SHADE_Y3/Assets/Scripts/Gameplay/AIBehaviour/Implemented/LeafNodes/LeafChase.cs

/*********************************************************************
 * \file   LeafChase.cs
 * \author Ryan Wang Nian Jing
 * \brief  Leaf node implementation for AI chasing the player
 *         
 *
 * \copyright Copyright (c) 2022 DigiPen Institute of Technology. Reproduction
   or disclosure of this file or its contents without the prior written
   consent of DigiPen Institute of Technology is prohibited.
 *********************************************************************/

using SHADE;
using SHADE_Scripting.AIBehaviour.BehaviourTree;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

//VARIABLES
public partial class LeafChase : BehaviourTreeNode
{
  //Used to move entity around
  private Transform transform;
  private RigidBody rb;
  private float chaseSpeed;
  private float turningSpeed;
  private float captureDistance;
  private float baseCaptureTime;
}

//FUNCTIONS
public partial class LeafChase : BehaviourTreeNode
{
  //Despite inheriting from BehaviourTreeNode, we don't have children to this node,
  //and hence we don't need to inherit its constructors
  public LeafChase(string name) : base (name)
  {
    //Debug.Log("LeafChase ctor");
  }

  //Helper, find which waypoint player is closest to
  private void determinePlayerWaypoint()
  {
    List<GameObject> waypoints = (List<GameObject>)GetNodeData("waypoints");
    Transform target = (Transform)GetNodeData("target");
    if (waypoints == null || target == null)
    {
      return;
    }

    int nearestWaypointIndex = 0;
    for (int i = 0; i < waypoints.Count; ++i)
    {
      if ((target.GlobalPosition - waypoints[i].GetComponent<Transform>().GlobalPosition).GetSqrMagnitude() <
        (target.GlobalPosition - waypoints[nearestWaypointIndex].GetComponent<Transform>().GlobalPosition).GetSqrMagnitude())
      {
        nearestWaypointIndex = i;
      }
    }
    //Debug.Log("Player is nearest " + nearestWaypointIndex);
    //Debug.Log("I'm at " + (int)GetNodeData("currentWaypointIndex"));
    SetNodeData("playerLastSightedWaypointIndex", nearestWaypointIndex);
  }

  public override BehaviourTreeNodeStatus Evaluate()
  {
    //Debug.LogWarning("LeafChase");

    onEnter(BehaviourTreeNodeStatus.RUNNING);

    //Get Data
    if (GetNodeData("transform") == null ||
        GetNodeData("rigidBody") == null ||
        GetNodeData("turningSpeed") == null ||
        GetNodeData("chaseSpeed") == null ||
        GetNodeData("distanceToCapture") == null ||
        GetNodeData("baseCaptureTime") == null)
    {
      status = BehaviourTreeNodeStatus.FAILURE;
      onExit(BehaviourTreeNodeStatus.FAILURE);
      return status;
    }
    else
    {
      transform = (Transform)GetNodeData("transform");
      rb = (RigidBody)GetNodeData("rigidBody");
      chaseSpeed = (float)GetNodeData("chaseSpeed");
      turningSpeed = (float)GetNodeData("turningSpeed");
      captureDistance = (float)GetNodeData("distanceToCapture");
      baseCaptureTime = (float)GetNodeData("baseCaptureTime");
    }

    //Fail if no target in blackboard
    if (GetNodeData("target") == null)
    {
      //Debug.Log("Failure: No target in blackboard");
      return BehaviourTreeNodeStatus.FAILURE;
    }
    Transform target = (Transform)GetNodeData("target");

    Vector3 normalisedDifference = target.GlobalPosition - transform.GlobalPosition;
    normalisedDifference.y = 0.0f; //Do not consider Y
    normalisedDifference /= normalisedDifference.GetMagnitude();

    //Over maximum distance, stop chase
    if ((transform.GlobalPosition - target.GlobalPosition).GetMagnitude() > 1000.0f)
    {
      //Debug.Log("Failure: Over maximum distance");
      ClearNodeData("target");

      if (GetNodeData("isAlert") != null && (bool)GetNodeData("isAlert") == true)
      {
        Audio.PlaySFXOnce2D("event:/Homeowner/humming");
      }
      SetNodeData("isAlert", false);

      status = BehaviourTreeNodeStatus.FAILURE;
      onExit(BehaviourTreeNodeStatus.FAILURE);
      return status;
    }
    else if (false) //TODO If collided against a wall
    {
      //Debug.Log("Running: Collided against wall");
      SetNodeData("isPathfinding", true);

      status = BehaviourTreeNodeStatus.RUNNING;
      onExit(BehaviourTreeNodeStatus.RUNNING);
      return BehaviourTreeNodeStatus.RUNNING;
    }
    //Keep chasing
    else if ((transform.GlobalPosition - target.GlobalPosition).GetMagnitude() > captureDistance)
    {
      //Debug.Log("Running: Chasing");
      Quaternion targetRotation = Quaternion.LookRotation(normalisedDifference, new Vector3(0.0f, 1.0f, 0.0f));
      transform.LocalRotation = Quaternion.Slerp(transform.LocalRotation, targetRotation, turningSpeed * Time.DeltaTimeF);


      //Determine the player's nearest waypoint as long as the AI can see the player
      //Head towards that waypoint in an attempt to chase the player
      determinePlayerWaypoint();

      //TODO delete this when original intendd code above works with velocity being limited correctly
      //Only chase the player directly if the player's waypoint matches the AI's own
      if (GetNodeData("currentWaypointIndex") != null && GetNodeData("playerLastSightedWaypointIndex") != null)
      {
        if ((int)GetNodeData("currentWaypointIndex") == (int)GetNodeData("playerLastSightedWaypointIndex"))
        {
          //Debug.Log("Waypoint indicees matching. Chasing directly");
          rb.LinearVelocity = normalisedDifference * chaseSpeed;
        }
        else
        {
          status = BehaviourTreeNodeStatus.FAILURE;
          onExit(BehaviourTreeNodeStatus.FAILURE);
          return BehaviourTreeNodeStatus.FAILURE;
        }
      }

      //Reset capture timing to base
      SetNodeData("captureTimeLeft", baseCaptureTime);

      //Not capturing, don't play SFX
      SetNodeData("isCapturing", false);

      status = BehaviourTreeNodeStatus.RUNNING;
      onExit(BehaviourTreeNodeStatus.RUNNING);
      return BehaviourTreeNodeStatus.RUNNING;
    }
    //Once player is close enough, perform attack
    else
    {
      //Debug.Log("Success: Near enough. Begin attack");
      //Look at the correct direction
      Quaternion targetRotation = Quaternion.LookRotation(normalisedDifference, new Vector3(0.0f, 1.0f, 0.0f));
      transform.LocalRotation = Quaternion.Slerp(transform.LocalRotation, targetRotation, turningSpeed * Time.DeltaTimeF);

      //Play SFX
      if (GetNodeData("isCapturing") != null && (bool)GetNodeData("isCapturing") == false)
      {
        //Debug.Log("AI Play capturing SFX");
      }
      SetNodeData("isCapturing", true);

      //TODO resetting the capture time once it's less than 0 doesn't work as
      //there is quite some time (about .1 seconds) after the timer falls below 0
      //that the capture actually happens

      status = BehaviourTreeNodeStatus.SUCCESS;
      onExit(BehaviourTreeNodeStatus.SUCCESS);
      return status;
    }
  }
}