Implemented entity transmit feature

configs/addons/counterstrikesharp/gamedata/gamedata.json

@@ -253,5 +253,11 @@
       "windows": 2,
       "linux": 0
     }
+  },
+  "CheckTransmitPlayerSlot": {
+    "offsets": {
+      "windows": 584,
+      "linux": 584
+    }
   }
 }

examples/WithCheckTransmit/README.md

@@ -0,0 +1,2 @@
+# With CheckTransmit
+This example shows how to work with the `CheckTransmit` listener.

examples/WithCheckTransmit/WithCheckTransmit.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\managed\CounterStrikeSharp.API\CounterStrikeSharp.API.csproj" />
+  </ItemGroup>
+
+</Project>

examples/WithCheckTransmit/WithCheckTransmitPlugin.cs

@@ -0,0 +1,115 @@
+using CounterStrikeSharp.API;
+using CounterStrikeSharp.API.Core;
+using CounterStrikeSharp.API.Core.Attributes;
+
+namespace WithCheckTransmit;
+
+[MinimumApiVersion(276)]
+public class WithCheckTransmitPlugin : BasePlugin
+{
+    public override string ModuleName => "Example: With CheckTransmit";
+    public override string ModuleVersion => "1.0.0";
+    public override string ModuleAuthor => "CounterStrikeSharp & Contributors";
+    public override string ModuleDescription => "A simple plugin that uses the CheckTransmit listener!";
+
+    private Dictionary<int, bool> ShouldSeeDoors = new Dictionary<int, bool>();
+
+    public override void Load(bool hotReload)
+    {
+        // This command is related to the following example.
+        AddCommand("nodoors", "Toggle door transmit", (player, info) =>
+        {
+            if (player == null)
+                return;
+
+            if (ShouldSeeDoors.ContainsKey(player.Slot))
+            {
+                ShouldSeeDoors[player.Slot] = !ShouldSeeDoors[player.Slot];
+            } else
+            {
+                ShouldSeeDoors.Add(player.Slot, false);
+            }
+
+            info.ReplyToCommand($"You should {(ShouldSeeDoors[player.Slot] ? "see" : "not see")} doors");
+        });
+
+        // In this example, we will hide every door for players that have enabled the option with the command 'nodoors'
+        RegisterListener<Listeners.CheckTransmit>((CCheckTransmitInfoList infoList) =>
+        {
+            // Get the list of the currently available doors (prop_door_rotating)
+            IEnumerable<CPropDoorRotating> doors = Utilities.FindAllEntitiesByDesignerName<CPropDoorRotating>("prop_door_rotating");
+
+            // Do nothing if there is none.
+            if (!doors.Any())
+                return;
+
+            // Go through every received info
+            foreach ((CCheckTransmitInfo info, CCSPlayerController? player) in infoList)
+            {
+                // If no player is found, we can continue
+                if (player == null)
+                    continue;
+
+                // Otherwise, lets do the work:
+
+                // Check if we should clear or not:
+
+                // If we have no data saved for this player, then we should not continue
+                if (!ShouldSeeDoors.ContainsKey(player.Slot))
+                    continue;
+
+                // If this value is true, then this player should see doors
+                if (ShouldSeeDoors[player.Slot])
+                    continue;
+
+                // Otherwise, lets remove the door entity indexes from the info list so they won't be transmitted
+                foreach (CPropDoorRotating door in doors)
+                {
+                    info.TransmitEntities.Remove(door);
+                }
+
+                // NOTE: this is a barebone example, saving data and doing sanity checks is up to you.
+            }
+        });
+
+        // In this example, we will hide other players in the same team as the player.
+        // NOTE: 'Hiding' players requires extra work to do, killing non-transmitted players results in crash.
+        RegisterListener<Listeners.CheckTransmit>((CCheckTransmitInfoList infoList) =>
+        {
+            // Get the list of the current players, we only work with this value later on
+            List<CCSPlayerController> players = Utilities.GetPlayers();
+
+            // Go through every received info
+            foreach ((CCheckTransmitInfo info, CCSPlayerController? player) in infoList)
+            {
+                // If no player is found, we can continue
+                if (player == null)
+                    continue;
+
+                // Otherwise, lets do the work:
+
+                // as an example, lets hide everyone for this player who is in the same team.
+                IEnumerable<CCSPlayerController> targetPlayers = players.Where(p =>
+                    // is the player and its pawn valid
+                    p.IsValid && p.Pawn.IsValid &&
+
+                    // we shouldn't hide ourselves
+                    p.Slot != player.Slot &&
+
+                    // is the player is in the same team
+                    p.Team == player.Team &&
+
+                    // is alive
+                    p.PlayerPawn.Value?.LifeState == (byte)LifeState_t.LIFE_ALIVE
+                );
+
+                foreach (CCSPlayerController targetPlayer in targetPlayers)
+                {
+                    // Calling 'Remove' will clear the entity index of the target player pawn from the transmission list
+                    // so it won't be transmitted for the 'player'.
+                    info.TransmitEntities.Remove(targetPlayer.Pawn);
+                }
+            }
+        });
+    }
+}

managed/CounterStrikeSharp.API/Core/Listeners.g.cs

@@ -163,5 +163,12 @@ public class Listeners {
         /// <param name="manifest">Resource Manifest</param>
         [ListenerName("OnServerPrecacheResources")]
         public delegate void OnServerPrecacheResources(ResourceManifest manifest);
+
+        /// <summary>
+        /// Called when checking transmit on entities.
+        /// </summary>
+        /// <param name="infoList">Transmit info list</param>
+        [ListenerName("CheckTransmit")]
+        public delegate void CheckTransmit([CastFrom(typeof(nint))]CCheckTransmitInfoList infoList);
     }
-}
+}

managed/CounterStrikeSharp.API/Core/Model/CCheckTransmitInfo.cs

@@ -0,0 +1,106 @@
+/*
+ *  This file is part of CounterStrikeSharp.
+ *  CounterStrikeSharp is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  CounterStrikeSharp is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with CounterStrikeSharp.  If not, see <https://www.gnu.org/licenses/>. *
+ */
+
+using System.Collections;
+using System.Runtime.InteropServices;
+
+namespace CounterStrikeSharp.API.Core
+{
+    [StructLayout(LayoutKind.Explicit)]
+    public struct CCheckTransmitInfo
+    {
+        /// <summary>
+        /// Entity n is already marked for transmission
+        /// </summary>
+        [FieldOffset(0x0)]
+        public CFixedBitVecBase TransmitEntities;
+
+        /// <summary>
+        /// Entity n is always send even if not in PVS (HLTV and Replay only)
+        /// </summary>
+        [FieldOffset(0x8)]
+        public CFixedBitVecBase TransmitAlways;
+    };
+
+    public sealed class CCheckTransmitInfoList : NativeObject, IReadOnlyList<(CCheckTransmitInfo, CCSPlayerController?)>
+    {
+        private int CheckTransmitPlayerSlotOffset = GameData.GetOffset("CheckTransmitPlayerSlot");
+
+        private unsafe nint* Inner => (nint*)base.Handle;
+
+        public unsafe int Count { get => (int)(*(this.Inner + 1)); }
+
+        public unsafe CCheckTransmitInfoList(IntPtr pointer) : base(pointer)
+            { }
+
+        /// <summary>
+        /// Get transmit info for the given index.
+        /// </summary>
+        /// <param name="index">Index of the info you want to retrieve from the list, should be between 0 and '<see cref="Count"/>' - 1</param>
+        /// <returns></returns>
+        public (CCheckTransmitInfo, CCSPlayerController?) this[int index]
+        {
+            get
+            {
+                var (transmit, slot) = this.Get(index);
+                CCSPlayerController? player = Utilities.GetPlayerFromSlot(slot);
+                return (transmit, player);
+            }
+        }
+
+        /// <summary>
+        /// Get transmit info for the given index.
+        /// </summary>
+        /// <param name="index">Index of the info you want to retrieve from the list, should be between 0 and '<see cref="Count"/>' - 1</param>
+        /// <returns></returns>
+        private unsafe (CCheckTransmitInfo, int) Get(int index)
+        {
+            if (index < 0 || index >= this.Count)
+            {
+                throw new ArgumentOutOfRangeException("index");
+            }
+
+            // 'base.Handle' holds the pointer for our 'CCheckTransmitInfoList' wrapper class
+
+            // Get the pointer to the array of 'CCheckTransmitInfo'
+            nint* infoListPtr = *(nint**)this.Inner; // Dereference 'Inner' to get the pointer to the array
+
+            // Access the specific 'CCheckTransmitInfo*'
+            nint infoPtr = *(infoListPtr + index);
+
+            // Retrieve the 'CCheckTransmitInfo' from the pointer
+            CCheckTransmitInfo info = Marshal.PtrToStructure<CCheckTransmitInfo>(infoPtr);
+
+            // Get player slot from the 'infoPtr' using the 'CheckTransmitPlayerSlotOffset' offset
+            int playerSlot = *(int*)((byte*)infoPtr + CheckTransmitPlayerSlotOffset);
+
+            return (info, playerSlot);
+        }
+
+        public IEnumerator<(CCheckTransmitInfo, CCSPlayerController?)> GetEnumerator()
+        {
+            for (int i = 0; i < this.Count; i++)
+            {
+                yield return this[i];
+            }
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return this.GetEnumerator();
+        }
+    }
+}

managed/CounterStrikeSharp.API/Core/Model/CFixedBitVecBase.cs

@@ -0,0 +1,81 @@
+/*
+ *  This file is part of CounterStrikeSharp.
+ *  CounterStrikeSharp is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  CounterStrikeSharp is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with CounterStrikeSharp.  If not, see <https://www.gnu.org/licenses/>. *
+ */
+
+using System.Runtime.InteropServices;
+
+namespace CounterStrikeSharp.API.Core
+{
+    // credits: qstage
+    [StructLayout(LayoutKind.Sequential)]
+    public unsafe struct CFixedBitVecBase
+    {
+        private const int LOG2_BITS_PER_INT = 5;
+        private const int BITS_PER_INT = 32;
+
+        private readonly uint* m_Ints;
+
+        public void Add(CEntityInstance entityInstance) => Write(entityInstance.Index);
+
+        public void Add(int bitNum) => Write(bitNum);
+
+        public void Add(uint bitNum) => Write(bitNum);
+
+        public void Remove(CEntityInstance entityInstance) => Clear(entityInstance.Index);
+
+        public void Remove(int bitNum) => Clear(bitNum);
+
+        public void Remove(uint bitNum) => Clear(bitNum);
+
+        public bool Contains(CEntityInstance entityInstance) => Contains(entityInstance.Index);
+
+        public bool Contains(uint bitNum) => Contains((int)bitNum);
+
+        private void Clear(uint bitNum) => Clear((int)bitNum);
+
+        private void Write(uint bitNum) => Write((int)bitNum);
+
+        private void Clear(int bitNum)
+        {
+            if (!(bitNum >= 0 && bitNum < Utilities.MaxEdicts))
+                return;
+
+            uint* pInt = m_Ints + BitVec_Int(bitNum);
+            *pInt &= ~(uint)BitVec_Bit(bitNum);
+        }
+
+        private void Write(int bitNum)
+        {
+            if (!(bitNum >= 0 && bitNum < Utilities.MaxEdicts))
+                return;
+
+            uint* pInt = m_Ints + BitVec_Int(bitNum);
+            *pInt |= (uint)BitVec_Bit(bitNum);
+        }
+
+        public bool Contains(int bitNum)
+        {
+            if (!(bitNum >= 0 && bitNum < Utilities.MaxEdicts))
+                return false;
+
+            uint* pInt = m_Ints + BitVec_Int(bitNum);
+            return (*pInt & (uint)BitVec_Bit(bitNum)) != 0;
+        }
+
+        private int BitVec_Int(int bitNum) => bitNum >> LOG2_BITS_PER_INT;
+
+        private int BitVec_Bit(int bitNum) => 1 << (bitNum & (BITS_PER_INT - 1));
+    }
+}