Proto-kinetic crusher (#16277)

Co-authored-by: AJCM-git <60196617+AJCM-git@users.noreply.github.com>

Content.Shared/Weapons/Marker/SharedDamageMarkerSystem.cs

@@ -0,0 +1,81 @@
+using Content.Shared.Damage;
+using Content.Shared.Projectiles;
+using Content.Shared.Weapons.Melee.Events;
+using Robust.Shared.Physics.Events;
+using Robust.Shared.Timing;
+
+namespace Content.Shared.Weapons.Marker;
+
+public abstract class SharedDamageMarkerSystem : EntitySystem
+{
+    [Dependency] private readonly IGameTiming _timing = default!;
+    [Dependency] private readonly SharedAudioSystem _audio = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeLocalEvent<DamageMarkerOnCollideComponent, StartCollideEvent>(OnMarkerCollide);
+        SubscribeLocalEvent<DamageMarkerComponent, EntityUnpausedEvent>(OnMarkerUnpaused);
+        SubscribeLocalEvent<DamageMarkerComponent, AttackedEvent>(OnMarkerAttacked);
+    }
+
+    private void OnMarkerAttacked(EntityUid uid, DamageMarkerComponent component, AttackedEvent args)
+    {
+        if (component.Marker != args.Used)
+            return;
+
+        args.BonusDamage += component.Damage;
+        RemCompDeferred<DamageMarkerComponent>(uid);
+        _audio.PlayPredicted(component.Sound, uid, args.User);
+    }
+
+    public override void Update(float frameTime)
+    {
+        base.Update(frameTime);
+
+        var query = EntityQueryEnumerator<DamageMarkerComponent>();
+
+        while (query.MoveNext(out var uid, out var comp))
+        {
+            if (comp.EndTime > _timing.CurTime)
+                continue;
+
+            RemCompDeferred<DamageMarkerComponent>(uid);
+        }
+    }
+
+    private void OnMarkerUnpaused(EntityUid uid, DamageMarkerComponent component, ref EntityUnpausedEvent args)
+    {
+        component.EndTime += args.PausedTime;
+    }
+
+    private void OnMarkerCollide(EntityUid uid, DamageMarkerOnCollideComponent component, ref StartCollideEvent args)
+    {
+        if (!args.OtherFixture.Hard ||
+            args.OurFixture.ID != SharedProjectileSystem.ProjectileFixture ||
+            component.Amount <= 0 ||
+            component.Whitelist?.IsValid(args.OtherEntity, EntityManager) == false ||
+            !TryComp<ProjectileComponent>(uid, out var projectile) ||
+            !projectile.Weapon.IsValid())
+        {
+            return;
+        }
+
+        // Markers are exclusive, deal with it.
+        var marker = EnsureComp<DamageMarkerComponent>(args.OtherEntity);
+        marker.Damage = new DamageSpecifier(component.Damage);
+        marker.Marker = projectile.Weapon;
+        marker.EndTime = _timing.CurTime + component.Duration;
+        component.Amount--;
+        Dirty(marker);
+
+        if (component.Amount <= 0)
+        {
+            QueueDel(uid);
+        }
+        else
+        {
+            Dirty(component);
+        }
+    }
+}