********************************/
// Convert any number to spoken digits
-string ConvertNumToSpokenDigits(string n);
+string ConvertNumToSpokenDigits(const string &n);
+
+// Convert an integer to spoken digits
+string ConvertNumToSpokenDigits(int n);
// Convert a 2 digit rwy number to a spoken-style string
string ConvertRwyNumToSpokenString(int n);
// Convert rwy number string to a spoken-style string
// eg "05L" to "zero five left"
-// Assumes we get a two-digit string optionally appended with R or L
+// Assumes we get a two-digit string optionally appended with R, L, or C
// eg 01 07L 29R 36
// Anything else is not guaranteed to be handled correctly!
-string ConvertRwyNumToSpokenString(string s);
+string ConvertRwyNumToSpokenString(const string &s);
// Return the phonetic letter of a letter represented as an integer 1->26
string GetPhoneticIdent(int i);
+// Return the phonetic letter of a character in the range a-z or A-Z.
+// Currently always returns prefixed by lowercase.
+string GetPhoneticIdent(char c);
+
+// Get the compass direction associated with a heading in degrees
+// Currently returns 8 direction resolution (N, NE, E etc...)
+// Might be modified in future to return 4, 8 or 16 resolution but defaulting to 8.
+string GetCompassDirection(double h);
/*******************************
*
********************************/
// Given two positions (lat & lon in degrees), get the HORIZONTAL separation (in meters)
-double dclGetHorizontalSeparation(Point3D pos1, Point3D pos2);
+double dclGetHorizontalSeparation(const Point3D& pos1, const Point3D& pos2);
// Given a point and a line, get the HORIZONTAL shortest distance from the point to a point on the line.
// Expects to be fed orthogonal co-ordinates, NOT lat & lon !
// Given a position (lat/lon/elev), heading, vertical angle, and distance, calculate the new position.
// Assumes that the ground is not hit!!! Expects heading and angle in degrees, distance in meters.
-Point3D dclUpdatePosition(Point3D pos, double heading, double angle, double distance);
+Point3D dclUpdatePosition(const Point3D& pos, double heading, double angle, double distance);
// Get a heading from one lat/lon to another (in degrees)
-double GetHeadingFromTo(Point3D A, Point3D B);
+double GetHeadingFromTo(const Point3D& A, const Point3D& B);
// Given a heading (in degrees), bound it from 0 -> 360
void dclBoundHeading(double &hdg);
+// smallest difference between two angles in degrees
+// difference is negative if a1 > a2 and positive if a2 > a1
+double GetAngleDiff_deg( const double &a1, const double &a2);
+
/*******************************
*
// find basic airport location info from airport database
bool dclFindAirportID( const string& id, FGAirport *a );
-// get airport elevation
+// get airport elevation IN METERS
double dclGetAirportElev( const string& id );
+// get airport position (elev portion in FEET)
+Point3D dclGetAirportPos( const string& id );
+
/****************
*
-* Runways
+* Runways
*
****************/
// Given a Point3D (lon/lat/elev) and an FGRunway struct, determine if the point lies on the runway
-bool OnRunway(Point3D pt, FGRunway* rwy);
+bool OnRunway(const Point3D& pt, const FGRunway& rwy);
+