From Benoit Laniel: replace SG threading constructs with those from OpenThreads

[simgear.git] / simgear / constants.h

diff --git a/simgear/constants.h b/simgear/constants.h
index 0ce5ab9e7866b26745ca10a832a654336f59fe0b..b6fd7a909affd3c208f4ccba1fb6bdf60ba7f2fa 100644 (file)
--- a/simgear/constants.h
+++ b/simgear/constants.h
@@ -75,6 +75,8 @@
  *  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
 
@@ -128,6 +130,12 @@
 /** Knots to Miles 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
+
 /** Miles per second to Miles per hour */
 #define SG_MPS_TO_MPH       2.2369362920544020312