hellbound/Assets/Sources/Feel/MMTools/Tools/MMAI/AIBrain.cs

217 lines
7.3 KiB
C#

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
namespace MoreMountains.Tools
{
/// <summary>
/// the AI brain is responsible from going from one state to the other based on the defined transitions. It's basically just a collection of states, and it's where you'll link all the actions, decisions, states and transitions together.
/// </summary>
[AddComponentMenu("More Mountains/Tools/AI/AIBrain")]
public class AIBrain : MonoBehaviour
{
/// the collection of states
public List<AIState> States;
/// whether or not this brain is active
public bool BrainActive = true;
/// this brain's current state
public AIState CurrentState { get; protected set; }
/// the time we've spent in the current state
[MMReadOnly]
public float TimeInThisState;
/// the current target
[MMReadOnly]
public Transform Target;
/// the last known world position of the target
[MMReadOnly]
public Vector3 _lastKnownTargetPosition = Vector3.zero;
[Header("Frequencies")]
/// the frequency (in seconds) at which to perform actions (lower values : higher frequency, high values : lower frequency but better performance)
public float ActionsFrequency = 0f;
/// the frequency (in seconds) at which to evaluate decisions
public float DecisionFrequency = 0f;
/// whether or not to randomize the action and decision frequencies
public bool RandomizeFrequencies = false;
/// the min and max values between which to randomize the action frequency
[MMVector("min","max")]
public Vector2 RandomActionFrequency = new Vector2(0.5f, 1f);
/// the min and max values between which to randomize the decision frequency
[MMVector("min","max")]
public Vector2 RandomDecisionFrequency = new Vector2(0.5f, 1f);
protected AIDecision[] _decisions;
protected float _lastActionsUpdate = 0f;
protected float _lastDecisionsUpdate = 0f;
protected AIState _initialState;
public virtual AIAction[] GetAttachedActions()
{
AIAction[] actions = this.gameObject.GetComponentsInChildren<AIAction>();
return actions;
}
public virtual AIDecision[] GetAttachedDecisions()
{
AIDecision[] decisions = this.gameObject.GetComponentsInChildren<AIDecision>();
return decisions;
}
/// <summary>
/// On awake we set our brain for all states
/// </summary>
protected virtual void Awake()
{
foreach (AIState state in States)
{
state.SetBrain(this);
}
_decisions = GetAttachedDecisions();
if (RandomizeFrequencies)
{
ActionsFrequency = Random.Range(RandomActionFrequency.x, RandomActionFrequency.y);
DecisionFrequency = Random.Range(RandomDecisionFrequency.x, RandomDecisionFrequency.y);
}
}
/// <summary>
/// On Start we set our first state
/// </summary>
protected virtual void Start()
{
ResetBrain();
}
/// <summary>
/// Every frame we update our current state
/// </summary>
protected virtual void Update()
{
if (!BrainActive || (CurrentState == null) || (Time.timeScale == 0f))
{
return;
}
if (Time.time - _lastActionsUpdate > ActionsFrequency)
{
CurrentState.PerformActions();
_lastActionsUpdate = Time.time;
}
if (Time.time - _lastDecisionsUpdate > DecisionFrequency)
{
CurrentState.EvaluateTransitions();
_lastDecisionsUpdate = Time.time;
}
TimeInThisState += Time.deltaTime;
StoreLastKnownPosition();
}
/// <summary>
/// Transitions to the specified state, trigger exit and enter states events
/// </summary>
/// <param name="newStateName"></param>
public virtual void TransitionToState(string newStateName)
{
if (CurrentState == null)
{
CurrentState = FindState(newStateName);
if (CurrentState != null)
{
CurrentState.EnterState();
}
return;
}
if (newStateName != CurrentState.StateName)
{
CurrentState.ExitState();
OnExitState();
CurrentState = FindState(newStateName);
if (CurrentState != null)
{
CurrentState.EnterState();
}
}
}
/// <summary>
/// When exiting a state we reset our time counter
/// </summary>
protected virtual void OnExitState()
{
TimeInThisState = 0f;
}
/// <summary>
/// Initializes all decisions
/// </summary>
protected virtual void InitializeDecisions()
{
if (_decisions == null)
{
_decisions = GetAttachedDecisions();
}
foreach(AIDecision decision in _decisions)
{
decision.Initialization();
}
}
/// <summary>
/// Returns a state based on the specified state name
/// </summary>
/// <param name="stateName"></param>
/// <returns></returns>
protected AIState FindState(string stateName)
{
foreach (AIState state in States)
{
if (state.StateName == stateName)
{
return state;
}
}
if (stateName != "")
{
Debug.LogError("You're trying to transition to state '" + stateName + "' in " + this.gameObject.name + "'s AI Brain, but no state of this name exists. Make sure your states are named properly, and that your transitions states match existing states.");
}
return null;
}
/// <summary>
/// Stores the last known position of the target
/// </summary>
protected virtual void StoreLastKnownPosition()
{
if (Target != null)
{
_lastKnownTargetPosition = Target.transform.position;
}
}
/// <summary>
/// Resets the brain, forcing it to enter its first state
/// </summary>
public virtual void ResetBrain()
{
InitializeDecisions();
if (CurrentState != null)
{
CurrentState.ExitState();
OnExitState();
}
if (States.Count > 0)
{
CurrentState = States[0];
CurrentState?.EnterState();
}
}
}
}