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| 1 | +using System.Runtime.CompilerServices; |
| 2 | +using Unity.Netcode; |
| 3 | +using UnityEngine; |
| 4 | + |
| 5 | +/// <summary> |
| 6 | +/// Example of using a <see cref="NetworkVariable{T}"/> to drive changes |
| 7 | +/// in state. |
| 8 | +/// </summary> |
| 9 | +/// <remarks> |
| 10 | +/// This is a simple state driven door example. |
| 11 | +/// This script was written with recommended usages patterns in mind. |
| 12 | +/// </remarks> |
| 13 | +public class Door : NetworkBehaviour, INetworkUpdateSystem |
| 14 | +{ |
| 15 | + /// <summary> |
| 16 | + /// The two door states. |
| 17 | + /// </summary> |
| 18 | + public enum DoorStates |
| 19 | + { |
| 20 | + Closed, |
| 21 | + Open |
| 22 | + } |
| 23 | + |
| 24 | + /// <summary> |
| 25 | + /// Initializes the door to a specific state (server side) when first spawned. |
| 26 | + /// </summary> |
| 27 | + [Tooltip("Configures the door's initial state when 1st spawned.")] |
| 28 | + public DoorStates InitialState = DoorStates.Closed; |
| 29 | + |
| 30 | + /// <summary> |
| 31 | + /// Used for <see cref="CanPlayerToggleState"/> example purposes. |
| 32 | + /// When true, only the server can open and close the door. |
| 33 | + /// Clients will receive a console log saying they could not open the door. |
| 34 | + /// </summary> |
| 35 | + public bool IsLocked; |
| 36 | + |
| 37 | + /// <summary> |
| 38 | + /// A simple door state where the server has write permissions and everyone has read permissions. |
| 39 | + /// </summary> |
| 40 | + private NetworkVariable<DoorStates> m_State = new NetworkVariable<DoorStates>(default, NetworkVariableReadPermission.Everyone, NetworkVariableWritePermission.Server); |
| 41 | + |
| 42 | + /// <summary> |
| 43 | + /// The current state of the door. |
| 44 | + /// </summary> |
| 45 | + public DoorStates CurrentState => m_State.Value; |
| 46 | + |
| 47 | + /// <summary> |
| 48 | + /// Invoked while the <see cref="NetworkObject"/> is in the middle of |
| 49 | + /// being spawned. |
| 50 | + /// </summary> |
| 51 | + public override void OnNetworkSpawn() |
| 52 | + { |
| 53 | + // The write authority (server) does not need to know about its |
| 54 | + // own changes (for this example) since it is the "single point |
| 55 | + // of truth" for the door instance. |
| 56 | + if (IsServer) |
| 57 | + { |
| 58 | + // Host/Server: |
| 59 | + // Applies the configurable state upon spawning. |
| 60 | + m_State.Value = InitialState; |
| 61 | + } |
| 62 | + else |
| 63 | + { |
| 64 | + // Clients: |
| 65 | + // Subscribe to changes in the door's state. |
| 66 | + m_State.OnValueChanged += OnStateChanged; |
| 67 | + } |
| 68 | + } |
| 69 | + |
| 70 | + /// <summary> |
| 71 | + /// Invoked once the door and all associated components |
| 72 | + /// have finished the spawn process. |
| 73 | + /// </summary> |
| 74 | + protected override void OnNetworkPostSpawn() |
| 75 | + { |
| 76 | + // Everyone updates their door state when finished spawning the door |
| 77 | + // in order to assure the door reflects (visually) its current state. |
| 78 | + UpdateFromState(); |
| 79 | + |
| 80 | + // Begin to start updating this NetworkBehaviour instance once all |
| 81 | + // netcode related components have finished the spawn process. |
| 82 | + NetworkUpdateLoop.RegisterNetworkUpdate(this, NetworkUpdateStage.Update); |
| 83 | + base.OnNetworkPostSpawn(); |
| 84 | + } |
| 85 | + |
| 86 | + /// <summary> |
| 87 | + /// Example of using the <see cref="INetworkUpdateSystem"/> usage pattern |
| 88 | + /// where it only updates while spawned. |
| 89 | + /// </summary> |
| 90 | + /// <param name="updateStage">The current update stage being invoked.</param> |
| 91 | + public void NetworkUpdate(NetworkUpdateStage updateStage) |
| 92 | + { |
| 93 | + switch (updateStage) |
| 94 | + { |
| 95 | + case NetworkUpdateStage.Update: |
| 96 | + { |
| 97 | + if (Input.GetKeyDown(KeyCode.Space)) |
| 98 | + { |
| 99 | + Interact(); |
| 100 | + } |
| 101 | + break; |
| 102 | + } |
| 103 | + } |
| 104 | + } |
| 105 | + |
| 106 | + /// <summary> |
| 107 | + /// Invoked just before this instance runs through its de-spawn |
| 108 | + /// sequence. A good time to unsubscribe from things. |
| 109 | + /// </summary> |
| 110 | + public override void OnNetworkPreDespawn() |
| 111 | + { |
| 112 | + if (!IsServer) |
| 113 | + { |
| 114 | + m_State.OnValueChanged -= OnStateChanged; |
| 115 | + } |
| 116 | + |
| 117 | + // Stop updating this NetworkBehaviour instance prior to running |
| 118 | + // through the de-spawn process. |
| 119 | + NetworkUpdateLoop.RegisterNetworkUpdate(this, NetworkUpdateStage.Update); |
| 120 | + base.OnNetworkPreDespawn(); |
| 121 | + } |
| 122 | + |
| 123 | + /// <summary> |
| 124 | + /// Server makes changes to the state. |
| 125 | + /// Clients receive the changes in state. |
| 126 | + /// </summary> |
| 127 | + /// <remarks> |
| 128 | + /// When the previous state equals the current state, we are a client |
| 129 | + /// that is doing its 1st synchronization of this door instance. |
| 130 | + /// </remarks> |
| 131 | + /// <param name="previous">The previous <see cref="DoorStates"/> state.</param> |
| 132 | + /// <param name="current">The current <see cref="DoorStates"/> state.</param> |
| 133 | + public void OnStateChanged(DoorStates previous, DoorStates current) |
| 134 | + { |
| 135 | + UpdateFromState(); |
| 136 | + } |
| 137 | + |
| 138 | + /// <summary> |
| 139 | + /// Invoke when the state is updated in order to apply the change |
| 140 | + /// in door state to the door asset itself. |
| 141 | + /// </summary> |
| 142 | + private void UpdateFromState() |
| 143 | + { |
| 144 | + switch(m_State.Value) |
| 145 | + { |
| 146 | + case DoorStates.Closed: |
| 147 | + { |
| 148 | + // door is open: |
| 149 | + // - rotate door transform |
| 150 | + // - play animations, sound etc. |
| 151 | + /// <see cref="Netcode.Components.Helpers.ComponentCont" |
| 152 | + break; |
| 153 | + } |
| 154 | + case DoorStates.Open: |
| 155 | + { |
| 156 | + // door is closed: |
| 157 | + // - rotate door transform |
| 158 | + // - play animations, sound etc. |
| 159 | + break; |
| 160 | + } |
| 161 | + } |
| 162 | + Debug.Log($"[{name}] Door is currently {m_State.Value}."); |
| 163 | + } |
| 164 | + |
| 165 | + /// <summary> |
| 166 | + /// Override to apply specific checks (like a player having the right |
| 167 | + /// key to open the door) or make it a non-virtual class and add logic |
| 168 | + /// directly to this method. |
| 169 | + /// </summary> |
| 170 | + /// <param name="player">The player attempting to open the door.</param> |
| 171 | + /// <returns></returns> |
| 172 | + protected virtual bool CanPlayerToggleState(NetworkObject player) |
| 173 | + { |
| 174 | + // For this example, if the door "is locked" then clients will |
| 175 | + // not be able to open the door but the host-client's player can. |
| 176 | + return !IsLocked || player.IsOwnedByServer; |
| 177 | + } |
| 178 | + |
| 179 | + /// <summary> |
| 180 | + /// Invoked by either a Host or clients to interact with the door. |
| 181 | + /// </summary> |
| 182 | + public void Interact() |
| 183 | + { |
| 184 | + // Optional: |
| 185 | + // This is only if you want clients to be able to |
| 186 | + // interact with doors. A dedicated server would not |
| 187 | + // be able to do this since it does not have a player. |
| 188 | + if (IsServer && !IsHost) |
| 189 | + { |
| 190 | + // Optional to log a warning about this. |
| 191 | + return; |
| 192 | + } |
| 193 | + |
| 194 | + if (IsHost) |
| 195 | + { |
| 196 | + ToggleState(NetworkManager.LocalClientId); |
| 197 | + } |
| 198 | + else |
| 199 | + { |
| 200 | + // Clients send an RPC to server (write authority) who applies the |
| 201 | + // change in state that will be synchronized with all client observers. |
| 202 | + ToggleStateRpc(); |
| 203 | + } |
| 204 | + } |
| 205 | + |
| 206 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 207 | + private DoorStates NextToggleState() |
| 208 | + { |
| 209 | + return m_State.Value == DoorStates.Open ? DoorStates.Closed : DoorStates.Open; |
| 210 | + } |
| 211 | + |
| 212 | + /// <summary> |
| 213 | + /// Invoked only server-side |
| 214 | + /// Primary method to handle toggling the door state. |
| 215 | + /// </summary> |
| 216 | + /// <param name="clientId">The client toggling the door state.</param> |
| 217 | + private void ToggleState(ulong clientId) |
| 218 | + { |
| 219 | + // Get the server-side client player instance |
| 220 | + var playerObject = NetworkManager.SpawnManager.GetPlayerNetworkObject(clientId); |
| 221 | + if (playerObject != null) |
| 222 | + { |
| 223 | + var nextToggleState = NextToggleState(); |
| 224 | + if (CanPlayerToggleState(playerObject)) |
| 225 | + { |
| 226 | + // Host toggles the state |
| 227 | + m_State.Value = nextToggleState; |
| 228 | + UpdateFromState(); |
| 229 | + } |
| 230 | + else |
| 231 | + { |
| 232 | + ToggleStateFailRpc(nextToggleState, RpcTarget.Single(clientId, RpcTargetUse.Temp)); |
| 233 | + } |
| 234 | + } |
| 235 | + else |
| 236 | + { |
| 237 | + // Optional as to how you handle this. Since ToggleState is only invoked by |
| 238 | + // sever-side only script, this could mean many things depending upon whether |
| 239 | + // or not a client could interact with something and not have a player object. |
| 240 | + // If that is the case, then don't even bother checking for a player object. |
| 241 | + // If that is not the case, then there could be a timing issue between when |
| 242 | + // something can be "interacted with" and when a player is about to be de-spawned. |
| 243 | + // For this example, we just log a warning as this example was built with |
| 244 | + // the requirement that a client has a spawned player object that is used for |
| 245 | + // reference to determine if the client's player can toggle the state of the |
| 246 | + // door or not. |
| 247 | + NetworkLog.LogWarningServer($"Client-{clientId} has no spawned player object!"); |
| 248 | + } |
| 249 | + } |
| 250 | + |
| 251 | + /// <summary> |
| 252 | + /// Invoked by clients. |
| 253 | + /// Re-directs to the common <see cref="ToggleState(ulong)"/> method. |
| 254 | + /// </summary> |
| 255 | + /// <param name="rpcParams">includes <see cref="RpcReceiveParams.SenderClientId"/> that is automatically populated for you.</param> |
| 256 | + [Rpc(SendTo.Server, InvokePermission = RpcInvokePermission.Everyone)] |
| 257 | + private void ToggleStateRpc(RpcParams rpcParams = default) |
| 258 | + { |
| 259 | + ToggleState(rpcParams.Receive.SenderClientId); |
| 260 | + } |
| 261 | + |
| 262 | + /// <summary> |
| 263 | + /// Optional: |
| 264 | + /// Handling when a player cannot open a door. |
| 265 | + /// </summary> |
| 266 | + /// <param name="rpcParams">includes <see cref="RpcReceiveParams.SenderClientId"/> that is automatically populated for you.</param> |
| 267 | + [Rpc(SendTo.SpecifiedInParams, InvokePermission = RpcInvokePermission.Server)] |
| 268 | + private void ToggleStateFailRpc(DoorStates doorState, RpcParams rpcParams = default) |
| 269 | + { |
| 270 | + // Provide player feedback that toggling failed. |
| 271 | + Debug.Log($"Failed to {doorState} the door!"); |
| 272 | + } |
| 273 | +} |
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