Add conditional camera offset based on cursor - Hristov Rework, Part 1 (#31626)

Content.Shared/Camera/GetEyePvsScaleEvent.cs

@@ -0,0 +1,33 @@
+using System.Numerics;
+using Content.Shared.Inventory;
+using Content.Shared.Movement.Systems;
+
+namespace Content.Shared.Camera;
+
+/// <summary>
+///     Raised directed by-ref when <see cref="SharedContentEyeSystem.UpdatePvsScale"/> is called.
+///     Should be subscribed to by any systems that want to modify an entity's eye PVS scale,
+///     so that they do not override each other. Keep in mind that this should be done serverside;
+///     the client may set a new PVS scale, but the server won't provide the data if it isn't done on the server.
+/// </summary>
+/// <param name="Scale">
+///     The total scale to apply.
+/// </param>
+/// <remarks>
+///     Note that in most cases <see cref="Scale"/> should be incremented or decremented by subscribers, not set.
+///     Otherwise, any offsets applied by previous subscribing systems will be overridden.
+/// </remarks>
+[ByRefEvent]
+public record struct GetEyePvsScaleEvent(float Scale);
+
+/// <summary>
+///     Raised on any equipped and in-hand items that may modify the eye offset.
+///     Pockets and suitstorage are excluded.
+/// </summary>
+[ByRefEvent]
+public sealed class GetEyePvsScaleRelayedEvent : EntityEventArgs, IInventoryRelayEvent
+{
+    public SlotFlags TargetSlots { get; } = ~(SlotFlags.POCKET & SlotFlags.SUITSTORAGE);
+
+    public float Scale;
+}