.. _program_listing_file_interfaces_lola_dem.h:

Program Listing for File lola_dem.h
===================================

|exhale_lsh| :ref:`Return to documentation for file <file_interfaces_lola_dem.h>` (``interfaces/lola_dem.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #pragma once
   
   #include <filesystem>
   #include <string>
   #include <vector>
   
   #include "lupnt/core/definitions.h"
   
   namespace lupnt {
   
     struct LolaSite {
       std::string id;    
       std::string name;  
       double lat_deg;    
       double lon_deg;    
     };
   
     const std::vector<LolaSite>& GetLolaSites();
   
     const LolaSite& SelectLolaSite(double lat_deg, double lon_deg);
   
     std::string LolaDemUrl(const std::string& site_id);
   
     std::filesystem::path DownloadLolaDem(const std::string& site_id);
   
     class LunarDem {
     public:
       LunarDem() = default;
   
       LunarDem(const MatXd& x, const MatXd& y, const MatXd& elev, const LolaSite& site);
   
       double GetElevation(double x, double y) const;
   
       double GetElevationLatLon(double lat_deg, double lon_deg) const;
   
       const MatXd& x() const { return x_; }             
       const MatXd& y() const { return y_; }             
       const MatXd& elevation() const { return elev_; }  
       const LolaSite& site() const { return site_; }    
   
       int rows() const { return static_cast<int>(elev_.rows()); }  
       int cols() const { return static_cast<int>(elev_.cols()); }  
   
       double x_min() const { return std::min(x_left_, x_right_); }    
       double x_max() const { return std::max(x_left_, x_right_); }    
       double y_min() const { return std::min(y_top_, y_bottom_); }    
       double y_max() const { return std::max(y_top_, y_bottom_); }    
       double center_x() const { return 0.5 * (x_left_ + x_right_); }  
       double center_y() const { return 0.5 * (y_top_ + y_bottom_); }  
   
     private:
       MatXd x_, y_, elev_;
       LolaSite site_;
   
       // Regular-grid parameters cached for fast bilinear lookup. Columns increase in x,
       // rows increase in y (dy_ is typically negative for a north-up raster).
       double x0_ = 0.0, y0_ = 0.0;  // coordinate of pixel-center (row 0, col 0)
       double dx_ = 1.0, dy_ = 1.0;  // per-column / per-row coordinate step [m]
       int nx_ = 0, ny_ = 0;
       double x_left_ = 0.0, x_right_ = 0.0, y_top_ = 0.0, y_bottom_ = 0.0;
     };
   
     LunarDem LoadLolaDem(double lat_deg, double lon_deg, double half_width_m = 5000.0,
                          double max_res = 20.0, const std::filesystem::path& dem_file = {});
   
   }  // namespace lupnt