/**
* See http://en.wikipedia.org/wiki/Latitude#Degree_length
*
* TODO: check if these calculatiosn (based on the oa2gm source code) are
* correct. I guess not, because they both use 6371e3 for computing
* new latitudinal and longitudinal points. This is not 100% correct.
* We should probably follow WGS84 or IERS 2003 ellipsoids.
*/
void Circle::discretize( std::vector<Coordinate>& coords, double resolution ) const
{
// Each circle must have *at least* 360 points (or more if the specified resolution is
// not satisfied when taking 360 points).
const int min_nb_points = 360;
int nbPoints = max((int)(2*pi*radius/resolution), min_nb_points);
coords.clear();
coords.reserve(nbPoints);
double deg_lat, deg_lon;
double angle;
Coordinate centerCoord = center.getCoordinate();
Latitude lat = centerCoord.getLatitude();
Longitude lon = centerCoord.getLongitude();
// Compute arcdegree of latitude respectively longitude difference of the center.
double arcdegree_lat = lat.getArcDegree();
double arcdegree_lon = lon.getArcDegree(lat);
for (int i = 0; i < nbPoints; ++i)
{
angle = 2*pi*i/nbPoints;
deg_lon = lon.getAngle() + getRadiusM()*cos(angle)/arcdegree_lon;
deg_lat = lat.getAngle() + getRadiusM()*sin(angle)/arcdegree_lat;
coords.push_back( Coordinate( deg_lat, deg_lon ) );
}
}
void Parser::handleLine(const std::string& line)
{
smatch matches;
if ( regex_match(line, matches, regexMap.find(REGEX_COMMENT)->second) )
{
// do nothing.
return;
}
if ( regex_match(line, matches, regexMap.find(REGEX_AC)->second) )
{
airspaces.push_back(new Airspace);
setCurrentDirection('+');
currentArcCenter.reset();
// Assign the parsed class to the current airspace.
string matched_text( matches[1].first, matches[1].second );
getCurrentAirspace()->setClass( parseAirspaceClass(matched_text) );
return;
}
if ( regex_match(line, matches, regexMap.find(REGEX_AN)->second) )
{
string airspace_name( matches[1].first, matches[1].second );
getCurrentAirspace()->setName(airspace_name);
return;
}
if ( regex_match(line, matches, regexMap.find(REGEX_AH)->second) )
{
string airspace_ceiling(matches[1].first, matches[1].second);
getCurrentAirspace()->setCeilingString(airspace_ceiling);
getCurrentAirspace()->setCeiling( parseAltitude(airspace_ceiling) );
return;
}
if ( regex_match(line, matches, regexMap.find(REGEX_AL)->second) )
{
string airspace_floor(matches[1].first, matches[1].second);
getCurrentAirspace()->setFloorString(airspace_floor);
getCurrentAirspace()->setFloor( parseAltitude(airspace_floor) );
return;
}
if ( regex_match(line, matches, regexMap.find(REGEX_AT)->second) )
{
string airspace_coordinate(matches[1].first, matches[1].second);
getCurrentAirspace()->add( Label(getCurrentAirspace()->getName(), parseCoordinate(airspace_coordinate)) );
return;
}
if ( regex_match(line, matches, regexMap.find(REGEX_VX)->second) )
{
string matched_text(matches[1].first, matches[1].second);
setCurrentArcCenter(parseCoordinate(matched_text));
return;
}
if ( regex_match(line, matches, regexMap.find(REGEX_VD)->second) )
{
string direction_string;
for (unsigned int i = 1; i < matches.size(); ++i)
{
direction_string.assign(matches[i].first, matches[i].second);
}
setCurrentDirection(direction_string[0]);
return;
}
if ( regex_match(line, matches, regexMap.find(REGEX_DP)->second) )
{
string point_coordinate( matches[1].first, matches[1].second );
getCurrentAirspace()->add( new Point(parseCoordinate(point_coordinate)) );
return;
}
if ( regex_match(line, matches, regexMap.find(REGEX_DA)->second) )
{
// Read the matched values and create our Arc.
string radiusNM( matches[1].first, matches[1].second );
string angleStart( matches[2].first, matches[2].second );
string angleEnd( matches[3].first, matches[3].second );
Arc arc( *(getCurrentArcCenter()), atof(radiusNM.c_str()),
atof(angleStart.c_str()), atof(angleEnd.c_str()), getCurrentDirection());
getCurrentAirspace()->add( &arc );
return;
}
if ( regex_match(line, matches, regexMap.find(REGEX_DB)->second) )
{
// We have a DB-record, now check if the coords are specified correctly...
string dbcoords( matches[1].first, matches[1].second );
if ( regex_match(dbcoords, matches, regexMap.find(REGEX_DB_COORDS)->second) )
{
// Fetch the start and end coordinate for this arc.
string coord1( matches[1].first, matches[1].second );
string coord2( matches[2].first, matches[2].second );
Coordinate c1 = parseCoordinate(coord1);
Coordinate c2 = parseCoordinate(coord2);
std::shared_ptr<Coordinate> currentArcCenter = getCurrentArcCenter();
// Retrieve latitude and longitude of the arc-center.
Latitude lat = currentArcCenter->getLatitude();
Longitude lon = currentArcCenter->getLongitude();
// Compute arcdegree of latitude respectively longitude, based on the center's coordinates.
double arcdegree_lat = lat.getArcDegree();
double arcdegree_lon = lon.getArcDegree(lat);
// Compute start and end angle (in standard coordinate frame!)
// Note that we have to take into account the arcdegrees here!!!
double dLat1 = ( c1.getLatitude().getAngle() - currentArcCenter->getLatitude().getAngle() )*arcdegree_lat;
double dLon1 = ( c1.getLongitude().getAngle() - currentArcCenter->getLongitude().getAngle() )*arcdegree_lon;
double dLat2 = ( c2.getLatitude().getAngle() - currentArcCenter->getLatitude().getAngle() )*arcdegree_lat;
double dLon2 = ( c2.getLongitude().getAngle() - currentArcCenter->getLongitude().getAngle() )*arcdegree_lon;
double startAngle = 180.0*atan2(dLat1, dLon1)/pi;
double endAngle = 180.0*atan2(dLat2, dLon2)/pi;
// Convert start and end angle to airspace coordinate frame.
startAngle = 90 - startAngle;
endAngle = 90 - endAngle;
// Use maximum of the two radii (for safety reasons).
//double radius = max( c1.getDistance(getCurrentCoordinate()), c2.getDistance(getCurrentCoordinate()) );
// Use minimum of the two radii.
//double radius = min( c1.getDistance(getCurrentCoordinate()), c2.getDistance(getCurrentCoordinate()) );
// Use average of the two radii.
double radius = ( c1.getDistance(*currentArcCenter) + c2.getDistance(*currentArcCenter) )*0.5;
// Add the arc points to this space's Polygon.
getCurrentAirspace()->add( new Arc(*currentArcCenter,
radius/1852.0, startAngle, endAngle, getCurrentDirection()) );
}
else
{
cout << "\nERROR: invalid coordinate string specification in DB-record: " << line << endl;
exit(1);
}
}
if ( regex_match(line, matches, regexMap.find(REGEX_DC)->second) )
{
// Get circle radius (in Nautical Miles) from what we've just read.
string radiusNM;
radiusNM.assign(matches[1].first, matches[1].second);
// Add circle to this Airspace.
Point center(*(getCurrentArcCenter()));
getCurrentAirspace()->add(new Circle(center, atof(radiusNM.c_str())));
}
}