2 Copyright (C) 2010 Paul Davis
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include "pbd/cartesian.h"
26 PBD::azi_ele_to_cart (double azi, double ele, double& x, double& y, double& z)
28 /* convert from cylindrical coordinates in degrees to cartesian */
30 static const double atorad = 2.0 * M_PI / 360.0 ;
32 x = cos (azi * atorad) * cos (ele * atorad);
33 y = sin (azi * atorad) * cos (ele * atorad);
34 z = sin (ele * atorad);
38 PBD::cart_to_azi_ele (double x, double y, double z, double& azimuth, double& elevation)
40 /* converts cartesian coordinates to cylindrical in degrees*/
42 const double atorad = 2.0 * M_PI / 360.0;
43 double atan_y_per_x, atan_x_pl_y_per_z;
47 atan_y_per_x = M_PI / 2;
49 atan_y_per_x = atan2 (y,x);
53 /* below x-axis: atan2 returns 0 .. -PI (negative) so convert to degrees and ADD to 180 */
54 azimuth = 180.0 + (atan_y_per_x / (M_PI/180.0) + 180.0);
56 /* above x-axis: atan2 returns 0 .. +PI so convert to degrees */
57 azimuth = atan_y_per_x / atorad;
60 distance = sqrt (x*x + y*y);
63 atan_x_pl_y_per_z = 0.0;
65 atan_x_pl_y_per_z = atan2 (z,distance);
68 if (distance == 0.0) {
70 atan_x_pl_y_per_z = -M_PI/2.0;
72 atan_x_pl_y_per_z = M_PI/2.0;
76 elevation = atan_x_pl_y_per_z / atorad;
78 // distance = sqrtf (x*x + y*y + z*z);