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constants.h
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1 // constants.h -- various constant definitions
2 //
3 // Written by Curtis Olson, started February 2000.
4 //
5 // Copyright (C) 2000 Curtis L. Olson - http://www.flightgear.org/~curt/
6 //
7 // This library is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU Library General Public
9 // License as published by the Free Software Foundation; either
10 // version 2 of the License, or (at your option) any later version.
11 //
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // Library General Public License for more details.
16 //
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 //
21 // $Id$
22 
28 #ifndef _SG_CONSTANTS_H
29 #define _SG_CONSTANTS_H
30 
31 
32 #include "compiler.h"
33 
34 #include <cmath>
35 
36 
37 // Make sure PI is defined in its various forms
38 
39 #ifndef SGD_PI // remove me once FlightGear no longer uses PLIB
40 
41 #ifdef M_PI
42 const double SGD_PI = M_PI;
43 const float SG_PI = M_PI;
44 #else
45 const float SG_PI = 3.1415926535f;
46 const double SGD_PI = 3.1415926535;
47 #endif
48 
49 #endif // of PLIB-SG guard
50 
52 const double SGD_2PI = SGD_PI * 2.0;
53 
55 #ifdef M_PI_2
56 # define SGD_PI_2 M_PI_2
57 #else
58 # define SGD_PI_2 1.57079632679489661923
59 #endif
60 
62 const double SGD_PI_4 = 0.78539816339744830961;
63 
64 #ifndef SGD_DEGREES_TO_RADIANS // // remove me once FlightGear no longer uses PLIB
65 
66 const double SGD_DEGREES_TO_RADIANS = SGD_PI / 180.0;
67 const double SGD_RADIANS_TO_DEGREES = 180.0 / SGD_PI;
68 
69 const float SG_DEGREES_TO_RADIANS = SG_PI / 180.0f;
70 const float SG_RADIANS_TO_DEGREES = 180.0f / SG_PI;
71 
72 #endif // of PLIB-SG guard
73 
75 #ifdef M_E
76 # define SG_E M_E
77 #else
78 # define SG_E 2.7182818284590452354
79 #endif
80 
82 #define SG_ONE_SECOND 4.848136811E-6
83 
84 
87 #define SG_EARTH_RAD 6378.155
88 
89 // Maximum terrain elevation from sea level
90 #define SG_MAX_ELEVATION_M 9000.0
91 
92 // Earth parameters for WGS 84, taken from LaRCsim/ls_constants.h
93 
95 #define SG_EQUATORIAL_RADIUS_FT 20925650.
96 
98 #define SG_EQUATORIAL_RADIUS_M 6378138.12
99 
101 #define SG_EQ_RAD_SQUARE_FT 437882827922500.
102 
104 #define SG_EQ_RAD_SQUARE_M 40680645877797.1344
105 
106 // Conversions
107 
109 #define SG_ARCSEC_TO_RAD 4.84813681109535993589e-06
110 
112 #define SG_RAD_TO_ARCSEC 206264.806247096355156
113 
115 #define SG_FEET_TO_METER 0.3048
116 
118 #define SG_METER_TO_FEET 3.28083989501312335958
119 
121 #define SG_METER_TO_NM 0.0005399568034557235
122 
124 #define SG_NM_TO_METER 1852.0000
125 
127 #define SG_METER_TO_SM 0.0006213699494949496
128 
130 #define SG_SM_TO_METER 1609.3412196
131 
133 #define SG_NM_TO_RAD 0.00029088820866572159
134 
136 #define SG_RAD_TO_NM 3437.7467707849392526
137 
139 #define SG_MPS_TO_KT 1.9438444924406046432
140 
142 #define SG_KT_TO_MPS 0.5144444444444444444
143 
145 #define SG_FPS_TO_KT 0.5924838012958962841
146 
148 #define SG_KT_TO_FPS 1.6878098571011956874
149 
151 #define SG_MPS_TO_MPH 2.2369362920544020312
152 
154 #define SG_MPH_TO_MPS 0.44704
155 
157 #define SG_MPS_TO_KMH 3.6
158 
160 #define SG_KMH_TO_MPS 0.2777777777777777778
161 
163 #define SG_PA_TO_INHG 0.0002952998330101010
164 
166 #define SG_INHG_TO_PA 3386.388640341
167 
168 
170 #define SG_EPSILON 0.0000001
171 
174 #define SG_BINOBJ_VERSION 6
175 
177 #define SG_SCENERY_FILE_FORMAT "0.4"
178 
179 
180 #endif // _SG_CONSTANTS_H
const double SGD_2PI
Definition: constants.h:52
const double SGD_PI_4
Definition: constants.h:62