+// ATCProjection.cxx - A convienience projection class for the ATC/AI system.
+//
+// Written by David Luff, started 2002.
+//
+// Copyright (C) 2002 David C Luff - david.luff@nottingham.ac.uk
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
#include "ATCProjection.hxx"
#include <math.h>
#include <simgear/constants.h>
-#define DCL_PI 3.1415926535f
-//#define SG_PI ((SGfloat) M_PI)
-#define DCL_DEGREES_TO_RADIANS (DCL_PI/180.0)
-#define DCL_RADIANS_TO_DEGREES (180.0/DCL_PI)
-
FGATCProjection::FGATCProjection() {
- origin.setlat(0.0);
- origin.setlon(0.0);
- origin.setelev(0.0);
- correction_factor = cos(origin.lat() * DCL_DEGREES_TO_RADIANS);
+ _origin.setlat(0.0);
+ _origin.setlon(0.0);
+ _origin.setelev(0.0);
+ _correction_factor = cos(_origin.lat() * SG_DEGREES_TO_RADIANS);
+}
+
+FGATCProjection::FGATCProjection(const Point3D& centre) {
+ _origin = centre;
+ _correction_factor = cos(_origin.lat() * SG_DEGREES_TO_RADIANS);
}
FGATCProjection::~FGATCProjection() {
}
-void FGATCProjection::Init(Point3D centre) {
- origin = centre;
- correction_factor = cos(origin.lat() * DCL_DEGREES_TO_RADIANS);
+void FGATCProjection::Init(const Point3D& centre) {
+ _origin = centre;
+ _correction_factor = cos(_origin.lat() * SG_DEGREES_TO_RADIANS);
}
-Point3D FGATCProjection::ConvertToLocal(Point3D pt) {
- double delta_lat = pt.lat() - origin.lat();
- double delta_lon = pt.lon() - origin.lon();
+Point3D FGATCProjection::ConvertToLocal(const Point3D& pt) {
+ double delta_lat = pt.lat() - _origin.lat();
+ double delta_lon = pt.lon() - _origin.lon();
- double y = sin(delta_lat * DCL_DEGREES_TO_RADIANS) * SG_EQUATORIAL_RADIUS_M;
- double x = sin(delta_lon * DCL_DEGREES_TO_RADIANS) * SG_EQUATORIAL_RADIUS_M * correction_factor;
+ double y = sin(delta_lat * SG_DEGREES_TO_RADIANS) * SG_EQUATORIAL_RADIUS_M;
+ double x = sin(delta_lon * SG_DEGREES_TO_RADIANS) * SG_EQUATORIAL_RADIUS_M * _correction_factor;
return(Point3D(x,y,0.0));
}
-Point3D FGATCProjection::ConvertFromLocal(Point3D pt) {
- return(Point3D(0,0,0));
+Point3D FGATCProjection::ConvertFromLocal(const Point3D& pt) {
+ double delta_lat = asin(pt.y() / SG_EQUATORIAL_RADIUS_M) * SG_RADIANS_TO_DEGREES;
+ double delta_lon = (asin(pt.x() / SG_EQUATORIAL_RADIUS_M) * SG_RADIANS_TO_DEGREES) / _correction_factor;
+
+ return(Point3D(_origin.lon()+delta_lon, _origin.lat()+delta_lat, 0.0));
}
/**********************************************************************************/
FGATCAlignedProjection::FGATCAlignedProjection() {
- origin.setlat(0.0);
- origin.setlon(0.0);
- origin.setelev(0.0);
- correction_factor = cos(origin.lat() * DCL_DEGREES_TO_RADIANS);
+ _origin.setlat(0.0);
+ _origin.setlon(0.0);
+ _origin.setelev(0.0);
+ _correction_factor = cos(_origin.lat() * SG_DEGREES_TO_RADIANS);
+}
+
+FGATCAlignedProjection::FGATCAlignedProjection(const Point3D& centre, double heading) {
+ _origin = centre;
+ _theta = heading * SG_DEGREES_TO_RADIANS;
+ _correction_factor = cos(_origin.lat() * SG_DEGREES_TO_RADIANS);
}
FGATCAlignedProjection::~FGATCAlignedProjection() {
}
-void FGATCAlignedProjection::Init(Point3D centre, double heading) {
- origin = centre;
- theta = heading * DCL_DEGREES_TO_RADIANS;
- correction_factor = cos(origin.lat() * DCL_DEGREES_TO_RADIANS);
+void FGATCAlignedProjection::Init(const Point3D& centre, double heading) {
+ _origin = centre;
+ _theta = heading * SG_DEGREES_TO_RADIANS;
+ _correction_factor = cos(_origin.lat() * SG_DEGREES_TO_RADIANS);
}
-Point3D FGATCAlignedProjection::ConvertToLocal(Point3D pt) {
+Point3D FGATCAlignedProjection::ConvertToLocal(const Point3D& pt) {
// convert from lat/lon to orthogonal
- double delta_lat = pt.lat() - origin.lat();
- double delta_lon = pt.lon() - origin.lon();
- double y = sin(delta_lat * DCL_DEGREES_TO_RADIANS) * SG_EQUATORIAL_RADIUS_M;
- double x = sin(delta_lon * DCL_DEGREES_TO_RADIANS) * SG_EQUATORIAL_RADIUS_M * correction_factor;
- //cout << "Before alignment, x = " << x << " y = " << y << '\n';
+ double delta_lat = pt.lat() - _origin.lat();
+ double delta_lon = pt.lon() - _origin.lon();
+ double y = sin(delta_lat * SG_DEGREES_TO_RADIANS) * SG_EQUATORIAL_RADIUS_M;
+ double x = sin(delta_lon * SG_DEGREES_TO_RADIANS) * SG_EQUATORIAL_RADIUS_M * _correction_factor;
// Align
- double xbar = x;
- x = x*cos(theta) - y*sin(theta);
- y = (xbar*sin(theta)) + (y*cos(theta));
- //cout << "After alignment, x = " << x << " y = " << y << '\n';
+ if(_theta != 0.0) {
+ double xbar = x;
+ x = x*cos(_theta) - y*sin(_theta);
+ y = (xbar*sin(_theta)) + (y*cos(_theta));
+ }
- return(Point3D(x,y,0.0));
+ return(Point3D(x,y,pt.elev()));
}
-Point3D FGATCAlignedProjection::ConvertFromLocal(Point3D pt) {
- return(Point3D(0,0,0));
+Point3D FGATCAlignedProjection::ConvertFromLocal(const Point3D& pt) {
+ // de-align
+ double thi = _theta * -1.0;
+ double x = pt.x()*cos(thi) - pt.y()*sin(thi);
+ double y = (pt.x()*sin(thi)) + (pt.y()*cos(thi));
+
+ // convert from orthogonal to lat/lon
+ double delta_lat = asin(y / SG_EQUATORIAL_RADIUS_M) * SG_RADIANS_TO_DEGREES;
+ double delta_lon = (asin(x / SG_EQUATORIAL_RADIUS_M) * SG_RADIANS_TO_DEGREES) / _correction_factor;
+
+ return(Point3D(_origin.lon()+delta_lon, _origin.lat()+delta_lat, pt.elev()));
}
projects / flightgear.git / blobdiff