Update mobj oldstates before all thinkers

src/p_map.c

@@ -103,7 +103,7 @@ boolean P_TeleportMove(mobj_t *thing, fixed_t x, fixed_t y, fixed_t z)
 	thing->floorrover = tmfloorrover;
 	thing->ceilingrover = tmceilingrover;
 
-	P_ResetInterpolationState(thing);
+	P_ResetMobjInterpolationState(thing);
 
 	return true;
 }

src/p_mobj.c

@@ -42,6 +42,77 @@ actioncache_t actioncachehead;
 
 static mobj_t *overlaycap = NULL;
 
+static mobj_t **interpolated_mobjs = NULL;
+static size_t interpolated_mobjs_len = 0;
+static size_t interpolated_mobjs_capacity = 0;
+
+// NOTE: This will NOT check that the mobj has already been added, for perf
+// reasons.
+static void AddInterpolatedMobj(mobj_t *mobj)
+{
+	if (interpolated_mobjs_len >= interpolated_mobjs_capacity)
+	{
+		if (interpolated_mobjs_capacity == 0)
+		{
+			interpolated_mobjs_capacity = 256;
+		}
+		else
+		{
+			interpolated_mobjs_capacity *= 2;
+		}
+
+		interpolated_mobjs = Z_ReallocAlign(
+			interpolated_mobjs,
+			sizeof(mobj_t *) * interpolated_mobjs_capacity,
+			PU_LEVEL,
+			NULL,
+			64
+		);
+	}
+
+	interpolated_mobjs[interpolated_mobjs_len] = mobj;
+	interpolated_mobjs_len += 1;
+}
+
+static void RemoveInterpolatedMobj(mobj_t *mobj)
+{
+	size_t i;
+
+	if (interpolated_mobjs_len == 0) return;
+
+	for (i = 0; i < interpolated_mobjs_len - 1; i++)
+	{
+		if (interpolated_mobjs[i] == mobj)
+		{
+			interpolated_mobjs[i] = interpolated_mobjs[
+				interpolated_mobjs_len - 1
+			];
+			interpolated_mobjs_len -= 1;
+			return;
+		}
+	}
+}
+
+void P_InitMobjInterpolators(void)
+{
+	// apparently it's not acceptable to free something already unallocated
+	// Z_Free(interpolated_mobjs);
+	interpolated_mobjs = NULL;
+	interpolated_mobjs_len = 0;
+	interpolated_mobjs_capacity = 0;
+}
+
+void P_UpdateMobjInterpolators(void)
+{
+	size_t i;
+	for (i = 0; i < interpolated_mobjs_len; i++)
+	{
+		mobj_t *mobj = interpolated_mobjs[i];
+		if (!P_MobjWasRemoved(mobj))
+			P_ResetMobjInterpolationState(mobj);
+	}
+}
+
 void P_InitCachedActions(void)
 {
 	actioncachehead.prev = actioncachehead.next = &actioncachehead;
@@ -893,11 +964,11 @@ void P_EmeraldManager(void)
 }
 
 //
-// P_ResetInterpolationState
+// P_ResetMobjInterpolationState
 //
 // Reset the rendering interpolation state of the mobj.
 //
-void P_ResetInterpolationState(mobj_t *mobj)
+void P_ResetMobjInterpolationState(mobj_t *mobj)
 {
 	mobj->old_x = mobj->x;
 	mobj->old_y = mobj->y;
@@ -913,11 +984,11 @@ void P_ResetInterpolationState(mobj_t *mobj)
 }
 
 //
-// P_ResetPrecipitationInterpolationState
+// P_ResetPrecipitationMobjInterpolationState
 //
 // Reset the rendering interpolation state of the precipmobj.
 //
-void P_ResetPrecipitationInterpolationState(precipmobj_t *mobj)
+void P_ResetPrecipitationMobjInterpolationState(precipmobj_t *mobj)
 {
 	mobj->old_x = mobj->x;
 	mobj->old_y = mobj->y;
@@ -4059,7 +4130,7 @@ void P_NullPrecipThinker(precipmobj_t *mobj)
 
 void P_SnowThinker(precipmobj_t *mobj)
 {
-	P_ResetPrecipitationInterpolationState(mobj);
+	P_ResetPrecipitationMobjInterpolationState(mobj);
 
 	P_CycleStateAnimation((mobj_t *)mobj);
 
@@ -4067,13 +4138,13 @@ void P_SnowThinker(precipmobj_t *mobj)
 	if ((mobj->z += mobj->momz) <= mobj->floorz)
 	{
 		mobj->z = mobj->ceilingz;
-		P_ResetPrecipitationInterpolationState(mobj);
+		P_ResetPrecipitationMobjInterpolationState(mobj);
 	}
 }
 
 void P_RainThinker(precipmobj_t *mobj)
 {
-	P_ResetPrecipitationInterpolationState(mobj);
+	P_ResetPrecipitationMobjInterpolationState(mobj);
 
 	P_CycleStateAnimation((mobj_t *)mobj);
 
@@ -4094,7 +4165,7 @@ void P_RainThinker(precipmobj_t *mobj)
 			return;
 
 		mobj->z = mobj->ceilingz;
-		P_ResetPrecipitationInterpolationState(mobj);
+		P_ResetPrecipitationMobjInterpolationState(mobj);
 		P_SetPrecipMobjState(mobj, S_RAIN1);
 
 		return;
@@ -10072,8 +10143,6 @@ void P_MobjThinker(mobj_t *mobj)
 	I_Assert(mobj != NULL);
 	I_Assert(!P_MobjWasRemoved(mobj));
 
-	P_ResetInterpolationState(mobj);
-
 	if (mobj->flags & MF_NOTHINK)
 		return;
 
@@ -10939,7 +11008,7 @@ mobj_t *P_SpawnMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype_t type)
 	if (CheckForReverseGravity && !(mobj->flags & MF_NOBLOCKMAP))
 		P_CheckGravity(mobj, false);
 
-	P_ResetInterpolationState(mobj);
+	AddInterpolatedMobj(mobj);
 
 	return mobj;
 }
@@ -10988,7 +11057,7 @@ static precipmobj_t *P_SpawnPrecipMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype
 	 || mobj->subsector->sector->floorpic == skyflatnum)
 		mobj->precipflags |= PCF_PIT;
 
-	P_ResetPrecipitationInterpolationState(mobj);
+	P_ResetPrecipitationMobjInterpolationState(mobj);
 
 	return mobj;
 }
@@ -11109,6 +11178,8 @@ void P_RemoveMobj(mobj_t *mobj)
 	memset((UINT8 *)mobj + sizeof(thinker_t), 0xff, sizeof(mobj_t) - sizeof(thinker_t));
 #endif
 
+	RemoveInterpolatedMobj(mobj);
+
 	// free block
 	if (!mobj->thinker.next)
 	{ // Uh-oh, the mobj doesn't think, P_RemoveThinker would never go through!

src/p_mobj.h

@@ -503,8 +503,12 @@ void P_RingZMovement(mobj_t *mo);
 boolean P_SceneryZMovement(mobj_t *mo);
 void P_PlayerZMovement(mobj_t *mo);
 void P_EmeraldManager(void);
-void P_ResetInterpolationState(mobj_t *mobj);
-void P_ResetPrecipitationInterpolationState(precipmobj_t *mobj);
+
+// Initialize internal mobj interpolator list (e.g. during level loading)
+void P_InitMobjInterpolators(void);
+void P_UpdateMobjInterpolators(void);
+void P_ResetMobjInterpolationState(mobj_t *mobj);
+void P_ResetPrecipitationMobjInterpolationState(precipmobj_t *mobj);
 
 extern INT32 modulothing;
 

src/p_setup.c

@@ -4376,6 +4376,7 @@ boolean P_LoadLevel(boolean fromnetsave, boolean reloadinggamestate)
 	R_InitializeLevelInterpolators();
 
 	P_InitThinkers();
+	P_InitMobjInterpolators();
 	P_InitCachedActions();
 
 	if (!fromnetsave && savedata.lives > 0)

src/p_tick.c

@@ -642,6 +642,8 @@ void P_Ticker(boolean run)
 
 	if (run)
 	{
+		P_UpdateMobjInterpolators();
+
 		if (demorecording)
 			G_WriteDemoTiccmd(&players[consoleplayer].cmd, 0);
 		if (demoplayback)