fgdata/Aircraft/c172p/Nasal/physics.nas

var reset_all_damage = func
{
    setprop("/engines/active-engine/crash-engine", 0);
    setprop("/engines/active-engine/kill-engine", 0);

    # Landing gear
    setprop("/fdm/jsbsim/gear/unit[0]/broken", 0);
    setprop("/fdm/jsbsim/gear/unit[1]/broken", 0);
    setprop("/fdm/jsbsim/gear/unit[2]/broken", 0);

    # Wings
    setprop("/fdm/jsbsim/wing-damage/left-wing", 0);
    setprop("/fdm/jsbsim/wing-damage/right-wing", 0);

    # Collapsed wings
    setprop("/fdm/jsbsim/crash", 0);

    # Pontoons
    setprop("/fdm/jsbsim/pontoon-damage/left-pontoon", 0);
    setprop("/fdm/jsbsim/pontoon-damage/right-pontoon", 0);
}

var repair_damage = func {
    set_bushkit(getprop("/fdm/jsbsim/bushkit"));
};

var killengine = func
{
    if (getprop("/fdm/jsbsim/settings/damage"))
        setprop("/engines/active-engine/crash-engine", 1);
}

# Check if on water
var poll_surface = func
{
    var engine_rpm = getprop("fdm/jsbsim/propulsion/engine/engine-rpm");
    var hydro_active_norm = getprop("/fdm/jsbsim/hydro/active-norm");
    var ground_splash_norm = getprop("/environment/aircraft-effects/ground-splash-norm");

    # Use engine RPM and speed to control ground splash if on the water
    # and below 2 meter AGL
    if (getprop("position/altitude-agl-m") < 2 and hydro_active_norm > 0) {
        var groundspeed_half_pc = 0.005 * getprop("velocities/groundspeed-kt");
        var engine_rpm_almost_nothing = 0.005 * 0.065 * engine_rpm;

        var splash_norm = std.max(engine_rpm_almost_nothing, groundspeed_half_pc);
        setprop("/environment/aircraft-effects/ground-splash-norm", splash_norm);
    }
    elsif (ground_splash_norm > 0)
        setprop("/environment/aircraft-effects/ground-splash-norm", ground_splash_norm - 0.005);
}

# Duration in which no damage will occur. Assumes the aircraft has
# stabilized within this duration.
var bushkit_change_timeout = 3.0;

var physics_loop = func
{
    if (getprop("/sim/freeze/replay-state")) {
        return;
    }
    if (getprop("/fdm/jsbsim/bushkit") == 3 or getprop("/fdm/jsbsim/bushkit") == 4)
        poll_surface();
    if (getprop("/fdm/jsbsim/contact/unit[9]/WOW") or getprop("/fdm/jsbsim/contact/unit[10]/WOW"))
        killengine();
}

var set_bushkit = func (bushkit) {
    setprop("/fdm/jsbsim/damage/repairing", 1);
    reset_all_damage();
    bushkit_changed_timer.restart(bushkit_change_timeout);
};

# This timer object is used to enable damage again a short time after
# changing to the last bush kit option.
var bushkit_changed_timer = maketimer(bushkit_change_timeout, func {
    setprop("/fdm/jsbsim/damage/repairing", 0);
});
bushkit_changed_timer.singleShot = 1;

setlistener("/sim/signals/fdm-initialized", func {
    # Update the 3D model when changing bush kit
    setlistener("/fdm/jsbsim/bushkit", func (n) {
        set_bushkit(n.getValue());
    }, 1, 0);

    setlistener("/fdm/jsbsim/crash", func (n) {
        if (n.getBoolValue() and getprop("position/altitude-agl-m") < 10) {
            killengine();
        }
    }, 0, 0);

    setlistener("/fdm/jsbsim/wing-damage/left-wing", func (n) {
        var damage = n.getValue();
        var altitude = getprop("position/altitude-agl-m");

        if (damage < 1.0 and damage > 0.0 and altitude < 10.0)
            killengine();
    }, 0, 0);

    setlistener("/fdm/jsbsim/wing-damage/right-wing", func (n) {
        var damage = n.getValue();
        var altitude = getprop("position/altitude-agl-m");

        if (damage < 1.0 and damage > 0.0 and altitude < 10.0)
            killengine();
    }, 0, 0);
});