Add tether gun (#16430)

Content.Client/Weapons/Misc/TetherGunSystem.cs

@@ -0,0 +1,103 @@
+using Content.Shared.Weapons.Misc;
+using Robust.Client.GameObjects;
+using Robust.Client.Graphics;
+using Robust.Client.Input;
+using Robust.Client.Player;
+using Robust.Shared.Map;
+using Robust.Shared.Timing;
+
+namespace Content.Client.Weapons.Misc;
+
+public sealed class TetherGunSystem : SharedTetherGunSystem
+{
+    [Dependency] private readonly IEyeManager _eyeManager = default!;
+    [Dependency] private readonly IGameTiming _timing = default!;
+    [Dependency] private readonly IInputManager _input = default!;
+    [Dependency] private readonly IMapManager _mapManager = default!;
+    [Dependency] private readonly IOverlayManager _overlay = default!;
+    [Dependency] private readonly IPlayerManager _player = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeLocalEvent<TetheredComponent, ComponentStartup>(OnTetheredStartup);
+        SubscribeLocalEvent<TetheredComponent, ComponentShutdown>(OnTetheredShutdown);
+        _overlay.AddOverlay(new TetherGunOverlay(EntityManager));
+    }
+
+    public override void Shutdown()
+    {
+        base.Shutdown();
+        _overlay.RemoveOverlay<TetherGunOverlay>();
+    }
+
+    protected override bool CanTether(EntityUid uid, TetherGunComponent component, EntityUid target, EntityUid? user)
+    {
+        // Need powercells predicted sadly :<
+        return false;
+    }
+
+    public override void Update(float frameTime)
+    {
+        base.Update(frameTime);
+
+        if (!_timing.IsFirstTimePredicted)
+            return;
+
+        var player = _player.LocalPlayer?.ControlledEntity;
+
+        if (player == null ||
+            !TryGetTetherGun(player.Value, out var gunUid, out var gun) ||
+            gun.TetherEntity == null)
+        {
+            return;
+        }
+
+        var mousePos = _input.MouseScreenPosition;
+        var mouseWorldPos = _eyeManager.ScreenToMap(mousePos);
+
+        if (mouseWorldPos.MapId == MapId.Nullspace)
+            return;
+
+        EntityCoordinates coords;
+
+        if (_mapManager.TryFindGridAt(mouseWorldPos, out var grid))
+        {
+            coords = EntityCoordinates.FromMap(grid.Owner, mouseWorldPos, TransformSystem);
+        }
+        else
+        {
+            coords = EntityCoordinates.FromMap(_mapManager.GetMapEntityId(mouseWorldPos.MapId), mouseWorldPos, TransformSystem);
+        }
+
+        const float BufferDistance = 0.1f;
+
+        if (TryComp<TransformComponent>(gun.TetherEntity, out var tetherXform) &&
+            tetherXform.Coordinates.TryDistance(EntityManager, TransformSystem, coords, out var distance) &&
+            distance < BufferDistance)
+        {
+            return;
+        }
+
+        RaisePredictiveEvent(new RequestTetherMoveEvent()
+        {
+            Coordinates = coords
+        });
+    }
+
+    private void OnTetheredStartup(EntityUid uid, TetheredComponent component, ComponentStartup args)
+    {
+        if (!TryComp<SpriteComponent>(uid, out var sprite))
+            return;
+
+        sprite.Color = Color.Orange;
+    }
+
+    private void OnTetheredShutdown(EntityUid uid, TetheredComponent component, ComponentShutdown args)
+    {
+        if (!TryComp<SpriteComponent>(uid, out var sprite))
+            return;
+
+        sprite.Color = Color.White;
+    }
+}