flightgear/src/Instrumentation/slip_skid_ball.cxx

// slip_skid_ball.cxx - an electric-powered turn indicator.
// Written by David Megginson, started 2003.
//
// This file is in the Public Domain and comes with no warranty.

#include "slip_skid_ball.hxx"
#include <Main/fg_props.hxx>
#include <Main/util.hxx>


SlipSkidBall::SlipSkidBall ( SGPropertyNode *node)
    :
    _name(node->getStringValue("name", "slip-skid-ball")),
    _num(node->getIntValue("number", 0))
{
}

SlipSkidBall::~SlipSkidBall ()
{
}

void
SlipSkidBall::init ()
{
    string branch;
    branch = "/instrumentation/" + _name;

    SGPropertyNode *node = fgGetNode(branch.c_str(), _num, true );
    _serviceable_node = node->getChild("serviceable", 0, true);
    _y_accel_node = fgGetNode("/accelerations/pilot/y-accel-fps_sec", true);
    _z_accel_node = fgGetNode("/accelerations/pilot/z-accel-fps_sec", true);
    _out_node = node->getChild("indicated-slip-skid", 0, true);
    _override_node = node->getChild("override", 0, true);
}

void
SlipSkidBall::update (double delta_time_sec)
{
    if (_serviceable_node->getBoolValue() && !_override_node->getBoolValue()) {
        double d = -_z_accel_node->getDoubleValue();
        if (d < 1.0)
            d = 1.0;
        double pos = _y_accel_node->getDoubleValue() / d * 10.0;
        pos = fgGetLowPass(_out_node->getDoubleValue(), pos, delta_time_sec);
        _out_node->setDoubleValue(pos);
    }
}

// end of slip_skid_ball.cxx