character-system/Runtime/Actions/ZombieFollowTargetAction.cs

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

namespace KairoEngine.CharacterSystem
{
    /// <summary>
    /// Action to make a Zombie follow a target transform using one of many animation varients.
    /// </summary>
    public class ZombieFollowTargetAction : IAction
    {
        CharacterController character;
        Transform target;
        float targetDistance;
        int varient;
        float speed;
        float animationSpeed;
        bool done = false;
        

        /// <summary>
        /// Action that will make a character follow a target transform playing a zombie walk or run animation varient.
        /// </summary>
        /// <param name="character">The CharacterController performing the action</param>
        /// <param name="target">The target Transform to be followed</param>
        /// <param name="targetDistance">Stop following when this distance is reached</param>
        /// <param name="varient">Type of zombie animation to play. 1 to 7 are walk animations and 8 to 9 are run animations</param>
        public ZombieFollowTargetAction(CharacterController character, Transform target, float targetDistance, int varient)
        {
            if(target == null) Debug.LogError("target Transform cannot be null in ZombieFollowTargetAction");
            if(character == null) Debug.LogError("character CharacterController cannot be null in ZombieFollowTargetAction");
            this.character = character;
            this.target = target;
            this.targetDistance = targetDistance;
            this.varient = varient;
            switch(varient)
            {
                case 1:
                    speed = 1.2f;
                    animationSpeed = 1f;
                    break;
                case 2:
                    speed = 1.2f;
                    animationSpeed = 1f;
                    break;
                case 3:
                    speed = 1.2f;
                    animationSpeed = 1f;
                    break;
                case 4:
                    speed = 1.2f;
                    animationSpeed = 1f;
                    break;
                case 5:
                    speed = 1.2f;
                    animationSpeed = 1f;
                    break;
                case 6:
                    speed = 1.2f;
                    animationSpeed = 1f;
                    break;
                case 7:
                    speed = 1.2f;
                    animationSpeed = 1f;
                    break;
                case 8:
                    speed = 2f;
                    animationSpeed = 2f;
                    break;
                case 9:
                    speed = 2.2f;
                    animationSpeed = 2f;
                    break;
                default:
                    speed = 1f;
                    animationSpeed = 1f;
                    break;
            }
        }

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

        public void Update()
        {
            character.animator.SetFloat("ZombieMoveVarient", varient);

            if(Vector3.Distance(character.transform.position, target.position) > targetDistance)
            {
                character.navMeshAgent.destination = target.position;
                character.navMeshAgent.isStopped = false;
                character.navMeshAgent.updatePosition = true;
            }
            if (character.navMeshAgent == null) return;
            if (character.navMeshAgent.pathPending)
            {
                //Debug.Log("Calculating path");
                return;
            } else
            {
                //Debug.Log($"Following path with {character.navMeshAgent.path.corners.Length} corners ({character.unique_name})");
            }
            if (character.navMeshAgent.path == null) {
                //Debug.Log("No path");
                return;
            }
            if (character.navMeshAgent.path.corners.Length == 0)
            {
                return;
            }
            if (character.navMeshAgent.isStopped) return;
            //Debug.Log($"Remaining distance: {character.navMeshAgent.remainingDistance} ({character.unique_name})");
            if (character.navMeshAgent.remainingDistance < character.navMeshAgent.stoppingDistance)
            {
                character.navMeshAgent.isStopped = true;
                character.navMeshAgent.path.ClearCorners();
                Stop();
                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);
        }

        private void Stop()
        {
            character.animator.SetFloat("horizontal", 0);
            character.animator.SetFloat("vertical", 0);
            character.navMeshAgent.isStopped = true;
            character.navMeshAgent.updatePosition = false;
            character.navMeshAgent.speed = 0;
            character.navMeshAgent.stoppingDistance = 0;
            character.navMeshAgent.destination = character.transform.position;
        }

        public void End()
        {
            Stop();
            done = true;
        }

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