flightgear/src/Instrumentation/airspeed_indicator.hxx

// airspeed_indicator.hxx - a regular VSI tied to the static port.
// Written by David Megginson, started 2002.
//
// This file is in the Public Domain and comes with no warranty.


#ifndef __INSTRUMENTS_AIRSPEED_INDICATOR_HXX
#define __INSTRUMENTS_AIRSPEED_INDICATOR_HXX 1

#ifndef __cplusplus
# error This library requires C++
#endif

#include <simgear/props/props.hxx>
#include <simgear/structure/subsystem_mgr.hxx>

// forward decls
class FGEnvironmentMgr;

/**
 * Model an airspeed indicator tied to the pitot and static ports.
 *
 * Input properties:
 *
 * /instrumentation/"name"/serviceable
 * "pitot_port"/total-pressure-inhg
 * "static_port"/pressure-inhg
 * /environment/density-slugft3
 *
 * Output properties:
 *
 * /instrumentation/"name"/indicated-speed-kt
 */
class AirspeedIndicator : public SGSubsystem
{

public:

    AirspeedIndicator ( SGPropertyNode *node );
    virtual ~AirspeedIndicator ();

    virtual void init ();
    virtual void update (double dt);

private:
    void computeMach(double ias);

    string _name;
    unsigned int _num;
    string _total_pressure;
    string _static_pressure;
    bool _has_overspeed;
    string _pressure_alt_source;
    double _ias_limit;
    double _mach_limit;
    double _alt_threshold;
    
    SGPropertyNode_ptr _ias_limit_node;
    SGPropertyNode_ptr _mach_limit_node;
    SGPropertyNode_ptr _alt_threshold_node;
    SGPropertyNode_ptr _serviceable_node;
    SGPropertyNode_ptr _total_pressure_node;
    SGPropertyNode_ptr _static_pressure_node;
    SGPropertyNode_ptr _density_node;
    SGPropertyNode_ptr _speed_node;
    SGPropertyNode_ptr _airspeed_limit;
    SGPropertyNode_ptr _pressure_alt;
    SGPropertyNode_ptr _mach_node;
    SGPropertyNode_ptr _tas_node;
    
    FGEnvironmentMgr* _environmentManager;
};

#endif // __INSTRUMENTS_AIRSPEED_INDICATOR_HXX