From 549a9d3cf0ae304d1ae40875e27fcad3e1eede03 Mon Sep 17 00:00:00 2001
From: "alexey.lysiuk" <alexey.lysiuk@gmail.com>
Date: Wed, 3 Jan 2018 10:48:10 +0200
Subject: [PATCH] Extended Actor.CheckMove() with optional position information

https://forum.zdoom.org/viewtopic.php?t=58964
---
 src/p_map.cpp                   | 19 ++++++++++++++++---
 wadsrc/static/zscript/actor.txt |  2 +-
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/p_map.cpp b/src/p_map.cpp
index ea4031eb48..7cab335c09 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -2784,9 +2784,8 @@ DEFINE_ACTION_FUNCTION(AActor, TryMove)
 //
 //==========================================================================
 
-bool P_CheckMove(AActor *thing, const DVector2 &pos, int flags)
+static bool P_CheckMove(AActor *thing, const DVector2 &pos, FCheckPosition& tm, int flags)
 {
-	FCheckPosition tm;
 	double		newz = thing->Z();
 
 	auto f1 = thing->flags & MF_PICKUP;
@@ -2879,13 +2878,27 @@ bool P_CheckMove(AActor *thing, const DVector2 &pos, int flags)
 	return true;
 }
 
+bool P_CheckMove(AActor *thing, const DVector2 &pos, int flags)
+{
+	FCheckPosition tm;
+	return P_CheckMove(thing, pos, tm, flags);
+}
+
 DEFINE_ACTION_FUNCTION(AActor, CheckMove)
 {
 	PARAM_SELF_PROLOGUE(AActor);
 	PARAM_FLOAT(x);
 	PARAM_FLOAT(y);
 	PARAM_INT_DEF(flags);
-	ACTION_RETURN_BOOL(P_CheckMove(self, DVector2(x, y), flags));
+	PARAM_POINTER_DEF(tm, FCheckPosition);
+	if (tm == nullptr)
+	{
+		ACTION_RETURN_BOOL(P_CheckMove(self, DVector2(x, y), flags));
+	}
+	else
+	{
+		ACTION_RETURN_BOOL(P_CheckMove(self, DVector2(x, y), *tm, flags));
+	}
 }
 
 
diff --git a/wadsrc/static/zscript/actor.txt b/wadsrc/static/zscript/actor.txt
index d9847e2b14..6dd222fbfc 100644
--- a/wadsrc/static/zscript/actor.txt
+++ b/wadsrc/static/zscript/actor.txt
@@ -624,7 +624,7 @@ class Actor : Thinker native
 	}
 	
 	native bool TryMove(vector2 newpos, int dropoff, bool missilecheck = false, FCheckPosition tm = null);
-	native bool CheckMove(vector2 newpos, int flags = 0);
+	native bool CheckMove(vector2 newpos, int flags = 0, FCheckPosition tm = null);
 	native void NewChaseDir();
 	native void RandomChaseDir();
 	native bool CheckMissileRange();