101 lines
3.3 KiB
C++
101 lines
3.3 KiB
C++
// include/geometry.hh
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// This file is part of libpbe; see http://svn.chezphil.org/libpbe/
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// (C) 2008 Philip Endecott
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 2 of the License, or
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// any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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#ifndef libpbe_geometry_hh
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#define libpbe_geometry_hh
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#include <cmath>
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namespace pbe {
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const float PI = 3.1415927F;
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const double PId = 3.1415927;
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const float earth_radius = 6372795.0F;
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template <typename T>
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inline T sqr(T x) { return x*x; }
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inline float deg2rad(float a) { return PI/180.0F * a; }
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inline float rad2deg(float a) { return 180.0F/PI * a; }
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inline float degsin(float a) { return sin(deg2rad(a)); }
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inline float degcos(float a) { return cos(deg2rad(a)); }
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inline float degtan(float a) { return tan(deg2rad(a)); }
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inline float degasin(float x) { return rad2deg(asin(x)); }
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inline float degacos(float x) { return rad2deg(acos(x)); }
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inline float degatan(float x) { return rad2deg(atan(x)); }
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inline float degatan2(float y, float x) { return rad2deg(atan2(y,x)); }
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inline double deg2rad(double a) { return PId/180.0 * a; }
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inline double rad2deg(double a) { return 180.0/PId * a; }
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inline double degsin(double a) { return sin(deg2rad(a)); }
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inline double degcos(double a) { return cos(deg2rad(a)); }
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inline double degtan(double a) { return tan(deg2rad(a)); }
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inline double degasin(double x) { return rad2deg(asin(x)); }
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inline double degacos(double x) { return rad2deg(acos(x)); }
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inline double degatan(double x) { return rad2deg(atan(x)); }
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inline double degatan2(double y, double x) { return rad2deg(atan2(y,x)); }
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inline float normalise_unsigned_angle(float a) { return a>0 ? fmod(a,360.0F) : 360.0F+fmod(a,360.0F); }
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inline float normalise_signed_angle(float a) { return normalise_unsigned_angle(a+180.0F)-180.0F; }
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struct position {
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float lng;
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float lat;
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float alt;
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position() {}
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position(float lng_, float lat_, float alt_):
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lng(lng_), lat(lat_), alt(alt_)
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{}
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};
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float distance(const position& a, const position& b); // Proper great circle calculation
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float bearing(const position& a, const position& b);
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float elevation(const position& a, const position& b);
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inline float cheap_distance(const position& a, const position& b) {
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return earth_radius / 360.0F * 2*PI
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* sqrt( sqr(a.lat-b.lat) + sqr((a.lng-b.lng)*degcos(a.lat)) );
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}
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inline float cheap_bearing(const position& a, const position& b) {
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float d = degatan2( (b.lng-a.lng) * degcos(a.lat),
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b.lat-a.lat );
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return normalise_unsigned_angle(d);
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}
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inline float elevation(const position& a, const position& b) {
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return degatan2(b.alt-a.alt,cheap_distance(a,b));
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}
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inline float rectilinear_elevation(const position& a, const position& b) {
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return rad2deg((b.alt-a.alt) / cheap_distance(a,b));
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}
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};
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#endif
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