static bool:OnFly[MAX_PLAYERS];  // true = player is flying, false = player on foot

// prototypes

forward InitFly(playerid);       // call this function in OnPlayerConnect
forward bool:StartFly(playerid);     // start flying
forward Fly(playerid);        // timer
forward bool:StopFly(playerid);      // stop flying
forward static SetPlayerLookAt(playerid,Float:x,Float:y);    // set player face position

// functions

InitFly(playerid)
{
  OnFly[playerid] = false;
  return;
}

bool:StartFly(playerid)
{
  if(OnFly[playerid])
         return false;
     OnFly[playerid] = true;
  new Float:x,Float:y,Float:z;
  GetPlayerPos(playerid,x,y,z);
  SetPlayerPos(playerid,x,y,z+5.0);
  ApplyAnimation(playerid,"PARACHUTE","PARA_steerR",6.1,1,1,1,1,0,1);
  Fly(playerid);
  GameTextForPlayer(playerid,"~y~Fly mode~n~~r~~k~~PED_FIREWEAPON~ ~w~- increase height~n~~r~RMB ~w~- reduce height~n~\
  ~r~~k~~PED_SPRINT~ ~w~- increase speed~n~\
  ~r~~k~~SNEAK_ABOUT~ ~w~- reduce speed",10000,3);
  return true;
}

public Fly(playerid)
{
  if(!IsPlayerConnected(playerid))
   return 1;
  new k, ud,lr;
  GetPlayerKeys(playerid,k,ud,lr);
  new Float:v_x,Float:v_y,Float:v_z,
   Float:x,Float:y,Float:z;
  if(ud < 0)    // forward
  {
   GetPlayerCameraFrontVector(playerid,x,y,z);
   v_x = x+0.1;
   v_y = y+0.1;
  }
  if(k & 128)    // down
   v_z = -0.2;
  else if(k & KEY_FIRE)    // up
   v_z = 0.2;
  if(k & KEY_WALK)    // slow
  {
   v_x /=5.0;
   v_y /=5.0;
   v_z /=5.0;
  }
  if(k & KEY_SPRINT)    // fast
  {
   v_x *=4.0;
   v_y *=4.0;
   v_z *=4.0;
  }
  if(v_z == 0.0)  
   v_z = 0.025;
  SetPlayerVelocity(playerid,v_x,v_y,v_z);
  if(v_x == 0 && v_y == 0)
  {  
   if(GetPlayerAnimationIndex(playerid) == 959)  
    ApplyAnimation(playerid,"PARACHUTE","PARA_steerR",6.1,1,1,1,1,0,1);
  }
  else  
  {
   GetPlayerCameraFrontVector(playerid,v_x,v_y,v_z);
   GetPlayerCameraPos(playerid,x,y,z);
   SetPlayerLookAt(playerid,v_x*500.0+x,v_y*500.0+y);
   if(GetPlayerAnimationIndex(playerid) != 959)
    ApplyAnimation(playerid,"PARACHUTE","FALL_SkyDive_Accel",6.1,1,1,1,1,0,1);
  }
  if(OnFly[playerid])
   SetTimerEx("Fly",100,false,"i",playerid);
  return 1;
}

bool:StopFly(playerid)
{
  if(!OnFly[playerid])
         return false;
  new Float:x,Float:y,Float:z;
  GetPlayerPos(playerid,x,y,z);
  SetPlayerPos(playerid,x,y,z);
  OnFly[playerid] = false;
  return true;
}

static SetPlayerLookAt(playerid,Float:x,Float:y)
{
  new Float:Px, Float:Py, Float: Pa;
  GetPlayerPos(playerid, Px, Py, Pa);
  Pa = floatabs(atan((y-Py)/(x-Px)));
  if (x <= Px && y >= Py)   Pa = floatsub(180.0, Pa);
  else if (x < Px && y < Py)   Pa = floatadd(Pa, 180.0);
  else if (x >= Px && y <= Py)    Pa = floatsub(360.0, Pa);
  Pa = floatsub(Pa, 90.0);
  if (Pa >= 360.0)  
   Pa = floatsub(Pa, 360.0);
  SetPlayerFacingAngle(playerid, Pa);
  return;
}

InitFly(playerid)     
bool:StartFly(playerid)     
bool:StopFly(playerid)

public OnPlayerConnect(playerid)
{
  InitFly(playerid);
  return 1;
}
public OnPlayerCommandText(playerid, cmdtext[])
{
  if(!strcmp(cmdtext,"/fly",true))
  {
      StartFly(playerid);
      return 1;
  }
  if(!strcmp(cmdtext,"/stopfly",true))
  {
      StopFly(playerid);
      return 1;
  }
  return 0;
}