[sampling] add free function to create point samplers

frackit/sampling/CMakeLists.txt

@@ -4,6 +4,7 @@ cylinderpointsampler.hh
 disksampler.hh
 geometrysampler.hh
 geometrypointsampler.hh
+makepointsampler.hh
 pointsampler.hh
 uniformpointsamplertraits.hh
 DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/frackit/sampling)

frackit/sampling/makepointsampler.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 Free functions to create point samplers from geometries.
+ */
+#ifndef FRACKIT_MAKE_POINT_SAMPLER_HH
+#define FRACKIT_MAKE_POINT_SAMPLER_HH
+
+#include "cylinderpointsampler.hh"
+#include "boxpointsampler.hh"
+
+namespace Frackit {
+
+/*!
+ * \brief Overload of the free function to create point
+ *        samplers for cylinders.
+ * \note Sampling along the radius coordinate occurs in the interval [0, r^2]
+ *       and the square root is taken after sampling. Thus, the provided distribution
+ *       must be for the squared radius rather than the radius itself.
+ */
+template< class Traits, class ctype >
+CylinderPointSampler< ctype, Traits >
+makePointSampler(const Cylinder<ctype>& cylinder)
+{
+    using Sampler = CylinderPointSampler<ctype, Traits>;
+    return Sampler( cylinder,
+                    typename Traits::DistributionBase1(0.0, cylinder.radius()*cylinder.radius()),
+                    typename Traits::DistributionBase2(0.0, 2*M_PI),
+                    typename Traits::DistributionBase3(0.0, cylinder.height()) );
+}
+
+/*!
+ * \brief Overload of the free function to create point
+ *        samplers for boxes.
+ */
+template< class Traits, class ctype >
+BoxPointSampler< ctype, Traits >
+makePointSampler(const Box<ctype>& box)
+{
+    using Sampler = BoxPointSampler<ctype, Traits>;
+    return Sampler( typename Traits::DistributionBase1(box.xMin(), box.xMax()),
+                    typename Traits::DistributionBase2(box.yMin(), box.yMax()),
+                    typename Traits::DistributionBase3(box.zMin(), box.zMax()) );
+}
+
+} // end namespace Frackit
+
+#endif // FRACKIT_MAKE_POINT_SAMPLER_HH