The NavigationSystem Class

  //---------------------------------------------------------------
  // Storage for UHF Modes
  //---------------------------------------------------------------

  UHF_Mode_Type  mUHFMode;

  //---------------------------------------------------------------
  // Storage for Datalink and Markpoint lists
  //---------------------------------------------------------------

  int       mCurrentMark;
  Mark_Struct  mpMarkPoints[MAX_MARKPOINTS];

  int       mCurrentDLink;
  DLink_Struct  mpDLinkPoints[MAX_DLINKPOINTS];
 

  char       mpDLinkThreat[15];
  char       mpDLinkTarget[15];

  //---------------------------------------------------------------
  // Control Variables and Lists
  //---------------------------------------------------------------

  Instrument_Mode   mInstrumentMode;      // (Instrument Mode Sel Switch)
  Tacan_Channel_Src   mCurrentTCNSrc;      // (AUXCOMM Master Switch)
  Tacan_Data_Str   mpCurrentTCN[TOTAL_SRC];   // Tacan station that the ICP and AUXCOMM currently point to
  TacanList::Domain   mpCurrentDomain[TOTAL_SRC];  // (AUXCOMM TR/AA_TR Switch && ICP Tacan Type)

  Ils_Data_Str    mpCurrentIls;

  //---------------------------------------------------------------
  // Station list held by the ICP
  //---------------------------------------------------------------

  Tacan_Data_LL_Str*  mpMissionTacans;      // Stations that are preset at the start of mission, info found from waypoint list
  Tacan_Data_LL_Str*  mpCurrentMissionTacan;

  //---------------------------------------------------------------
  // Utility Functions
  //---------------------------------------------------------------

  void CopyMissionTCNData(Tacan_Data_Str*, Tacan_Data_LL_Str*);      // Just a conveience function
  void FindTacanStation(VU_ID*, Tacan_Channel_Src, int, TacanList::StationSet); // Nice wrapper interface for searching
                            // the TacanList, when TacanList
                            // changes its search interface we
                            // only have to change the guts of                            // this function
public:

  //---------------------------------------------------------------
  // Constructors and Destructors
  //---------------------------------------------------------------

  NavigationSystem();
  ~NavigationSystem();
 

  //---------------------------------------------------------------
  // UHF stuff
  //---------------------------------------------------------------
  void       ToggleUHFSrc(void);
  UHF_Mode_Type    GetUHFSrc(void);

  //---------------------------------------------------------------
  // Get the values of the Tacan Station and ILS Data
  //---------------------------------------------------------------

  BOOL       GetTCNAttribute(Attribute, float*);
  BOOL       GetILSAttribute(Attribute, VU_ID*);
  BOOL       GetILSAttribute(Attribute, float*);
  BOOL       GetILSAttribute(Attribute, char*);    //Pass pointer to char[4], function will fill

  //---------------------------------------------------------------
  // Initialize the Mission Pre-set Tacan List
  //---------------------------------------------------------------

  void       SetMissionTacans(AircraftClass*);
  void       DeleteMissionTacans(void);

  //---------------------------------------------------------------
  // Control Switches and buttons
  //---------------------------------------------------------------

  void       SetDomain(Tacan_Channel_Src, TacanList::Domain);
  void       SetDomain(Type);
  TacanList::Domain   GetDomain(Tacan_Channel_Src);
  TacanList::Domain   ToggleDomain(Tacan_Channel_Src); // Returns new state
  void       ToggleControlSrc(void);
  Tacan_Channel_Src   GetControlSrc(void);

  //---------------------------------------------------------------
  // Overall Instrument Mode
  //---------------------------------------------------------------

  void       SetInstrumentMode(Instrument_Mode);
  Instrument_Mode   GetInstrumentMode(void);
  void       StepInstrumentMode(void);
 

  //---------------------------------------------------------------
  // ILS Functions
  //---------------------------------------------------------------
  void       SetIlsData(VU_ID, int);
  void       ExecIls(void);

  //---------------------------------------------------------------
  // Mark and DLink Functions
  //---------------------------------------------------------------

  void       GetMarkPoint(Point_Type*, char*, char*);
  void       GetMarkWayPoint(WayPointClass**);
  void       GetMarkWayPoint(int, WayPointClass**);
  int       GetMarkIndex(void);
  void       SetMarkPoint(Point_Type, float, float, float, long);
  void       GotoPrevMark(void);
  void       GotoNextMark(void);

  void       GetDataLink(FalconDLinkMessage::DLinkPointType*, int*, char*, char*, char*, char*, char*);
  void       SetDataLinks(char, USHORT, USHORT, FalconDLinkMessage::DLinkPointType*, short*, short*, short*, long*);
  void       GetDLinkWayPoint(WayPointClass**);
  void       GetDLinkWayPoint(int, WayPointClass**);
  void       GotoPrevDLink(void);
  void       GotoNextDLink(void);
  int       GetDLinkIndex(void);

  //---------------------------------------------------------------
  // Tacan Station Functions
  //---------------------------------------------------------------

  void       SetTacanChannel(Tacan_Channel_Src, int, int);    // For setting a single digit
  int       GetTacanChannel(Tacan_Channel_Src, int);      // For getting a single digit

  void       SetTacanChannel(Tacan_Channel_Src, int);      // For setting the full channel
  int       GetTacanChannel(Tacan_Channel_Src);        // For getting the full channel

  void       SetTacanChannel(Tacan_Channel_Src, int, TacanList::StationSet); // For setting everything
  void       GetTacanChannel(Tacan_Channel_Src, int*, TacanList::StationSet*); // For getting everything

  void       SetTacanBand(Tacan_Channel_Src, TacanList::StationSet); // For setting the band
  TacanList::StationSet GetTacanBand(Tacan_Channel_Src);         // For getting the band

  void       GetTacanVUID(Tacan_Channel_Src, VU_ID*);      // For getting the Id of the tacan object

  void       StepTacanChannelDigit(Tacan_Channel_Src, int);
  void       StepTacanBand(Tacan_Channel_Src);

  void       StepPreviousTacan(void);           // For ICP List only
  void       StepNextTacan(void);             // For ICP List only
  void       GetHomeID(VU_ID*);             // For ICP List only
  void       GetCurrentID(VU_ID*);            // For ICP List only
  Type       GetType(void);               // For ICP List only

  //---------------------------------------------------------------
  // Miscellaneous Functions
  //--------------------------------------------------------------

  BOOL       IsTCNTanker(void);
  BOOL       IsTCNCarrier(void);
  BOOL       IsTCNAirbase(void);
  void       GetAirbase(VU_ID*);

  typedef enum Point_Type
  {
   NODATA,
   GMPOINT,
   POS
  };

  typedef struct Mark_Struct
  {
   Point_Type   pointType;
   char     pLatStr[40];
   char     pLongStr[40];
   WayPointClass*  pWaypoint;
  } Mark_Struct;

  typedef struct DLink_Struct
  {
   FalconDLinkMessage::DLinkPointType  pointType;
   WayPointClass*         pWaypoint;
   char            pTypeStr[5];
   char            pTarget[15];  // class pointer, primary target
   char            pThreat[15];  // class pointer, primary threat
   char            attackHeading[4];
   char            distance[5];
  } DLinkStruct;

  typedef enum Type {
   AIRBASE,
   CARRIER,
   TANKER,
   TOTAL_TYPES
  };

  // Storage for Tacan Data
  typedef enum Tacan_Channel_Src
  {
   ICP,
   AUXCOMM,
   TOTAL_SRC
  };

  typedef enum Instrument_Mode
  {
   NAV,
   ILS_NAV,
   ILS_TACAN,
   TACAN,
   TOTAL_MODES
  };

  typedef enum Attribute
  {
   X_POS,
   Y_POS,
   Z_POS,
   RWY_NUM,
   GP_DEV,
   GS_DEV,
   AIRBASE_ID,
   TOTAL_ATTRIBUTES
  };

  typedef struct Tacan_Data_Str
  {
   int       channel;
   int       digits[3];  //Element #2 = MSB, Element #0 = LSB
   TacanList::StationSet set;
   VU_ID       vuID;
  } Tacan_Data_Str;

  typedef struct Ils_Data_Str
  {
   float       frontx;
   float       fronty;
   float       backx;
   float       backy;
   float       z;
   int       rwyidx;
   char       rwynum[4];
   int       heading;
   float       sinHeading;
   float       cosHeading;
   float       gpDeviation;
   float       gsDeviation;
   VU_ID       vuID;    // id of airbase
   ObjectiveClass*  pobjective;
  } Ils_Data_Str;

  typedef struct Tacan_Data_LL_Str
  {
   Tacan_Data_LL_Str *pNext;
   Tacan_Data_LL_Str *pPrevious;
   Tacan_Data_Str  *pData;
   Type    type;
  } Tacan_Data_LL_Str;