X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fconstants.h;h=8a93990733de36e61a5632862e460c474bdaeba8;hb=598b64fa9569c16878c904e344e2e2775e210c42;hp=8438e1321f08ff6d8af22886024dd21717f146f8;hpb=dca07c5634604c18213d08b688e894de354ea335;p=simgear.git

diff --git a/simgear/constants.h b/simgear/constants.h
index 8438e132..8a939907 100644
--- a/simgear/constants.h
+++ b/simgear/constants.h
@@ -1,6 +1,7 @@
 // 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 - http://www.flightgear.org/~curt/
 //
@@ -34,15 +35,22 @@
 #include <cmath>
 
 
-#include <plib/sg.h>
+// Make sure PI is defined in its various forms
 
+#ifndef SGD_PI // remove me once FlightGear no longer uses PLIB
 
-// Make sure PI is defined in its various forms
+#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
 
-// SG_PI and SGD_PI (float and double) come from plib/sg.h
+#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
@@ -52,7 +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
@@ -86,6 +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 */
@@ -148,6 +197,9 @@
 /** 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