- Added a NODELAY state flag. This is only valid for a state immediately following a Spawn label.

When set, the actor will run this state during its first tick. This means Spawn
  states may now run an action function if you set this flag. Note that this action function
  is executed during the actor's first tick, which is not the same as when it is spawned.

SVN r4240 (trunk)

src/dthinker.cpp

@@ -448,7 +448,7 @@ int DThinker::TickThinkers (FThinkerList *list, FThinkerList *dest)
 		NextToThink = node->NextThinker;
 		if (node->ObjectFlags & OF_JustSpawned)
 		{
-			node->ObjectFlags &= ~OF_JustSpawned;
+			// Leave OF_JustSpawn set until after Tick() so the ticker can check it.
 			if (dest != NULL)
 			{ // Move thinker from this list to the destination list
 				node->Remove();
@@ -463,7 +463,8 @@ int DThinker::TickThinkers (FThinkerList *list, FThinkerList *dest)
 
 		if (!(node->ObjectFlags & OF_EuthanizeMe))
 		{ // Only tick thinkers not scheduled for destruction
-			node->Tick ();
+			node->Tick();
+			node->ObjectFlags &= ~OF_JustSpawned;
 			GC::CheckGC();
 		}
 		node = NextToThink;

src/info.h

@@ -75,6 +75,7 @@ struct FState
 	BYTE		Fullbright:1;	// State is fullbright
 	BYTE		SameFrame:1;	// Ignore Frame (except when spawning actor)
 	BYTE		Fast:1;
+	BYTE		NoDelay:1;		// Spawn states executes its action normally
 	int			ParameterIndex;
 
 	inline int GetFrame() const
@@ -109,6 +110,10 @@ struct FState
 	{
 		return NextState;
 	}
+	inline bool GetNoDelay() const
+	{
+		return NoDelay;
+	}
 	inline void SetFrame(BYTE frame)
 	{
 		Frame = frame - 'A';

src/p_mobj.cpp

@@ -3496,22 +3496,35 @@ void AActor::Tick ()
 	}
 
 	// cycle through states, calling action functions at transitions
+	assert (state != NULL);
+	if (ObjectFlags & OF_JustSpawned && state->GetNoDelay())
+	{
+		// For immediately spawned objects with the NoDelay flag set for their
+		// Spawn state, explicitly set the current state so that it calls its
+		// action and chains 0-tic states.
+		int starttics = tics;
+		SetState(state);
+		// If the initial state had a duration of 0 tics, let the next state run
+		// normally. Otherwise, increment tics by 1 so that we don't double up ticks.
+		if (starttics > 0 && tics >= 0)
+		{
+			tics++;
+		}
+	}
 	if (tics != -1)
 	{
 		// [RH] Use tics <= 0 instead of == 0 so that spawnstates
 		// of 0 tics work as expected.
 		if (tics <= 0)
 		{
-			assert (state != NULL);
 			if (state == NULL)
 			{
 				Destroy();
 				return;
 			}
-			if (!SetState (state->GetNextState()))
+			if (!SetState(state->GetNextState()))
 				return; 		// freed itself
 		}
-
 		tics--;
 	}
 	else
@@ -3983,13 +3996,6 @@ void AActor::PostBeginPlay ()
 		Renderer->StateChanged(this);
 	}
 	PrevAngle = angle;
-
-	// [BL] Run zero-delay spawn states now so that we don't create a tic later
-	if(tics == 0 && state)
-	{
-		if (!SetState (state->GetNextState()))
-			return; 		// freed itself
-	}
 }
 
 void AActor::MarkPrecacheSounds() const

src/p_states.cpp

@@ -334,8 +334,8 @@ FStateDefine *FStateDefinitions::FindStateLabelInList(TArray<FStateDefine> & lis
 	if (create)
 	{
 		FStateDefine def;
-		def.Label=name;
-		def.State=NULL;
+		def.Label = name;
+		def.State = NULL;
 		def.DefineFlags = SDF_NEXT;
 		return &list[list.Push(def)];
 	}
@@ -351,12 +351,11 @@ FStateDefine *FStateDefinitions::FindStateLabelInList(TArray<FStateDefine> & lis
 
 FStateDefine * FStateDefinitions::FindStateAddress(const char *name)
 {
-	FStateDefine * statedef=NULL;
-
+	FStateDefine *statedef = NULL;
 	TArray<FName> &namelist = MakeStateNameList(name);
+	TArray<FStateDefine> *statelist = &StateLabels;
 
-	TArray<FStateDefine> * statelist = &StateLabels;
-	for(unsigned i=0;i<namelist.Size();i++)
+	for(unsigned i = 0; i < namelist.Size(); i++)
 	{
 		statedef = FindStateLabelInList(*statelist, namelist[i], true);
 		statelist = &statedef->Children;
@@ -379,7 +378,7 @@ void FStateDefinitions::SetStateLabel (const char *statename, FState *state, BYT
 
 //==========================================================================
 //
-// Adds a new state to the curremt list
+// Adds a new state to the current list
 //
 //==========================================================================
 
@@ -393,6 +392,24 @@ void FStateDefinitions::AddStateLabel (const char *statename)
 	lastlabel = index;
 }
 
+//==========================================================================
+//
+// Returns the index a state label points to. May only be called before
+// installing states.
+//
+//==========================================================================
+
+int FStateDefinitions::GetStateLabelIndex (FName statename)
+{
+	FStateDefine *std = FindStateLabelInList(StateLabels, statename, false);
+	if (std == NULL)
+	{
+		return -1;
+	}
+	assert((size_t)std->State <= StateArray.Size() + 1);
+	return (int)((ptrdiff_t)std->State - 1);
+}
+
 //==========================================================================
 //
 // Finds the state associated with the given name
@@ -863,6 +880,9 @@ bool FStateDefinitions::AddStates(FState *state, const char *framechars)
 		state->Frame = frame;
 		state->SameFrame = noframe;
 		StateArray.Push(*state);
+
+		// NODELAY flag is not carried past the first state
+		state->NoDelay = false;
 	}
 	laststate = &StateArray[StateArray.Size() - 1];
 	laststatebeforelabel = laststate;

src/thingdef/thingdef.h

@@ -91,6 +91,7 @@ public:
 
 	void SetStateLabel (const char * statename, FState * state, BYTE defflags = SDF_STATE);
 	void AddStateLabel (const char * statename);
+	int GetStateLabelIndex (FName statename);
 	void InstallStates(FActorInfo *info, AActor *defaults);
 	int FinishStates (FActorInfo *actor, AActor *defaults);
 

src/thingdef/thingdef_states.cpp

@@ -275,6 +275,18 @@ do_stop:
 					state.Fast = true;
 					continue;
 				}
+				if (sc.Compare("NODELAY"))
+				{
+					if (bag.statedef.GetStateLabelIndex(NAME_Spawn) == bag.statedef.GetStateCount())
+					{
+						state.NoDelay = true;
+					}
+					else
+					{
+						sc.ScriptMessage("NODELAY may only be used immediately after Spawn:");
+					}
+					continue;
+				}
 				if (sc.Compare("OFFSET"))
 				{
 					// specify a weapon offset
@@ -338,8 +350,7 @@ do_stop:
 						int paramindex = PrepareStateParameters(&state, numparams, bag.Info->Class);
 						int paramstart = paramindex;
 						bool varargs = params[numparams - 1] == '+';
-						int varargcount=0;
-
+						int varargcount = 0;
 
 						if (varargs)
 						{