Gun spread overlay (#8588)

Content.Client/Weapons/Ranged/GunSpreadOverlay.cs

@@ -0,0 +1,76 @@
+using Content.Client.Weapons.Ranged.Systems;
+using Robust.Client.Graphics;
+using Robust.Client.Input;
+using Robust.Client.Player;
+using Robust.Shared.Enums;
+using Robust.Shared.Map;
+using Robust.Shared.Timing;
+
+namespace Content.Client.Weapons.Ranged;
+
+public sealed class GunSpreadOverlay : Overlay
+{
+    public override OverlaySpace Space => OverlaySpace.WorldSpace;
+
+    private IEntityManager _entManager;
+    private IEyeManager _eye;
+    private IGameTiming _timing;
+    private IInputManager _input;
+    private IPlayerManager _player;
+    private GunSystem _guns;
+
+    public GunSpreadOverlay(IEntityManager entManager, IEyeManager eyeManager, IGameTiming timing, IInputManager input, IPlayerManager player, GunSystem system)
+    {
+        _entManager = entManager;
+        _eye = eyeManager;
+        _input = input;
+        _timing = timing;
+        _player = player;
+        _guns = system;
+    }
+
+    protected override void Draw(in OverlayDrawArgs args)
+    {
+        var worldHandle = args.WorldHandle;
+
+        var player = _player.LocalPlayer?.ControlledEntity;
+
+        if (player == null ||
+            !_entManager.TryGetComponent<TransformComponent>(player, out var xform)) return;
+
+        var mapPos = xform.MapPosition;
+
+        if (mapPos.MapId == MapId.Nullspace) return;
+
+        var gun = _guns.GetGun(player.Value);
+
+        if (gun == null) return;
+
+        var mouseScreenPos = _input.MouseScreenPosition;
+        var mousePos = _eye.ScreenToMap(mouseScreenPos);
+
+        if (mapPos.MapId != mousePos.MapId) return;
+
+        // (☞ﾟヮﾟ)☞
+        var maxSpread = gun.MaxAngle;
+        var minSpread = gun.MinAngle;
+        var timeSinceLastFire = (_timing.CurTime - gun.NextFire).TotalSeconds;
+        var currentAngle = new Angle(MathHelper.Clamp(gun.CurrentAngle.Theta - gun.AngleDecay.Theta * timeSinceLastFire,
+            gun.MinAngle.Theta, gun.MaxAngle.Theta));
+        var direction = (mousePos.Position - mapPos.Position);
+
+        worldHandle.DrawLine(mapPos.Position, mousePos.Position + direction, Color.Orange);
+
+        // Show max spread either side
+        worldHandle.DrawLine(mapPos.Position, mousePos.Position + maxSpread.RotateVec(direction), Color.Red);
+        worldHandle.DrawLine(mapPos.Position, mousePos.Position + (-maxSpread).RotateVec(direction), Color.Red);
+
+        // Show min spread either side
+        worldHandle.DrawLine(mapPos.Position, mousePos.Position + minSpread.RotateVec(direction), Color.Green);
+        worldHandle.DrawLine(mapPos.Position, mousePos.Position + (-minSpread).RotateVec(direction), Color.Green);
+
+        // Show current angle
+        worldHandle.DrawLine(mapPos.Position, mousePos.Position + currentAngle.RotateVec(direction), Color.Yellow);
+        worldHandle.DrawLine(mapPos.Position, mousePos.Position + (-currentAngle).RotateVec(direction), Color.Yellow);
+    }
+}