BITFALL/Assets/Artists/Scripts/BulletService/BulletService.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using BITFALL.Bullet;
using UnityEngine;
using BITKit;
using BITKit.Core.Entites;
using BITKit.Entities;
using Cysharp.Threading.Tasks;
using UnityEditor;
using UnityEngine.Animations;
using UnityEngine.UIElements;

namespace BITFALL
{
    [Serializable]
    public record InstanceBullet : SpawnBullet
    {
        public Vector3 currentPos;
        public float currentSpeed = 64;
        public float ElapsedTime; 
        public BITBullet model;
    }
    [Serializable]
    public class BulletServiceSingleton : IBulletService
    {
            public void Spawn(SpawnBullet bullet)=>BulletService.Spawn?.Invoke(bullet);
    }
    public class BulletService : MonoBehaviour, IBulletService
    {
        public static Action<SpawnBullet> Spawn;
        
        [Header(Constant.Header.Settings)]
        public LayerMask layerMask;

        [Header(Constant.Header.Providers)]
        [SerializeField, SerializeReference, SubclassSelector]
        private IEntitiesService entitiesService;
        [SerializeField, SerializeReference, SubclassSelector]
        private INetProvider netProvider;
        [SerializeField, SerializeReference, SubclassSelector]
        private IDamageService damageService;
        
        [Header(Constant.Header.Settings)]
        [SerializeField] private UnityPool<BITBullet> pool = new();
        
        [Header(Constant.Header.InternalVariables)]
        private readonly List<InstanceBullet> instances = new();
        private readonly RaycastHit[] _raycastHits = new RaycastHit[16];
        private void Start()
        {
            Spawn += SpawnBullet;
        }
        private void OnDestroy()
        {
            Spawn -= SpawnBullet;
        }
        private void FixedUpdate()
        {
            foreach (var bullet in instances.ToArray())
            {
                var size = Physics.RaycastNonAlloc(bullet.currentPos, bullet.forward, _raycastHits, bullet.currentSpeed * Time.fixedDeltaTime, layerMask);
                var validHit = false;
                foreach (var raycastHit in _raycastHits.Take(size).OrderBy(x => Vector3.Distance(bullet.pos, x.point)))
                {
                    if (!IsValidHit(raycastHit, bullet))
                        continue;
                    validHit = true;
                    break;
                }

                if (validHit ||bullet.currentSpeed <= 0)
                {
                    instances.TryRemove(bullet);
                    pool.Return(bullet.model);
                }
                else
                {
                    // 计算子弹的下坠距离
                    float distance = 0.5f * Physics.gravity.y * bullet.ElapsedTime * bullet.ElapsedTime;
                    
                    bullet.currentSpeed -= bullet.startSpeed * Time.fixedDeltaTime;
                    bullet.currentPos += (Vector3)bullet.forward * (bullet.currentSpeed * Time.fixedDeltaTime);
                    bullet.currentPos += Vector3.up * distance;
                    bullet.model.transform.position = bullet.currentPos;
                    
                    bullet.ElapsedTime += Time.fixedDeltaTime;
                }
            }
        }
        private async void RpcSpawnBullet(SpawnBullet x)
        {
            await UniTask.SwitchToMainThread();
            var instance = pool.Get();
            InstanceBullet bullet = new()
            {
                initiator = x.initiator,
                currentPos = x.pos,
                pos = x.pos,
                rot = x.rot,
                forward = x.forward,
                initialDamage = x.initialDamage,
                model = instance,
                InitialForce = x.InitialForce,
            };
            var instanceTransform = instance.transform;
            instanceTransform.SetPositionAndRotation(x.pos, x.rot);
            instanceTransform.forward = x.forward;
            instances.Add(bullet);
        }
        private void SpawnBullet(SpawnBullet x)
        {
            RpcSpawnBullet(x);
        }

        private bool IsValidHit(RaycastHit raycastHit, InstanceBullet bullet)
        {
            if (layerMask.Includes(raycastHit.collider.gameObject.layer) is false) return false;
            raycastHit.collider.TryGetComponentAny<IPhysicsInfo>(out var physicsInfo);
            var force = (raycastHit.point - (Vector3)bullet.pos).normalized * (physicsInfo?.AddForceMultiple ?? 64);
            if (raycastHit.collider.TryGetComponent<IDamagable>(out var damagable))
            {
                if (damagable.Entity.Id == bullet.initiator) return false;
                if (layerMask.Includes(raycastHit.collider.gameObject.layer) is false) return false;
                var msg = new DamageMessage()
                {
                    Target = damagable.Entity,
                    Hit = damagable,
                    Damage = bullet.initialDamage,
                };
                damageService.Execute(msg);
            }

            var _rigidbody = (raycastHit.rigidbody,damagable?.Rigidbody) switch
            {
                (null, null) => null,
                (null, not null) => damagable?.Rigidbody,
                (not null, null) => raycastHit.rigidbody,
                (not null, not null) => damagable?.Rigidbody,
            };
            if (_rigidbody is not null && _rigidbody.gameObject.layer is not 0)
            {
                _rigidbody.AddForceAtPositionAsync(force, raycastHit.point, ForceMode.Impulse).Forget();
            }
           

            List<string> tags = new()
            {
                "BulletHit",
            };
            if (raycastHit.transform.TryGetComponent<ITag>(out var _tag))
            {
                tags.AddRange(_tag.GetTags());
            }

            Location location = new()
            {
                position = raycastHit.point,
                forward = raycastHit.normal,
            };
            var vfx = DI.Get<VFXService>().Spawn(location, tags.ToArray());
            var constraint = vfx.gameObject.GetOrAddComponent<ParentConstraint>();
            var sourceTransform = raycastHit.transform;
            while (constraint.sourceCount>0)
            {
                constraint.RemoveSource(0);
            }
            constraint.AddSource(new ConstraintSource()
            {
                sourceTransform = sourceTransform,
                weight = 1,
            });

            var positionOffset = sourceTransform.InverseTransformPoint(raycastHit.point);
            var rotationOffset = Quaternion.Inverse(sourceTransform.rotation) * transform.rotation;

            constraint.SetTranslationOffset(0, positionOffset);
            //constraint.SetRotationOffset(0, rotationOffset.eulerAngles);

            constraint.weight = 1;
            constraint.constraintActive = true;
            return true;
        }

        void IBulletService.Spawn(SpawnBullet bullet) => SpawnBullet(bullet);
    }
}