[pointsampler] implement point sampler on boxes

frackit/sampling/CMakeLists.txt

 install(FILES
+boxpointsampler.hh
 disksampler.hh
 geometrysampler.hh
 geometrypointsampler.hh

frackit/sampling/boxpointsampler.hh

+// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+// vi: set et ts=4 sw=4 sts=4:
+/*****************************************************************************
+ *   See the file COPYING for full copying permissions.                      *
+ *                                                                           *
+ *   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.                                     *
+ *                                                                           *
+ *   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 <http://www.gnu.org/licenses/>.   *
+ *****************************************************************************/
+/*!
+ * \file
+ * \brief Class to randomly generate points on boxes.
+ */
+#ifndef FRACKIT_BOX_POINT_SAMPLER_HH
+#define FRACKIT_BOX_POINT_SAMPLER_HH
+
+#include <random>
+#include <frackit/geometry/box.hh>
+#include "pointsampler.hh"
+
+namespace Frackit {
+
+/*!
+ * \brief Class to randomly generate points within boxes
+ *        following the provided distributions. The type of
+ *        distribution to be used can be specified via traits,
+ *        which are required to exporrt the distributions to be
+ *        used for the x, y and z-coordinate, using the naming
+ *        convention for three-dimensional geometries,
+ *        i.e. they must export:
+ *        using DistributionBase1 = ...; // Distribution for x-coordinate
+ *        using DistributionBase2 = ...; // Distribution for y-coordinate
+ *        using DistributionBase3 = ...; // Distribution for z-coordinate
+ *
+ * \tparam ctype The type used for coordinates
+ * \tparam T The traits class containing the distributions
+ */
+template<class ctype, class T>
+class BoxPointSampler
+: public PointSampler< typename Box<ctype>::Point >
+{
+    using DistroX = typename T::DistributionBase1;
+    using DistroY = typename T::DistributionBase2;
+    using DistroZ = typename T::DistributionBase3;
+
+public:
+    //! export resulting point type
+    using Point = typename Box<ctype>::Point;
+
+    //! export traits class
+    using Traits = T;
+
+    /*!
+     * \brief Constructor from distributions.
+     */
+    BoxPointSampler(const DistroX& px,
+                    const DistroY& py,
+                    const DistroZ& pz)
+    : generator_(std::random_device{}())
+    , p_x_(px)
+    , p_y_(py)
+    , p_z_(pz)
+    {}
+
+    /*!
+     * \brief Sample a point from the distributions.
+     */
+    Point operator() () override
+    {
+        return Point( {p_x_(generator_),
+                       p_y_(generator_),
+                       p_z_(generator_)} );
+    }
+
+ private:
+    std::default_random_engine generator_;
+    DistroX p_x_;
+    DistroY p_y_;
+    DistroZ p_z_;
+};
+
+} // end namespace Frackit
+
+#endif // FRACKIT_BOX_POINT_SAMPLER_HH