MOOSE/Moose Development/Moose/AI/AI_A2G_CAS.lua

--- **AI** -- Models the process of air to ground engagement for airplanes and helicopters.
--
-- This is a class used in the @{AI_A2G_Dispatcher}.
-- 
-- ===
-- 
-- ### Author: **FlightControl**
-- 
-- ===       
--
-- @module AI.AI_A2G_CAS
-- @image AI_Air_To_Ground_Engage.JPG



--- @type AI_A2G_CAS
-- @extends AI.AI_A2G_Patrol#AI_A2G_PATROL


--- Implements the core functions to intercept intruders. Use the Engage trigger to intercept intruders.
-- 
-- ===
-- 
-- @field #AI_A2G_CAS
AI_A2G_CAS = {
  ClassName = "AI_A2G_CAS",
}



--- Creates a new AI_A2G_CAS object
-- @param #AI_A2G_CAS self
-- @param Wrapper.Group#GROUP AIGroup
-- @param DCS#Speed  EngageMinSpeed The minimum speed of the @{Wrapper.Group} in km/h when engaging a target.
-- @param DCS#Speed  EngageMaxSpeed The maximum speed of the @{Wrapper.Group} in km/h when engaging a target.
-- @param DCS#Altitude EngageFloorAltitude The lowest altitude in meters where to execute the engagement.
-- @param DCS#Altitude EngageCeilingAltitude The highest altitude in meters where to execute the engagement.
-- @param Core.Zone#ZONE_BASE PatrolZone The @{Zone} where the patrol needs to be executed.
-- @param DCS#Altitude PatrolFloorAltitude The lowest altitude in meters where to execute the patrol.
-- @param DCS#Altitude PatrolCeilingAltitude The highest altitude in meters where to execute the patrol.
-- @param DCS#Speed  PatrolMinSpeed The minimum speed of the @{Wrapper.Group} in km/h.
-- @param DCS#Speed  PatrolMaxSpeed The maximum speed of the @{Wrapper.Group} in km/h.
-- @param DCS#AltitudeType PatrolAltType The altitude type ("RADIO"=="AGL", "BARO"=="ASL"). Defaults to RADIO
-- @return #AI_A2G_CAS
function AI_A2G_CAS:New( AIGroup, EngageMinSpeed, EngageMaxSpeed, EngageFloorAltitude, EngageCeilingAltitude, PatrolZone, PatrolFloorAltitude, PatrolCeilingAltitude, PatrolMinSpeed, PatrolMaxSpeed, PatrolAltType )

  -- Inherits from BASE
  local self = BASE:Inherit( self, AI_A2G_PATROL:New( AIGroup, EngageMinSpeed, EngageMaxSpeed, EngageFloorAltitude, EngageCeilingAltitude, PatrolZone, PatrolFloorAltitude, PatrolCeilingAltitude, PatrolMinSpeed, PatrolMaxSpeed, PatrolAltType ) ) -- #AI_A2G_CAS

  local RTBSpeedMax = AIGroup:GetSpeedMax() or 9999

  self:SetRTBSpeed( RTBSpeedMax * 0.50, RTBSpeedMax * 0.75 )

  return self
end


--- @param #AI_A2G_CAS self
-- @param Wrapper.Group#GROUP DefenderGroup The GroupGroup managed by the FSM.
-- @param #string From The From State string.
-- @param #string Event The Event string.
-- @param #string To The To State string.
function AI_A2G_CAS:onafterEngage( DefenderGroup, From, Event, To, AttackSetUnit )

  self:F( { DefenderGroup, From, Event, To, AttackSetUnit} )
  
  local DefenderGroupName = DefenderGroup:GetName()

  self.AttackSetUnit = AttackSetUnit -- Kept in memory in case of resume from refuel in air!

  local AttackCount = AttackSetUnit:Count()
  
  if AttackCount > 0 then

    if DefenderGroup:IsAlive() then

      local EngageAltitude = math.random( self.EngageFloorAltitude or 500, self.EngageCeilingAltitude or 1000 )
      local EngageSpeed = math.random( self.EngageMinSpeed, self.EngageMaxSpeed )

      local DefenderCoord = DefenderGroup:GetPointVec3()
      DefenderCoord:SetY( EngageAltitude ) -- Ground targets don't have an altitude.

      local TargetCoord = AttackSetUnit:GetFirst():GetPointVec3()
      TargetCoord:SetY( EngageAltitude ) -- Ground targets don't have an altitude.
      
      local TargetDistance = DefenderCoord:Get2DDistance( TargetCoord )
      local EngageDistance = ( DefenderGroup:IsHelicopter() and 5000 ) or ( DefenderGroup:IsAirPlane() and 10000 )
      
      local EngageRoute = {}
      local AttackTasks = {}
      
      local FromWP = DefenderCoord:WaypointAir( 
        self.PatrolAltType or "RADIO", 
        POINT_VEC3.RoutePointType.TurningPoint, 
        POINT_VEC3.RoutePointAction.TurningPoint, 
        EngageSpeed, 
        true 
      )
      EngageRoute[#EngageRoute+1] = FromWP

      self:SetTargetDistance( TargetCoord ) -- For RTB status check

      local FromEngageAngle = DefenderCoord:GetAngleDegrees( DefenderCoord:GetDirectionVec3( TargetCoord ) )
      local ToWP = DefenderCoord:Translate( EngageDistance, FromEngageAngle, true ):WaypointAir( 
        self.PatrolAltType or "RADIO", 
        POINT_VEC3.RoutePointType.TurningPoint, 
        POINT_VEC3.RoutePointAction.TurningPoint, 
        EngageSpeed, 
        true 
      )
      EngageRoute[#EngageRoute+1] = ToWP

      if TargetDistance <= EngageDistance * 3 then
      
        local AttackUnitTasks = {}
        
        local AttackSetUnitPerThreatLevel = AttackSetUnit:GetSetPerThreatLevel( 10, 0 )
        for AttackUnitIndex, AttackUnit in ipairs( AttackSetUnitPerThreatLevel or {} ) do
          if AttackUnit then
            if AttackUnit:IsAlive() and AttackUnit:IsGround() then
              self:T( { "CAS Unit:", AttackUnit:GetName() } )
              AttackUnitTasks[#AttackUnitTasks+1] = DefenderGroup:TaskAttackUnit( AttackUnit, true, false, nil, nil, EngageAltitude )
            end
          end
        end
  
          
        if #AttackUnitTasks == 0 then
          self:I( DefenderGroupName .. ": No targets found -> Going RTB")
          self:Return()
          self:__RTB( self.TaskDelay )
        else
          DefenderGroup:OptionROEOpenFire()
          DefenderGroup:OptionROTEvadeFire()
          DefenderGroup:OptionKeepWeaponsOnThreat()
  
          AttackTasks[#AttackTasks+1] = DefenderGroup:TaskCombo( AttackUnitTasks )
        end
      end
      
      AttackTasks[#AttackTasks+1] = DefenderGroup:TaskFunction( "AI_A2G_ENGAGE.___Engage", self, AttackSetUnit )
      EngageRoute[#EngageRoute].task = DefenderGroup:TaskCombo( AttackTasks )
      
      DefenderGroup:Route( EngageRoute, self.TaskDelay )
    end
  else
    self:I( DefenderGroupName .. ": No targets found -> Going RTB")
    self:Return()
    self:__RTB( self.TaskDelay )
  end
end

--- @param Wrapper.Group#GROUP AIEngage
function AI_A2G_CAS.Resume( AIEngage, Fsm )

  AIEngage:F( { "AI_A2G_CAS.Resume:", AIEngage:GetName() } )
  if AIEngage:IsAlive() then
    Fsm:__Reset( Fsm.TaskDelay )
    Fsm:__EngageRoute( Fsm.TaskDelay, Fsm.AttackSetUnit )
  end
  
end