Show held item next to cursor (option). (#4658)

* Show held item next to cursor (option).

* UI scale

Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>

Content.Client/Hands/ShowHandItemOverlay.cs

@@ -0,0 +1,66 @@
+using Content.Shared.CCVar;
+using Robust.Client.Graphics;
+using Robust.Client.Input;
+using Robust.Shared;
+using Robust.Shared.Configuration;
+using Robust.Shared.Enums;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Maths;
+
+namespace Content.Client.Hands
+{
+    public sealed class ShowHandItemOverlay : Overlay
+    {
+        [Dependency] private readonly IConfigurationManager _cfg = default!;
+        [Dependency] private readonly IInputManager _inputManager = default!;
+        [Dependency] private readonly IClyde _clyde = default!;
+
+        private readonly IRenderTexture _renderBackbuffer;
+
+        public override OverlaySpace Space => OverlaySpace.ScreenSpace;
+
+        public ShowHandItemOverlay()
+        {
+            IoCManager.InjectDependencies(this);
+
+            _renderBackbuffer = _clyde.CreateRenderTarget(
+                (64, 64),
+                new RenderTargetFormatParameters(RenderTargetColorFormat.Rgba8Srgb, true),
+                new TextureSampleParameters
+                {
+                    Filter = true
+                }, nameof(ShowHandItemOverlay));
+        }
+
+        protected override void DisposeBehavior()
+        {
+            base.DisposeBehavior();
+
+            _renderBackbuffer.Dispose();
+        }
+
+        protected override void Draw(in OverlayDrawArgs args)
+        {
+            var sys = EntitySystem.Get<HandsSystem>();
+            var handEntity = sys.GetActiveHandEntity();
+
+            if (handEntity == null || !_cfg.GetCVar(CCVars.HudHeldItemShow))
+                return;
+
+            var screen = args.ScreenHandle;
+            var halfSize = _renderBackbuffer.Size / 2;
+
+            screen.RenderInRenderTarget(_renderBackbuffer, () =>
+            {
+                screen.DrawEntity(handEntity, halfSize, new Vector2(1f, 1f) * _cfg.GetCVar(CVars.DisplayUIScale), Direction.South);
+            }, Color.Transparent);
+
+            var offset = _cfg.GetCVar(CCVars.HudHeldItemOffset);
+
+            var mousePos = _inputManager.MouseScreenPosition.Position;
+            screen.DrawTexture(_renderBackbuffer.Texture, mousePos - halfSize + offset, Color.White.WithAlpha(0.75f));
+            // screen.DrawRect(UIBox2.FromDimensions((offset, offset) + mousePos, (32, 32)), Color.Red);
+        }
+    }
+}