character-system/Runtime/CombatSystem/DamageController.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Sirenix.OdinInspector;
using QFSW.MOP2;
using KairoEngine.Core;
using KairoEngine.Inventory;

namespace KairoEngine.CharacterSystem
{
    public class DamageController : MonoBehaviour
    {   
        public CharacterController character;
        [SerializeField, ShowInInspector] private int hitPoints = 100;
        [SerializeField, ShowInInspector]private int maxHitPoints = 100;
        [SerializeField, ShowInInspector] private int armorPoints = 4;

        //public GameObject hitPrefab;
        public string hitFxName = "BloodSpillFx";

        public int HP { get { return hitPoints; } }
        public int maxHP { get { return maxHitPoints; } }
        public int armor { get { return armorPoints; } }

        private List<Bullet> bulletHits = new List<Bullet>();

        void Start()
        {
            if(HP <= 0)
            {
                character.Die();
                DamageEvents.DeathEvent(this, null);
            }
        }
        public void OnCollisionEnter(Collision collision)
        {
            Vector3 point = collision.contacts[0].point;
            if (collision.gameObject.tag == "Bullet")
            {
                Bullet bullet = collision.gameObject.GetComponent<Bullet>();
                Damage(bullet, point);
            }
            DamageEmitter damageEmitter = collision.gameObject.GetComponent<DamageEmitter>();
            if(damageEmitter != null)
            {
                if(damageEmitter.character != character && damageEmitter.enabled == true)
                {
                    Damage(damageEmitter, point);
                }
                
            }
        }

        public void Damage(Bullet bullet, Vector3 point, DamagePoint damagePoint = null)
        {
            float damageMultiplier = 1f;
            if(damagePoint != null) damageMultiplier = damagePoint.damageMultiplier;
            // Don't damage the shooter
            if(bullet.character == character) return;
            // Each bullet only damages once
            for (int i = 0; i < bulletHits.Count; i++)
            {
                if(bulletHits[i] == bullet) return;
            }
            bulletHits.Add(bullet);
            StartCoroutine(Timer.Start(0.5f, false, () => { bulletHits.Remove(bullet); }));
            // Get firearm properties to calculate damage
            ItemBaseFirearm firearmItem = (ItemBaseFirearm)bullet.firearmRef.item;
            int firearmDamage = firearmItem.CalculateDamage(bullet.firearmRef, bullet.startPos, point);
            // Distance damage falloff calculation
            float travelDistance = Vector3.Distance(bullet.startPos, bullet.transform.position);
            if(travelDistance < firearmItem.minDistance) 
            {
                firearmDamage = (int)((float)firearmDamage * 1.25f);
            }
            else if(travelDistance > firearmItem.halfDistance)
            {
                float modifier = ((firearmItem.maxDistance - firearmItem.halfDistance)/100) * (travelDistance - firearmItem.halfDistance);
                firearmDamage = (int)((float)firearmDamage - (float)firearmDamage * modifier);
                if(firearmDamage < 0) firearmDamage = 0;
            } 
            else if(travelDistance > firearmItem.maxDistance) 
            {
                firearmDamage = 0;
            }
            // Critical Hit calculation
            bool criticalHit = false;
            float roll = Random.Range(0, 100);
            if(roll <= firearmItem.criticalChanceModifier) criticalHit = true;
            // Calculate damage
            int armorPiercing = bullet.firearmRef.ammoType.armorPiercing;
            int damage = CalculateDamage(firearmDamage, armorPiercing);
            if(criticalHit) damage = damage * 2;
            damage = Mathf.FloorToInt(damage * damageMultiplier);
            // Remove hitpoints and start events
            //if(damage == 0) return;
            hitPoints -= damage;
            GameObject obj = bullet.character.gameObject;
            DamageData damageData = new DamageData(this, damagePoint, damage, obj, bullet.character, bullet, null, point, bullet.startPos, hitPoints <= 0);
            DamageEvents.DamageEvent(damageData);
            if(character != null) 
            {
                character.Injury();
                if(hitPoints <= 0)
                {
                    character.Die();
                    DamageEvents.DeathEvent(this, bullet.character);
                }
            }
            SpawnHitFX(point);
            
        }

        public void Damage(DamageEmitter damageEmitter, Vector3 point, DamagePoint damagePoint = null)
        {
            int damage = CalculateDamage(damageEmitter.damage, damageEmitter.armorPiercing);
            hitPoints -= damage;
            GameObject obj = damageEmitter.character.gameObject;
            DamageData damageData = new DamageData(this, damagePoint, damage, obj, damageEmitter.character, null, damageEmitter, point, obj.transform.position, hitPoints <= 0);
            DamageEvents.DamageEvent(damageData);
            if(character != null) 
            {
                character.Injury();
                
                if(hitPoints <= 0)
                {
                    character.Die();
                    if(damageEmitter.character != null) DamageEvents.DeathEvent(this, damageEmitter.character);
                }
            }
            SpawnHitFX(point);
        }

        private int CalculateDamage(int baseDamage, int armorPiercing)
        {
            int defense = armor - armorPiercing;
            if(defense < 0) defense = 0;
            int damage = baseDamage - defense;
            if(damage < 0) damage = 0;
            return damage;
        }
    
        private void SpawnHitFX(Vector3 position)
        {
            //if(hitPrefab == null) return;
            //var prefab = Instantiate(hitPrefab, position, transform.rotation) as GameObject;
            MasterObjectPooler.Instance.GetPool(hitFxName).GetObject(position, transform.rotation);
        }
    
        public void Heal(int value)
        {
            if(hitPoints + value < maxHitPoints) hitPoints += value;
            else 
            {
                value = maxHitPoints - hitPoints;
                hitPoints = maxHitPoints;
            }
            DamageEvents.HealEvent(this, value);
        }

        public void SetHP(int value) => hitPoints = value;
        public void SetMaxHP(int value) => maxHitPoints = value;
        public void SetArmor(int value) => armorPoints = value;
    }
}