NPCLoader.cs

Go to the documentation of this file.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using Terraria.GameContent.UI;
using Terraria.ID;
using Terraria.Localization;

namespace Terraria.ModLoader
{
    //todo: further documentation
    public static class NPCLoader
    {
        internal static bool loaded = false;
        private static int nextNPC = NPCID.Count;
        internal static readonly IList<ModNPC> npcs = new List<ModNPC>();
        internal static readonly IList<GlobalNPC> globalNPCs = new List<GlobalNPC>();
        internal static GlobalNPC[] InstancedGlobals = new GlobalNPC[0];
        internal static readonly IDictionary<string, int> globalIndexes = new Dictionary<string, int>();
        internal static readonly IDictionary<Type, int> globalIndexesByType = new Dictionary<Type, int>();
        internal static readonly IDictionary<int, int> bannerToItem = new Dictionary<int, int>();
        private static int vanillaSkeletonCount = NPCID.Sets.Skeletons.Count;
        private static readonly int[] shopToNPC = new int[Main.MaxShopIDs - 1];
        public static readonly IList<int> blockLoot = new List<int>();

        private class HookList
        {
            public GlobalNPC[] arr = new GlobalNPC[0];
            public readonly MethodInfo method;

            public HookList(MethodInfo method) {
                this.method = method;
            }
        }

        private static List<HookList> hooks = new List<HookList>();

        private static HookList AddHook<F>(Expression<Func<GlobalNPC, F>> func) {
            var hook = new HookList(ModLoader.Method(func));
            hooks.Add(hook);
            return hook;
        }

        static NPCLoader() {
            shopToNPC[1] = NPCID.Merchant;
            shopToNPC[2] = NPCID.ArmsDealer;
            shopToNPC[3] = NPCID.Dryad;
            shopToNPC[4] = NPCID.Demolitionist;
            shopToNPC[5] = NPCID.Clothier;
            shopToNPC[6] = NPCID.GoblinTinkerer;
            shopToNPC[7] = NPCID.Wizard;
            shopToNPC[8] = NPCID.Mechanic;
            shopToNPC[9] = NPCID.SantaClaus;
            shopToNPC[10] = NPCID.Truffle;
            shopToNPC[11] = NPCID.Steampunker;
            shopToNPC[12] = NPCID.DyeTrader;
            shopToNPC[13] = NPCID.PartyGirl;
            shopToNPC[14] = NPCID.Cyborg;
            shopToNPC[15] = NPCID.Painter;
            shopToNPC[16] = NPCID.WitchDoctor;
            shopToNPC[17] = NPCID.Pirate;
            shopToNPC[18] = NPCID.Stylist;
            shopToNPC[19] = NPCID.TravellingMerchant;
            shopToNPC[20] = NPCID.SkeletonMerchant;
            shopToNPC[21] = NPCID.DD2Bartender;
        }

        internal static int ReserveNPCID() {
            if (ModNet.AllowVanillaClients) throw new Exception("Adding npcs breaks vanilla client compatibility");

            int reserveID = nextNPC;
            nextNPC++;
            return reserveID;
        }

        public static int NPCCount => nextNPC;

        public static ModNPC GetNPC(int type) {
            return type >= NPCID.Count && type < NPCCount ? npcs[type - NPCID.Count] : null;
        }
        //change initial size of Terraria.Player.npcTypeNoAggro and NPCBannerBuff to NPCLoader.NPCCount()
        //in Terraria.Main.MouseText replace 251 with NPCLoader.NPCCount()
        //in Terraria.Main.DrawNPCs and Terraria.NPC.NPCLoot remove type too high check
        //replace a lot of 540 immediates
        //in Terraria.GameContent.UI.EmoteBubble make CountNPCs internal
        internal static void ResizeArrays(bool unloading) {
            Array.Resize(ref Main.NPCLoaded, nextNPC);
            Array.Resize(ref Main.townNPCCanSpawn, nextNPC);
            Array.Resize(ref Main.slimeRainNPC, nextNPC);
            Array.Resize(ref Main.npcTexture, nextNPC);
            Array.Resize(ref Main.npcAltTextures, nextNPC);
            Array.Resize(ref Main.npcCatchable, nextNPC);
            Array.Resize(ref Main.npcFrameCount, nextNPC);
            Array.Resize(ref NPC.killCount, nextNPC);
            Array.Resize(ref NPC.npcsFoundForCheckActive, nextNPC);
            Array.Resize(ref Lang._npcNameCache, nextNPC);
            Array.Resize(ref EmoteBubble.CountNPCs, nextNPC);
            Array.Resize(ref WorldGen.TownManager._hasRoom, nextNPC);
            Array.Resize(ref NPCID.Sets.TrailingMode, nextNPC);
            Array.Resize(ref NPCID.Sets.BelongsToInvasionOldOnesArmy, nextNPC);
            Array.Resize(ref NPCID.Sets.TeleportationImmune, nextNPC);
            Array.Resize(ref NPCID.Sets.UsesNewTargetting, nextNPC);
            Array.Resize(ref NPCID.Sets.FighterUsesDD2PortalAppearEffect, nextNPC);
            Array.Resize(ref NPCID.Sets.StatueSpawnedDropRarity, nextNPC);
            Array.Resize(ref NPCID.Sets.NoEarlymodeLootWhenSpawnedFromStatue, nextNPC);
            Array.Resize(ref NPCID.Sets.NeedsExpertScaling, nextNPC);
            Array.Resize(ref NPCID.Sets.ProjectileNPC, nextNPC);
            Array.Resize(ref NPCID.Sets.SavesAndLoads, nextNPC);
            Array.Resize(ref NPCID.Sets.TrailCacheLength, nextNPC);
            Array.Resize(ref NPCID.Sets.MPAllowedEnemies, nextNPC);
            Array.Resize(ref NPCID.Sets.TownCritter, nextNPC);
            Array.Resize(ref NPCID.Sets.HatOffsetY, nextNPC);
            Array.Resize(ref NPCID.Sets.FaceEmote, nextNPC);
            Array.Resize(ref NPCID.Sets.ExtraFramesCount, nextNPC);
            Array.Resize(ref NPCID.Sets.AttackFrameCount, nextNPC);
            Array.Resize(ref NPCID.Sets.DangerDetectRange, nextNPC);
            Array.Resize(ref NPCID.Sets.AttackTime, nextNPC);
            Array.Resize(ref NPCID.Sets.AttackAverageChance, nextNPC);
            Array.Resize(ref NPCID.Sets.AttackType, nextNPC);
            Array.Resize(ref NPCID.Sets.PrettySafe, nextNPC);
            Array.Resize(ref NPCID.Sets.MagicAuraColor, nextNPC);
            Array.Resize(ref NPCID.Sets.BossHeadTextures, nextNPC);
            Array.Resize(ref NPCID.Sets.ExcludedFromDeathTally, nextNPC);
            Array.Resize(ref NPCID.Sets.TechnicallyABoss, nextNPC);
            Array.Resize(ref NPCID.Sets.MustAlwaysDraw, nextNPC);
            Array.Resize(ref NPCID.Sets.ExtraTextureCount, nextNPC);
            Array.Resize(ref NPCID.Sets.NPCFramingGroup, nextNPC);
            Array.Resize(ref NPCID.Sets.TownNPCsFramingGroups, nextNPC);
            for (int k = NPCID.Count; k < nextNPC; k++) {
                Main.NPCLoaded[k] = true;
                Main.npcFrameCount[k] = 1;
                Lang._npcNameCache[k] = LocalizedText.Empty;
                NPCID.Sets.TrailingMode[k] = -1;
                NPCID.Sets.StatueSpawnedDropRarity[k] = -1f;
                NPCID.Sets.TrailCacheLength[k] = 10;
                NPCID.Sets.DangerDetectRange[k] = -1;
                NPCID.Sets.AttackTime[k] = -1;
                NPCID.Sets.AttackAverageChance[k] = 1;
                NPCID.Sets.AttackType[k] = -1;
                NPCID.Sets.PrettySafe[k] = -1;
                NPCID.Sets.MagicAuraColor[k] = Color.White;
                NPCID.Sets.BossHeadTextures[k] = -1;
            }

            InstancedGlobals = globalNPCs.Where(g => g.InstancePerEntity).ToArray();
            for (int i = 0; i < InstancedGlobals.Length; i++) {
                InstancedGlobals[i].instanceIndex = i;
            }
            foreach (var hook in hooks) {
                hook.arr = ModLoader.BuildGlobalHook(globalNPCs, hook.method);
            }

            if (!unloading) {
                loaded = true;
            }
        }

        internal static void Unload() {
            loaded = false;
            npcs.Clear();
            nextNPC = NPCID.Count;
            globalNPCs.Clear();
            globalIndexes.Clear();
            globalIndexesByType.Clear();
            bannerToItem.Clear();
            while (NPCID.Sets.Skeletons.Count > vanillaSkeletonCount) {
                NPCID.Sets.Skeletons.RemoveAt(NPCID.Sets.Skeletons.Count - 1);
            }
        }

        internal static bool IsModNPC(NPC npc) {
            return npc.type >= NPCID.Count;
        }

        private static HookList HookSetDefaults = AddHook<Action<NPC>>(g => g.SetDefaults);

        internal static void SetDefaults(NPC npc, bool createModNPC = true) {
            if (IsModNPC(npc)) {
                if (createModNPC) {
                    npc.modNPC = GetNPC(npc.type).NewInstance(npc);
                }
                else //the default NPCs created and bound to ModNPCs are initialized before ResizeArrays. They come here during SetupContent.
                {
                    Array.Resize(ref npc.buffImmune, BuffLoader.BuffCount);
                }
            }
            npc.globalNPCs = InstancedGlobals.Select(g => g.NewInstance(npc)).ToArray();
            npc.modNPC?.SetDefaults();
            foreach (GlobalNPC g in HookSetDefaults.arr) {
                g.Instance(npc).SetDefaults(npc);
            }
        }

        internal static GlobalNPC GetGlobalNPC(NPC npc, Mod mod, string name) {
            int index;
            return globalIndexes.TryGetValue(mod.Name + ':' + name, out index) ? globalNPCs[index].Instance(npc) : null;
        }

        internal static GlobalNPC GetGlobalNPC(NPC npc, Type type) {
            int index;
            return globalIndexesByType.TryGetValue(type, out index) ? (index > -1 ? globalNPCs[index].Instance(npc) : null) : null;
        }

        private static HookList HookScaleExpertStats = AddHook<Action<NPC, int, float>>(g => g.ScaleExpertStats);

        public static void ScaleExpertStats(NPC npc, int numPlayers, float bossLifeScale) {
            npc.modNPC?.ScaleExpertStats(numPlayers, bossLifeScale);

            foreach (GlobalNPC g in HookScaleExpertStats.arr) {
                g.Instance(npc).ScaleExpertStats(npc, numPlayers, bossLifeScale);
            }
        }

        private static HookList HookResetEffects = AddHook<Action<NPC>>(g => g.ResetEffects);

        public static void ResetEffects(NPC npc) {
            npc.modNPC?.ResetEffects();

            foreach (GlobalNPC g in HookResetEffects.arr) {
                g.Instance(npc).ResetEffects(npc);
            }
        }

        public static void NPCAI(NPC npc) {
            if (PreAI(npc)) {
                int type = npc.type;
                bool useAiType = npc.modNPC != null && npc.modNPC.aiType > 0;
                if (useAiType) {
                    npc.type = npc.modNPC.aiType;
                }
                npc.VanillaAI();
                if (useAiType) {
                    npc.type = type;
                }
                AI(npc);
            }
            PostAI(npc);
        }

        private static HookList HookPreAI = AddHook<Func<NPC, bool>>(g => g.PreAI);

        public static bool PreAI(NPC npc) {
            bool result = true;
            foreach (GlobalNPC g in HookPreAI.arr) {
                result &= g.Instance(npc).PreAI(npc);
            }
            if (result && npc.modNPC != null) {
                return npc.modNPC.PreAI();
            }
            return result;
        }

        private static HookList HookAI = AddHook<Action<NPC>>(g => g.AI);

        public static void AI(NPC npc) {
            npc.modNPC?.AI();

            foreach (GlobalNPC g in HookAI.arr) {
                g.Instance(npc).AI(npc);
            }
        }

        private static HookList HookPostAI = AddHook<Action<NPC>>(g => g.PostAI);

        public static void PostAI(NPC npc) {
            npc.modNPC?.PostAI();

            foreach (GlobalNPC g in HookPostAI.arr) {
                g.Instance(npc).PostAI(npc);
            }
        }

        public static void SendExtraAI(NPC npc, BinaryWriter writer) {
            if (npc.modNPC != null) {
                byte[] data;
                using (MemoryStream stream = new MemoryStream()) {
                    using (BinaryWriter modWriter = new BinaryWriter(stream)) {
                        npc.modNPC.SendExtraAI(modWriter);
                        modWriter.Flush();
                        data = stream.ToArray();
                    }
                }
                writer.Write((byte)data.Length);
                if (data.Length > 0) {
                    writer.Write(data);
                }
            }
        }

        public static void ReceiveExtraAI(NPC npc, BinaryReader reader) {
            if (npc.modNPC != null) {
                byte[] extraAI = reader.ReadBytes(reader.ReadByte());
                if (extraAI.Length > 0) {
                    using (MemoryStream stream = new MemoryStream(extraAI)) {
                        using (BinaryReader modReader = new BinaryReader(stream)) {
                            npc.modNPC.ReceiveExtraAI(modReader);
                        }
                    }
                }
            }
        }

        private static HookList HookFindFrame = AddHook<Action<NPC, int>>(g => g.FindFrame);

        public static void FindFrame(NPC npc, int frameHeight) {
            int type = npc.type;
            if (npc.modNPC != null && npc.modNPC.animationType > 0) {
                npc.type = npc.modNPC.animationType;
            }
            npc.VanillaFindFrame(frameHeight);
            npc.type = type;
            npc.modNPC?.FindFrame(frameHeight);

            foreach (GlobalNPC g in HookFindFrame.arr) {
                g.Instance(npc).FindFrame(npc, frameHeight);
            }
        }

        private static HookList HookHitEffect = AddHook<Action<NPC, int, double>>(g => g.HitEffect);

        public static void HitEffect(NPC npc, int hitDirection, double damage) {
            npc.VanillaHitEffect(hitDirection, damage);
            npc.modNPC?.HitEffect(hitDirection, damage);

            foreach (GlobalNPC g in HookHitEffect.arr) {
                g.Instance(npc).HitEffect(npc, hitDirection, damage);
            }
        }

        private delegate void DelegateUpdateLifeRegen(NPC npc, ref int damage);
        private static HookList HookUpdateLifeRegen = AddHook<DelegateUpdateLifeRegen>(g => g.UpdateLifeRegen);

        public static void UpdateLifeRegen(NPC npc, ref int damage) {
            npc.modNPC?.UpdateLifeRegen(ref damage);

            foreach (GlobalNPC g in HookUpdateLifeRegen.arr) {
                g.Instance(npc).UpdateLifeRegen(npc, ref damage);
            }
        }

        private static HookList HookCheckActive = AddHook<Func<NPC, bool>>(g => g.CheckActive);

        public static bool CheckActive(NPC npc) {
            if (npc.modNPC != null && !npc.modNPC.CheckActive()) {
                return false;
            }
            foreach (GlobalNPC g in HookCheckActive.arr) {
                if (!g.Instance(npc).CheckActive(npc)) {
                    return false;
                }
            }
            return true;
        }

        private static HookList HookCheckDead = AddHook<Func<NPC, bool>>(g => g.CheckDead);

        public static bool CheckDead(NPC npc) {
            bool result = true;

            if (npc.modNPC != null) {
                result = npc.modNPC.CheckDead();
            }

            foreach (GlobalNPC g in HookCheckDead.arr) {
                result &= g.Instance(npc).CheckDead(npc);
            }

            return result;
        }

        private static HookList HookSpecialNPCLoot = AddHook<Func<NPC, bool>>(g => g.SpecialNPCLoot);

        public static bool SpecialNPCLoot(NPC npc) {
            foreach (GlobalNPC g in HookSpecialNPCLoot.arr) {
                if (g.Instance(npc).SpecialNPCLoot(npc)) {
                    return true;
                }
            }
            if (npc.modNPC != null) {
                return npc.modNPC.SpecialNPCLoot();
            }
            return false;
        }

        private static HookList HookPreNPCLoot = AddHook<Func<NPC, bool>>(g => g.PreNPCLoot);

        public static bool PreNPCLoot(NPC npc) {
            bool result = true;
            foreach (GlobalNPC g in HookPreNPCLoot.arr) {
                result &= g.Instance(npc).PreNPCLoot(npc);
            }

            if (result && npc.modNPC != null) {
                result = npc.modNPC.PreNPCLoot();
            }

            if (!result) {
                blockLoot.Clear();
                return false;
            }

            return true;
        }

        private static HookList HookNPCLoot = AddHook<Action<NPC>>(g => g.NPCLoot);

        public static void NPCLoot(NPC npc) {
            npc.modNPC?.NPCLoot();

            foreach (GlobalNPC g in HookNPCLoot.arr) {
                g.Instance(npc).NPCLoot(npc);
            }
            blockLoot.Clear();
        }

        public static void BossLoot(NPC npc, ref string name, ref int potionType) {
            npc.modNPC?.BossLoot(ref name, ref potionType);
        }

        public static void BossBag(NPC npc, ref int bagType) {
            if (npc.modNPC != null) {
                bagType = npc.modNPC.bossBag;
            }
        }

        private static HookList HookOnCatchNPC = AddHook<Action<NPC, Player, Item>>(g => g.OnCatchNPC);

        public static void OnCatchNPC(NPC npc, Player player, Item item) {
            npc.modNPC?.OnCatchNPC(player, item);

            foreach (GlobalNPC g in HookOnCatchNPC.arr) {
                g.Instance(npc).OnCatchNPC(npc, player, item);
            }
        }

        private delegate bool DelegateCanHitPlayer(NPC npc, Player target, ref int cooldownSlot);
        private static HookList HookCanHitPlayer = AddHook<DelegateCanHitPlayer>(g => g.CanHitPlayer);

        public static bool CanHitPlayer(NPC npc, Player target, ref int cooldownSlot) {
            foreach (GlobalNPC g in HookCanHitPlayer.arr) {
                if (!g.Instance(npc).CanHitPlayer(npc, target, ref cooldownSlot)) {
                    return false;
                }
            }
            if (npc.modNPC != null) {
                return npc.modNPC.CanHitPlayer(target, ref cooldownSlot);
            }
            return true;
        }

        private delegate void DelegateModifyHitPlayer(NPC npc, Player target, ref int damage, ref bool crit);
        private static HookList HookModifyHitPlayer = AddHook<DelegateModifyHitPlayer>(g => g.ModifyHitPlayer);

        public static void ModifyHitPlayer(NPC npc, Player target, ref int damage, ref bool crit) {
            npc.modNPC?.ModifyHitPlayer(target, ref damage, ref crit);

            foreach (GlobalNPC g in HookModifyHitPlayer.arr) {
                g.Instance(npc).ModifyHitPlayer(npc, target, ref damage, ref crit);
            }
        }

        private static HookList HookOnHitPlayer = AddHook<Action<NPC, Player, int, bool>>(g => g.OnHitPlayer);

        public static void OnHitPlayer(NPC npc, Player target, int damage, bool crit) {
            npc.modNPC?.OnHitPlayer(target, damage, crit);

            foreach (GlobalNPC g in HookOnHitPlayer.arr) {
                g.Instance(npc).OnHitPlayer(npc, target, damage, crit);
            }
        }

        private static HookList HookCanHitNPC = AddHook<Func<NPC, NPC, bool?>>(g => g.CanHitNPC);

        public static bool? CanHitNPC(NPC npc, NPC target) {
            bool? flag = null;
            foreach (GlobalNPC g in HookCanHitNPC.arr) {
                bool? canHit = g.Instance(npc).CanHitNPC(npc, target);
                if (canHit.HasValue && !canHit.Value) {
                    return false;
                }
                if (canHit.HasValue) {
                    flag = canHit.Value;
                }
            }
            if (npc.modNPC != null) {
                bool? canHit = npc.modNPC.CanHitNPC(target);
                if (canHit.HasValue && !canHit.Value) {
                    return false;
                }
                if (canHit.HasValue) {
                    flag = canHit.Value;
                }
            }
            return flag;
        }

        private delegate void DelegateModifyHitNPC(NPC npc, NPC target, ref int damage, ref float knockback, ref bool crit);
        private static HookList HookModifyHitNPC = AddHook<DelegateModifyHitNPC>(g => g.ModifyHitNPC);

        public static void ModifyHitNPC(NPC npc, NPC target, ref int damage, ref float knockback, ref bool crit) {
            npc.modNPC?.ModifyHitNPC(target, ref damage, ref knockback, ref crit);

            foreach (GlobalNPC g in HookModifyHitNPC.arr) {
                g.Instance(npc).ModifyHitNPC(npc, target, ref damage, ref knockback, ref crit);
            }
        }

        private static HookList HookOnHitNPC = AddHook<Action<NPC, NPC, int, float, bool>>(g => g.OnHitNPC);

        public static void OnHitNPC(NPC npc, NPC target, int damage, float knockback, bool crit) {
            npc.modNPC?.OnHitNPC(target, damage, knockback, crit);
            foreach (GlobalNPC g in HookOnHitNPC.arr) {
                g.Instance(npc).OnHitNPC(npc, target, damage, knockback, crit);
            }
        }

        private static HookList HookCanBeHitByItem = AddHook<Func<NPC, Player, Item, bool?>>(g => g.CanBeHitByItem);

        public static bool? CanBeHitByItem(NPC npc, Player player, Item item) {
            bool? flag = null;
            foreach (GlobalNPC g in HookCanBeHitByItem.arr) {
                bool? canHit = g.Instance(npc).CanBeHitByItem(npc, player, item);
                if (canHit.HasValue && !canHit.Value) {
                    return false;
                }
                if (canHit.HasValue) {
                    flag = canHit.Value;
                }
            }
            if (npc.modNPC != null) {
                bool? canHit = npc.modNPC.CanBeHitByItem(player, item);
                if (canHit.HasValue && !canHit.Value) {
                    return false;
                }
                if (canHit.HasValue) {
                    flag = canHit.Value;
                }
            }
            return flag;
        }

        private delegate void DelegateModifyHitByItem(NPC npc, Player player, Item item, ref int damage, ref float knockback, ref bool crit);
        private static HookList HookModifyHitByItem = AddHook<DelegateModifyHitByItem>(g => g.ModifyHitByItem);

        public static void ModifyHitByItem(NPC npc, Player player, Item item, ref int damage, ref float knockback, ref bool crit) {
            npc.modNPC?.ModifyHitByItem(player, item, ref damage, ref knockback, ref crit);

            foreach (GlobalNPC g in HookModifyHitByItem.arr) {
                g.Instance(npc).ModifyHitByItem(npc, player, item, ref damage, ref knockback, ref crit);
            }
        }

        private static HookList HookOnHitByItem = AddHook<Action<NPC, Player, Item, int, float, bool>>(g => g.OnHitByItem);

        public static void OnHitByItem(NPC npc, Player player, Item item, int damage, float knockback, bool crit) {
            npc.modNPC?.OnHitByItem(player, item, damage, knockback, crit);

            foreach (GlobalNPC g in HookOnHitByItem.arr) {
                g.Instance(npc).OnHitByItem(npc, player, item, damage, knockback, crit);
            }
        }

        private static HookList HookCanBeHitByProjectile = AddHook<Func<NPC, Projectile, bool?>>(g => g.CanBeHitByProjectile);

        public static bool? CanBeHitByProjectile(NPC npc, Projectile projectile) {
            bool? flag = null;
            foreach (GlobalNPC g in HookCanBeHitByProjectile.arr) {
                bool? canHit = g.Instance(npc).CanBeHitByProjectile(npc, projectile);
                if (canHit.HasValue && !canHit.Value) {
                    return false;
                }
                if (canHit.HasValue) {
                    flag = canHit.Value;
                }
            }
            if (npc.modNPC != null) {
                bool? canHit = npc.modNPC.CanBeHitByProjectile(projectile);
                if (canHit.HasValue && !canHit.Value) {
                    return false;
                }
                if (canHit.HasValue) {
                    flag = canHit.Value;
                }
            }
            return flag;
        }

        private delegate void DelegateModifyHitByProjectile(NPC npc, Projectile projectile, ref int damage, ref float knockback, ref bool crit, ref int hitDirection);
        private static HookList HookModifyHitByProjectile = AddHook<DelegateModifyHitByProjectile>(g => g.ModifyHitByProjectile);

        public static void ModifyHitByProjectile(NPC npc, Projectile projectile, ref int damage, ref float knockback, ref bool crit, ref int hitDirection) {
            npc.modNPC?.ModifyHitByProjectile(projectile, ref damage, ref knockback, ref crit, ref hitDirection);

            foreach (GlobalNPC g in HookModifyHitByProjectile.arr) {
                g.Instance(npc).ModifyHitByProjectile(npc, projectile, ref damage, ref knockback, ref crit, ref hitDirection);
            }
        }

        private static HookList HookOnHitByProjectile = AddHook<Action<NPC, Projectile, int, float, bool>>(g => g.OnHitByProjectile);

        public static void OnHitByProjectile(NPC npc, Projectile projectile, int damage, float knockback, bool crit) {
            npc.modNPC?.OnHitByProjectile(projectile, damage, knockback, crit);

            foreach (GlobalNPC g in HookOnHitByProjectile.arr) {
                g.Instance(npc).OnHitByProjectile(npc, projectile, damage, knockback, crit);
            }
        }

        private delegate bool DelegateStrikeNPC(NPC npc, ref double damage, int defense, ref float knockback, int hitDirection, ref bool crit);
        private static HookList HookStrikeNPC = AddHook<DelegateStrikeNPC>(g => g.StrikeNPC);

        public static bool StrikeNPC(NPC npc, ref double damage, int defense, ref float knockback, int hitDirection, ref bool crit) {
            bool flag = true;
            if (npc.modNPC != null) {
                flag = npc.modNPC.StrikeNPC(ref damage, defense, ref knockback, hitDirection, ref crit);
            }
            foreach (GlobalNPC g in HookStrikeNPC.arr) {
                if (!g.Instance(npc).StrikeNPC(npc, ref damage, defense, ref knockback, hitDirection, ref crit)) {
                    flag = false;
                }
            }
            return flag;
        }

        private delegate void DelegateBossHeadSlot(NPC npc, ref int index);
        private static HookList HookBossHeadSlot = AddHook<DelegateBossHeadSlot>(g => g.BossHeadSlot);

        public static void BossHeadSlot(NPC npc, ref int index) {
            npc.modNPC?.BossHeadSlot(ref index);

            foreach (GlobalNPC g in HookBossHeadSlot.arr) {
                g.Instance(npc).BossHeadSlot(npc, ref index);
            }
        }

        private delegate void DelegateBossHeadRotation(NPC npc, ref float rotation);
        private static HookList HookBossHeadRotation = AddHook<DelegateBossHeadRotation>(g => g.BossHeadRotation);

        public static void BossHeadRotation(NPC npc, ref float rotation) {
            npc.modNPC?.BossHeadRotation(ref rotation);

            foreach (GlobalNPC g in HookBossHeadRotation.arr) {
                g.Instance(npc).BossHeadRotation(npc, ref rotation);
            }
        }

        private delegate void DelegateBossHeadSpriteEffects(NPC npc, ref SpriteEffects spriteEffects);
        private static HookList HookBossHeadSpriteEffects = AddHook<DelegateBossHeadSpriteEffects>(g => g.BossHeadSpriteEffects);

        public static void BossHeadSpriteEffects(NPC npc, ref SpriteEffects spriteEffects) {
            npc.modNPC?.BossHeadSpriteEffects(ref spriteEffects);

            foreach (GlobalNPC g in HookBossHeadSpriteEffects.arr) {
                g.Instance(npc).BossHeadSpriteEffects(npc, ref spriteEffects);
            }
        }

        private static HookList HookGetAlpha = AddHook<Func<NPC, Color, Color?>>(g => g.GetAlpha);

        public static Color? GetAlpha(NPC npc, Color lightColor) {
            foreach (GlobalNPC g in HookGetAlpha.arr) {
                Color? color = g.Instance(npc).GetAlpha(npc, lightColor);
                if (color.HasValue) {
                    return color.Value;
                }
            }
            return npc.modNPC?.GetAlpha(lightColor);
        }

        private delegate void DelegateDrawEffects(NPC npc, ref Color drawColor);
        private static HookList HookDrawEffects = AddHook<DelegateDrawEffects>(g => g.DrawEffects);

        public static void DrawEffects(NPC npc, ref Color drawColor) {
            npc.modNPC?.DrawEffects(ref drawColor);

            foreach (GlobalNPC g in HookDrawEffects.arr) {
                g.Instance(npc).DrawEffects(npc, ref drawColor);
            }
        }

        private static HookList HookPreDraw = AddHook<Func<NPC, SpriteBatch, Color, bool>>(g => g.PreDraw);

        public static bool PreDraw(NPC npc, SpriteBatch spriteBatch, Color drawColor) {
            bool result = true;
            foreach (GlobalNPC g in HookPreDraw.arr) {
                result &= g.Instance(npc).PreDraw(npc, spriteBatch, drawColor);
            }
            if (result && npc.modNPC != null) {
                return npc.modNPC.PreDraw(spriteBatch, drawColor);
            }
            return result;
        }

        private static HookList HookPostDraw = AddHook<Action<NPC, SpriteBatch, Color>>(g => g.PostDraw);

        public static void PostDraw(NPC npc, SpriteBatch spriteBatch, Color drawColor) {
            npc.modNPC?.PostDraw(spriteBatch, drawColor);

            foreach (GlobalNPC g in HookPostDraw.arr) {
                g.Instance(npc).PostDraw(npc, spriteBatch, drawColor);
            }
        }

        private static HookList HookDrawBehind = AddHook<Action<NPC, int>>(g => g.DrawBehind);

        internal static void DrawBehind(NPC npc, int index)
        {
            npc.modNPC?.DrawBehind(index);

            foreach (GlobalNPC g in HookDrawBehind.arr) {
                g.Instance(npc).DrawBehind(npc, index);
            }
        }

        private delegate bool? DelegateDrawHealthBar(NPC npc, byte bhPosition, ref float scale, ref Vector2 position);
        private static HookList HookDrawHealthBar = AddHook<DelegateDrawHealthBar>(g => g.DrawHealthBar);

        public static bool DrawHealthBar(NPC npc, ref float scale) {
            Vector2 position = new Vector2(npc.position.X + npc.width / 2, npc.position.Y + npc.gfxOffY);
            if (Main.HealthBarDrawSettings == 1) {
                position.Y += npc.height + 10f + Main.NPCAddHeight(npc.whoAmI);
            }
            else if (Main.HealthBarDrawSettings == 2) {
                position.Y -= 24f + Main.NPCAddHeight(npc.whoAmI) / 2f;
            }
            foreach (GlobalNPC g in HookDrawHealthBar.arr) {
                bool? result = g.Instance(npc).DrawHealthBar(npc, Main.HealthBarDrawSettings, ref scale, ref position);
                if (result.HasValue) {
                    if (result.Value) {
                        DrawHealthBar(npc, position, scale);
                    }
                    return false;
                }
            }
            if (NPCLoader.IsModNPC(npc)) {
                bool? result = npc.modNPC.DrawHealthBar(Main.HealthBarDrawSettings, ref scale, ref position);
                if (result.HasValue) {
                    if (result.Value) {
                        DrawHealthBar(npc, position, scale);
                    }
                    return false;
                }
            }
            return true;
        }

        private static void DrawHealthBar(NPC npc, Vector2 position, float scale) {
            float alpha = Lighting.Brightness((int)(npc.Center.X / 16f), (int)(npc.Center.Y / 16f));
            Main.instance.DrawHealthBar(position.X, position.Y, npc.life, npc.lifeMax, alpha, scale);
        }

        private delegate void DelegateEditSpawnRate(Player player, ref int spawnRate, ref int maxSpawns);
        private static HookList HookEditSpawnRate = AddHook<DelegateEditSpawnRate>(g => g.EditSpawnRate);

        public static void EditSpawnRate(Player player, ref int spawnRate, ref int maxSpawns) {
            foreach (GlobalNPC g in HookEditSpawnRate.arr) {
                g.EditSpawnRate(player, ref spawnRate, ref maxSpawns);
            }
        }

        private delegate void DelegateEditSpawnRange(Player player, ref int spawnRangeX, ref int spawnRangeY,
            ref int safeRangeX, ref int safeRangeY);
        private static HookList HookEditSpawnRange = AddHook<DelegateEditSpawnRange>(g => g.EditSpawnRange);

        public static void EditSpawnRange(Player player, ref int spawnRangeX, ref int spawnRangeY,
            ref int safeRangeX, ref int safeRangeY) {
            foreach (GlobalNPC g in HookEditSpawnRange.arr) {
                g.EditSpawnRange(player, ref spawnRangeX, ref spawnRangeY, ref safeRangeX, ref safeRangeY);
            }
        }

        private static HookList HookEditSpawnPool = AddHook<Action<Dictionary<int, float>, NPCSpawnInfo>>(g => g.EditSpawnPool);

        public static int? ChooseSpawn(NPCSpawnInfo spawnInfo) {
            NPCSpawnHelper.Reset();
            NPCSpawnHelper.DoChecks(spawnInfo);
            IDictionary<int, float> pool = new Dictionary<int, float>();
            pool[0] = 1f;
            foreach (ModNPC npc in npcs) {
                float weight = npc.SpawnChance(spawnInfo);
                if (weight > 0f) {
                    pool[npc.npc.type] = weight;
                }
            }
            foreach (GlobalNPC g in HookEditSpawnPool.arr) {
                g.EditSpawnPool(pool, spawnInfo);
            }
            float totalWeight = 0f;
            foreach (int type in pool.Keys) {
                if (pool[type] < 0f) {
                    pool[type] = 0f;
                }
                totalWeight += pool[type];
            }
            float choice = (float)Main.rand.NextDouble() * totalWeight;
            foreach (int type in pool.Keys) {
                float weight = pool[type];
                if (choice < weight) {
                    return type;
                }
                choice -= weight;
            }
            return null;
        }

        private static HookList HookSpawnNPC = AddHook<Action<int, int, int>>(g => g.SpawnNPC);

        public static int SpawnNPC(int type, int tileX, int tileY) {
            var npc = type >= NPCID.Count ?
                GetNPC(type).SpawnNPC(tileX, tileY) :
                NPC.NewNPC(tileX * 16 + 8, tileY * 16, type);

            foreach (GlobalNPC g in HookSpawnNPC.arr) {
                g.Instance(Main.npc[npc]).SpawnNPC(npc, tileX, tileY);
            }

            return npc;
        }

        public static void CanTownNPCSpawn(int numTownNPCs, int money) {
            foreach (ModNPC npc in npcs) {
                if (npc.npc.townNPC && NPC.TypeToHeadIndex(npc.npc.type) >= 0 && !NPC.AnyNPCs(npc.npc.type) &&
                    npc.CanTownNPCSpawn(numTownNPCs, money)) {
                    Main.townNPCCanSpawn[npc.npc.type] = true;
                    if (WorldGen.prioritizedTownNPC == 0) {
                        WorldGen.prioritizedTownNPC = npc.npc.type;
                    }
                }
            }
        }

        public static bool CheckConditions(int type) {
            return GetNPC(type)?.CheckConditions(WorldGen.roomX1, WorldGen.roomX2, WorldGen.roomY1, WorldGen.roomY2) ?? true;
        }

        public static string TownNPCName(int type) {
            return GetNPC(type)?.TownNPCName() ?? "";
        }

        public static bool UsesPartyHat(NPC npc) {
            return npc.modNPC?.UsesPartyHat() ?? true;
        }

        private static HookList HookCanChat = AddHook<Func<NPC, bool?>>(g => g.CanChat);

        public static bool CanChat(NPC npc, bool vanillaCanChat) {
            bool defaultCanChat = npc.modNPC?.CanChat() ?? vanillaCanChat;

            foreach (GlobalNPC g in HookCanChat.arr) {
                bool? canChat = g.Instance(npc).CanChat(npc);
                if (canChat.HasValue) {
                    if (!canChat.Value) {
                        return false;
                    }
                    defaultCanChat = true;
                }
            }

            return defaultCanChat;
        }

        private delegate void DelegateGetChat(NPC npc, ref string chat);
        private static HookList HookGetChat = AddHook<DelegateGetChat>(g => g.GetChat);

        public static void GetChat(NPC npc, ref string chat) {
            if (npc.modNPC != null) {
                chat = npc.modNPC.GetChat();
            }
            else if (chat.Equals("")) {
                chat = Language.GetTextValue("tModLoader.DefaultTownNPCChat");
            }
            foreach (GlobalNPC g in HookGetChat.arr) {
                g.Instance(npc).GetChat(npc, ref chat);
            }
        }

        public static void SetChatButtons(ref string button, ref string button2) {
            if (Main.player[Main.myPlayer].talkNPC >= 0) {
                NPC npc = Main.npc[Main.player[Main.myPlayer].talkNPC];
                npc.modNPC?.SetChatButtons(ref button, ref button2);
            }
        }

        private static HookList HookPreChatButtonClicked = AddHook<Func<NPC, bool, bool>>(g => g.PreChatButtonClicked);

        public static bool PreChatButtonClicked(bool firstButton) {
            NPC npc = Main.npc[Main.LocalPlayer.talkNPC];

            bool result = true;
            foreach (GlobalNPC g in HookPreChatButtonClicked.arr) {
                result &= g.Instance(npc).PreChatButtonClicked(npc, firstButton);
            }

            if (!result) {
                Main.PlaySound(SoundID.MenuTick);
                return false;
            }

            return true;
        }

        private delegate void DelegateOnChatButtonClicked(NPC npc, bool firstButton);
        private static HookList HookOnChatButtonClicked = AddHook<DelegateOnChatButtonClicked>(g => g.OnChatButtonClicked);

        public static void OnChatButtonClicked(bool firstButton) {
            NPC npc = Main.npc[Main.LocalPlayer.talkNPC];
            bool shop = false;

            if (npc.modNPC != null) {
                npc.modNPC.OnChatButtonClicked(firstButton, ref shop);
                Main.PlaySound(SoundID.MenuTick);
                if (shop) {
                    Main.playerInventory = true;
                    Main.npcChatText = "";
                    Main.npcShop = Main.MaxShopIDs - 1;
                    Main.instance.shop[Main.npcShop].SetupShop(npc.type);
                }
            }
            foreach (GlobalNPC g in HookOnChatButtonClicked.arr) {
                g.Instance(npc).OnChatButtonClicked(npc, firstButton);
            }
        }

        private delegate void DelegateSetupShop(int type, Chest shop, ref int nextSlot);
        private static HookList HookSetupShop = AddHook<DelegateSetupShop>(g => g.SetupShop);

        public static void SetupShop(int type, Chest shop, ref int nextSlot) {
            if (type < shopToNPC.Length) {
                type = shopToNPC[type];
            }
            else {
                GetNPC(type)?.SetupShop(shop, ref nextSlot);
            }
            foreach (GlobalNPC g in HookSetupShop.arr) {
                g.SetupShop(type, shop, ref nextSlot);
            }
        }

        private delegate void DelegateSetupTravelShop(int[] shop, ref int nextSlot);
        private static HookList HookSetupTravelShop = AddHook<DelegateSetupTravelShop>(g => g.SetupTravelShop);

        public static void SetupTravelShop(int[] shop, ref int nextSlot) {
            foreach (GlobalNPC g in HookSetupTravelShop.arr) {
                g.SetupTravelShop(shop, ref nextSlot);
            }
        }

        private static HookList HookCanGoToStatue = AddHook<Func<NPC, bool, bool?>>(g => g.CanGoToStatue);

        public static bool CanGoToStatue(NPC npc, bool toKingStatue, bool vanillaCanGo) {
            bool defaultCanGo = npc.modNPC?.CanGoToStatue(toKingStatue) ?? vanillaCanGo;

            foreach (GlobalNPC g in HookCanGoToStatue.arr) {
                bool? canGo = g.Instance(npc).CanGoToStatue(npc, toKingStatue);
                if (canGo.HasValue) {
                    if (!canGo.Value) {
                        return false;
                    }
                    defaultCanGo = true;
                }
            }

            return defaultCanGo;
        }

        private static HookList HookOnGoToStatue = AddHook<Action<NPC, bool>>(g => g.OnGoToStatue);

        public static void OnGoToStatue(NPC npc, bool toKingStatue) {
            npc.modNPC?.OnGoToStatue(toKingStatue);

            foreach (GlobalNPC g in HookOnGoToStatue.arr) {
                g.OnGoToStatue(npc, toKingStatue);
            }
        }

        private delegate void DelegateBuffTownNPC(ref float damageMult, ref int defense);
        private static HookList HookBuffTownNPC = AddHook<DelegateBuffTownNPC>(g => g.BuffTownNPC);

        public static void BuffTownNPC(ref float damageMult, ref int defense) {
            foreach (GlobalNPC g in HookBuffTownNPC.arr) {
                g.BuffTownNPC(ref damageMult, ref defense);
            }
        }
        //attack type 0 = throwing
        //  num405 = type, num406 = damage, knockBack, scaleFactor7 = speed multiplier, num407 = attack delay
        //  num408 = unknown, maxValue3 = unknown, num409 = gravity correction factor, num411 = random speed offset
        //attack type 1 = shooting
        //  num413 = type, num414 = damage, scaleFactor8 = speed multiplier, num415 = attack delay,
        //  num416 = unknown, maxValue4 = unknown, knockBack2, num417 = gravity correction,
        //  flag53 = in between shots, num418 = random speed offset
        //attack type 2 = magic
        //  num423 = type, num424 = damage, scaleFactor9 = speed multiplier, num425 = attack delay,
        //  num426 = unknown, maxValue5 = unknown, knockBack3, num427 = gravity correction factor,
        //  num429 = aura light multiplier, num430 = random speed offset
        //attack type 3 = swinging
        //  num439 = unknown, maxValue6 = unknown, num440 = damage, num441 = knockback,
        //  num442 = item width, num443 = item height
        //unknowns are associated with ai[1], localAI[1], and localAI[3] when ai[0] is either 0 or 8
        //check patch files for town NPC attacks
        private delegate void DelegateTownNPCAttackStrength(NPC npc, ref int damage, ref float knockback);
        private static HookList HookTownNPCAttackStrength = AddHook<DelegateTownNPCAttackStrength>(g => g.TownNPCAttackStrength);

        public static void TownNPCAttackStrength(NPC npc, ref int damage, ref float knockback) {
            npc.modNPC?.TownNPCAttackStrength(ref damage, ref knockback);

            foreach (GlobalNPC g in HookTownNPCAttackStrength.arr) {
                g.Instance(npc).TownNPCAttackStrength(npc, ref damage, ref knockback);
            }
        }

        private delegate void DelegateTownNPCAttackCooldown(NPC npc, ref int cooldown, ref int randExtraCooldown);
        private static HookList HookTownNPCAttackCooldown = AddHook<DelegateTownNPCAttackCooldown>(g => g.TownNPCAttackCooldown);

        public static void TownNPCAttackCooldown(NPC npc, ref int cooldown, ref int randExtraCooldown) {
            npc.modNPC?.TownNPCAttackCooldown(ref cooldown, ref randExtraCooldown);

            foreach (GlobalNPC g in HookTownNPCAttackCooldown.arr) {
                g.Instance(npc).TownNPCAttackCooldown(npc, ref cooldown, ref randExtraCooldown);
            }
        }

        private delegate void DelegateTownNPCAttackProj(NPC npc, ref int projType, ref int attackDelay);
        private static HookList HookTownNPCAttackProj = AddHook<DelegateTownNPCAttackProj>(g => g.TownNPCAttackProj);

        public static void TownNPCAttackProj(NPC npc, ref int projType, ref int attackDelay) {
            npc.modNPC?.TownNPCAttackProj(ref projType, ref attackDelay);

            foreach (GlobalNPC g in HookTownNPCAttackProj.arr) {
                g.Instance(npc).TownNPCAttackProj(npc, ref projType, ref attackDelay);
            }
        }

        private delegate void DelegateTownNPCAttackProjSpeed(NPC npc, ref float multiplier, ref float gravityCorrection,
            ref float randomOffset);
        private static HookList HookTownNPCAttackProjSpeed = AddHook<DelegateTownNPCAttackProjSpeed>(g => g.TownNPCAttackProjSpeed);

        public static void TownNPCAttackProjSpeed(NPC npc, ref float multiplier, ref float gravityCorrection,
            ref float randomOffset) {
            npc.modNPC?.TownNPCAttackProjSpeed(ref multiplier, ref gravityCorrection, ref randomOffset);

            foreach (GlobalNPC g in HookTownNPCAttackProjSpeed.arr) {
                g.Instance(npc).TownNPCAttackProjSpeed(npc, ref multiplier, ref gravityCorrection, ref randomOffset);
            }
        }

        private delegate void DelegateTownNPCAttackShoot(NPC npc, ref bool inBetweenShots);
        private static HookList HookTownNPCAttackShoot = AddHook<DelegateTownNPCAttackShoot>(g => g.TownNPCAttackShoot);

        public static void TownNPCAttackShoot(NPC npc, ref bool inBetweenShots) {
            npc.modNPC?.TownNPCAttackShoot(ref inBetweenShots);

            foreach (GlobalNPC g in HookTownNPCAttackShoot.arr) {
                g.Instance(npc).TownNPCAttackShoot(npc, ref inBetweenShots);
            }
        }

        private delegate void DelegateTownNPCAttackMagic(NPC npc, ref float auraLightMultiplier);
        private static HookList HookTownNPCAttackMagic = AddHook<DelegateTownNPCAttackMagic>(g => g.TownNPCAttackMagic);

        public static void TownNPCAttackMagic(NPC npc, ref float auraLightMultiplier) {
            npc.modNPC?.TownNPCAttackMagic(ref auraLightMultiplier);

            foreach (GlobalNPC g in HookTownNPCAttackMagic.arr) {
                g.Instance(npc).TownNPCAttackMagic(npc, ref auraLightMultiplier);
            }
        }

        private delegate void DelegateTownNPCAttackSwing(NPC npc, ref int itemWidth, ref int itemHeight);
        private static HookList HookTownNPCAttackSwing = AddHook<DelegateTownNPCAttackSwing>(g => g.TownNPCAttackSwing);

        public static void TownNPCAttackSwing(NPC npc, ref int itemWidth, ref int itemHeight) {
            npc.modNPC?.TownNPCAttackSwing(ref itemWidth, ref itemHeight);

            foreach (GlobalNPC g in HookTownNPCAttackSwing.arr) {
                g.Instance(npc).TownNPCAttackSwing(npc, ref itemWidth, ref itemHeight);
            }
        }

        private delegate void DelegateDrawTownAttackGun(NPC npc, ref float scale, ref int item, ref int closeness);
        private static HookList HookDrawTownAttackGun = AddHook<DelegateDrawTownAttackGun>(g => g.DrawTownAttackGun);

        public static void DrawTownAttackGun(NPC npc, ref float scale, ref int item, ref int closeness) {
            npc.modNPC?.DrawTownAttackGun(ref scale, ref item, ref closeness);

            foreach (GlobalNPC g in HookDrawTownAttackGun.arr) {
                g.Instance(npc).DrawTownAttackGun(npc, ref scale, ref item, ref closeness);
            }
        }

        private delegate void DelegateDrawTownAttackSwing(NPC npc, ref Texture2D item, ref int itemSize, ref float scale, ref Vector2 offset);
        private static HookList HookDrawTownAttackSwing = AddHook<DelegateDrawTownAttackSwing>(g => g.DrawTownAttackSwing);

        public static void DrawTownAttackSwing(NPC npc, ref Texture2D item, ref int itemSize, ref float scale, ref Vector2 offset) {
            npc.modNPC?.DrawTownAttackSwing(ref item, ref itemSize, ref scale, ref offset);

            foreach (GlobalNPC g in HookDrawTownAttackSwing.arr) {
                g.Instance(npc).DrawTownAttackSwing(npc, ref item, ref itemSize, ref scale, ref offset);
            }
        }

        private static bool HasMethod(Type t, string method, params Type[] args) {
            return t.GetMethod(method, args).DeclaringType != typeof(GlobalNPC);
        }

        internal static void VerifyGlobalNPC(GlobalNPC npc) {
            var type = npc.GetType();

            bool hasInstanceFields = type.GetFields(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic)
                .Any(f => f.DeclaringType != typeof(GlobalNPC));
            if (hasInstanceFields) {
                if (!npc.InstancePerEntity) {
                    throw new Exception(type + " has instance fields but does not set InstancePerEntity to true. Either use static fields, or per instance globals");
                }
            }
        }
    }
}