From b8f4592ad52442d27149871516278883455b468c Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@zdoom.fake>
Date: Sun, 6 Mar 2011 14:21:44 +0000
Subject: [PATCH] - added A_FaceTracer/A_FaceMaster submission.

SVN r3161 (trunk)
---
 src/p_enemy.cpp                | 53 +++++++++++++++++++++++++++-------
 wadsrc/static/actors/actor.txt |  2 ++
 2 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/src/p_enemy.cpp b/src/p_enemy.cpp
index e25444b15..0931c4d51 100644
--- a/src/p_enemy.cpp
+++ b/src/p_enemy.cpp
@@ -2705,11 +2705,13 @@ void A_Chase(AActor *self)
 //=============================================================================
 //
 // A_FaceTarget
+// A_FaceMaster
+// A_FaceTracer
 //
 //=============================================================================
-void A_FaceTarget (AActor *self, angle_t max_turn)
+void A_Face (AActor *self, AActor *other, angle_t max_turn)
 {
-	if (!self->target)
+	if (!other)
 		return;
 
 	// [RH] Andy Baker's stealth monsters
@@ -2720,15 +2722,15 @@ void A_FaceTarget (AActor *self, angle_t max_turn)
 
 	self->flags &= ~MF_AMBUSH;
 
-	angle_t target_angle = R_PointToAngle2 (self->x, self->y, self->target->x, self->target->y);
+	angle_t other_angle = R_PointToAngle2 (self->x, self->y, other->x, other->y);
 
 	// 0 means no limit. Also, if we turn in a single step anyways, no need to go through the algorithms.
-	// It also means that there is no need to check for going past the target.
-	if (max_turn && (max_turn < (angle_t)abs(self->angle - target_angle)))
+	// It also means that there is no need to check for going past the other.
+	if (max_turn && (max_turn < (angle_t)abs(self->angle - other_angle)))
 	{
-		if (self->angle > target_angle)
+		if (self->angle > other_angle)
 		{
-			if (self->angle - target_angle < ANGLE_180)
+			if (self->angle - other_angle < ANGLE_180)
 			{
 				self->angle -= max_turn;
 			}
@@ -2739,7 +2741,7 @@ void A_FaceTarget (AActor *self, angle_t max_turn)
 		}
 		else
 		{
-			if (target_angle - self->angle < ANGLE_180)
+			if (other_angle - self->angle < ANGLE_180)
 			{
 				self->angle += max_turn;
 			}
@@ -2751,16 +2753,31 @@ void A_FaceTarget (AActor *self, angle_t max_turn)
 	}
 	else
 	{
-		self->angle = target_angle;
+		self->angle = other_angle;
 	}
 
 	// This will never work well if the turn angle is limited.
-	if (max_turn == 0 && (self->angle == target_angle) && self->target->flags & MF_SHADOW)
+	if (max_turn == 0 && (self->angle == other_angle) && other->flags & MF_SHADOW)
     {
 		self->angle += pr_facetarget.Random2() << 21;
     }
 }
 
+void A_FaceTarget (AActor *self, angle_t max_turn)
+{
+	A_Face(self, self->target, max_turn);
+}
+
+void A_FaceMaster (AActor *self, angle_t max_turn)
+{
+	A_Face(self, self->master, max_turn);
+}
+
+void A_FaceTracer (AActor *self, angle_t max_turn)
+{
+	A_Face(self, self->tracer, max_turn);
+}
+
 DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_FaceTarget)
 {
 	ACTION_PARAM_START(1);
@@ -2769,6 +2786,22 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_FaceTarget)
 	A_FaceTarget(self, max_turn);
 }
 
+DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_FaceMaster)
+{
+	ACTION_PARAM_START(1);
+	ACTION_PARAM_ANGLE(max_turn, 0);
+
+	A_FaceMaster(self, max_turn);
+}
+
+DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_FaceTracer)
+{
+	ACTION_PARAM_START(1);
+	ACTION_PARAM_ANGLE(max_turn, 0);
+
+	A_FaceTracer(self, max_turn);
+}
+
 //===========================================================================
 //
 // [RH] A_MonsterRail
diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index 5e71ac555..065ee6281 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -66,6 +66,8 @@ ACTOR Actor native //: Thinker
 	action native A_Look();
 	action native A_Chase(state melee = "*", state missile = "none", int flags = 0);
 	action native A_FaceTarget(float max_turn = 0);
+	action native A_FaceTracer(float max_turn = 0);
+	action native A_FaceMaster(float max_turn = 0);
 	action native A_PosAttack();
 	action native A_Scream();
 	action native A_SPosAttack();