- added DavidPH's A_FaceTarget patch but modified it so that if a turn angle is set the MF_SHADOW flag is ignored.

SVN r2316 (trunk)

src/p_enemy.cpp

@@ -2671,7 +2671,7 @@ void A_Chase(AActor *self)
 // A_FaceTarget
 //
 //=============================================================================
-void A_FaceTarget (AActor *self)
+void A_FaceTarget (AActor *self, angle_t max_turn)
 {
 	if (!self->target)
 		return;
@@ -2683,18 +2683,54 @@ void A_FaceTarget (AActor *self)
 	}
 
 	self->flags &= ~MF_AMBUSH;
-	self->angle = R_PointToAngle2 (self->x, self->y,
-									self->target->x, self->target->y);
 
-	if (self->target->flags & MF_SHADOW)
+	angle_t target_angle = R_PointToAngle2 (self->x, self->y, self->target->x, self->target->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 < abs(self->angle - target_angle)))
+	{
+		if (self->angle > target_angle)
+		{
+			if (self->angle - target_angle < ANGLE_180)
+			{
+				self->angle -= max_turn;
+			}
+			else
+			{
+				self->angle += max_turn;
+			}
+		}
+		else
+		{
+			if (target_angle - self->angle < ANGLE_180)
+			{
+				self->angle += max_turn;
+			}
+			else
+			{
+				self->angle -= max_turn;
+			}
+		}
+	}
+	else
+	{
+		self->angle = target_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)
     {
 		self->angle += pr_facetarget.Random2() << 21;
     }
 }
 
-DEFINE_ACTION_FUNCTION(AActor, A_FaceTarget)
+DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_FaceTarget)
 {
-	A_FaceTarget(self);
+	ACTION_PARAM_START(1);
+	ACTION_PARAM_ANGLE(max_turn, 0);
+
+	A_FaceTarget(self, max_turn);
 }
 
 //===========================================================================

src/p_enemy.h

@@ -69,7 +69,7 @@ DECLARE_ACTION(A_FreezeDeathChunks)
 DECLARE_ACTION(A_BossDeath)
 
 void A_Chase(AActor *self);
-void A_FaceTarget (AActor *actor);
+void A_FaceTarget (AActor *actor, angle_t max_turn = 0);
 
 bool A_RaiseMobj (AActor *, fixed_t speed);
 bool A_SinkMobj (AActor *, fixed_t speed);

wadsrc/static/actors/actor.txt

@@ -61,7 +61,7 @@ ACTOR Actor native //: Thinker
 	action native A_XScream();
 	action native A_Look();
 	action native A_Chase(state melee = "*", state missile = "none", int flags = 0);
-	action native A_FaceTarget();
+	action native A_FaceTarget(float max_turn = 0);
 	action native A_PosAttack();
 	action native A_Scream();
 	action native A_SPosAttack();