Zombies recover faster from crit. They heal Piercing damage (#16325)

Content.Server/Zombies/ZombieSystem.cs

@@ -14,6 +14,8 @@ using Content.Shared.Damage;
 using Content.Shared.Inventory;
 using Content.Shared.Mobs;
 using Content.Shared.Mobs.Components;
+using Content.Shared.Mobs.Systems;
+using Content.Shared.Popups;
 using Content.Shared.Weapons.Melee.Events;
 using Content.Shared.Zombies;
 using Robust.Shared.Prototypes;
@@ -35,6 +37,9 @@ namespace Content.Server.Zombies
         [Dependency] private readonly AutoEmoteSystem _autoEmote = default!;
         [Dependency] private readonly EmoteOnDamageSystem _emoteOnDamage = default!;
         [Dependency] private readonly HumanoidAppearanceSystem _humanoidSystem = default!;
+        [Dependency] private readonly MobThresholdSystem _mobThreshold = default!;
+        [Dependency] private readonly MobStateSystem _mobState = default!;
+        [Dependency] private readonly SharedPopupSystem _popup = default!;
 
         public override void Initialize()
         {
@@ -60,12 +65,15 @@ namespace Content.Server.Zombies
         public override void Update(float frameTime)
         {
             base.Update(frameTime);
-            var query = EntityQueryEnumerator<PendingZombieComponent>();
+            var query = EntityQueryEnumerator<PendingZombieComponent, DamageableComponent>();
             var curTime = _timing.CurTime;
 
+            var zombQuery = EntityQueryEnumerator<ZombieComponent, DamageableComponent, MobStateComponent>();
+
             // Hurt the living infected
-            while (query.MoveNext(out var uid, out var comp))
+            while (query.MoveNext(out var uid, out var comp, out var damage))
             {
+                // Process only once per second
                 if (comp.NextTick + TimeSpan.FromSeconds(1) > curTime)
                     continue;
 
@@ -74,18 +82,34 @@ namespace Content.Server.Zombies
                 // 1x at 30s, 3x at 60s, 6x at 90s, 10x at 120s.
                 var pain_multiple = 0.1 + 0.02 * comp.InfectedSecs + 0.0005 * comp.InfectedSecs * comp.InfectedSecs;
                 comp.NextTick = curTime;
-                _damageable.TryChangeDamage(uid, comp.Damage * pain_multiple, true, false);
+                _damageable.TryChangeDamage(uid, comp.Damage * pain_multiple, true, false, damage);
             }
 
-            var zomb_query = EntityQueryEnumerator<ZombieComponent>();
             // Heal the zombified
-            while (zomb_query.MoveNext(out var uid, out var comp))
+            while (zombQuery.MoveNext(out var uid, out var comp, out var damage, out var mobState))
             {
+                // Process only once per second
                 if (comp.NextTick + TimeSpan.FromSeconds(1) > curTime)
                     continue;
 
                 comp.NextTick = curTime;
-                _damageable.TryChangeDamage(uid, comp.Damage, true, false);
+
+                if (comp.Permadeath)
+                {
+                    // No healing
+                    continue;
+                }
+
+                if (mobState.CurrentState == MobState.Alive)
+                {
+                    // Gradual healing for living zombies.
+                    _damageable.TryChangeDamage(uid, comp.Damage, true, false, damage);
+                }
+                else if (_random.Prob(comp.ZombieReviveChance))
+                {
+                    // There's a small chance to reverse all the zombie's damage (damage.Damage) in one go
+                    _damageable.TryChangeDamage(uid, -damage.Damage, true, false, damage);
+                }
             }
         }
 
@@ -128,6 +152,19 @@ namespace Content.Server.Zombies
 
                 // Stop random groaning
                 _autoEmote.RemoveEmote(uid, "ZombieGroan");
+
+                if (args.NewMobState == MobState.Dead)
+                {
+                    // Roll to see if this zombie is not coming back.
+                    //   Note that due to damage reductions it takes a lot of hits to gib a zombie without this.
+                    if (_random.Prob(component.ZombiePermadeathChance))
+                    {
+                        // You're dead! No reviving for you.
+                        _mobThreshold.SetAllowRevives(uid, false);
+                        component.Permadeath = true;
+                        _popup.PopupEntity(Loc.GetString("zombie-permadeath"), uid, uid);
+                    }
+                }
             }
         }