Refactor trackercap

- Don't clear every tic. This is what P_RemoveTracker is
  for.
- Link in P_SpawnMobj. Should cover all cases.
- Remove excess objects. These were leftover from when
  Shrink destroyed items. Just track Jawz, SPB and Break
  the Capsules.

src/k_kart.c

@@ -6105,7 +6105,6 @@ void K_DropHnextList(player_t *player, boolean keepshields)
 		dropwork = P_SpawnMobj(work->x, work->y, work->z, type);
 
 		P_SetTarget(&dropwork->target, player->mo);
-		P_AddKartItem(dropwork); // needs to be called here so shrink can bust items off players in front of the user.
 
 		dropwork->angle = work->angle;
 

src/p_mobj.c

@@ -5210,30 +5210,6 @@ boolean P_IsKartFieldItem(INT32 type)
 	}
 }
 
-boolean P_IsKartItem(INT32 type)
-{
-	switch (type)
-	{
-		case MT_EGGMANITEM_SHIELD:
-		case MT_BANANA_SHIELD:
-		case MT_DROPTARGET_SHIELD:
-		case MT_ORBINAUT_SHIELD:
-		case MT_JAWZ_SHIELD:
-		case MT_SSMINE_SHIELD:
-		case MT_SINK_SHIELD:
-		case MT_HYUDORO:
-			return true;
-
-		// Primarily for minimap data, handle with care
-		case MT_SPB:
-		case MT_BATTLECAPSULE:
-			return true;
-
-		default:
-			return P_IsKartFieldItem(type);
-	}
-}
-
 boolean K_IsMissileOrKartItem(mobj_t *mo)
 {
 	if (mo->flags & MF_MISSILE)
@@ -5260,8 +5236,25 @@ boolean P_CanDeleteKartItem(INT32 type)
 	return P_IsKartFieldItem(type);
 }
 
-// Called when a kart item "thinks"
-void P_AddKartItem(mobj_t *thing)
+static boolean P_IsTrackerType(INT32 type)
+{
+	switch (type)
+	{
+		// Bots need to know if another Jawz is targetting a player
+		case MT_JAWZ:
+			return true;
+
+		// Primarily for minimap data, handle with care
+		case MT_SPB:
+		case MT_BATTLECAPSULE:
+			return true;
+
+		default:
+			return false;
+	}
+}
+
+static void P_LinkTracker(mobj_t *thing)
 {
 	I_Assert(thing != NULL);
 
@@ -5280,9 +5273,9 @@ void P_AddKartItem(mobj_t *thing)
 	P_SetTarget(&thing->itnext, NULL);
 }
 
-// Called only when a kart item is removed
-// Keeps the hnext list from corrupting.
-static void P_RemoveKartItem(mobj_t *thing)
+// Called only when a tracker is removed
+// Keeps the itnext list from corrupting.
+static void P_RemoveTracker(mobj_t *thing)
 {
 	mobj_t *mo, **p;
 	for (mo = *(p = &trackercap); mo; mo = *(p = &mo->itnext))
@@ -5296,20 +5289,6 @@ static void P_RemoveKartItem(mobj_t *thing)
 	}
 }
 
-// Doesn't actually do anything since items have their own thinkers,
-// but this is necessary for the sole purpose of updating kitemcap
-void P_RunKartItems(void)
-{
-	mobj_t *mobj, *next;
-
-	for (mobj = trackercap; mobj; mobj = next)
-	{
-		next = mobj->itnext;
-		P_SetTarget(&mobj->itnext, NULL);
-	}
-	P_SetTarget(&trackercap, NULL);
-}
-
 void P_RunOverlays(void)
 {
 	// run overlays
@@ -9811,9 +9790,6 @@ void P_MobjThinker(mobj_t *mobj)
 			K_HandleDirectionalInfluence(mobj->player);
 		}
 
-		if (P_IsKartItem(mobj->type))	// mobj is a kart item we want on the list:
-			P_AddKartItem(mobj);		// add to kitem list
-
 		return;
 	}
 
@@ -10054,9 +10030,6 @@ void P_MobjThinker(mobj_t *mobj)
 	if (P_MobjWasRemoved(mobj))
 		return; // obligatory paranoia check
 
-	if (P_IsKartItem(mobj->type))	// mobj is a kart item we want on the list:
-		P_AddKartItem(mobj);		// add to kitem list
-
 	// Can end up here if a player dies.
 	if (mobj->player)
 		P_CyclePlayerMobjState(mobj);
@@ -10970,6 +10943,10 @@ mobj_t *P_SpawnMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype_t type)
 
 	R_AddMobjInterpolator(mobj);
 
+
+	if (P_IsTrackerType(mobj->type))
+		P_LinkTracker(mobj);
+
 	return mobj;
 }
 
@@ -11112,8 +11089,8 @@ void P_RemoveMobj(mobj_t *mobj)
 	if (mobj->type == MT_SPB)
 		spbplace = -1;
 
-	if (P_IsKartItem(mobj->type))
-		P_RemoveKartItem(mobj);
+	if (P_IsTrackerType(mobj->type))
+		P_RemoveTracker(mobj);
 
 	if (mobj->player && mobj->player->followmobj)
 	{

src/p_mobj.h

@@ -511,13 +511,9 @@ void P_InitCachedActions(void);
 void P_RunCachedActions(void);
 void P_AddCachedAction(mobj_t *mobj, INT32 statenum);
 
-// kartitem stuff: Returns true if the specified 'type' is one of the kart item constants we want in the kitemcap list
 boolean P_IsKartFieldItem(INT32 type);
-boolean P_IsKartItem(INT32 type);
 boolean K_IsMissileOrKartItem(mobj_t *mo);
 boolean P_CanDeleteKartItem(INT32 type);
-void P_AddKartItem(mobj_t *thing);	// needs to be called in k_kart.c
-void P_RunTrackers(void);
 
 // check mobj against water content, before movement code
 void P_MobjCheckWater(mobj_t *mobj);

src/p_tick.c

@@ -636,9 +636,6 @@ void P_Ticker(boolean run)
 	if (!demo.playback) // Don't increment if a demo is playing.
 		gamedata->totalplaytime++;
 
-	// formality so kitemcap gets updated properly each frame.
-	P_RunKartItems();
-
 	if (run)
 	{
 		ps_thinkertime = I_GetPreciseTime();