make syndie bag and rigs explosion resistant (#22088)

* remove empty file real

* support explosion resistance for non-worn things

* remove redundant entitystorage resistance

* port entitystorage optimisation to apply for everything with 100% resistance

* add explosion resistance for bag contents

* make thing reusable

* add resistance to chest rig too

* medical chest rig too

---------

Co-authored-by: deltanedas <@deltanedas:kde.org>

Content.Server/Explosion/Components/ExplosionResistanceComponent.cs

@@ -5,7 +5,9 @@ using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototy
 namespace Content.Server.Explosion.Components;
 
 /// <summary>
-///     Component that provides entities with explosion resistance.
+/// Component that provides entities with explosion resistance.
+/// By default this is applied when worn, but to solely protect the entity itself and
+/// not the wearer use <c>worn: false</c>.
 /// </summary>
 /// <remarks>
 ///     This is desirable over just using damage modifier sets, given that equipment like bomb-suits need to
@@ -21,6 +23,20 @@ public sealed partial class ExplosionResistanceComponent : Component
     [DataField("damageCoefficient")]
     public float DamageCoefficient = 1;
 
+    /// <summary>
+    /// When true, resistances will be applied to the entity wearing this item.
+    /// When false, only this entity will get th resistance.
+    /// </summary>
+    [DataField, ViewVariables(VVAccess.ReadWrite)]
+    public bool Worn = true;
+
+    /// <summary>
+    /// Examine string for explosion resistance.
+    /// Passed <c>value</c> from 0 to 100.
+    /// </summary>
+    [DataField, ViewVariables(VVAccess.ReadWrite)]
+    public LocId Examine = "explosion-resistance-coefficient-value";
+
     /// <summary>
     ///     Modifiers specific to each explosion type for more customizability.
     /// </summary>

Content.Server/Explosion/EntitySystems/ExplosionSystem.Processing.cs

@@ -389,7 +389,13 @@ public sealed partial class ExplosionSystem
     private void GetEntitiesToDamage(EntityUid uid, DamageSpecifier originalDamage, string prototype)
     {
         _toDamage.Clear();
-        _toDamage.Add((uid, GetDamage(uid, prototype, originalDamage)));
+
+        // don't raise BeforeExplodeEvent if the entity is completely immune to explosions
+        var thisDamage = GetDamage(uid, prototype, originalDamage);
+        if (!thisDamage.Any())
+            return;
+
+        _toDamage.Add((uid, thisDamage));
 
         for (var i = 0; i < _toDamage.Count; i++)
         {

Content.Server/Explosion/EntitySystems/ExplosionSystem.cs

@@ -132,7 +132,8 @@ public sealed partial class ExplosionSystem : EntitySystem
     private void RelayedResistance(EntityUid uid, ExplosionResistanceComponent component,
         InventoryRelayedEvent<GetExplosionResistanceEvent> args)
     {
-        OnGetResistance(uid, component, ref args.Args);
+        if (component.Worn)
+            OnGetResistance(uid, component, ref args.Args);
     }
 
     private void OnGetResistance(EntityUid uid, ExplosionResistanceComponent component, ref GetExplosionResistanceEvent args)
@@ -378,9 +379,9 @@ public sealed partial class ExplosionSystem : EntitySystem
 
     private void OnArmorExamine(EntityUid uid, ExplosionResistanceComponent component, ref ArmorExamineEvent args)
     {
+        var value = MathF.Round((1f - component.DamageCoefficient) * 100, 1);
+
         args.Msg.PushNewline();
-        args.Msg.AddMarkup(Loc.GetString("explosion-resistance-coefficient-value",
-            ("value", MathF.Round((1f - component.DamageCoefficient) * 100, 1))
-            ));
+        args.Msg.AddMarkup(Loc.GetString(component.Examine, ("value", value)));
     }
 }