libcommon: Added optional definition ID for finales

Fixes the problem where a new instance of the "help" script would
get pushed onto the stack every time F1 was pressed. Now only
one instance is started -- attempts to start the "help" script again
while it's already running will be ignored (with a console message).

doomsday/plugins/common/include/fi_lib.h

@@ -59,13 +59,28 @@ void FI_StackShutdown(void);
 /**
  * Push a new set of Finale commands onto the LIFO stack, suspending any
  * existing Finale on the stack until command interpretation completes.
+ * The script will have no definition ID on the stack; you can start an
+ * unlimited number of instances of the script.
  *
  * @param commands One or more Finale (script) commands to be executed.
  * @param flags  @see finaleFlags
  * @param mode  @see finaleMode
  */
 void FI_StackExecute(const char* commands, int flags, finale_mode_t mode);
 
+/**
+ * Push a new set of Finale commands onto the LIFO stack, suspending any
+ * existing Finale on the stack until command interpretation completes.
+ * If a script with the same definition ID is already on the stack, the
+ * script is not started.
+ *
+ * @param commands One or more Finale (script) commands to be executed.
+ * @param flags  @see finaleFlags
+ * @param mode  @see finaleMode
+ * @param defId  Script's definition ID.
+ */
+void FI_StackExecuteWithId(const char* scriptSrc, int flags, finale_mode_t mode, const char* defId);
+
 /**
  * Clear the LIFO Finale stack of any active scripts.
  */

doomsday/plugins/common/src/fi_lib.c

@@ -52,11 +52,19 @@ typedef struct {
 } fi_state_conditions_t;
 
 typedef struct {
-    finaleid_t finaleId;
+    finaleid_t finaleId;   
     finale_mode_t mode;
     fi_state_conditions_t conditions;
+
     /// Gamestate before the finale began.
     gamestate_t initialGamestate;
+
+    /**
+     * Optionally the ID of the source script definition. A new script is
+     * not started if its definition ID matches one already on the stack.
+     * @note Maximum ID length defined in the DED Reader implementation.
+     */
+    char defId[64];
 } fi_state_t;
 
 // EXTERNAL FUNCTION PROTOTYPES --------------------------------------------
@@ -152,19 +160,42 @@ static fi_state_t* stateForFinaleId(finaleid_t id)
     return 0;
 }
 
+static boolean stackHasDefId(const char* defId)
+{
+    uint i;
+    for(i = 0; i < finaleStackSize; ++i)
+    {
+        fi_state_t* s = &finaleStack[i];
+        if(!stricmp(s->defId, defId))
+            return true;
+    }
+    return false;
+}
+
 static __inline fi_state_t* stackTop(void)
 {
     return (finaleStackSize == 0? 0 : &finaleStack[finaleStackSize-1]);
 }
 
-static fi_state_t* stackPush(finaleid_t finaleId, finale_mode_t mode, gamestate_t prevGamestate)
+static fi_state_t* stackPush(finaleid_t finaleId, finale_mode_t mode, gamestate_t prevGamestate,
+                             const char* defId)
 {
     fi_state_t* s;
     finaleStack = Z_Realloc(finaleStack, sizeof(*finaleStack) * ++finaleStackSize, PU_GAMESTATIC);
     s = &finaleStack[finaleStackSize-1];
     s->finaleId = finaleId;
     s->mode = mode;
     s->initialGamestate = prevGamestate;
+    if(defId)
+    {
+        (void) strncpy(s->defId, defId, sizeof(s->defId) - 1);
+        s->defId[sizeof(s->defId) - 1] = 0; // terminate
+    }
+    else
+    {
+        // Source ID not provided.
+        memset(s->defId, 0, sizeof(s->defId));
+    }
     initStateConditions(s);
     return s;
 }
@@ -242,6 +273,11 @@ void FI_StackShutdown(void)
 }
 
 void FI_StackExecute(const char* scriptSrc, int flags, finale_mode_t mode)
+{
+    FI_StackExecuteWithId(scriptSrc, flags, mode, NULL);
+}
+
+void FI_StackExecuteWithId(const char* scriptSrc, int flags, finale_mode_t mode, const char* defId)
 {
     fi_state_t* s, *prevTopScript;
     gamestate_t prevGamestate;
@@ -251,6 +287,13 @@ void FI_StackExecute(const char* scriptSrc, int flags, finale_mode_t mode)
 
     if(!finaleStackInited) Con_Error("FI_StackExecute: Not initialized yet!");
 
+    // Should we ignore this?
+    if(defId && stackHasDefId(defId))
+    {
+        Con_Message("There already is a finale running with ID \"%s\"; won't execute again.\n", defId);
+        return;
+    }
+
     prevGamestate = G_GameState();
     prevTopScript = stackTop();
 
@@ -315,7 +358,7 @@ void FI_StackExecute(const char* scriptSrc, int flags, finale_mode_t mode)
         FI_ScriptSuspend(prevTopScript->finaleId);
     }
 
-    s = stackPush(finaleId, mode, prevGamestate);
+    s = stackPush(finaleId, mode, prevGamestate, defId);
 
     // Do we need to transmit the state conditions to clients?
     if(IS_SERVER && !(flags & FF_LOCAL))

doomsday/plugins/common/src/g_game.c

@@ -1084,7 +1084,7 @@ void G_ChangeGameState(gamestate_t state)
     DD_Executef(true, "%sactivatebcontext game", gameActive? "" : "de");
 }
 
-boolean G_StartFinale(const char* script, int flags, finale_mode_t mode)
+boolean G_StartFinale(const char* script, int flags, finale_mode_t mode, const char* defId)
 {
     assert(script && script[0]);
     { uint i;
@@ -1101,7 +1101,7 @@ boolean G_StartFinale(const char* script, int flags, finale_mode_t mode)
 #endif
     }}
     G_SetGameAction(GA_NONE);
-    FI_StackExecute(script, flags, mode);
+    FI_StackExecuteWithId(script, flags, mode, defId);
     return true;
 }
 
@@ -1119,7 +1119,7 @@ void G_StartTitle(void)
     if(!Def_Get(DD_DEF_FINALE, "title", &fin))
         Con_Error("G_StartTitle: A title script must be defined.");
 
-    G_StartFinale(fin.script, FF_LOCAL, FIMODE_NORMAL);
+    G_StartFinale(fin.script, FF_LOCAL, FIMODE_NORMAL, "title");
 }
 
 /**
@@ -1133,7 +1133,7 @@ void G_StartHelp(void)
     if(Def_Get(DD_DEF_FINALE, "help", &fin))
     {
         Hu_MenuCommand(MCMD_CLOSEFAST);
-        G_StartFinale(fin.script, FF_LOCAL, FIMODE_NORMAL);
+        G_StartFinale(fin.script, FF_LOCAL, FIMODE_NORMAL, "help");
         return;
     }
     Con_Message("Warning: InFine script 'help' not defined, ignoring.\n");
@@ -1295,7 +1295,7 @@ void G_DoLoadMap(void)
     // Start a briefing, if there is one.
     if(hasBrief)
     {
-        G_StartFinale(fin.script, 0, FIMODE_BEFORE);
+        G_StartFinale(fin.script, 0, FIMODE_BEFORE, 0);
     }
     else // No briefing, start the map.
     {
@@ -2302,7 +2302,7 @@ void G_WorldDone(void)
     FI_StackClear();
 
     if(G_DebriefingEnabled(gameEpisode, gameMap, &fin) &&
-       G_StartFinale(fin.script, 0, FIMODE_AFTER))
+       G_StartFinale(fin.script, 0, FIMODE_AFTER, 0))
     {
         return;
     }