DOCUMENTATION.md

API Documentation

This file contains the description of all the functions exported by the FFI library in Lua.

XPData functions

General

• bool xpdata_is_ready()
  • It returns true if the data from XP files have been successfully read. The return value is false until the worker thread finished its execution or if it encouters an error. This function should be verified to be true before calling any other xpdata_ function.
• bool xpdata_is_error()
  • It returns true if an error occurred during the reading of X-Plane files. If the error is not critical, the xpdata_is_ready may still be true but partial data are available.
• void xpdata_force_refresh()
  • Force the refresh of cached data (nearest airport, ...).
  • This function is very computational intensive and should be called only when really needed.

NAV Aids

• struct xpdata_navaid_list_t xpdata_navaid_by_coords(int type, double lat, double lon, bool extended_range)

  • It finds the nearest navaids of the given type (see NAV_ID_* constants) and the coordinates. If extended_range is false, the search is limited in a square of aprox. 180nm each side. If extended_range is true, the search is performed in a square of at least 360nm each side, but the performance penalty is high.

• struct xpdata_navaid_list_t xpdata_navaid_by_freq(int type, double freq)

  • It finds the nearest navaids of the given type (see NAV_ID_* constants) and frequency.

• struct xpdata_navaid_list_t xpdata_navaid_by_name(int type, const char name)*

  • It finds the nearest navaids of the given type (see NAV_ID_* constants) and short name (e.g. 'SRN').

Airport

• struct xpdata_airport_t xpdata_find_nearest_airport()

  • It returns the nearest airport. The result is cached inside the function and updated every 5 seconds (computer time, not simulation time).
  • A forced refresh can be asked via xpdata_force_refresh().

• struct xpdata_airport_t xpdata_find_airport_by_coords(double lat, double lon)

  • It finds the nearest airport with respect to the provided latitude and longitude.
  • This is an heavy sequential operation, caching the result is encouraged. ... TODO ...

XPData data structure

struct xpdata_coords_t {
    double lat;
    double lon;
};

struct xpdata_navaid_t {
    const char *id; // e.g., SRN
    const char *full_name;  // Saronno VOR
    int type;                // Constants NAV_ID_* 
    xpdata_coords_t coords;
    double altitude;
    double frequency;
};

struct xpdata_navaid_list_t {
    struct xpdata_navaid_t **navaid;
    int nr_elements;
};

struct xpdata_airport_t {
    const char *id; // e.g., LIML
    const char *full_name;
    xpdata_coords_t coords;
    double altitude;

};