land

clearscreen.
print "Landing sequence initiated...".
set prep to 200.
set atalt to 90000.
set hvkOffset to -0.25.
set hk to False.
set alt0 to 0.
set t1 to -99.
set T to 0.
global sbound is ship:bounds.

lock throttle to T.
lock head TO ship:retrograde.
LOCK STEERING TO head.

run landdata.
//set aG to -1*ship:sensors:grav:mag.
//set maxAccel to ship:maxthrust/ship:mass.
//set accel to (throttle*ship:maxthrust)/ship:mass.
//set nMaxAccel to maxAccel + aG.
//set nAccel to accel + aG.
//set estTime to ship:verticalspeed/nMaxAccel.
//set estAlt to ship:verticalspeed * estTime + 0.5 * nMaxAccel * estTime^2.


//set aG to ship:sensor:grav * 9.802.

//print "maxAccel: " + maxAccel at(0,5).
//print "estTime: " + estTime at(0,6).
//print "estAlt: " + estAlt at(0,7).
//print "accel: " + accel at(0,8).
//print "nMaxAccel: " + nMaxAccel at(0,9).
//print "aG: " + aG at(0,10).
//print "acc2: " + ship:sensors:acc:mag at(0,14).


wait until alt:radar < atalt.

if ship:groundspeed > 0.1 and hk{
  set hvk to node(time:seconds + 30,0,0,hvkOffset*ship:groundspeed).
  add hvk.
  run nexec.
}.
brakes on.

set ninit to True.
LOCK STEERING TO head.
lock head TO ship:srfretrograde.
lock throttle to T.
set dtl to 0.
until altrad < 0.1 or ship:status = "LANDED" and throttle < 0.01 and dtl > 5
{
  if altrad < 0.1 or ship:status = "LANDED"
  {
    if t1 < 0
    {
      set t1 to time:seconds.
    }
    set t2 to time:seconds.
    set dtl to t2 - t1.
  }else{
    set t1 to -99.
  }
  set Tdiff to 0.
  run landdata. //VERY IMPORTANT GETS ALL DATA


  if altrad <= estAlt + prep or altrad < 1000 or ship:verticalspeed > 0.01 or estAlt < 100 {
    if ninit {
      gear on.
      set alt0 to altrad.
      set ninit to False.
    }.

    if ship:verticalspeed < -1000{
      set Tdiff to 0.1.
    } else {
      if ship:verticalspeed < -100 and T < 1 and altrad < 1500{
        set Tdiff to 0.1.
      } else if ship:verticalspeed < -50 and T < 1 and altrad < 100{
        set Tdiff to 0.1.
      } else if ship:verticalspeed < -10 and T < 1 and altrad < 50{
        set Tdiff to 0.01.
      } else if ship:verticalspeed < -5 and T < 1 and altrad < 25{
        set Tdiff to 0.001.
      }else if ship:verticalspeed < -1 and T < 1 and altrad < 10{
        set Tdiff to 0.0001.
      }else if ship:verticalspeed < -0.5 and altrad < 5{
        set Tdiff to 0.000005.
      }else if ship:verticalspeed > 0 and T > 0 {
        set Tdiff to - 1.
      }else if ship:verticalspeed > -0.5 and T > 0 {
        set Tdiff to - 0.000001.
      }else if ship:verticalspeed > -1 and T > 0 {
        set Tdiff to - 0.0001.
      }else if ship:verticalspeed > -5 and T > 0 {
        set Tdiff to - 0.001.
      } else if ship:verticalspeed > -10 and T > 0 {
        set Tdiff to - 0.01.
      } else if ship:verticalspeed > -50 and T > 0 {
        set Tdiff to - 0.1.
      } else if ship:verticalspeed > -100 and T > 0 {
        set Tdiff to - 0.1.
      }.
    }.

    if ship:verticalspeed > -20 or ship:groundspeed < 1{
      lock head to heading(90,90).
    }else {
      lock head to ship:srfretrograde.
    }.

  }else if altrad > estAlt + (prep){
    set Tdiff to - 0.1.
  }.
  //throttle change
  set T to T + Tdiff.
  if T > 1 {
    set T to 1.
  } else if T < 0 {
    set T to 0.
  }.
}.

if ship:status = "LANDED" {
  lock head to heading(90,90).

}.