X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fconstants.h;h=8a93990733de36e61a5632862e460c474bdaeba8;hb=b7df9026c038f0c80501f4d563de7232196248e2;hp=f0a094350f05457f55f55b5383311cca206955b7;hpb=e2b4c0787a4398199ef2d35e05963acd58b7a04c;p=simgear.git diff --git a/simgear/constants.h b/simgear/constants.h index f0a09435..8a939907 100644 --- a/simgear/constants.h +++ b/simgear/constants.h @@ -1,8 +1,9 @@ // 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 @@ -14,10 +15,9 @@ // 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. // // $Id$ @@ -32,24 +32,25 @@ #include -#ifdef SG_HAVE_STD_INCLUDES -# include -#else -# ifdef SG_MATH_EXCEPTION_CLASH -# define exception C_exception -# endif -# include -#endif - -#include +#include // Make sure PI is defined in its various forms -// SG_PI and SGD_PI (float and double) come from plib/sg.h +#ifndef SGD_PI // remove me once FlightGear no longer uses PLIB + +#ifdef M_PI +const double SGD_PI = M_PI; +const float SG_PI = M_PI; +#else +const float SG_PI = 3.1415926535f; +const double SGD_PI = 3.1415926535; +#endif + +#endif // of PLIB-SG guard /** 2 * PI */ -#define SGD_2PI 6.28318530717958647692 +const double SGD_2PI = SGD_PI * 2.0; /** PI / 2 */ #ifdef M_PI_2 @@ -59,7 +60,17 @@ #endif /** PI / 4 */ -#define SGD_PI_4 0.78539816339744830961 +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; + +#endif // of PLIB-SG guard /** \def SG_E "e" */ #ifdef M_E @@ -76,6 +87,8 @@ * 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 @@ -91,6 +104,37 @@ /** 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 + + // Conversions /** Arc seconds to radians. (arcsec*pi)/(3600*180) = rad */ @@ -106,24 +150,63 @@ #define SG_METER_TO_FEET 3.28083989501312335958 /** Meters to Nautical Miles. 1 nm = 6076.11549 feet */ -#define SG_METER_TO_NM 0.00053995680 +#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 + +/** Knots to Feet per second */ +#define SG_KT_TO_FPS 1.6878098571011956874 + +/** meters per second to Miles per hour */ +#define SG_MPS_TO_MPH 2.2369362920544020312 + +/** meetrs per hour to Miles per second */ +#define SG_MPH_TO_MPS 0.44704 + +/** Meters per second to Kilometers per hour */ +#define SG_MPS_TO_KMH 3.6 + +/** Kilometers per hour to meters per second */ +#define SG_KMH_TO_MPS 0.2777777777777777778 + +/** Pascal to Inch Mercury */ +#define SG_PA_TO_INHG 0.0002952998330101010 + +/** Inch Mercury to Pascal */ +#define SG_INHG_TO_PA 3386.388640341 + +/** slug/ft3 to kg/m3 */ +#define SG_SLUGFT3_TO_KGPM3 515.379 + + /** 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 5 +#define SG_BINOBJ_VERSION 6 /** for backwards compatibility */ #define SG_SCENERY_FILE_FORMAT "0.4"