simgear/Math/polar3d.hxx
1999-01-27 04:46:14 +00:00

121 lines
3.8 KiB
C++

// polar.hxx -- routines to deal with polar math and transformations
//
// Written by Curtis Olson, started June 1997.
//
// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
//
// 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., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$
// (Log is kept at end of this file)
#ifndef _POLAR_HXX
#define _POLAR_HXX
#ifndef __cplusplus
# error This library requires C++
#endif
#include <Include/fg_constants.h>
#include <Math/point3d.hxx>
// Find the Altitude above the Ellipsoid (WGS84) given the Earth
// Centered Cartesian coordinate vector Distances are specified in
// meters.
double fgGeodAltFromCart(const Point3D& cp);
// Convert a polar coordinate to a cartesian coordinate. Lon and Lat
// must be specified in radians. The FG convention is for distances
// to be specified in meters
inline Point3D fgPolarToCart3d(const Point3D& p) {
double tmp = cos( p.lat() ) * p.radius();
return Point3D( cos( p.lon() ) * tmp,
sin( p.lon() ) * tmp,
sin( p.lat() ) * p.radius() );
}
// Convert a cartesian coordinate to polar coordinates (lon/lat
// specified in radians. Distances are specified in meters.
inline Point3D fgCartToPolar3d(const Point3D& cp) {
return Point3D( atan2( cp.y(), cp.x() ),
FG_PI_2 -
atan2( sqrt(cp.x()*cp.x() + cp.y()*cp.y()), cp.z() ),
sqrt(cp.x()*cp.x() + cp.y()*cp.y() + cp.z()*cp.z()) );
}
#endif // _POLAR_HXX
// $Log$
// Revision 1.5 1999/01/27 04:46:20 curt
// Portability tweaks by Bernie Bright.
//
// Revision 1.4 1998/10/16 19:30:07 curt
// C++-ified the comments.
//
// Revision 1.3 1998/10/16 00:50:30 curt
// Added point3d.hxx to replace cheezy fgPoint3d struct.
//
// Revision 1.2 1998/08/24 20:04:12 curt
// Various "inline" code optimizations contributed by Norman Vine.
//
// Revision 1.1 1998/07/08 14:40:09 curt
// polar3d.[ch] renamed to polar3d.[ch]xx, vector.[ch] renamed to vector.[ch]xx
// Updated fg_geodesy comments to reflect that routines expect and produce
// meters.
//
// Revision 1.1 1998/05/02 01:50:11 curt
// polar.[ch] renamed to polar3d.[ch]
//
// Revision 1.9 1998/04/25 22:06:23 curt
// Edited cvs log messages in source files ... bad bad bad!
//
// Revision 1.8 1998/04/21 17:03:50 curt
// Prepairing for C++ integration.
//
// Revision 1.7 1998/01/27 00:48:00 curt
// Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
// system and commandline/config file processing code.
//
// Revision 1.6 1998/01/22 02:59:39 curt
// Changed #ifdef FILE_H to #ifdef _FILE_H
//
// Revision 1.5 1998/01/19 19:27:13 curt
// Merged in make system changes from Bob Kuehne <rpk@sgi.com>
// This should simplify things tremendously.
//
// Revision 1.4 1997/12/15 23:54:55 curt
// Add xgl wrappers for debugging.
// Generate terrain normals on the fly.
//
// Revision 1.3 1997/07/31 22:52:28 curt
// Working on redoing internal coordinate systems & scenery transformations.
//
// Revision 1.2 1997/07/23 21:52:21 curt
// Put comments around the text after an #endif for increased portability.
//
// Revision 1.1 1997/07/07 21:02:37 curt
// Initial revision.
//