X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FInstrumentation%2Faltimeter.cxx;h=3924ed7c92dabd7d5885acf706f41f80c0ee46c3;hb=1df5347a06d5f38bc6d6267f242d5331b7c6f02b;hp=08cfcb36e1fb623b36711bb0c35051aac9732ff3;hpb=8685e68b995ebf436c0e2a0441fc1c9c672dc8d0;p=flightgear.git

diff --git a/src/Instrumentation/altimeter.cxx b/src/Instrumentation/altimeter.cxx
index 08cfcb36e..3924ed7c9 100644
--- a/src/Instrumentation/altimeter.cxx
+++ b/src/Instrumentation/altimeter.cxx
@@ -1,93 +1,119 @@
 // altimeter.cxx - an altimeter tied to the static port.
 // Written by David Megginson, started 2002.
+// Modified by John Denker in 2007 to use a two layer atmosphere
+// model in src/Environment/atmosphere.?xx
 //
 // This file is in the Public Domain and comes with no warranty.
 
+// Example invocation, in the instrumentation.xml file:
+//      <altimeter>
+//        <name>encoder</name>
+//        <number>0</number>
+//        <static-pressure>/systems/static/pressure-inhg</static-pressure>
+//        <quantum>10</quantum>
+//        <tau>0</tau>
+//      </altimeter>
+// Note non-default name, quantum, and tau values.
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
 #include <simgear/math/interpolater.hxx>
+#include <simgear/math/SGMath.hxx>
 
-#include "altimeter.hxx"
 #include <Main/fg_props.hxx>
 #include <Main/util.hxx>
+#include <Environment/atmosphere.hxx>
 
+#include "altimeter.hxx"
 
-// Altitude based on pressure difference from sea level.
-// pressure difference inHG, altitude ft
-static double altitude_data[][2] = {
-    -8.41, -8858.27,
-    0.00, 0.00,
-    3.05, 2952.76,
-    5.86, 5905.51,
-    8.41, 8858.27,
-    10.74, 11811.02,
-    12.87, 14763.78,
-    14.78, 17716.54,
-    16.55, 20669.29,
-    18.13, 23622.05,
-    19.62, 26574.80,
-    20.82, 29527.56,
-    21.96, 32480.31,
-    23.01, 35433.07,
-    23.91, 38385.83,
-    24.71, 41338.58,
-    25.40, 44291.34,
-    26.00, 47244.09,
-    26.51, 50196.85,
-    26.96, 53149.61,
-    27.35, 56102.36,
-    27.68, 59055.12,
-    27.98, 62007.87,
-    29.62, 100000.00            // just to fill it in
-    -1, -1,
-};
-
-
-Altimeter::Altimeter ()
-    : _altitude_table(new SGInterpTable)
-{
+const double hPa2inHg = 29.92 / 1013.25;
 
-    for (int i = 0; altitude_data[i][0] != -1; i++)
-        _altitude_table->addEntry(altitude_data[i][0], altitude_data[i][1]);
+Altimeter::Altimeter ( SGPropertyNode *node, double quantum )
+    : _rootNode( 
+       fgGetNode("/instrumentation",true)->
+           getChild( node->getStringValue("name", "altimeter"),
+                     node->getIntValue("number", 0),
+                     true)),
+      _static_pressure(node->getStringValue("static-pressure", "/systems/static/pressure-inhg")),
+      _tau(node->getDoubleValue("tau", 0.1)),
+      _quantum(node->getDoubleValue("quantum", quantum)),
+      _settingInHg(29.921260)
+{
+    _tiedProperties.setRoot( _rootNode );
 }
 
 Altimeter::~Altimeter ()
+{}
+
+double
+Altimeter::getSettingInHg() const
 {
-    delete _altitude_table;
+    return _settingInHg;
 }
 
+void
+Altimeter::setSettingInHg( double value )
+{
+    _settingInHg = value;
+}
+
+double
+Altimeter::getSettingHPa() const
+{
+    return _settingInHg / hPa2inHg;
+}
+
+void
+Altimeter::setSettingHPa( double value )
+{
+    _settingInHg = value * hPa2inHg;
+}
+
+
 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);
+    raw_PA = 0.0;
+    _kollsman = 0.0;
+    _pressure_node     = fgGetNode(_static_pressure.c_str(), true);
+    _serviceable_node  = _rootNode->getChild("serviceable", 0, true);
+    _press_alt_node    = _rootNode->getChild("pressure-alt-ft", 0, true);
+    _mode_c_node       = _rootNode->getChild("mode-c-alt-ft", 0, true);
+    _altitude_node     = _rootNode->getChild("indicated-altitude-ft", 0, true);
 }
 
 void
-Altimeter::bind ()
+Altimeter::bind()
 {
+    _tiedProperties.Tie("setting-inhg", this, &Altimeter::getSettingInHg, &Altimeter::setSettingInHg );
+    _tiedProperties.Tie("setting-hpa", this, &Altimeter::getSettingHPa, &Altimeter::setSettingHPa );
 }
 
 void
-Altimeter::unbind ()
+Altimeter::unbind()
 {
+    _tiedProperties.Untie();
 }
 
 void
 Altimeter::update (double dt)
 {
     if (_serviceable_node->getBoolValue()) {
+        double trat = _tau > 0 ? dt/_tau : 100;
         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);
+        double press_alt = _press_alt_node->getDoubleValue();
+        // The mechanism settles slowly toward new pressure altitude:
+        raw_PA = fgGetLowPass(raw_PA, _altimeter.press_alt_ft(pressure), trat);
+        _mode_c_node->setDoubleValue(100 * SGMiscd::round(raw_PA/100));
+        _kollsman = fgGetLowPass(_kollsman, _altimeter.kollsman_ft(_settingInHg), trat);
+        if (_quantum)
+            press_alt = _quantum * SGMiscd::round(raw_PA/_quantum);
+        else
+            press_alt = raw_PA;
+        _press_alt_node->setDoubleValue(press_alt);
+        _altitude_node->setDoubleValue(press_alt - _kollsman);
     }
 }