Adds grappling gun (#16662)

Content.Client/Physics/JointVisualsOverlay.cs

@@ -0,0 +1,74 @@
+using Content.Shared.Physics;
+using Robust.Client.GameObjects;
+using Robust.Client.Graphics;
+using Robust.Shared.Enums;
+using Robust.Shared.Physics;
+using Robust.Shared.Physics.Dynamics.Joints;
+
+namespace Content.Client.Physics;
+
+/// <summary>
+/// Draws a texture on top of a joint.
+/// </summary>
+public sealed class JointVisualsOverlay : Overlay
+{
+    public override OverlaySpace Space => OverlaySpace.WorldSpaceBelowFOV;
+
+    private IEntityManager _entManager;
+
+    private HashSet<Joint> _drawn = new();
+
+    public JointVisualsOverlay(IEntityManager entManager)
+    {
+        _entManager = entManager;
+    }
+
+    protected override void Draw(in OverlayDrawArgs args)
+    {
+        _drawn.Clear();
+        var worldHandle = args.WorldHandle;
+
+        var spriteSystem = _entManager.System<SpriteSystem>();
+        var xformSystem = _entManager.System<SharedTransformSystem>();
+        var joints = _entManager.EntityQueryEnumerator<JointVisualsComponent, TransformComponent>();
+        var xformQuery = _entManager.GetEntityQuery<TransformComponent>();
+
+        while (joints.MoveNext(out var visuals, out var xform))
+        {
+            if (xform.MapID != args.MapId)
+                continue;
+
+            var other = visuals.Target;
+
+            if (!xformQuery.TryGetComponent(other, out var otherXform))
+                continue;
+
+            if (xform.MapID != otherXform.MapID)
+                continue;
+
+            var texture = spriteSystem.Frame0(visuals.Sprite);
+            var width = texture.Width / (float) EyeManager.PixelsPerMeter;
+
+            var coordsA = xform.Coordinates;
+            var coordsB = otherXform.Coordinates;
+
+            var rotA = xform.LocalRotation;
+            var rotB = otherXform.LocalRotation;
+
+            coordsA = coordsA.Offset(rotA.RotateVec(visuals.OffsetA));
+            coordsB = coordsB.Offset(rotB.RotateVec(visuals.OffsetB));
+
+            var posA = coordsA.ToMapPos(_entManager, xformSystem);
+            var posB = coordsB.ToMapPos(_entManager, xformSystem);
+            var diff = (posB - posA);
+            var length = diff.Length;
+
+            var midPoint = diff / 2f + posA;
+            var angle = (posB - posA).ToWorldAngle();
+            var box = new Box2(-width / 2f, -length / 2f, width / 2f, length / 2f);
+            var rotate = new Box2Rotated(box.Translated(midPoint), angle, midPoint);
+
+            worldHandle.DrawTextureRect(texture, rotate);
+        }
+    }
+}