Add a command which will setup the temperature field in the boundary and

aloft layers to match a current OAT at the current altitude.  This can be
run from an external script or gui.

Given the specified OAT (and the current aircraft altitude), the code
calculates the equivalent sea level temperature, and then assigns that to
all active boundary and aloft environment layers.

diff --git a/src/Main/fg_commands.cxx b/src/Main/fg_commands.cxx
index 6769654f5ed3cf5af8cbd4960caa6049d30e503a..5fef48aee532ae6120de3df51c83b4c4b2650632 100644 (file)
--- a/src/Main/fg_commands.cxx
+++ b/src/Main/fg_commands.cxx
@@ -16,6 +16,7 @@
 
 #include <Cockpit/panel.hxx>
 #include <Cockpit/panel_io.hxx>
+#include <Environment/environment.hxx>
 #include <FDM/flight.hxx>
 #include <GUI/gui.h>
 #include <GUI/new_gui.hxx>
@@ -470,6 +471,55 @@ do_tile_cache_reload (const SGPropertyNode * arg)
 }
 
 
+/**
+ * Set the outside air temperature at the "current" altitude by first
+ * calculating the corresponding sea level temp, and assigning that to
+ * all boundary and aloft environment layers.
+ */
+static bool
+do_set_oat_degc (const SGPropertyNode * arg)
+{
+    const string &temp_str = arg->getStringValue("temp-degc", "15.0");
+
+    static const SGPropertyNode *altitude_ft
+      = fgGetNode("/position/altitude-ft");
+
+    FGEnvironment dummy;       // instantiate a dummy so we can leech a method
+    dummy.set_elevation_ft( altitude_ft->getDoubleValue() );
+    dummy.set_temperature_degc( atof( temp_str.c_str() ) );
+    double temp_sea_level_degc = dummy.get_temperature_sea_level_degc();
+
+    cout << "Altitude = " << altitude_ft->getDoubleValue() << endl;
+    cout << "Temp at alt (C) = " << atof( temp_str.c_str() ) << endl;
+    cout << "Temp sea level (C) = " << temp_sea_level_degc << endl;
+ 
+    SGPropertyNode *node, *child;
+
+    // boundary layers
+    node = fgGetNode( "/environment/config/boundary" );
+    if ( node != NULL ) {
+      int i = 0;
+      while ( ( child = node->getNode( "entry", i ) ) != NULL ) {
+       child->setDoubleValue( "temperature-sea-level-degc",
+                              temp_sea_level_degc );
+       ++i;
+      }
+    }
+
+    // aloft layers
+    node = fgGetNode( "/environment/config/aloft" );
+    if ( node != NULL ) {
+      int i = 0;
+      while ( ( child = node->getNode( "entry", i ) ) != NULL ) {
+       child->setDoubleValue( "temperature-sea-level-degc",
+                              temp_sea_level_degc );
+       ++i;
+      }
+    }
+
+    return true;
+}
+
 /**
  * Update the lighting manually.
  */
@@ -983,6 +1033,7 @@ static struct {
     { "view-cycle", do_view_cycle },
     { "screen-capture", do_screen_capture },
     { "tile-cache-reload", do_tile_cache_reload },
+    { "set-outside-air-temp-degc", do_set_oat_degc },
     { "timeofday", do_timeofday },
     { "property-toggle", do_property_toggle },
     { "property-assign", do_property_assign },