trigger enter monitor system

DamageOnTriggerEnterSystem.cs

using CyberSnake.ECS.Authoring;
using CyberSnake.ECS.ComponentData;
using Unity.Burst;
using Unity.Collections;
using Unity.Entities;
using Unity.Physics;

namespace CyberSnake.ECS.Systems
{
    [UpdateInGroup(typeof(FixedStepSimulationSystemGroup))]
    [BurstCompile]
    public partial struct DamageOnTriggerEnterSystem : ISystem
    {
        private ComponentLookup<DamageOnTriggerEnter> _damageGiver;
        private ComponentLookup<MaxHealth> _damageReceiver;

        [BurstCompile]
        public void OnCreate(ref SystemState state)
        {
            state.RequireForUpdate<BeginSimulationEntityCommandBufferSystem.Singleton>();
            state.RequireForUpdate<SimulationSingleton>();
            state.RequireForUpdate<DamageOnTriggerEnter>();

            _damageGiver = state.GetComponentLookup<DamageOnTriggerEnter>(true);
            _damageReceiver = state.GetComponentLookup<MaxHealth>(true);
        }

        [BurstCompile]
        public void OnUpdate(ref SystemState state)
        {
            _damageReceiver.Update(ref state);
            _damageGiver.Update(ref state);
            var ecbSingleton = SystemAPI.GetSingleton<BeginSimulationEntityCommandBufferSystem.Singleton>();
            var ecb = ecbSingleton.CreateCommandBuffer(state.WorldUnmanaged);
            var simulationSingleton = SystemAPI.GetSingleton<SimulationSingleton>();

            var jobHandle = new ApplyDamageJob
            {
                CommandBuffer = ecb,
                DamageGiver = _damageGiver,
                DamageReceiver = _damageReceiver
            }.Schedule(simulationSingleton, state.Dependency);
            jobHandle.Complete();
        }

        [BurstCompile]
        public struct ApplyDamageJob : ITriggerEventsJob
        {
            [ReadOnly] public ComponentLookup<DamageOnTriggerEnter> DamageGiver;
            [ReadOnly] public ComponentLookup<MaxHealth> DamageReceiver;
            public EntityCommandBuffer CommandBuffer;

            [BurstCompile]
            public void Execute(TriggerEvent triggerEvent)
            {
                var entityA = triggerEvent.EntityA;
                var entityB = triggerEvent.EntityB;

                DamageOnTriggerEnter giver;
                if (DamageGiver.TryGetComponent(entityA, out giver) && DamageReceiver.HasComponent(entityB))
                {
                    CommandBuffer.AddComponent(entityB, new ComponentData.Damage { Value = giver.Damage });
                    CommandBuffer.AddComponent(entityA, new TriggerEnteredTag());
                }

                if (DamageGiver.TryGetComponent(entityB, out giver) && DamageReceiver.HasComponent(entityA))
                {
                    CommandBuffer.AddComponent(entityA, new ComponentData.Damage { Value = giver.Damage });
                    CommandBuffer.AddComponent(entityB, new TriggerEnteredTag());
                }
            }
        }
    }
}