From 7d502e77892d2d05dc6e906463f8092161678894 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Thu, 24 Nov 2011 04:27:47 +0000
Subject: [PATCH] - Added SMF_CURSPEED flag for A_SeekerMissile to cause it to
 use the missile's current speed rather than its Speed property.

SVN r3318 (trunk)
---
 src/p_local.h                      |  2 +-
 src/p_mobj.cpp                     | 18 +++++++++++-------
 src/thingdef/thingdef_codeptr.cpp  |  3 ++-
 wadsrc/static/actors/constants.txt |  1 +
 4 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/src/p_local.h b/src/p_local.h
index 3c3040e66b..879a876ad3 100644
--- a/src/p_local.h
+++ b/src/p_local.h
@@ -97,7 +97,7 @@ APlayerPawn *P_SpawnPlayer (FMapThing *mthing, bool tempplayer=false);
 
 void P_ThrustMobj (AActor *mo, angle_t angle, fixed_t move);
 int P_FaceMobj (AActor *source, AActor *target, angle_t *delta);
-bool P_SeekerMissile (AActor *actor, angle_t thresh, angle_t turnMax, bool precise = false);
+bool P_SeekerMissile (AActor *actor, angle_t thresh, angle_t turnMax, bool precise = false, bool usecurspeed=false);
 
 enum EPuffFlags
 {
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index c77128a224..1057726218 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -1468,16 +1468,18 @@ bool AActor::CanSeek(AActor *target) const
 //
 //----------------------------------------------------------------------------
 
-bool P_SeekerMissile (AActor *actor, angle_t thresh, angle_t turnMax, bool precise)
+bool P_SeekerMissile (AActor *actor, angle_t thresh, angle_t turnMax, bool precise, bool usecurspeed)
 {
 	int dir;
 	int dist;
 	angle_t delta;
 	angle_t angle;
 	AActor *target;
+	fixed_t speed;
 
+	speed = !usecurspeed ? actor->Speed : xs_CRoundToInt(TVector3<double>(actor->velx, actor->vely, actor->velz).Length());
 	target = actor->tracer;
-	if (target == NULL || actor->Speed == 0 || !actor->CanSeek(target))
+	if (target == NULL || speed == 0 || !actor->CanSeek(target))
 	{
 		return false;
 	}
@@ -1507,8 +1509,8 @@ bool P_SeekerMissile (AActor *actor, angle_t thresh, angle_t turnMax, bool preci
 	
 	if (!precise)
 	{
-		actor->velx = FixedMul (actor->Speed, finecosine[angle]);
-		actor->vely = FixedMul (actor->Speed, finesine[angle]);
+		actor->velx = FixedMul (speed, finecosine[angle]);
+		actor->vely = FixedMul (speed, finesine[angle]);
 
 		if (!(actor->flags3 & (MF3_FLOORHUGGER|MF3_CEILINGHUGGER)))
 		{
@@ -1516,7 +1518,7 @@ bool P_SeekerMissile (AActor *actor, angle_t thresh, angle_t turnMax, bool preci
 				target->z + target->height < actor->z)
 			{ // Need to seek vertically
 				dist = P_AproxDistance (target->x - actor->x, target->y - actor->y);
-				dist = dist / actor->Speed;
+				dist = dist / speed;
 				if (dist < 1)
 				{
 					dist = 1;
@@ -1541,8 +1543,8 @@ bool P_SeekerMissile (AActor *actor, angle_t thresh, angle_t turnMax, bool preci
 			pitch >>= ANGLETOFINESHIFT;
 		}
 
-		fixed_t xyscale = FixedMul(actor->Speed, finecosine[pitch]);
-		actor->velz = FixedMul(actor->Speed, finesine[pitch]);
+		fixed_t xyscale = FixedMul(speed, finecosine[pitch]);
+		actor->velz = FixedMul(speed, finesine[pitch]);
 		actor->velx = FixedMul(xyscale, finecosine[angle]);
 		actor->vely = FixedMul(xyscale, finesine[angle]);
 	}
@@ -1872,6 +1874,7 @@ fixed_t P_XYMovement (AActor *mo, fixed_t scrollx, fixed_t scrolly)
 					}
 
 
+
 					// Reflect the missile along angle
 					mo->angle = angle;
 					angle >>= ANGLETOFINESHIFT;
@@ -2468,6 +2471,7 @@ void P_NightmareRespawn (AActor *mobj)
 
 	z = mo->z;
 
+
 	// inherit attributes from deceased one
 	mo->SpawnPoint[0] = mobj->SpawnPoint[0];
 	mo->SpawnPoint[1] = mobj->SpawnPoint[1];
diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index 965d4de08a..c265107275 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -487,6 +487,7 @@ enum
 {
 	SMF_LOOK = 1,
 	SMF_PRECISE = 2,
+	SMF_CURSPEED = 4,
 };
 DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_SeekerMissile)
 {
@@ -501,7 +502,7 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_SeekerMissile)
 	{
 		self->tracer = P_RoughMonsterSearch (self, distance);
 	}
-	P_SeekerMissile(self, clamp<int>(ang1, 0, 90) * ANGLE_1, clamp<int>(ang2, 0, 90) * ANGLE_1, !!(flags & SMF_PRECISE));
+	P_SeekerMissile(self, clamp<int>(ang1, 0, 90) * ANGLE_1, clamp<int>(ang2, 0, 90) * ANGLE_1, !!(flags & SMF_PRECISE), !!(flags & SMF_CURSPEED));
 }
 
 //==========================================================================
diff --git a/wadsrc/static/actors/constants.txt b/wadsrc/static/actors/constants.txt
index fa8f37e95b..fe84014e2c 100644
--- a/wadsrc/static/actors/constants.txt
+++ b/wadsrc/static/actors/constants.txt
@@ -124,6 +124,7 @@ const int BF_AFFECTBOSSES = 4;
 // Flags for A_SeekerMissile
 const int SMF_LOOK = 1;
 const int SMF_PRECISE = 2;
+const int SMF_CURSPEED = 4;
 
 // Flags for A_CustomPunch
 const int CPF_USEAMMO = 1;