character-system/Runtime/Actions/CharacterFollowTargetAction.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using KairoEngine.Core;

namespace KairoEngine.CharacterSystem
{
    /// <summary>
    /// Action to move a character in a certain direction and speed.
    /// </summary>
    public class CharacterFollowTargetAction : IAction
    {
        CharacterController character;
        Transform target;
        float speed = 1f;
        float animationSpeed = 1f;
        float targetDistance;
        bool done = false;
        

        // Constructor
        public CharacterFollowTargetAction(CharacterController character, Transform target, float targetDistance, float speed, float animationSpeed = 1f)
        {
            this.character = character;
            this.target = target;
            this.targetDistance = targetDistance;
            this.speed = speed;
            this.animationSpeed = animationSpeed;
            
        }

        public void Start()
        {
            character.navMeshAgent.destination = target.position;
            character.navMeshAgent.updatePosition = true;
            character.navMeshAgent.updateRotation = false;
            character.navMeshAgent.isStopped = false;
            character.navMeshAgent.speed = speed;
        }

        public void Update()
        {
            if(Vector3.Distance(character.navMeshAgent.destination, target.position) > targetDistance)
            {
                character.navMeshAgent.destination = target.position;
            }
            if (character.navMeshAgent == null) return;
            if (character.navMeshAgent.pathPending)
            {
                //Debug.Log("Calculating path");
                return;
            } else
            {
                //Debug.Log($"Following path with {character.navMeshAgent.path.corners.Length} corners ({character.unique_name})");
            }
            if (character.navMeshAgent.path == null) {
                //Debug.Log("No path");
                return;
            }
            if (character.navMeshAgent.path.corners.Length == 0)
            {
                //End();
                return;
            }
            if (character.navMeshAgent.isStopped) return;
            //Debug.Log($"Remaining distance: {character.navMeshAgent.remainingDistance} ({character.unique_name})");
            if (character.navMeshAgent.remainingDistance < character.navMeshAgent.stoppingDistance)
            {
                character.navMeshAgent.isStopped = true;
                character.navMeshAgent.path.ClearCorners();
                //End();
                return;
            }
            TurnToPoint(character.navMeshAgent.steeringTarget);
            Vector3 heading = character.navMeshAgent.steeringTarget - character.transform.position;
            float distance = heading.magnitude;
            Vector3 direction = heading / distance;
            character.animator.SetFloat("horizontal", 0);
            character.animator.SetFloat("vertical", animationSpeed);
        }

        private void TurnToPoint(Vector3 point)
        {
            Quaternion targetRotation = Quaternion.LookRotation (point - character.transform.position);
            character.animator.transform.rotation = Quaternion.Slerp (character.animator.transform.rotation, targetRotation, 100f * Time.deltaTime);
        }

        public void End()
        {
            character.animator.SetFloat("horizontal", 0);
            character.animator.SetFloat("vertical", 0);
            character.navMeshAgent.isStopped = true;
            character.navMeshAgent.speed = 0;
            done = true;
        }

        public bool IsDone()
        {
            return done;
        }
    }
}