1 /**************************************************************************
2 * constants.h -- various constant definitions
4 * Written by Curtis Olson, started July 1997.
6 * Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of the
11 * License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 * (Log is kept at end of this file)
24 **************************************************************************/
34 /* Make sure PI is defined in its various forms */
38 # define FG_PI 3.14159265358979323846 /* pi */
42 # define FG_PI_2 M_PI_2
44 # define FG_PI_2 1.57079632679489661923 /* pi/2 */
47 #define FG_2PI (FG_PI + FG_PI) /* 2*pi */
50 /* Radius of Earth in kilometers at the equator. Another source had
51 * 6378.165 but this is probably close enough */
52 #define EARTH_RAD 6378.155
55 /* Degrees to Radians */
56 #define DEG_TO_RAD 0.017453292 /* deg*pi/180 = rad */
58 /* Radians to Degrees */
59 #define RAD_TO_DEG 57.29577951 /* rad*180/pi = deg */
61 /* Arc seconds to radians */ /* (arcsec*pi)/(3600*180) = rad */
62 #define ARCSEC_TO_RAD 4.84813681109535993589e-06
64 /* Radians to arc seconds */ /* (rad*3600*180)/pi = arcsec */
65 #define RAD_TO_ARCSEC 206264.806247096355156
68 #define FEET_TO_METER 0.3048
71 #define METER_TO_FEET 3.28083989501312335958
74 /* For divide by zero avoidance, this will be close enough to zero */
75 #define EPSILON 0.000001
82 /* Revision 1.6 1997/07/21 14:45:01 curt
85 * Revision 1.5 1997/07/19 23:04:46 curt
86 * Added an initial weather section.
88 * Revision 1.4 1997/07/19 22:37:03 curt
89 * Added various PI definitions.
91 * Revision 1.3 1997/07/14 16:26:03 curt
92 * Testing/playing -- placed objects randomly across the entire terrain.
94 * Revision 1.2 1997/07/08 18:20:11 curt
95 * Working on establishing a hard ground.
97 * Revision 1.1 1997/07/07 21:02:36 curt