Add lava (#13438)

Content.Server/Tiles/LavaSystem.cs

@@ -0,0 +1,39 @@
+using Content.Server.Atmos.Components;
+using Content.Server.Atmos.EntitySystems;
+using Content.Shared.StepTrigger.Systems;
+
+namespace Content.Server.Tiles;
+
+public sealed class LavaSystem : EntitySystem
+{
+    [Dependency] private readonly FlammableSystem _flammable = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeLocalEvent<LavaComponent, StepTriggeredEvent>(OnLavaStepTriggered);
+        SubscribeLocalEvent<LavaComponent, StepTriggerAttemptEvent>(OnLavaStepTriggerAttempt);
+    }
+
+
+    private void OnLavaStepTriggerAttempt(EntityUid uid, LavaComponent component, ref StepTriggerAttemptEvent args)
+    {
+        if (!HasComp<FlammableComponent>(args.Tripper))
+            return;
+
+        args.Continue = true;
+    }
+
+    private void OnLavaStepTriggered(EntityUid uid, LavaComponent component, ref StepTriggeredEvent args)
+    {
+        var otherUid = args.Tripper;
+
+        if (TryComp<FlammableComponent>(otherUid, out var flammable))
+        {
+            // Apply the fury of a thousand suns
+            var multiplier = flammable.FireStacks == 0f ? 5f : 1f;
+            _flammable.AdjustFireStacks(otherUid, component.FireStacks * multiplier, flammable);
+            _flammable.Ignite(otherUid, flammable);
+        }
+    }
+}