Add SetActorFlag ACS function

int SetActorFlag(int tid, str flagname, bool value);

- Mimics DECORATE's A_ChangeFlag
- Returns number of actors affected (number of things with the flag)
- Affects activator if TID is 0

# Conflicts:
#	src/p_acs.cpp

src/p_acs.cpp

@@ -4451,6 +4451,7 @@ enum EACSFunctions
 
 	ACSF_CheckClass = 200,
 	ACSF_DamageActor, // [arookas]
+	ACSF_SetActorFlag,
 
 	// ZDaemon
 	ACSF_GetTeamScore = 19620,	// (int team)
@@ -6046,6 +6047,34 @@ doplaysound:			if (funcIndex == ACSF_PlayActorSound)
 			return P_DamageMobj(target, inflictor, inflictor, args[4], damagetype);
 		}
 
+		case ACSF_SetActorFlag:
+		{
+			int tid = args[0];
+			FString flagname = FBehavior::StaticLookupString(args[1]);
+			bool flagvalue = !!args[2];
+			int count = 0; // Return value; number of actors affected
+			if (tid == 0)
+			{
+				if (ModActorFlag(activator, flagname, flagvalue))
+				{
+					++count;
+				}
+			}
+			else
+			{
+				FActorIterator it(tid);
+				while ((actor = it.Next()) != nullptr)
+				{
+					// Don't log errors when affecting many actors because things might share a TID but not share the flag
+					if (ModActorFlag(actor, flagname, flagvalue, false))
+					{
+						++count;
+					}
+				}
+			}
+			return count;
+		}
+
 		default:
 			break;
 	}

src/thingdef/thingdef.h

@@ -30,6 +30,7 @@ void HandleDeprecatedFlags(AActor *defaults, PClassActor *info, bool set, int in
 bool CheckDeprecatedFlags(const AActor *actor, PClassActor *info, int index);
 const char *GetFlagName(unsigned int flagnum, int flagoffset);
 void ModActorFlag(AActor *actor, FFlagDef *fd, bool set);
+bool ModActorFlag(AActor *actor, FString &flagname, bool set, bool printerror = true);
 INTBOOL CheckActorFlag(const AActor *actor, FFlagDef *fd);
 INTBOOL CheckActorFlag(const AActor *owner, const char *flagname, bool printerror = true);
 

src/thingdef/thingdef_codeptr.cpp

@@ -4681,90 +4681,7 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_ChangeFlag)
 	PARAM_STRING	(flagname);
 	PARAM_BOOL		(value);
 
-	const char *dot = strchr(flagname, '.');
+	ModActorFlag(self, flagname, value);
-	FFlagDef *fd;
-	PClassActor *cls = self->GetClass();
-
-	if (dot != NULL)
-	{
-		FString part1(flagname.GetChars(), dot - flagname);
-		fd = FindFlag(cls, part1, dot + 1);
-	}
-	else
-	{
-		fd = FindFlag(cls, flagname, NULL);
-	}
-
-	if (fd != NULL)
-	{
-		bool kill_before, kill_after;
-		INTBOOL item_before, item_after;
-		INTBOOL secret_before, secret_after;
-
-		kill_before = self->CountsAsKill();
-		item_before = self->flags & MF_COUNTITEM;
-		secret_before = self->flags5 & MF5_COUNTSECRET;
-
-		if (fd->structoffset == -1)
-		{
-			HandleDeprecatedFlags(self, cls, value, fd->flagbit);
-		}
-		else
-		{
-			ActorFlags *flagp = (ActorFlags*) (((char*)self) + fd->structoffset);
-
-			// If these 2 flags get changed we need to update the blockmap and sector links.
-			bool linkchange = flagp == &self->flags && (fd->flagbit == MF_NOBLOCKMAP || fd->flagbit == MF_NOSECTOR);
-
-			if (linkchange) self->UnlinkFromWorld();
-			ModActorFlag(self, fd, value);
-			if (linkchange) self->LinkToWorld();
-		}
-		kill_after = self->CountsAsKill();
-		item_after = self->flags & MF_COUNTITEM;
-		secret_after = self->flags5 & MF5_COUNTSECRET;
-		// Was this monster previously worth a kill but no longer is?
-		// Or vice versa?
-		if (kill_before != kill_after)
-		{
-			if (kill_after)
-			{ // It counts as a kill now.
-				level.total_monsters++;
-			}
-			else
-			{ // It no longer counts as a kill.
-				level.total_monsters--;
-			}
-		}
-		// same for items
-		if (item_before != item_after)
-		{
-			if (item_after)
-			{ // It counts as an item now.
-				level.total_items++;
-			}
-			else
-			{ // It no longer counts as an item
-				level.total_items--;
-			}
-		}
-		// and secretd
-		if (secret_before != secret_after)
-		{
-			if (secret_after)
-			{ // It counts as an secret now.
-				level.total_secrets++;
-			}
-			else
-			{ // It no longer counts as an secret
-				level.total_secrets--;
-			}
-		}
-	}
-	else
-	{
-		Printf("Unknown flag '%s' in '%s'\n", flagname.GetChars(), cls->TypeName.GetChars());
-	}
 	return 0;
 }
 

src/thingdef/thingdef_properties.cpp

@@ -162,6 +162,71 @@ void ModActorFlag(AActor *actor, FFlagDef *fd, bool set)
 #endif
 }
 
+//==========================================================================
+//
+// Finds a flag by name and sets or clears it
+//
+// Returns true if the flag was found for the actor; else returns false
+//
+//==========================================================================
+
+bool ModActorFlag(AActor *actor, FString &flagname, bool set, bool printerror)
+{
+	bool found = false;
+
+	if (actor != NULL)
+	{
+		const char *dot = strchr(flagname, '.');
+		FFlagDef *fd;
+		PClassActor *cls = actor->GetClass();
+
+		if (dot != NULL)
+		{
+			FString part1(flagname.GetChars(), dot - flagname);
+			fd = FindFlag(cls, part1, dot + 1);
+		}
+		else
+		{
+			fd = FindFlag(cls, flagname, NULL);
+		}
+
+		if (fd != NULL)
+		{
+			found = true;
+
+			if (actor->CountsAsKill() && actor->health > 0) --level.total_monsters;
+			if (actor->flags & MF_COUNTITEM) --level.total_items;
+			if (actor->flags5 & MF5_COUNTSECRET) --level.total_secrets;
+
+			if (fd->structoffset == -1)
+			{
+				HandleDeprecatedFlags(actor, cls, set, fd->flagbit);
+			}
+			else
+			{
+				ActorFlags *flagp = (ActorFlags*)(((char*)actor) + fd->structoffset);
+
+				// If these 2 flags get changed we need to update the blockmap and sector links.
+				bool linkchange = flagp == &actor->flags && (fd->flagbit == MF_NOBLOCKMAP || fd->flagbit == MF_NOSECTOR);
+
+				if (linkchange) actor->UnlinkFromWorld();
+				ModActorFlag(actor, fd, set);
+				if (linkchange) actor->LinkToWorld();
+			}
+
+			if (actor->CountsAsKill() && actor->health > 0) ++level.total_monsters;
+			if (actor->flags & MF_COUNTITEM) ++level.total_items;
+			if (actor->flags5 & MF5_COUNTSECRET) ++level.total_secrets;
+		}
+		else if (printerror)
+		{
+			DPrintf(DMSG_ERROR, "ACS/DECORATE: '%s' is not a flag in '%s'\n", flagname.GetChars(), cls->TypeName.GetChars());
+		}
+	}
+
+	return found;
+}
+
 //==========================================================================
 //
 // Returns whether an actor flag is true or not.