Modified Files:

[flightgear.git] / src / Instrumentation / altimeter.cxx

diff --git a/src/Instrumentation/altimeter.cxx b/src/Instrumentation/altimeter.cxx
index 993672e6fbeffe1ce101da32eea180ffb05d18cb..ebd2f6d0de6fee2f28ac253f49db61322253c58e 100644 (file)
--- a/src/Instrumentation/altimeter.cxx
+++ b/src/Instrumentation/altimeter.cxx
@@ -10,6 +10,10 @@
 #include <Main/util.hxx>
 
 
+// A higher number means more responsive
+#define RESPONSIVENESS 10.0
+
+
 // Altitude based on pressure difference from sea level.
 // pressure difference inHG, altitude ft
 static double altitude_data[][2] = {
@@ -41,11 +45,14 @@ static double altitude_data[][2] = {
 };
 
 
-Altimeter::Altimeter ()
-    : _altitude_table(new SGInterpTable)
+Altimeter::Altimeter ( SGPropertyNode *node )
+    : _name(node->getStringValue("name", "altimeter")),
+      _num(node->getIntValue("number", 0)),
+      _static_pressure(node->getStringValue("static-pressure", "/systems/static/pressure-inhg")),
+      _altitude_table(new SGInterpTable)
 {
-
-    for (int i = 0; altitude_data[i][0] != -1; i++)
+    int i;
+    for (i = 0; altitude_data[i][0] != -1; i++)
         _altitude_table->addEntry(altitude_data[i][0], altitude_data[i][1]);
 }
 
@@ -57,14 +64,15 @@ Altimeter::~Altimeter ()
 void
 Altimeter::init ()
 {
-    _serviceable_node =
-        fgGetNode("/instrumentation/altimeter/serviceable", true);
-    _setting_node =
-        fgGetNode("/instrumentation/altimeter/setting-inhg", true);
-    _pressure_node =
-        fgGetNode("/systems/static/pressure-inhg", true);
-    _altitude_node =
-        fgGetNode("/instrumentation/altimeter/indicated-altitude-ft", true);
+    string branch;
+    branch = "/instrumentation/" + _name;
+
+    SGPropertyNode *node = fgGetNode(branch.c_str(), _num, true );
+
+    _serviceable_node = node->getChild("serviceable", 0, true);
+    _setting_node = node->getChild("setting-inhg", 0, true);
+    _pressure_node = fgGetNode(_static_pressure.c_str(), true);
+    _altitude_node = node->getChild("indicated-altitude-ft", 0, true);
 }
 
 void
@@ -73,11 +81,14 @@ Altimeter::update (double dt)
     if (_serviceable_node->getBoolValue()) {
         double pressure = _pressure_node->getDoubleValue();
         double setting = _setting_node->getDoubleValue();
-        double altitude =
-            fgGetLowPass(_altitude_node->getDoubleValue(),
-                         _altitude_table->interpolate(setting - pressure),
-                         dt * 10);
-        _altitude_node->setDoubleValue(altitude);
+
+                                // Move towards the current setting
+        double last_altitude = _altitude_node->getDoubleValue();
+        double current_altitude =
+            _altitude_table->interpolate(setting - pressure);
+        _altitude_node->setDoubleValue(fgGetLowPass(last_altitude,
+                                                    current_altitude,
+                                                    dt * RESPONSIVENESS));
     }
 }