// constants.h -- various constant definitions
//
// Written by Curtis Olson, started February 2000.
+// Last change by Eric van den Berg, Feb 2013
//
-// Copyright (C) 2000 Curtis L. Olson - curt@flightgear.org
+// Copyright (C) 2000 Curtis L. Olson - http://www.flightgear.org/~curt/
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
-// You should have received a copy of the GNU Library General Public
-// License along with this library; if not, write to the
-// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-// Boston, MA 02111-1307, USA.
+// 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
+/** \file constants.h
+ * Various constant definitions.
+ */
+
#ifndef _SG_CONSTANTS_H
#define _SG_CONSTANTS_H
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
-
#include <simgear/compiler.h>
-#ifdef FG_HAVE_STD_INCLUDES
-# include <cmath>
-#else
-# ifdef FG_MATH_EXCEPTION_CLASH
-# define exception C_exception
-# endif
-# include <math.h>
-#endif
+#include <cmath>
// Make sure PI is defined in its various forms
-// PI, only PI, and nothing but PI
+#ifndef SGD_PI // remove me once FlightGear no longer uses PLIB
+
#ifdef M_PI
-# define FG_PI M_PI
+const double SGD_PI = M_PI;
+const float SG_PI = M_PI;
#else
-# define FG_PI 3.14159265358979323846
+const float SG_PI = 3.1415926535f;
+const double SGD_PI = 3.1415926535;
#endif
-// 2 * PI
-#define FG_2PI 6.28318530717958647692
+#endif // of PLIB-SG guard
+
+/** 2 * PI */
+const double SGD_2PI = SGD_PI * 2.0;
-// PI / 2
+/** PI / 2 */
#ifdef M_PI_2
-# define FG_PI_2 M_PI_2
+# define SGD_PI_2 M_PI_2
#else
-# define FG_PI_2 1.57079632679489661923
+# define SGD_PI_2 1.57079632679489661923
#endif
-// PI / 4
-#define FG_PI_4 0.78539816339744830961
+/** PI / 4 */
+const double SGD_PI_4 = 0.78539816339744830961;
+
+#ifndef SGD_DEGREES_TO_RADIANS // // remove me once FlightGear no longer uses PLIB
+
+const double SGD_DEGREES_TO_RADIANS = SGD_PI / 180.0;
+const double SGD_RADIANS_TO_DEGREES = 180.0 / SGD_PI;
+
+const float SG_DEGREES_TO_RADIANS = SG_PI / 180.0f;
+const float SG_RADIANS_TO_DEGREES = 180.0f / SG_PI;
-#ifndef M_E
-# define M_E 2.7182818284590452354
+#endif // of PLIB-SG guard
+
+/** \def SG_E "e" */
+#ifdef M_E
+# define SG_E M_E
+#else
+# define SG_E 2.7182818284590452354
#endif
-// ONE_SECOND is pi/180/60/60, or about 100 feet at earths' equator
-#define ONE_SECOND 4.848136811E-6
+/** pi/180/60/60, or about 100 feet at earths' equator */
+#define SG_ONE_SECOND 4.848136811E-6
-// Radius of Earth in kilometers at the equator. Another source had
-// 6378.165 but this is probably close enough
-#define EARTH_RAD 6378.155
+/** Radius of Earth in kilometers at the equator. Another source had
+ * 6378.165 but this is probably close enough */
+#define SG_EARTH_RAD 6378.155
+// Maximum terrain elevation from sea level
+#define SG_MAX_ELEVATION_M 9000.0
// Earth parameters for WGS 84, taken from LaRCsim/ls_constants.h
-// Value of earth radius from [8]
-#define EQUATORIAL_RADIUS_FT 20925650. // ft
-#define EQUATORIAL_RADIUS_M 6378138.12 // meter
-// Radius squared
-#define RESQ_FT 437882827922500. // ft
-#define RESQ_M 40680645877797.1344 // meter
+/** Value of earth radius from LaRCsim (ft) */
+#define SG_EQUATORIAL_RADIUS_FT 20925650.
-#if 0
-// Value of earth flattening parameter from ref [8]
-//
-// Note: FP = f
-// E = 1-f
-// EPS = sqrt(1-(1-f)^2)
-//
+/** Value of earth radius from LaRCsim (meter) */
+#define SG_EQUATORIAL_RADIUS_M 6378138.12
-#define FP 0.003352813178
-#define E 0.996647186
-#define EPS 0.081819221
-#define INVG 0.031080997
+/** Radius squared (ft) */
+#define SG_EQ_RAD_SQUARE_FT 437882827922500.
-// Time Related Parameters
+/** Radius squared (meter) */
+#define SG_EQ_RAD_SQUARE_M 40680645877797.1344
+
+
+// Physical Constants, SI
+
+/**mean gravity on earth */
+#define SG_g0_m_p_s2 9.80665 // m/s2
+
+/**standard pressure at SL */
+#define SG_p0_Pa 101325.0 // Pa
+
+/**standard density at SL */
+#define SG_rho0_kg_p_m3 1.225 // kg/m3
+
+/**standard temperature at SL */
+#define SG_T0_K 288.15 // K (=15degC)
+
+/**specific gas constant of air*/
+#define SG_R_m2_p_s2_p_K 287.05 // m2/s2/K
+
+/**specific heat constant at constant pressure*/
+#define SG_cp_m2_p_s2_p_K 1004.68 // m2/s2/K
+
+/**ratio of specific heats of air*/
+#define SG_gamma 1.4 // =cp/cv (cp = 1004.68 m2/s2 K , cv = 717.63 m2/s2 K)
+
+/**constant beta used to calculate dynamic viscosity */
+#define SG_beta_kg_p_sm_sqrK 1.458e-06 // kg/s/m/SQRT(K)
+
+/** Sutherland constant */
+#define SG_S_K 110.4 // K
-#define MJD0 2415020.0
-#define J2000 (2451545.0 - MJD0)
-#define SIDRATE .9972695677
-#endif
// Conversions
-// Degrees to Radians
-#define DEG_TO_RAD 0.017453292 // deg*pi/180 = rad
+/** Arc seconds to radians. (arcsec*pi)/(3600*180) = rad */
+#define SG_ARCSEC_TO_RAD 4.84813681109535993589e-06
+
+/** Radians to arc seconds. (rad*3600*180)/pi = arcsec */
+#define SG_RAD_TO_ARCSEC 206264.806247096355156
+
+/** Feet to Meters */
+#define SG_FEET_TO_METER 0.3048
+
+/** Meters to Feet */
+#define SG_METER_TO_FEET 3.28083989501312335958
+
+/** Meters to Nautical Miles. 1 nm = 6076.11549 feet */
+#define SG_METER_TO_NM 0.0005399568034557235
+
+/** Nautical Miles to Meters */
+#define SG_NM_TO_METER 1852.0000
+
+/** Meters to Statute Miles. */
+#define SG_METER_TO_SM 0.0006213699494949496
+
+/** Statute Miles to Meters. */
+#define SG_SM_TO_METER 1609.3412196
+
+/** Radians to Nautical Miles. 1 nm = 1/60 of a degree */
+#define SG_NM_TO_RAD 0.00029088820866572159
+
+/** Nautical Miles to Radians */
+#define SG_RAD_TO_NM 3437.7467707849392526
+
+/** meters per second to Knots */
+#define SG_MPS_TO_KT 1.9438444924406046432
+
+/** Knots to meters per second */
+#define SG_KT_TO_MPS 0.5144444444444444444
+
+/** Feet per second to Knots */
+#define SG_FPS_TO_KT 0.5924838012958962841
-// Radians to Degrees
-#define RAD_TO_DEG 57.29577951 // rad*180/pi = deg
+/** Knots to Feet per second */
+#define SG_KT_TO_FPS 1.6878098571011956874
-// Arc seconds to radians // (arcsec*pi)/(3600*180) = rad
-#define ARCSEC_TO_RAD 4.84813681109535993589e-06
+/** meters per second to Miles per hour */
+#define SG_MPS_TO_MPH 2.2369362920544020312
-// Radians to arc seconds // (rad*3600*180)/pi = arcsec
-#define RAD_TO_ARCSEC 206264.806247096355156
+/** meetrs per hour to Miles per second */
+#define SG_MPH_TO_MPS 0.44704
-// Feet to Meters
-#define FEET_TO_METER 0.3048
+/** Meters per second to Kilometers per hour */
+#define SG_MPS_TO_KMH 3.6
-// Meters to Feet
-#define METER_TO_FEET 3.28083989501312335958
+/** Kilometers per hour to meters per second */
+#define SG_KMH_TO_MPS 0.2777777777777777778
-// Meters to Nautical Miles, 1 nm = 6076.11549 feet
-#define METER_TO_NM 0.00053995680
+/** Pascal to Inch Mercury */
+#define SG_PA_TO_INHG 0.0002952998330101010
-// Nautical Miles to Meters
-#define NM_TO_METER 1852.0000
+/** Inch Mercury to Pascal */
+#define SG_INHG_TO_PA 3386.388640341
-// Radians to Nautical Miles, 1 nm = 1/60 of a degree
-#define NM_TO_RAD 0.00029088820866572159
+/** slug/ft3 to kg/m3 */
+#define SG_SLUGFT3_TO_KGPM3 515.379
-// Nautical Miles to Radians
-#define RAD_TO_NM 3437.7467707849392526
-// For divide by zero avoidance, this will be close enough to zero
-#define FG_EPSILON 0.0000001
+/** For divide by zero avoidance, this will be close enough to zero */
+#define SG_EPSILON 0.0000001
+/** Highest binobj format version we know how to read/write. This starts at
+ * 0 and can go up to 65535 */
+#define SG_BINOBJ_VERSION 6
-// Highest binobj format version we know how to read/write. This starts at
-// 0 and can go up to 65535
-#define SG_BINOBJ_VERSION 5
-// for backwards compatibility
+/** for backwards compatibility */
#define SG_SCENERY_FILE_FORMAT "0.4"
projects / simgear.git / blobdiff