src/Instrumentation/vertical_speed_indicator.cxx

   1 // vertical_speed_indicator.cxx - a regular VSI.
   2 // Written by David Megginson, started 2002.
   3 //
   4 // This file is in the Public Domain and comes with no warranty.
   5
   6 #include <simgear/math/interpolater.hxx>
   7
   8 #include "vertical_speed_indicator.hxx"
   9 #include <Main/fg_props.hxx>
  10 #include <Main/util.hxx>
  11
  12
  13 VerticalSpeedIndicator::VerticalSpeedIndicator ()
  14     : _internal_pressure_inhg(29.92)
  15 {
  16 }
  17
  18 VerticalSpeedIndicator::~VerticalSpeedIndicator ()
  19 {
  20 }
  21
  22 void
  23 VerticalSpeedIndicator::init ()
  24 {
  25     _serviceable_node =
  26         fgGetNode("/instrumentation/vertical-speed-indicator/serviceable",
  27                   true);
  28     _pressure_node =
  29         fgGetNode("/systems/static/pressure-inhg", true);
  30     _speed_node =
  31         fgGetNode("/instrumentation/vertical-speed-indicator/indicated-speed-fpm",
  32                   true);
  33 }
  34
  35 void
  36 VerticalSpeedIndicator::bind ()
  37 {
  38 }
  39
  40 void
  41 VerticalSpeedIndicator::unbind ()
  42 {
  43 }
  44
  45 void
  46 VerticalSpeedIndicator::update (double dt)
  47 {
  48                                 // model take from steam.cxx, with change
  49                                 // from 10000 to 10500 for manual factor
  50     if (_serviceable_node->getBoolValue()) {
  51         double pressure = _pressure_node->getDoubleValue();
  52         _speed_node
  53             ->setDoubleValue((_internal_pressure_inhg - pressure) * 10500);
  54         _internal_pressure_inhg =
  55             fgGetLowPass(_internal_pressure_inhg,
  56                          _pressure_node->getDoubleValue(),
  57                          dt/6.0);
  58     }
  59 }
  60
  61 // end of vertical_speed_indicator.cxx