Add tile entity occlusion (#14626)

Content.Shared/Movement/Components/FloorOccluderComponent.cs

@@ -0,0 +1,12 @@
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.Movement.Components;
+
+/// <summary>
+/// Applies floor occlusion to any <see cref="FloorOcclusionComponent"/> that intersect us.
+/// </summary>
+[RegisterComponent, NetworkedComponent]
+public sealed partial class FloorOccluderComponent : Component
+{
+
+}

Content.Shared/Movement/Components/FloorOcclusionComponent.cs

@@ -0,0 +1,19 @@
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.Movement.Components;
+
+/// <summary>
+/// Applies an occlusion shader to this entity if it's colliding with a <see cref="FloorOccluderComponent"/>
+/// </summary>
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState(true)]
+public sealed partial class FloorOcclusionComponent : Component
+{
+    /// <summary>
+    /// Is the shader currently enabled.
+    /// </summary>
+    [ViewVariables(VVAccess.ReadWrite), DataField("enabled"), AutoNetworkedField]
+    public bool Enabled;
+
+    [DataField("colliding")]
+    public List<EntityUid> Colliding = new();
+}