python-bindings/source/triangulation_wrapper.cc
@@ -563,6 +563,20 @@ namespace python
 
 
 
+    template <int dim>
+    void
+    generate_cylinder(const double radius,
+                      const double half_length,
+                      void        *triangulation)
+    {
+      Triangulation<dim> *tria =
+        static_cast<Triangulation<dim> *>(triangulation);
+      tria->clear();
+      GridGenerator::cylinder(*tria, radius, half_length);
+    }
+
+
+
     template <int dim, int spacedim>
     void
     scale(const double scaling_factor, void *triangulation)
@@ -1601,6 +1615,22 @@ namespace python
 
 
 
+  void
+  TriangulationWrapper::generate_cylinder(const double radius,
+                                          const double half_length)
+  {
+    AssertThrow(
+      dim == spacedim,
+      ExcMessage(
+        "This function is only implemented for dim equal to spacedim."));
+    if (dim == 2)
+      internal::generate_cylinder<2>(radius, half_length, triangulation);
+    else
+      internal::generate_cylinder<3>(radius, half_length, triangulation);
+  }
+
+
+
   void
   TriangulationWrapper::generate_hyper_cube_with_cylindrical_hole(
     const double       inner_radius,
diff --git a/contrib/python-bindings/tests/triangulation_wrapper.py b/contrib/python-bindings/tests/triangulation_wrapper.py
index a2763730fb..5a645be1f0 100644
--- a/contrib/python-bindings/tests/triangulation_wrapper.py
+++ b/contrib/python-bindings/tests/triangulation_wrapper.py
@@ -377,6 +377,17 @@ class TestTriangulationWrapper(unittest.TestCase):
             n_cells = triangulation.n_active_cells()
             self.assertEqual(n_cells, n_cells_ref)
 
+    def test_cylinder(self):
+        for dim in self.dim:
+            triangulation = Triangulation(dim[0])
+            if (dim[0] == '2D'):
+                n_cells_ref = 1
+            else:
+                n_cells_ref = 10
+            triangulation.generate_cylinder()
+            n_cells = triangulation.n_active_cells()
+            self.assertEqual(n_cells, n_cells_ref)
+
     def test_shift_and_merge(self):
         for dim in self.dim:
             triangulation_1 = self.build_hyper_cube_triangulation(dim)
-- 
2.39.5