From 1812a7295f0a96332fef1c165b7e6479b72dcde1 Mon Sep 17 00:00:00 2001
From: kraflab <kraflab@gmail.com>
Date: Thu, 1 Apr 2021 19:08:47 +0200
Subject: [PATCH] Add kill monsters special

---
 prboom2/src/p_mobj.c | 20 ++++++++++++++++++++
 prboom2/src/p_spec.h |  1 +
 2 files changed, 21 insertions(+)

diff --git a/prboom2/src/p_mobj.c b/prboom2/src/p_mobj.c
index fee615a63..f116dcf8e 100644
--- a/prboom2/src/p_mobj.c
+++ b/prboom2/src/p_mobj.c
@@ -1058,6 +1058,26 @@ void P_MobjThinker (mobj_t* mobj)
       mobj->intflags &= ~MIF_FALLING, mobj->gear = 0;  // Reset torque
   }
 
+  if (mbf21)
+  {
+    sector_t* sector = mobj->subsector->sector;
+
+    if (
+      sector->special & KILL_MONSTERS_MASK &&
+      mobj->z == mobj->floorz &&
+      mobj->player == NULL &&
+      mobj->flags & MF_SHOOTABLE &&
+      !(mobj->flags & MF_FLOAT)
+    )
+    {
+      P_DamageMobj(mobj, NULL, NULL, 10000);
+
+      // must have been removed
+      if (mobj->thinker.function != P_MobjThinker)
+        return;
+    }
+  }
+
   // cycle through states,
   // calling action functions at transitions
   if (mobj->tics != -1)
diff --git a/prboom2/src/p_spec.h b/prboom2/src/p_spec.h
index 2862221d3..2829a7b39 100644
--- a/prboom2/src/p_spec.h
+++ b/prboom2/src/p_spec.h
@@ -94,6 +94,7 @@
 #define DEATH_MASK 0x1000 // bit 12
 #define DEATH_RADSUIT 0x20 // bit 5
 #define DEATH_INVULN 0x40 // bit 6
+#define KILL_MONSTERS_MASK 0x2000 // bit 13
 
 //jff 02/04/98 Define masks, shifts, for fields in
 // generalized linedef types