54 lines
1.5 KiB
C++
54 lines
1.5 KiB
C++
// vertical_speed_indicator.cxx - a regular VSI.
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// Written by David Megginson, started 2002.
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//
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// This file is in the Public Domain and comes with no warranty.
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#include <simgear/math/interpolater.hxx>
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#include "vertical_speed_indicator.hxx"
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#include <Main/fg_props.hxx>
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#include <Main/util.hxx>
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VerticalSpeedIndicator::VerticalSpeedIndicator ()
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: _internal_pressure_inhg(29.92)
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{
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}
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VerticalSpeedIndicator::~VerticalSpeedIndicator ()
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{
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}
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void
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VerticalSpeedIndicator::init ()
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{
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_serviceable_node =
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fgGetNode("/instrumentation/vertical-speed-indicator/serviceable",
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true);
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_pressure_node =
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fgGetNode("/systems/static/pressure-inhg", true);
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_speed_node =
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fgGetNode("/instrumentation/vertical-speed-indicator/indicated-speed-fpm",
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true);
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// Initialize at ambient pressure
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_internal_pressure_inhg = _pressure_node->getDoubleValue();
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}
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void
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VerticalSpeedIndicator::update (double dt)
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{
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// model taken from steam.cxx, with change
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// from 10000 to 10500 for manual factor
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if (_serviceable_node->getBoolValue()) {
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double pressure = _pressure_node->getDoubleValue();
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_speed_node
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->setDoubleValue((_internal_pressure_inhg - pressure) * 10500);
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_internal_pressure_inhg =
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fgGetLowPass(_internal_pressure_inhg,
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_pressure_node->getDoubleValue(),
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dt/6.0);
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}
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}
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// end of vertical_speed_indicator.cxx
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