feat: Add NPC spawner and spawn rate multiplier

src/TerraSharp/Core/Hotkeys.cs

@@ -28,6 +28,7 @@ public static class Hotkeys
         new(InterfaceGroup, "Menu", "Open / close menu", () => WindowManager.Toggle(WindowManager.Menu)),
         new(InterfaceGroup, "ItemBrowser", "Item Browser", () => WindowManager.Toggle(WindowManager.Items)),
         new(InterfaceGroup, "BuffBrowser", "Buff Browser", () => WindowManager.Toggle(WindowManager.Buffs)),
+        new(InterfaceGroup, "NpcSpawner", "NPC Spawner", () => WindowManager.Toggle(WindowManager.Npcs)),
 
         Toggle("Player", "GodMode", "God Mode", () => Settings.GodMode, v => Settings.GodMode = v),
         Toggle("Player", "AutoHeal", "Auto Heal", () => Settings.AutoHeal, v => Settings.AutoHeal = v),
@@ -69,6 +70,7 @@ public static class Hotkeys
         Toggle("Visuals", "Shine", "Shine", () => Settings.Shine, v => Settings.Shine = v),
 
         Toggle("World", "FreezeTime", "Freeze Time", () => Settings.FreezeTime, v => Settings.FreezeTime = v),
+        Toggle("World", "SpawnRate", "Spawn Rate", () => Settings.SpawnRateBoost, v => Settings.SpawnRateBoost = v),
         new("World", "SavePosition", "Save Current Position", Waypoints.AddHere),
     ];
 

src/TerraSharp/Core/Settings.Json.cs

@@ -104,6 +104,8 @@ public static partial class Settings
         [nameof(BiomeSight)] = "Vision.BiomeSight",
 
         [nameof(FreezeTime)] = "World.FreezeTime",
+        [nameof(SpawnRateBoost)] = "World.SpawnRate.Enabled",
+        [nameof(SpawnRateMult)] = "World.SpawnRate.Multiplier",
 
         [nameof(LogBallistics)] = "Ballistics.Log",
     };

src/TerraSharp/Core/Settings.cs

@@ -48,7 +48,8 @@ public static partial class Settings
     public static Color ColLocal = Color.White, ColPlayers = new(70, 200, 255), ColHostile = new(235, 60, 60), ColCritters = new(200, 170, 120), ColTown = new(80, 220, 110), ColBoss = new(255, 120, 40), ColItems = new(255, 210, 70), ColProjHostile = new(255, 80, 200), ColProjFriendly = new(120, 160, 255), ColWaypoint = new(220, 90, 255);
     public static bool Spelunker, Hunter, Shine, NightOwl, DangerSense, BiomeSight;
 
-    public static bool FreezeTime;
+    public static bool FreezeTime, SpawnRateBoost;
+    public static float SpawnRateMult = 5f;
 
     public static bool LogBallistics = true;
 

src/TerraSharp/Features/NpcSpawner.cs

@@ -0,0 +1,59 @@
+using System;
+using Terraria;
+using Terraria.DataStructures;
+using Terraria.ID;
+using TerraSharp.Core;
+
+namespace TerraSharp.Features;
+
+public static class NpcSpawner
+{
+    const float SpawnDistance = 10 * 16f;
+    const int MultiplayerClient = 1;
+
+#if TMODLOADER
+    static readonly EntitySource_DebugCommand Source = new(nameof(NpcSpawner));
+#else
+    static readonly EntitySource_DebugCommand Source = new();
+#endif
+
+    public static bool Multiplayer => Main.netMode == MultiplayerClient;
+
+    // The server only honors summon requests for these types.
+    public static bool CanSummon(int type) => type >= 0 && type < NPCID.Sets.MPAllowedEnemies.Length && NPCID.Sets.MPAllowedEnemies[type];
+
+    public static bool Available(int type) => !Multiplayer || CanSummon(type);
+
+    public static void Spawn(int type, int count)
+    {
+        if (Multiplayer)
+        {
+            if (CanSummon(type))
+                NetMessage.SendData(MessageID.SpawnBossUseLicenseStartEvent, -1, -1, null, Main.myPlayer, type);
+            return;
+        }
+
+        Player player = Main.LocalPlayer;
+        int x = (int)(player.Center.X + player.direction * SpawnDistance);
+        int y = (int)player.Bottom.Y;
+        for (int i = 0; i < count; i++)
+            if (NPC.NewNPC(Source, x, y, type) >= Main.maxNPCs)
+                break;
+    }
+
+    // Spawner.GetSpawnRate postfix; spawnRate is the 1-in-N chance per tick.
+    public static void ScaleSpawnRate(ref int spawnRate, ref int maxSpawns)
+    {
+        if (!Settings.SpawnRateBoost)
+            return;
+
+        if (Settings.SpawnRateMult <= 0f)
+        {
+            maxSpawns = 0;
+            return;
+        }
+
+        spawnRate = Math.Max(1, (int)(spawnRate / Settings.SpawnRateMult));
+        maxSpawns = (int)Math.Ceiling(maxSpawns * Settings.SpawnRateMult);
+    }
+}

src/TerraSharp/Patches/HookRegistry.cs

@@ -21,6 +21,7 @@ internal sealed class HookRegistry : IDisposable
             MainPatches.Install(hooks);
             PlayerPatches.Install(hooks);
             NpcPatches.Install(hooks);
+            SpawnRatePatch.Install(hooks);
             ItemCheckShootPatch.Install(hooks);
             SandboxGuards.Install(hooks);
             return hooks;

src/TerraSharp/Patches/SpawnRatePatch.cs

@@ -0,0 +1,53 @@
+using System;
+using Terraria;
+using TerraSharp.Core;
+using TerraSharp.Features;
+#if TMODLOADER
+using Terraria.ModLoader;
+#endif
+
+namespace TerraSharp.Patches;
+
+// Natural spawns run only in single player and on the server.
+internal static class SpawnRatePatch
+{
+#if TMODLOADER
+    // tModLoader's NPC.SpawnNPC passes the final rate through NPCLoader.EditSpawnRate.
+    delegate void Original(Player player, ref int spawnRate, ref int maxSpawns);
+    delegate void Hooked(Original original, Player player, ref int spawnRate, ref int maxSpawns);
+
+    internal static void Install(HookRegistry hooks) => hooks.Add(typeof(NPCLoader), nameof(NPCLoader.EditSpawnRate), (Hooked)EditSpawnRate);
+
+    static void EditSpawnRate(Original original, Player player, ref int spawnRate, ref int maxSpawns)
+    {
+        original(player, ref spawnRate, ref maxSpawns);
+        Scale(ref spawnRate, ref maxSpawns);
+    }
+#else
+    delegate void Original(NPC.Spawner self, Player player, out int spawnRate, out int maxSpawns);
+    delegate void Hooked(Original original, NPC.Spawner self, Player player, out int spawnRate, out int maxSpawns);
+
+    internal static void Install(HookRegistry hooks) => hooks.Add(typeof(NPC.Spawner), "GetSpawnRate", (Hooked)GetSpawnRate);
+
+    static void GetSpawnRate(Original original, NPC.Spawner self, Player player, out int spawnRate, out int maxSpawns)
+    {
+        original(self, player, out spawnRate, out maxSpawns);
+        Scale(ref spawnRate, ref maxSpawns);
+    }
+#endif
+
+    static void Scale(ref int spawnRate, ref int maxSpawns)
+    {
+        if (!Plugin.Active)
+            return;
+
+        try
+        {
+            NpcSpawner.ScaleSpawnRate(ref spawnRate, ref maxSpawns);
+        }
+        catch (Exception e)
+        {
+            Log.Error("Spawn rate", e);
+        }
+    }
+}

src/TerraSharp/UI/IdIndex.cs

@@ -27,6 +27,8 @@ public sealed class IdIndex(Func<int> count, Func<int, string?> name)
 
     public string Name(int id) => id > 0 && id < Names.Length ? Names[id] : "";
 
+    public void Refresh() => _lastQuery = null;
+
     public void Filter(string query, Func<int, bool> fits)
     {
         query = query.Trim();

src/TerraSharp/UI/MainWindow.Pages.cs

@@ -228,6 +228,13 @@ public sealed partial class MainWindow
         if (WorldFeatures.InvasionName is { } active && Buttons($"Stop {active}") == 0)
             WorldFeatures.StopInvasion();
 
+        Group("Spawning");
+        Note(NpcSpawner.Multiplayer ? "Multiplayer: boss summons only, spawn rate is ignored." : "Spawn rate only affects single player.");
+        if (Toggle("Spawn Rate", ref Settings.SpawnRateBoost))
+            Sub(() => Slider("Multiplier", ref Settings.SpawnRateMult, 0f, 20f, 5f, "x{0:0.0}", v => v < 0.05f ? "No spawns" : null));
+        if (Buttons(WindowManager.Npcs.Open ? "Close NPC Spawner" : "NPC Spawner") == 0)
+            WindowManager.Toggle(WindowManager.Npcs);
+
         Group("Waypoints");
         Note("Saved per world.");
         if (Buttons("Save Current Position") == 0)

src/TerraSharp/UI/MainWindow.cs

@@ -35,7 +35,7 @@ public sealed partial class MainWindow : Window
             new Page("Combat", CombatPage, () => Count(Settings.RapidAttack, Settings.AutoSwing, Settings.DamageBoost, Settings.NoManaCost, Settings.NoSpread, Settings.Aimbot, Settings.AutoAttack, Settings.KillAura, Settings.HitMagnet, Settings.FreezeEnemies, Settings.WeakenEnemies)),
             new Page("Items", ItemsPage, () => Count(Settings.InstantBreak, Settings.InfItems, Settings.ItemVacuum, Settings.AutoFish, Settings.Sonar)),
             new Page("Visuals", VisualsPage, () => Count(Settings.Esp, Settings.Spelunker, Settings.Hunter, Settings.Shine, Settings.NightOwl, Settings.DangerSense, Settings.BiomeSight)),
-            new Page("World", WorldPage, () => Count(Settings.FreezeTime)),
+            new Page("World", WorldPage, () => Count(Settings.FreezeTime, Settings.SpawnRateBoost)),
             new Page("Keys", KeysPage, () => 0),
         ];
 

src/TerraSharp/UI/NpcBrowser.cs

@@ -0,0 +1,62 @@
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+using Terraria;
+using Terraria.ID;
+#if TMODLOADER
+using Terraria.ModLoader;
+#endif
+using TerraSharp.Features;
+
+namespace TerraSharp.UI;
+
+public sealed class NpcBrowser() : GridBrowser("npcs", "NPC Spawner", new Vector2(660, 140), 532, 520, "Search NPCs by name or ID", "NPCs", new IdIndex(() => NpcCount, Lang.GetNPCNameValue), Categories)
+{
+    const int Batch = 10;
+
+#if TMODLOADER
+    static int NpcCount => NPCLoader.NPCCount;
+#else
+    static int NpcCount => NPCID.Count;
+#endif
+
+    static readonly BrowserCategory[] Categories = [new("All", NpcSpawner.Available), new("Bosses", type => NpcSpawner.Available(type) && IsBoss(type)), new("Enemies", type => NpcSpawner.Available(type) && Sample(type) is { friendly: false, townNPC: false } && !IsBoss(type) && !IsCritter(type)), new("Town", type => NpcSpawner.Available(type) && Sample(type) is { townNPC: true }), new("Critters", type => NpcSpawner.Available(type) && IsCritter(type))];
+
+    bool _multiplayer;
+
+    static NPC? Sample(int type) => ContentSamples.NpcsByNetId.TryGetValue(type, out NPC? npc) ? npc : null;
+
+    static bool IsBoss(int type) => Sample(type) is { boss: true };
+
+    static bool IsCritter(int type) => NPCID.Sets.CountsAsCritter[type] || Main.npcCatchable[type];
+
+    protected override void DrawContent(Rectangle body)
+    {
+        if (_multiplayer != NpcSpawner.Multiplayer)
+        {
+            _multiplayer = NpcSpawner.Multiplayer;
+            Index.Refresh();
+        }
+
+        DrawSearchGrid(body, body.Y, body.Bottom - 30);
+        string hint = _multiplayer ? "Multiplayer: only boss summons the server accepts" : $"Click: spawn in front of you   Shift click: spawn {Batch}";
+        Render.TextMid(Widgets.SpriteBatch, hint, new Rectangle(body.X + 4, body.Bottom - 26, body.Width, 26), Widgets.Dim, 0.72f);
+    }
+
+    protected override void DrawSlot(int type, Rectangle bounds, bool hot)
+    {
+        Widgets.Slot(bounds, hot);
+        Main.instance.LoadNPC(type);
+        if (GameTextures.Get("Npc", type) is { } texture)
+            Widgets.Icon(texture, new Rectangle(bounds.X + 4, bounds.Y + 4, bounds.Width - 8, bounds.Height - 8), GameTextures.Frame(texture, 1, Main.npcFrameCount[type], 0, 0));
+        if (!hot)
+            return;
+
+        string action = _multiplayer ? "Click to summon" : "Click to spawn";
+        Widgets.Tooltip = $"{Index.Name(type)}\n{(IsBoss(type) ? "Boss" : "NPC")} #{type}   {action}";
+        if (!Widgets.Click)
+            return;
+
+        NpcSpawner.Spawn(type, Widgets.Shift ? Batch : 1);
+        Widgets.Sound(12);
+    }
+}

src/TerraSharp/UI/WindowManager.cs

@@ -13,11 +13,12 @@ public static class WindowManager
     public static readonly MainWindow Menu = new();
     public static readonly ItemBrowser Items = new();
     public static readonly BuffBrowser Buffs = new();
+    public static readonly NpcBrowser Npcs = new();
 
     const int TitleHeight = 40;
     const int MaxInputLength = 40;
 
-    static readonly List<Window> Stack = [Items, Buffs, Menu];
+    static readonly List<Window> Stack = [Items, Buffs, Npcs, Menu];
     static Window? _dragging;
     static Vector2 _dragOffset;