From 201ae3c60f22be1bfd80a33c3968401c7ae804ce Mon Sep 17 00:00:00 2001
From: Major Cooke <paul.growney22@gmail.com>
Date: Fri, 30 Sep 2016 15:02:22 -0500
Subject: [PATCH] Added OverlayID() for retrieving psprite layer numbers.

---
 src/p_pspr.cpp                 | 19 +++++++++++++++++++
 wadsrc/static/actors/actor.txt |  1 +
 2 files changed, 20 insertions(+)

diff --git a/src/p_pspr.cpp b/src/p_pspr.cpp
index 67a447f61f..fab7e38d8d 100644
--- a/src/p_pspr.cpp
+++ b/src/p_pspr.cpp
@@ -1049,6 +1049,25 @@ DEFINE_ACTION_FUNCTION(AActor, A_OverlayFlags)
 	return 0;
 }
 
+//---------------------------------------------------------------------------
+//
+// PROC OverlayID
+// Because non-action functions cannot acquire the ID of the overlay...
+//---------------------------------------------------------------------------
+
+DEFINE_ACTION_FUNCTION(AActor, OverlayID)
+{
+	PARAM_ACTION_PROLOGUE;
+
+	if (ACTION_CALL_FROM_PSPRITE())
+	{
+		ACTION_RETURN_INT(stateinfo->mPSPIndex);
+	}
+	ACTION_RETURN_INT(0);
+}
+
+
+
 //---------------------------------------------------------------------------
 //
 // PROC A_Lower
diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index c82be96cdd..44b801f511 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -57,6 +57,7 @@ ACTOR Actor native //: Thinker
 	native float GetSpriteAngle(int ptr = AAPTR_DEFAULT);
 	native float GetSpriteRotation(int ptr = AAPTR_DEFAULT);
 	native int GetMissileDamage(int mask, int add, int ptr = AAPTR_DEFAULT);
+	action native int OverlayID();
 
 	// Action functions
 	// Meh, MBF redundant functions. Only for DeHackEd support.