Changing Freesurface post-processing routine to a Sampler (#1187)

* remove incomplete, unused python script
* add FreeSurfaceSampler to reg test
* documentation
* python scripts that pass with ctest (to be added later)

amr-wind/utilities/sampling/CMakeLists.txt

@@ -13,7 +13,7 @@ target_sources(${amr_wind_lib_name}
   FieldNorms.cpp
   KineticEnergy.cpp
   Enstrophy.cpp
-  FreeSurface.cpp
+  FreeSurfaceSampler.cpp
   VolumeSampler.cpp
   WaveEnergy.cpp
   )

amr-wind/utilities/sampling/FreeSurfaceSampler.H

@@ -0,0 +1,114 @@
+#ifndef FREESURFACESAMPLER_H
+#define FREESURFACESAMPLER_H
+
+#include "amr-wind/CFDSim.H"
+#include "amr-wind/utilities/sampling/SamplerBase.H"
+
+namespace amr_wind::sampling {
+
+class FreeSurfaceSampler : public SamplerBase::Register<FreeSurfaceSampler>
+{
+public:
+    static std::string identifier() { return "FreeSurfaceSampler"; }
+
+    FreeSurfaceSampler(CFDSim& /*sim*/);
+
+    ~FreeSurfaceSampler() override;
+
+    //! Read user inputs and create mesh-based information for locating
+    //! interface
+    void initialize(const std::string& key) override;
+
+    //! Populate and return a vector of probe locations to be sampled
+    void sampling_locations(SampleLocType& /*locs*/) const override;
+    void output_locations(SampleLocType& locs) const override
+    {
+        return sampling_locations(locs);
+    }
+
+    //! Find heights associated with 2D sample locations
+    void update_sampling_locations() override;
+
+    //! Redo some of the initialization work when the grid changes
+    void post_regrid_actions() override;
+
+    void
+    define_netcdf_metadata(const ncutils::NCGroup& /*unused*/) const override;
+    void
+    populate_netcdf_metadata(const ncutils::NCGroup& /*unused*/) const override;
+    void output_netcdf_data(
+        const ncutils::NCGroup& /*unused*/,
+        const size_t /*unused*/) const override;
+
+    //! Name of this sampling object
+    std::string label() const override { return m_label; }
+    std::string& label() override { return m_label; }
+
+    //! Type of this sampling object
+    std::string sampletype() const override { return identifier(); }
+
+    //! Unique identifier for this set of probe locations
+    int id() const override { return m_id; }
+    int& id() override { return m_id; }
+
+    //! Output functions for private variables
+    //! Number of 2D grid points
+    int num_gridpoints() const { return m_npts; }
+    //! Number of instances
+    int num_instances() const { return m_ninst; }
+    //! Number of points, total
+    long num_points() const override
+    {
+        return static_cast<long>(m_npts) * m_ninst;
+    }
+    long num_output_points() const override
+    {
+        return static_cast<long>(m_npts) * m_ninst;
+    }
+    //! Locations
+    amrex::Vector<amrex::Array<amrex::Real, 2>> grid_locations() const
+    {
+        return m_grid_locs;
+    }
+    //! Outputs (heights)
+    amrex::Vector<amrex::Real> heights() const { return m_out; }
+
+private:
+    CFDSim& m_sim;
+
+    //! reference to VOF
+    const Field& m_vof;
+
+    //! Number or points on 2D grid in each direction
+    amrex::Vector<int> m_npts_dir;
+    int m_npts{0};
+    //! Number of instances (possible sampling points per location, like in the
+    //! case of a breaking wave)
+    int m_ninst{1};
+
+    //! Coordinate direction to search along, default is z
+    //! (this also determines the meaning of start and end points)
+    int m_coorddir{2};
+    //! Grid coordinates, determined as a function of m_coorddir
+    int m_gc0 = 0;
+    int m_gc1 = 1;
+
+    //! Parameters to set up plane
+    amrex::Vector<amrex::Real> m_start, m_end;
+    //! Locations of points in 2D grid
+    amrex::Vector<amrex::Array<amrex::Real, 2>> m_grid_locs;
+    //! Output coordinate
+    amrex::Vector<amrex::Real> m_out;
+
+    //! Max number of sample points found in a single cell
+    int m_ncomp{1};
+    //! Max number of sample points allowed in a single cell
+    int m_ncmax{8};
+
+    std::string m_label;
+    int m_id{-1};
+};
+
+} // namespace amr_wind::sampling
+
+#endif /* FREESURFACESAMPLER_H */