libcommon: Added a basic GameStateReaderFactory

With runtime registration so that new IGameStateReaders can be added
without requiring the factory to have compile time knowledge of the
derived classes.

Todo: The implementation could probably be improved (factory should
return instances with std::auto_ptr?). Perhaps libdeng2 could provide
the abstract components necessary for building a factory?

doomsday/plugins/common/include/common.h

@@ -50,6 +50,14 @@
 DENG_EXTERN_C dd_bool sc_FileScripts;
 DENG_EXTERN_C char const *sc_ScriptsDir;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 int Common_GetInteger(int id);
 
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
 #endif // LIBCOMMON_GAME_INCLUDES

doomsday/plugins/common/include/gamestatereader.h

@@ -44,28 +44,89 @@ class IGameStateReader
      * Attempt to load (read/interpret) the saved game state.
      *
      * @param info  SaveInfo for the saved game state to be read/interpreted.
-     * @param path  Path to the resource file to be recognized.
+     * @param path  Path to the saved game state to be read.
+     *
+     * @todo @a path should be provided by SaveInfo.
      */
     virtual void read(SaveInfo &info, Str const *path) = 0;
 };
 
 /**
- * @ingroup libcommon
- * @see GameStateWriter
+ * Game state recognizer function ptr.
+ *
+ * The job of a recognizer function is to determine whether the resource file on @a path is interpretable
+ * as a potentially loadable game state.
+ *
+ * @param info  SaveInfo to attempt to read game session header into.
+ * @param path  Path to the resource file to be recognized.
  */
-class GameStateReader : public IGameStateReader
+typedef bool (*GameStateRecognizeFunc)(SaveInfo &info, Str const *path);
+
+/// Game state reader instantiator function ptr.
+typedef IGameStateReader *(*GameStateReaderMakeFunc)();
+
+/**
+ * Factory for the construction of new IGameStateReader-derived instances.
+ */
+class GameStateReaderFactory
 {
 public:
-    GameStateReader();
-    ~GameStateReader();
+    /**
+     * Register a game state reader.
+     *
+     * @param recognizer  Game state recognizer function.
+     * @param maker       Game state reader instantiator function.
+     */
+    void declareReader(GameStateRecognizeFunc recognizer, GameStateReaderMakeFunc maker)
+    {
+        ReaderInfo info;
+        info.recognize    = recognizer;
+        info.makeInstance = maker;
+        readers.push_back(info);
+    }
 
     /**
-     * Determines whether the resource file on @a path is interpretable as a game state which can
-     * be loaded with a GameStateReader.
+     * Returns a new IGameStateReader instance appropriate for the specified save game @a info.
      *
      * @param info  SaveInfo to attempt to read game session header into.
      * @param path  Path to the resource file to be recognized.
+     *
+     * @return  New reader instance if recognized; otherwise @c 0. Ownership given to the caller.
      */
+    IGameStateReader *newReaderFor(SaveInfo &info, Str const *path)
+    {
+        DENG2_FOR_EACH_CONST(ReaderInfos, i, readers)
+        {
+            if(i->recognize(info, path))
+            {
+                return i->makeInstance();
+            }
+        }
+        return 0; // Unrecognized
+    }
+
+private:
+    struct ReaderInfo {
+        GameStateRecognizeFunc recognize;
+        GameStateReaderMakeFunc makeInstance;
+    };
+    typedef std::list<ReaderInfo> ReaderInfos;
+    ReaderInfos readers;
+};
+
+/**
+ * Native saved game state reader.
+ *
+ * @ingroup libcommon
+ * @see GameStateWriter
+ */
+class GameStateReader : public IGameStateReader
+{
+public:
+    GameStateReader();
+    ~GameStateReader();
+
+    static IGameStateReader *make();
     static bool recognize(SaveInfo &info, Str const *path);
 
     void read(SaveInfo &info, Str const *path);

doomsday/plugins/common/include/gamestatewriter.h

@@ -26,6 +26,8 @@
 #include <de/Error>
 
 /**
+ * Native saved game state writer.
+ *
  * @ingroup libcommon
  * @see GameStateReader
  */
@@ -38,7 +40,7 @@ class GameStateWriter
 public:
     GameStateWriter();
 
-    void write(SaveInfo *saveInfo, Str const *path);
+    void write(SaveInfo &info, Str const *path);
 
 private:
     DENG2_PRIVATE(d)

doomsday/plugins/common/include/p_saveg.h

@@ -132,6 +132,16 @@ void SV_SaveInfo_Read(SaveInfo *info, Reader *reader);
 #endif
 
 #ifdef __cplusplus
+#include "gamestatereader.h"
+
+/**
+ * Declare a new saved game state reader/interpreter.
+ *
+ * @param recognizer  Format recognizer function.
+ * @param maker       Reader instantiator function.
+ */
+void SV_DeclareGameStateReader(GameStateRecognizeFunc recognizer, GameStateReaderMakeFunc maker);
+
 class MapStateReader;
 class MapStateWriter;
 

doomsday/plugins/common/src/gamestatereader.cpp

@@ -323,6 +323,11 @@ bool GameStateReader::recognize(SaveInfo &info, Str const *path) // static
     return true;
 }
 
+IGameStateReader *GameStateReader::make() // static
+{
+    return new GameStateReader;
+}
+
 void GameStateReader::read(SaveInfo &info, Str const *path)
 {
     DENG_ASSERT(path != 0);

doomsday/plugins/common/src/gamestatewriter.cpp

@@ -123,10 +123,10 @@ DENG2_PIMPL(GameStateWriter)
 GameStateWriter::GameStateWriter() : d(new Instance(this))
 {}
 
-void GameStateWriter::write(SaveInfo *saveInfo, Str const *path)
+void GameStateWriter::write(SaveInfo &info, Str const *path)
 {
-    DENG_ASSERT(saveInfo != 0 && path != 0);
-    d->saveInfo = saveInfo;
+    DENG_ASSERT(path != 0);
+    d->saveInfo = &info;
 
     // In networked games the server tells the clients to save their games.
 #if !__JHEXEN__

doomsday/plugins/common/src/p_saveg.cpp

@@ -30,19 +30,14 @@
 #include "gamestatereader.h"
 #include "mapstatereader.h"
 #include "mapstatewriter.h"
-#if __JDOOM__
-#  include "doomv9gamestatereader.h"
-#endif
-#if __JHERETIC__
-#  include "hereticv13gamestatereader.h"
-#endif
 #include <de/String>
 #include <de/memory.h>
 #include <cstdio>
 #include <cstring>
 
 static bool inited = false;
 
+static GameStateReaderFactory gameStateReaderFactory;
 static SaveSlots sslots(NUMSAVESLOTS);
 SaveSlots *saveSlots = &sslots;
 
@@ -880,6 +875,12 @@ void SV_Initialize()
     // (Re)Initialize the saved game paths, possibly creating them if they do not exist.
     SV_ConfigureSavePaths();
 
+    if(!inited)
+    {
+        // Declare the native game state reader.
+        gameStateReaderFactory.declareReader(&GameStateReader::recognize, &GameStateReader::make);
+    }
+
     inited = true;
 }
 
@@ -893,6 +894,23 @@ void SV_Shutdown()
     inited = false;
 }
 
+void SV_DeclareGameStateReader(GameStateRecognizeFunc recognizer, GameStateReaderMakeFunc maker)
+{
+    DENG_ASSERT(inited);
+    gameStateReaderFactory.declareReader(recognizer, maker);
+}
+
+static std::auto_ptr<IGameStateReader> gameStateReaderFor(SaveInfo &info, Str const *path)
+{
+    std::auto_ptr<IGameStateReader> p(gameStateReaderFactory.newReaderFor(info, path));
+    if(!p.get())
+    {
+        /// @throw Error The saved game state format was not recognized.
+        throw de::Error("gameStateReaderFor", "Unrecognized savegame format");
+    }
+    return p;
+}
+
 dd_bool SV_LoadGame(int slot)
 {
     DENG_ASSERT(inited);
@@ -931,28 +949,8 @@ dd_bool SV_LoadGame(int slot)
     {
         SaveInfo &info = saveSlots->saveInfo(logicalSlot);
 
-        if(GameStateReader::recognize(info, path))
-        {
-            GameStateReader().read(info, path);
-        }
-        // Perhaps an original game state?
-#if __JDOOM__
-        else if(DoomV9GameStateReader::recognize(info, path))
-        {
-            DoomV9GameStateReader().read(info, path);
-        }
-#endif
-#if __JHERETIC__
-        else if(HereticV13GameStateReader::recognize(info, path))
-        {
-            HereticV13GameStateReader().read(info, path);
-        }
-#endif
-        else
-        {
-            /// @throw Error The savegame was not recognized.
-            throw de::Error("loadGameState", "Unrecognized savegame format");
-        }
+        // Attempt to recognize and load the saved game state.
+        gameStateReaderFor(info, path)->read(info, path);
 
         // Make note of the last used save slot.
         Con_SetInteger2("game-save-last-slot", slot, SVF_WRITE_OVERRIDE);
@@ -1000,7 +998,7 @@ dd_bool SV_SaveGame(int slot, char const *description)
     SaveInfo *info = SaveInfo::newWithCurrentSessionMetadata(AutoStr_FromTextStd(description));
     try
     {
-        GameStateWriter().write(info, path);
+        GameStateWriter().write(*info, path);
 
         // Swap the save info.
         saveSlots->replaceSaveInfo(logicalSlot, info);

doomsday/plugins/doom/doom.pro

@@ -75,7 +75,7 @@ SOURCES += \
     src/d_api.c \
     src/d_console.c \
     src/d_items.c \
-    src/d_main.c \
+    src/d_main.cpp \
     src/d_refresh.c \
     src/doomv9gamestatereader.cpp \
     src/m_cheat.c \

doomsday/plugins/doom/include/acfnlink.h

@@ -37,7 +37,7 @@ typedef struct {
     void (C_DECL *func)();  // Pointer to the function.
 } actionlink_t;
 
-extern actionlink_t actionlinks[];
+DENG_EXTERN_C actionlink_t actionlinks[];
 
 void C_DECL A_BabyMetal();
 void C_DECL A_BFGsound();

doomsday/plugins/doom/include/d_main.h

@@ -1,25 +1,21 @@
-/**\file d_main.h
- *\section License
- * License: GPL
- * Online License Link: http://www.gnu.org/licenses/gpl.html
+/** @file d_main.h  Doom-specific game initialization
  *
- *\author Copyright © 2003-2013 Jaakko Keränen <jaakko.keranen@iki.fi>
- *\author Copyright © 2005-2013 Daniel Swanson <danij@dengine.net>
+ * @authors Copyright © 2003-2013 Jaakko Keränen <jaakko.keranen@iki.fi>
+ * @authors Copyright © 2005-2013 Daniel Swanson <danij@dengine.net>
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * @par License
+ * GPL: http://www.gnu.org/licenses/gpl.html
  *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor,
- * Boston, MA  02110-1301  USA
+ * <small>This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version. This program is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details. You should have received a copy of the GNU
+ * General Public License along with this program; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA</small>
  */
 
 #ifndef LIBJDOOM_MAIN_H
@@ -31,40 +27,37 @@
 
 #include "doomdef.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-extern int verbose;
+DENG_EXTERN_C int verbose;
 
-//extern dd_bool noMonstersParm; // checkparm of -nomonsters
-//extern dd_bool respawnParm; // checkparm of -respawn
-//extern dd_bool turboParm; // checkparm of -turbo
-//extern dd_bool randomClassParm; // checkparm of -randclass
-//extern dd_bool devParm; // checkparm of -devparm
-//extern dd_bool fastParm; // checkparm of -fast
+DENG_EXTERN_C float turboMul; // Multiplier for turbo.
 
-extern float turboMul; // Multiplier for turbo.
+DENG_EXTERN_C gamemode_t gameMode;
+DENG_EXTERN_C int gameModeBits;
 
-extern gamemode_t gameMode;
-extern int gameModeBits;
+DENG_EXTERN_C char *borderGraphics[];
 
-extern char* borderGraphics[];
+DENG_EXTERN_C float defFontRGB[];
+DENG_EXTERN_C float defFontRGB2[];
+DENG_EXTERN_C float defFontRGB3[];
 
-extern float defFontRGB[];
-extern float defFontRGB2[];
-extern float defFontRGB3[];
+DENG_EXTERN_C dd_bool monsterInfight;
 
-extern dd_bool monsterInfight;
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 void D_PreInit(void);
+
 void D_PostInit(void);
+
 void D_Shutdown(void);
+
 int D_GetInteger(int id);
-void* D_GetVariable(int id);
+
+void *D_GetVariable(int id);
 
 #ifdef __cplusplus
 } // extern "C"
 #endif
 
-#endif /* LIBJDOOM_MAIN_H */
+#endif // LIBJDOOM_MAIN_H