float last_alt;
float last_time;
float last_move;
float boost;
integer controls;

float MIN_SPEED = 2.0;
float WANT_SPEED = 20.0;
float MAX_SPEED = 25.0;
float MIN_TIME = 1.0;
float DEFAULT_BOOST = 0.5;

float FAST_TICK = 0.1;
float SLOW_TICK = 1.0;
float LONG_TIME = 5.0; // reset boost if no work in a long time

float MIN_BOOST_HEIGHT = 72.0;
float MIN_BOOST_CLEARANCE = 36.0;

integer flying = -1;
integer falling = -1;
integer hovering = -1;
integer dimmed = -1;

integer HUD_OFF = 0;
integer HUD_ALWAYS = -1;
integer HUD_ON = 1;
integer hud_state = 1; // default HUD_ON

string last_hud_text;
integer hud_active = 0;
float last_hud_time = 0;
show_hud()
{
    if(hud_state == HUD_ALWAYS)
        hud_active = 1;
    else if(hud_state == HUD_ON)
    {
        if(hud_active >= 0 && flying == 0 && hovering == 0 && falling == 0) hud_active = 0;
        else if(hud_active <= 0 && (flying > 0 || hovering > 0 || falling > 0)) hud_active = 1;
    }
    else if(hud_active == 1)
        hud_active = 0;

    if(hud_active == 1) {
        float time = llGetTime();
        if(last_hud_time > time - 1) return;
        vector v = llGetVel();
        vector p = llGetPos();
        string hover_text = "";
        if(hovering && controls == 0)
            hover_text = " (hover)";
        string boost_text = "Standby";
        if(!hovering)
            boost_text = "Passive";
        if(falling)
            boost_text = "Inactive";
        if(boost > 0 && controls > 0)
            boost_text = "Boost "+((string)llFloor(boost * 100.0 / 6.0 + 0.5))+"%";
        string hud_text = "";
        if(hud_state == HUD_ALWAYS)
            hud_text = "\nHUD locked";

        string t =
            "<"+((string)llFloor(p.x+0.5))+","+((string)llFloor(p.y+0.5))+","+((string)llFloor(p.z+0.5))+">"+
            " ("+((string)(llFloor(p.z-llGround(<0,0,0>)+0.5)))+"m AGL)\n"+
            "<"+((string)llFloor(v.x+0.5))+","+((string)llFloor(v.y+0.5))+","+((string)llFloor(v.z+0.5))+">"+
            " ("+((string)llFloor(llVecMag(v)))+"m/s)\n"+
              boost_text+hover_text+hud_text;
        if(last_hud_text != t) {
            vector color = <1,1,1>;
            if(hud_state == HUD_ALWAYS)
                color = <.3,1,.3>;
           // llSetText(t, color, 1);
            last_hud_text = t;
            last_hud_time = time;
        }
    } else if(hud_active == 0) {
        last_hud_text = "";
        last_hud_time = 0;
      //  llSetText("", ZERO_VECTOR, 0);
        hud_active = -1;
    }
}
 init2(){  llReleaseControls();}

set_hover(integer active)
{
    if(active == hovering) return;
    hovering = active;
    if(hovering)
        llSetForce(<0,0,9.8> * llGetMass(), FALSE);
    else
        llSetForce(<0,0,0>, FALSE);
}

float last_tick = -1;
set_tick(float tick)
{
    if(tick == last_tick) return;
    last_tick = tick;
    llSetTimerEvent(tick);
}

float last_boost_height;
float average_boost;
check_boost()
{
    flying = 1;
    falling = 0;

    integer info = llGetAgentInfo(llGetOwner());

    if((info & AGENT_FLYING) == 0)
    {
        set_hover(FALSE);
        falling = (info & AGENT_IN_AIR) != 0;
        flying = 0;
        boost = 0;
        set_tick(SLOW_TICK);
        return;
    }

    vector pos = llGetPos();
    if(pos.z < last_boost_height / 2) // trim running average of boost if big altitude drop
        average_boost = average_boost * (pos.z / last_boost_height)
                      + DEFAULT_BOOST * (1.0 - pos.z / last_boost_height);

    if(pos.z < MIN_BOOST_HEIGHT || pos.z - llGround(<0,0,0>) < MIN_BOOST_CLEARANCE)
    {
        set_hover(FALSE);
        set_tick(SLOW_TICK);
        boost = 0;
        return;
    }

    set_hover(TRUE);

    if(controls <= 0) return;

    vector vel = llGetVel();
    float time = llGetTime();
    float speed = vel.z;
    float target = WANT_SPEED;
    float window = WANT_SPEED / 20;

    if(speed > 0)
        last_move = time;

    if(time - last_time >= LONG_TIME)
        boost = 0;
    else
    {
        if(speed < target - window)
        {
            if(boost == 0)
                boost = average_boost;
            if(time - last_move > MIN_TIME) boost += 0.4;
            else if(speed < target * 0.25) boost += 0.2;
            else if(speed < target * 0.5 ) boost += 0.1;
            else if(speed < target * 0.75) boost += 0.05;
            else if(speed < target - window * 4) boost += 0.02;
            else boost += 0.01;
        }
        else if(speed > MAX_SPEED) boost -= 0.5;
        else if(speed > target + window * 4) boost -= 0.1;
        else if(speed > target + window * 2) boost -= 0.03;
        else if(speed > target + window) boost -= 0.01;

        if(boost <= 0)
            boost = 0;
        if(boost > 0) {
            llApplyImpulse(<0,0,boost> * llGetMass(), FALSE);
            average_boost = average_boost * 0.9 + boost * 0.1; // 10 sample running average
            last_boost_height = pos.z;
        }
    }

    if(boost) set_tick(FAST_TICK);
    else set_tick(SLOW_TICK);
    last_alt = pos.z;
    last_time = time;
}

take_controls()
{
    llTakeControls(CONTROL_UP|CONTROL_DOWN,TRUE,TRUE);
}

request_perms()
{
    if(llGetPermissions() & PERMISSION_TAKE_CONTROLS)
        take_controls();
    else
        llRequestPermissions(llGetOwner(), PERMISSION_TAKE_CONTROLS);
}

init()
{
    boost = 0;

    flying = -1;
    falling = -1;
    hovering = -1;
    dimmed = -1;
    hud_state = HUD_ON;

    set_tick(SLOW_TICK);
    if(llGetAttached()) request_perms();
}






key uuid;integer on = FALSE;





integer knob=0;



key Owner;

default
{
    state_entry()
    {
        Owner = llGetOwner();
    }





    run_time_permissions(integer mask)
    {
        if(mask & PERMISSION_TAKE_CONTROLS) take_controls();


}control(key id, integer level, integer edge)
    {
        controls = 0;
        if(level & CONTROL_UP) controls++;
        if(level & CONTROL_DOWN) controls--;
        check_boost();
    }

timer()
    {
        check_boost();
        show_hud();
        if(flying && boost > 0)
        {
            if(dimmed != 0)

            dimmed = 0;
        }
        else
        {
            integer dimness = 4;
            if(hud_state == HUD_ON) dimness = 5;
            else if(hud_state == HUD_ALWAYS) dimness = 6;
            if(dimmed != dimness) {
                float alpha = ((float)dimness) / 10;

            }
            dimmed = dimness;
        }
    }
    touch_start(integer det)
    {
        key id = llDetectedKey(0);
        if(id == Owner)
        {
          if(knob==0)
        {


              init();


knob=1;llOwnerSay ("Im activating flight mode");

              }else if(knob==1)
        {knob=0;   init2();

            llOwnerSay("flight mode off :");knob=0;

        }}}}