Creating a behavior tree agent

To use our behavior tree, we can replace the finite state machine and perform the same update loop on our behavior tree instead. Regardless, if our agent is using a decision tree, state machine, or behavior tree, its actions will be nearly identical, as the logic is merely translated from one decision structure to another:

IndirectSoldierAgent.lua:

local soldier;
local soldierController;
local soldierBT;
local soldierUserData;

function Agent_Initialize(agent)

    ...
    
    soldierBT = SoldierLogic_BehaviorTree(
        soldierUserData);
end

function Agent_Update(agent, deltaTimeInMillis)
    if (soldierUserData.alive) then
        soldierBT:Update(deltaTimeInMillis);
    end

    soldierController:Update(agent, deltaTimeInMillis);
end