From 105a62cc20f878e86ad3b348888d327aea330d5b Mon Sep 17 00:00:00 2001
From: MajorCooke <paul.growney22@gmail.com>
Date: Mon, 19 Jan 2015 14:54:20 -0600
Subject: [PATCH] - Added pointer field to A_ChangeVelocity. - Defaults to
 AAPTR_DEFAULT, otherwise known as the calling actor.

---
 src/thingdef/thingdef_codeptr.cpp | 27 ++++++++++++++++++---------
 wadsrc/static/actors/actor.txt    |  2 +-
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index 300ee75569..d522f284a3 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -4029,12 +4029,21 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_ChangeVelocity)
 	ACTION_PARAM_FIXED(y, 1);
 	ACTION_PARAM_FIXED(z, 2);
 	ACTION_PARAM_INT(flags, 3);
+	ACTION_PARAM_INT(ptr, 4);
 
-	INTBOOL was_moving = self->velx | self->vely | self->velz;
+	AActor *ref = COPY_AAPTR(self, ptr);
+
+	if (!ref)
+	{
+		ACTION_SET_RESULT(false);
+		return;
+	}
+
+	INTBOOL was_moving = ref->velx | ref->vely | ref->velz;
 
 	fixed_t vx = x, vy = y, vz = z;
-	fixed_t sina = finesine[self->angle >> ANGLETOFINESHIFT];
-	fixed_t cosa = finecosine[self->angle >> ANGLETOFINESHIFT];
+	fixed_t sina = finesine[ref->angle >> ANGLETOFINESHIFT];
+	fixed_t cosa = finecosine[ref->angle >> ANGLETOFINESHIFT];
 
 	if (flags & 1)	// relative axes - make x, y relative to actor's current angle
 	{
@@ -4043,15 +4052,15 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_ChangeVelocity)
 	}
 	if (flags & 2)	// discard old velocity - replace old velocity with new velocity
 	{
-		self->velx = vx;
-		self->vely = vy;
-		self->velz = vz;
+		ref->velx = vx;
+		ref->vely = vy;
+		ref->velz = vz;
 	}
 	else	// add new velocity to old velocity
 	{
-		self->velx += vx;
-		self->vely += vy;
-		self->velz += vz;
+		ref->velx += vx;
+		ref->vely += vy;
+		ref->velz += vz;
 	}
 
 	if (was_moving)
diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index b2fa80c302..44ba7f9b65 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -293,7 +293,7 @@ ACTOR Actor native //: Thinker
 	action native A_SetPitch(float pitch, int flags = 0);
 	action native A_SetRoll(float roll, int flags = 0);
 	action native A_ScaleVelocity(float scale);
-	action native A_ChangeVelocity(float x = 0, float y = 0, float z = 0, int flags = 0);
+	action native A_ChangeVelocity(float x = 0, float y = 0, float z = 0, int flags = 0, int ptr = AAPTR_DEFAULT);
 	action native A_SetArg(int pos, int value);
 	action native A_SetUserVar(name varname, int value);
 	action native A_SetUserArray(name varname, int index, int value);