(svn r27650) -Codechange: Replace SaveOrLoadMode by FileOperation and DetailedFileType.

16 files changed, 114 insertions, 101 deletions

diff --git a/src/console_cmds.cpp b/src/console_cmds.cpp
index a486ea282..c26f17f29 100644
--- a/src/console_cmds.cpp
+++ b/src/console_cmds.cpp
@@ -318,7 +318,7 @@ DEF_CONSOLE_CMD(ConSave)
 		char *filename = str_fmt("%s.sav", argv[1]);
 		IConsolePrint(CC_DEFAULT, "Saving map...");
 
-		if (SaveOrLoad(filename, SL_SAVE, SAVE_DIR) != SL_OK) {
+		if (SaveOrLoad(filename, FOP_SAVE, DFT_GAME_FILE, SAVE_DIR) != SL_OK) {
 			IConsolePrint(CC_ERROR, "Saving map failed");
 		} else {
 			IConsolePrintF(CC_DEFAULT, "Map successfully saved to %s", filename);
diff --git a/src/crashlog.cpp b/src/crashlog.cpp
index 4000cfb03..83beb94ff 100644
--- a/src/crashlog.cpp
+++ b/src/crashlog.cpp
@@ -388,7 +388,7 @@ bool CrashLog::WriteSavegame(char *filename, const char *filename_last) const
 		seprintf(filename, filename_last, "%scrash.sav", _personal_dir);
 
 		/* Don't do a threaded saveload. */
-		return SaveOrLoad(filename, SL_SAVE, NO_DIRECTORY, false) == SL_OK;
+		return SaveOrLoad(filename, FOP_SAVE, DFT_GAME_FILE, NO_DIRECTORY, false) == SL_OK;
 	} catch (...) {
 		return false;
 	}
diff --git a/src/fileio_type.h b/src/fileio_type.h
index 4fae7b392..0c4602bba 100644
--- a/src/fileio_type.h
+++ b/src/fileio_type.h
@@ -47,8 +47,11 @@ enum DetailedFileType {
 
 /** Operation performed on the file. */
 enum FileOperation {
-	FOP_LOAD, ///< File is being loaded.
-	FOP_SAVE, ///< File is being saved.
+	FOP_CHECK,   ///< Load file for checking and/or preview.
+	FOP_LOAD,    ///< File is being loaded.
+	FOP_SAVE,    ///< File is being saved.
+
+	FOP_INVALID, ///< Unknown file operation.
 };
 
 /**
diff --git a/src/fios_gui.cpp b/src/fios_gui.cpp
index a4e495b49..0c09f96ab 100644
--- a/src/fios_gui.cpp
+++ b/src/fios_gui.cpp
@@ -584,7 +584,7 @@ public:
 
 							if (GetDetailedFileType(file->type) == DFT_GAME_FILE) {
 								/* Other detailed file types cannot be checked before. */
-								SaveOrLoad(name, SL_LOAD_CHECK, NO_DIRECTORY, false);
+								SaveOrLoad(name, FOP_CHECK, DFT_GAME_FILE, NO_DIRECTORY, false);
 							}
 
 							this->InvalidateData(1);
@@ -777,7 +777,7 @@ void ShowSaveLoadDialog(AbstractFileType abstract_filetype, FileOperation fop)
 		sld = (abstract_filetype == FT_HEIGHTMAP) ? &_load_heightmap_dialog_desc : &_load_dialog_desc;
 	}
 
-	_file_to_saveload.filetype = abstract_filetype;
+	_file_to_saveload.abstract_ftype = abstract_filetype;
 
 	new SaveLoadWindow(sld, abstract_filetype, fop);
 }
diff --git a/src/genworld.cpp b/src/genworld.cpp
index 2b2dfb5fd..95e28fcdf 100644
--- a/src/genworld.cpp
+++ b/src/genworld.cpp
@@ -204,7 +204,7 @@ static void _GenerateWorld(void *)
 		if (_debug_desync_level > 0) {
 			char name[MAX_PATH];
 			seprintf(name, lastof(name), "dmp_cmds_%08x_%08x.sav", _settings_game.game_creation.generation_seed, _date);
-			SaveOrLoad(name, SL_SAVE, AUTOSAVE_DIR, false);
+			SaveOrLoad(name, FOP_SAVE, DFT_GAME_FILE, AUTOSAVE_DIR, false);
 		}
 	} catch (...) {
 		BasePersistentStorageArray::SwitchMode(PSM_LEAVE_GAMELOOP, true);
diff --git a/src/genworld_gui.cpp b/src/genworld_gui.cpp
index 61e114311..359709e36 100644
--- a/src/genworld_gui.cpp
+++ b/src/genworld_gui.cpp
@@ -833,7 +833,7 @@ static void _ShowGenerateLandscape(GenerateLandscapeWindowMode mode)
 
 	if (mode == GLWM_HEIGHTMAP) {
 		/* If the function returns negative, it means there was a problem loading the heightmap */
-		if (!GetHeightmapDimensions(_file_to_saveload.name, &x, &y)) return;
+		if (!GetHeightmapDimensions(_file_to_saveload.detail_ftype, _file_to_saveload.name, &x, &y)) return;
 	}
 
 	WindowDesc *desc = (mode == GLWM_HEIGHTMAP) ? &_heightmap_load_desc : &_generate_landscape_desc;
diff --git a/src/heightmap.cpp b/src/heightmap.cpp
index ec3125728..630dc69d7 100644
--- a/src/heightmap.cpp
+++ b/src/heightmap.cpp
@@ -102,7 +102,7 @@ static void ReadHeightmapPNGImageData(byte *map, png_structp png_ptr, png_infop
  * If map == NULL only the size of the PNG is read, otherwise a map
  * with grayscale pixels is allocated and assigned to *map.
  */
-static bool ReadHeightmapPNG(char *filename, uint *x, uint *y, byte **map)
+static bool ReadHeightmapPNG(const char *filename, uint *x, uint *y, byte **map)
 {
 	FILE *fp;
 	png_structp png_ptr = NULL;
@@ -232,7 +232,7 @@ static void ReadHeightmapBMPImageData(byte *map, BmpInfo *info, BmpData *data)
  * If map == NULL only the size of the BMP is read, otherwise a map
  * with grayscale pixels is allocated and assigned to *map.
  */
-static bool ReadHeightmapBMP(char *filename, uint *x, uint *y, byte **map)
+static bool ReadHeightmapBMP(const char *filename, uint *x, uint *y, byte **map)
 {
 	FILE *f;
 	BmpInfo info;
@@ -444,45 +444,56 @@ void FixSlopes()
 }
 
 /**
- * Reads the heightmap with the correct file reader
+ * Reads the heightmap with the correct file reader.
+ * @param dft Type of image file.
+ * @param filename Name of the file to load.
+ * @param [out] x Length of the image.
+ * @param [out] y Height of the image.
+ * @param [inout] map If not \c NULL, destination to store the loaded block of image data.
+ * @return Whether loading was successful.
  */
-static bool ReadHeightMap(char *filename, uint *x, uint *y, byte **map)
+static bool ReadHeightMap(DetailedFileType dft, const char *filename, uint *x, uint *y, byte **map)
 {
-	switch (_file_to_saveload.mode) {
-		default: NOT_REACHED();
+	switch (dft) {
+		default:
+			NOT_REACHED();
+
 #ifdef WITH_PNG
-		case SL_PNG:
+		case DFT_HEIGHTMAP_PNG:
 			return ReadHeightmapPNG(filename, x, y, map);
 #endif /* WITH_PNG */
-		case SL_BMP:
+
+		case DFT_HEIGHTMAP_BMP:
 			return ReadHeightmapBMP(filename, x, y, map);
 	}
 }
 
 /**
  * Get the dimensions of a heightmap.
+ * @param dft Type of image file.
  * @param filename to query
  * @param x dimension x
  * @param y dimension y
  * @return Returns false if loading of the image failed.
  */
-bool GetHeightmapDimensions(char *filename, uint *x, uint *y)
+bool GetHeightmapDimensions(DetailedFileType dft, const char *filename, uint *x, uint *y)
 {
-	return ReadHeightMap(filename, x, y, NULL);
+	return ReadHeightMap(dft, filename, x, y, NULL);
 }
 
 /**
  * Load a heightmap from file and change the map in his current dimensions
  *  to a landscape representing the heightmap.
  * It converts pixels to height. The brighter, the higher.
+ * @param dft Type of image file.
  * @param filename of the heightmap file to be imported
  */
-void LoadHeightmap(char *filename)
+void LoadHeightmap(DetailedFileType dft, const char *filename)
 {
 	uint x, y;
 	byte *map = NULL;
 
-	if (!ReadHeightMap(filename, &x, &y, &map)) {
+	if (!ReadHeightMap(dft, filename, &x, &y, &map)) {
 		free(map);
 		return;
 	}
diff --git a/src/heightmap.h b/src/heightmap.h
index 08ae200ec..67349df48 100644
--- a/src/heightmap.h
+++ b/src/heightmap.h
@@ -12,6 +12,8 @@
 #ifndef HEIGHTMAP_H
 #define HEIGHTMAP_H
 
+#include "fileio_type.h"
+
 /**
  * Order of these enums has to be the same as in lang/english.txt
  * Otherwise you will get inconsistent behaviour.
@@ -21,8 +23,8 @@ enum HeightmapRotation {
 	HM_CLOCKWISE,         ///< Rotate the map clockwise 45 degrees
 };
 
-bool GetHeightmapDimensions(char *filename, uint *x, uint *y);
-void LoadHeightmap(char *filename);
+bool GetHeightmapDimensions(DetailedFileType dft, const char *filename, uint *x, uint *y);
+void LoadHeightmap(DetailedFileType dft, const char *filename);
 void FlatEmptyWorld(byte tile_height);
 void FixSlopes();
 
diff --git a/src/landscape.cpp b/src/landscape.cpp
index d2b1b98cd..185e84a80 100644
--- a/src/landscape.cpp
+++ b/src/landscape.cpp
@@ -1222,7 +1222,7 @@ void GenerateLandscape(byte mode)
 
 	if (mode == GWM_HEIGHTMAP) {
 		SetGeneratingWorldProgress(GWP_LANDSCAPE, steps + GLS_HEIGHTMAP);
-		LoadHeightmap(_file_to_saveload.name);
+		LoadHeightmap(_file_to_saveload.detail_ftype, _file_to_saveload.name);
 		IncreaseGeneratingWorldProgress(GWP_LANDSCAPE);
 	} else if (_settings_game.game_creation.land_generator == LG_TERRAGENESIS) {
 		SetGeneratingWorldProgress(GWP_LANDSCAPE, steps + GLS_TERRAGENESIS);
diff --git a/src/network/network_client.cpp b/src/network/network_client.cpp
index d4d294146..a33e5c681 100644
--- a/src/network/network_client.cpp
+++ b/src/network/network_client.cpp
@@ -520,7 +520,7 @@ bool ClientNetworkGameSocketHandler::IsConnected()
  *   DEF_CLIENT_RECEIVE_COMMAND has parameter: Packet *p
  ************/
 
-extern bool SafeLoad(const char *filename, int mode, GameMode newgm, Subdirectory subdir, struct LoadFilter *lf = NULL);
+extern bool SafeLoad(const char *filename, FileOperation fop, DetailedFileType dft, GameMode newgm, Subdirectory subdir, struct LoadFilter *lf = NULL);
 
 NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_FULL(Packet *p)
 {
@@ -836,7 +836,7 @@ NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_MAP_DONE(Packet
 
 	/* The map is done downloading, load it */
 	ClearErrorMessages();
-	bool load_success = SafeLoad(NULL, SL_LOAD, GM_NORMAL, NO_DIRECTORY, lf);
+	bool load_success = SafeLoad(NULL, FOP_LOAD, DFT_GAME_FILE, GM_NORMAL, NO_DIRECTORY, lf);
 
 	/* Long savegame loads shouldn't affect the lag calculation! */
 	this->last_packet = _realtime_tick;
diff --git a/src/openttd.cpp b/src/openttd.cpp
index bd8ac4253..4464e8016 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -328,7 +328,7 @@ static void LoadIntroGame(bool load_newgrfs = true)
 	SetupColoursAndInitialWindow();
 
 	/* Load the default opening screen savegame */
-	if (SaveOrLoad("opntitle.dat", SL_LOAD, BASESET_DIR) != SL_OK) {
+	if (SaveOrLoad("opntitle.dat", FOP_LOAD, DFT_GAME_FILE, BASESET_DIR) != SL_OK) {
 		GenerateWorld(GWM_EMPTY, 64, 64); // if failed loading, make empty world.
 		WaitTillGeneratedWorld();
 		SetLocalCompany(COMPANY_SPECTATOR);
@@ -619,8 +619,9 @@ int openttd_main(int argc, char *argv[])
 		case 'g':
 			if (mgo.opt != NULL) {
 				strecpy(_file_to_saveload.name, mgo.opt, lastof(_file_to_saveload.name));
-				_switch_mode = (_switch_mode == SM_EDITOR || _switch_mode == SM_LOAD_SCENARIO ? SM_LOAD_SCENARIO : SM_LOAD_GAME);
-				_file_to_saveload.mode = SL_LOAD;
+				bool is_scenario = _switch_mode == SM_EDITOR || _switch_mode == SM_LOAD_SCENARIO;
+				_switch_mode = is_scenario ? SM_LOAD_SCENARIO : SM_LOAD_GAME;
+				_file_to_saveload.SetMode(FOP_LOAD, is_scenario ? FT_SCENARIO : FT_SAVEGAME, DFT_GAME_FILE);
 
 				/* if the file doesn't exist or it is not a valid savegame, let the saveload code show an error */
 				const char *t = strrchr(_file_to_saveload.name, '.');
@@ -650,7 +651,7 @@ int openttd_main(int argc, char *argv[])
 			FiosGetSavegameListCallback(FOP_LOAD, mgo.opt, strrchr(mgo.opt, '.'), title, lastof(title));
 
 			_load_check_data.Clear();
-			SaveOrLoadResult res = SaveOrLoad(mgo.opt, SL_LOAD_CHECK, SAVE_DIR, false);
+			SaveOrLoadResult res = SaveOrLoad(mgo.opt, FOP_CHECK, DFT_GAME_FILE, SAVE_DIR, false);
 			if (res != SL_OK || _load_check_data.HasErrors()) {
 				fprintf(stderr, "Failed to open savegame\n");
 				if (_load_check_data.HasErrors()) {
@@ -997,14 +998,15 @@ static void MakeNewEditorWorld()
  * @param subdir default directory to look for filename, set to 0 if not needed
  * @param lf Load filter to use, if NULL: use filename + subdir.
  */
-bool SafeLoad(const char *filename, int mode, GameMode newgm, Subdirectory subdir, struct LoadFilter *lf = NULL)
+bool SafeLoad(const char *filename, FileOperation fop, DetailedFileType dft, GameMode newgm, Subdirectory subdir, struct LoadFilter *lf = NULL)
 {
-	assert(mode == SL_LOAD || (lf == NULL && mode == SL_OLD_LOAD));
+	assert(fop == FOP_LOAD);
+	assert(dft == DFT_GAME_FILE || (lf == NULL && dft == DFT_OLD_GAME_FILE));
 	GameMode ogm = _game_mode;
 
 	_game_mode = newgm;
 
-	switch (lf == NULL ? SaveOrLoad(filename, mode, subdir) : LoadWithFilter(lf)) {
+	switch (lf == NULL ? SaveOrLoad(filename, fop, dft, subdir) : LoadWithFilter(lf)) {
 		case SL_OK: return true;
 
 		case SL_REINIT:
@@ -1093,11 +1095,11 @@ void SwitchToMode(SwitchMode new_mode)
 			ResetGRFConfig(true);
 			ResetWindowSystem();
 
-			if (!SafeLoad(_file_to_saveload.name, _file_to_saveload.mode, GM_NORMAL, NO_DIRECTORY)) {
+			if (!SafeLoad(_file_to_saveload.name, _file_to_saveload.file_op, _file_to_saveload.detail_ftype, GM_NORMAL, NO_DIRECTORY)) {
 				SetDParamStr(0, GetSaveLoadErrorString());
 				ShowErrorMessage(STR_JUST_RAW_STRING, INVALID_STRING_ID, WL_ERROR);
 			} else {
-				if (_file_to_saveload.filetype == FT_SCENARIO) {
+				if (_file_to_saveload.abstract_ftype == FT_SCENARIO) {
 					/* Reset engine pool to simplify changing engine NewGRFs in scenario editor. */
 					EngineOverrideManager::ResetToCurrentNewGRFConfig();
 				}
@@ -1134,7 +1136,7 @@ void SwitchToMode(SwitchMode new_mode)
 			break;
 
 		case SM_LOAD_SCENARIO: { // Load scenario from scenario editor
-			if (SafeLoad(_file_to_saveload.name, _file_to_saveload.mode, GM_EDITOR, NO_DIRECTORY)) {
+			if (SafeLoad(_file_to_saveload.name, _file_to_saveload.file_op, _file_to_saveload.detail_ftype, GM_EDITOR, NO_DIRECTORY)) {
 				SetLocalCompany(OWNER_NONE);
 				_settings_newgame.game_creation.starting_year = _cur_year;
 				/* Cancel the saveload pausing */
@@ -1156,7 +1158,7 @@ void SwitchToMode(SwitchMode new_mode)
 
 		case SM_SAVE_GAME: // Save game.
 			/* Make network saved games on pause compatible to singleplayer */
-			if (SaveOrLoad(_file_to_saveload.name, SL_SAVE, NO_DIRECTORY) != SL_OK) {
+			if (SaveOrLoad(_file_to_saveload.name, FOP_SAVE, DFT_GAME_FILE, NO_DIRECTORY) != SL_OK) {
 				SetDParamStr(0, GetSaveLoadErrorString());
 				ShowErrorMessage(STR_JUST_RAW_STRING, INVALID_STRING_ID, WL_ERROR);
 			} else {
@@ -1367,7 +1369,7 @@ void StateGameLoop()
 			/* Save the desync savegame if needed. */
 			char name[MAX_PATH];
 			seprintf(name, lastof(name), "dmp_cmds_%08x_%08x.sav", _settings_game.game_creation.generation_seed, _date);
-			SaveOrLoad(name, SL_SAVE, AUTOSAVE_DIR, false);
+			SaveOrLoad(name, FOP_SAVE, DFT_GAME_FILE, AUTOSAVE_DIR, false);
 		}
 
 		CheckCaches();
@@ -1424,7 +1426,7 @@ static void DoAutosave()
 	}
 
 	DEBUG(sl, 2, "Autosaving to '%s'", buf);
-	if (SaveOrLoad(buf, SL_SAVE, AUTOSAVE_DIR) != SL_OK) {
+	if (SaveOrLoad(buf, FOP_SAVE, DFT_GAME_FILE, AUTOSAVE_DIR) != SL_OK) {
 		ShowErrorMessage(STR_ERROR_AUTOSAVE_FAILED, INVALID_STRING_ID, WL_ERROR);
 	}
 }
diff --git a/src/saveload/afterload.cpp b/src/saveload/afterload.cpp
index 969048115..de3f7ccff 100644
--- a/src/saveload/afterload.cpp
+++ b/src/saveload/afterload.cpp
@@ -248,7 +248,7 @@ static void InitializeWindowsAndCaches()
 		/* For each company, verify (while loading a scenario) that the inauguration date is the current year and set it
 		 * accordingly if it is not the case.  No need to set it on companies that are not been used already,
 		 * thus the MIN_YEAR (which is really nothing more than Zero, initialized value) test */
-		if (_file_to_saveload.filetype == FT_SCENARIO && c->inaugurated_year != MIN_YEAR) {
+		if (_file_to_saveload.abstract_ftype == FT_SCENARIO && c->inaugurated_year != MIN_YEAR) {
 			c->inaugurated_year = _cur_year;
 		}
 	}
diff --git a/src/saveload/saveload.cpp b/src/saveload/saveload.cpp
index b5fdda27a..4dd8a4c7b 100644
--- a/src/saveload/saveload.cpp
+++ b/src/saveload/saveload.cpp
@@ -2778,10 +2778,10 @@ SaveOrLoadResult LoadWithFilter(LoadFilter *reader)
  * @param threaded True when threaded saving is allowed
  * @return Return the result of the action. #SL_OK, #SL_ERROR, or #SL_REINIT ("unload" the game)
  */
-SaveOrLoadResult SaveOrLoad(const char *filename, int mode, Subdirectory sb, bool threaded)
+SaveOrLoadResult SaveOrLoad(const char *filename, FileOperation fop, DetailedFileType dft, Subdirectory sb, bool threaded)
 {
 	/* An instance of saving is already active, so don't go saving again */
-	if (_sl.saveinprogress && mode == SL_SAVE && threaded) {
+	if (_sl.saveinprogress && fop == FOP_SAVE && dft == DFT_GAME_FILE && threaded) {
 		/* if not an autosave, but a user action, show error message */
 		if (!_do_autosave) ShowErrorMessage(STR_ERROR_SAVE_STILL_IN_PROGRESS, INVALID_STRING_ID, WL_ERROR);
 		return SL_OK;
@@ -2790,7 +2790,7 @@ SaveOrLoadResult SaveOrLoad(const char *filename, int mode, Subdirectory sb, boo
 
 	try {
 		/* Load a TTDLX or TTDPatch game */
-		if (mode == SL_OLD_LOAD) {
+		if (fop == FOP_LOAD && dft == DFT_OLD_GAME_FILE) {
 			InitializeGame(256, 256, true, true); // set a mapsize of 256x256 for TTDPatch games or it might get confused
 
 			/* TTD/TTO savegames have no NewGRFs, TTDP savegame have them
@@ -2811,25 +2811,35 @@ SaveOrLoadResult SaveOrLoad(const char *filename, int mode, Subdirectory sb, boo
 			return SL_OK;
 		}
 
-		switch (mode) {
-			case SL_LOAD_CHECK: _sl.action = SLA_LOAD_CHECK; break;
-			case SL_LOAD: _sl.action = SLA_LOAD; break;
-			case SL_SAVE: _sl.action = SLA_SAVE; break;
+		assert(dft == DFT_GAME_FILE);
+		switch (dft) {
+			case FOP_CHECK:
+				_sl.action = SLA_LOAD_CHECK;
+				break;
+
+			case FOP_LOAD:
+				_sl.action = SLA_LOAD;
+				break;
+
+			case FOP_SAVE:
+				_sl.action = SLA_SAVE;
+				break;
+
 			default: NOT_REACHED();
 		}
 
-		FILE *fh = (mode == SL_SAVE) ? FioFOpenFile(filename, "wb", sb) : FioFOpenFile(filename, "rb", sb);
+		FILE *fh = (fop == FOP_SAVE) ? FioFOpenFile(filename, "wb", sb) : FioFOpenFile(filename, "rb", sb);
 
 		/* Make it a little easier to load savegames from the console */
-		if (fh == NULL && mode != SL_SAVE) fh = FioFOpenFile(filename, "rb", SAVE_DIR);
-		if (fh == NULL && mode != SL_SAVE) fh = FioFOpenFile(filename, "rb", BASE_DIR);
-		if (fh == NULL && mode != SL_SAVE) fh = FioFOpenFile(filename, "rb", SCENARIO_DIR);
+		if (fh == NULL && fop != FOP_SAVE) fh = FioFOpenFile(filename, "rb", SAVE_DIR);
+		if (fh == NULL && fop != FOP_SAVE) fh = FioFOpenFile(filename, "rb", BASE_DIR);
+		if (fh == NULL && fop != FOP_SAVE) fh = FioFOpenFile(filename, "rb", SCENARIO_DIR);
 
 		if (fh == NULL) {
-			SlError(mode == SL_SAVE ? STR_GAME_SAVELOAD_ERROR_FILE_NOT_WRITEABLE : STR_GAME_SAVELOAD_ERROR_FILE_NOT_READABLE);
+			SlError(fop == FOP_SAVE ? STR_GAME_SAVELOAD_ERROR_FILE_NOT_WRITEABLE : STR_GAME_SAVELOAD_ERROR_FILE_NOT_READABLE);
 		}
 
-		if (mode == SL_SAVE) { // SAVE game
+		if (fop == FOP_SAVE) { // SAVE game
 			DEBUG(desync, 1, "save: %08x; %02x; %s", _date, _date_fract, filename);
 			if (_network_server || !_settings_client.gui.threaded_saves) threaded = false;
 
@@ -2837,24 +2847,25 @@ SaveOrLoadResult SaveOrLoad(const char *filename, int mode, Subdirectory sb, boo
 		}
 
 		/* LOAD game */
-		assert(mode == SL_LOAD || mode == SL_LOAD_CHECK);
+		assert(fop == FOP_LOAD || fop == FOP_CHECK);
 		DEBUG(desync, 1, "load: %s", filename);
-		return DoLoad(new FileReader(fh), mode == SL_LOAD_CHECK);
+		return DoLoad(new FileReader(fh), fop == FOP_CHECK);
 	} catch (...) {
+		/* This code may be executed both for old and new save games. */
 		ClearSaveLoadState();
 
 		/* Skip the "colour" character */
-		if (mode != SL_LOAD_CHECK) DEBUG(sl, 0, "%s", GetSaveLoadErrorString() + 3);
+		if (fop != FOP_CHECK) DEBUG(sl, 0, "%s", GetSaveLoadErrorString() + 3);
 
 		/* A saver/loader exception!! reinitialize all variables to prevent crash! */
-		return (mode == SL_LOAD || mode == SL_OLD_LOAD) ? SL_REINIT : SL_ERROR;
+		return (fop == FOP_LOAD) ? SL_REINIT : SL_ERROR;
 	}
 }
 
 /** Do a save when exiting the game (_settings_client.gui.autosave_on_exit) */
 void DoExitSave()
 {
-	SaveOrLoad("exit.sav", SL_SAVE, AUTOSAVE_DIR);
+	SaveOrLoad("exit.sav", FOP_SAVE, DFT_GAME_FILE, AUTOSAVE_DIR);
 }
 
 /**
@@ -2898,34 +2909,27 @@ void GenerateDefaultSaveName(char *buf, const char *last)
  */
 void FileToSaveLoad::SetMode(FiosType ft)
 {
-	switch (ft) {
-		case FIOS_TYPE_FILE:
-		case FIOS_TYPE_SCENARIO:
-			this->mode = SL_LOAD;
-			break;
-
-		case FIOS_TYPE_OLDFILE:
-		case FIOS_TYPE_OLD_SCENARIO:
-			this->mode = SL_OLD_LOAD;
-			break;
-
-#ifdef WITH_PNG
-		case FIOS_TYPE_PNG:
-			this->mode = SL_PNG;
-			break;
-#endif /* WITH_PNG */
-
-		case FIOS_TYPE_BMP:
-			this->mode = SL_BMP;
-			break;
+	this->SetMode(FOP_LOAD, GetAbstractFileType(ft), GetDetailedFileType(ft));
+}
 
-		default:
-			this->mode = SL_INVALID;
-			break;
+/**
+ * Set the mode and file type of the file to save or load.
+ * @param fop File operation being performed.
+ * @param aft Abstract file type.
+ * @param dft Detailed file type.
+ */
+void FileToSaveLoad::SetMode(FileOperation fop, AbstractFileType aft, DetailedFileType dft)
+{
+	if (aft == FT_INVALID || aft == FT_NONE) {
+		this->file_op = FOP_INVALID;
+		this->detail_ftype = DFT_INVALID;
+		this->abstract_ftype = FT_INVALID;
+		return;
 	}
 
-	this->filetype = GetAbstractFileType(ft);
-	if (this->filetype == FT_NONE) this->filetype = FT_INVALID;
+	this->file_op = fop;
+	this->detail_ftype = dft;
+	this->abstract_ftype = aft;
 }
 
 #if 0
diff --git a/src/saveload/saveload.h b/src/saveload/saveload.h
index 43b9d5d3c..7b0ae8f48 100644
--- a/src/saveload/saveload.h
+++ b/src/saveload/saveload.h
@@ -22,25 +22,16 @@ enum SaveOrLoadResult {
 	SL_REINIT = 2, ///< error that was caught in the middle of updating game state, need to clear it. (can only happen during load)
 };
 
-/** Save or load mode. @see SaveOrLoad */
-enum SaveOrLoadMode {
-	SL_INVALID    = -1, ///< Invalid mode.
-	SL_LOAD       =  0, ///< Load game.
-	SL_SAVE       =  1, ///< Save game.
-	SL_OLD_LOAD   =  2, ///< Load old game.
-	SL_PNG        =  3, ///< Load PNG file (height map).
-	SL_BMP        =  4, ///< Load BMP file (height map).
-	SL_LOAD_CHECK =  5, ///< Load for game preview.
-};
-
 /** Deals with the type of the savegame, independent of extension */
 struct FileToSaveLoad {
-	SaveOrLoadMode mode;       ///< savegame/scenario type (old, new)
-	AbstractFileType filetype; ///< what type of file are we dealing with
-	char name[MAX_PATH];       ///< name
-	char title[255];           ///< internal name of the game
+	FileOperation file_op;           ///< File operation to perform.
+	DetailedFileType detail_ftype;   ///< Concrete file type (PNG, BMP, old save, etc).
+	AbstractFileType abstract_ftype; ///< Abstract type of file (scenario, heightmap, etc).
+	char name[MAX_PATH];             ///< Name of the file.
+	char title[255];                 ///< Internal name of the game.
 
 	void SetMode(FiosType ft);
+	void SetMode(FileOperation fop, AbstractFileType aft, DetailedFileType dft);
 };
 
 /** Types of save games. */
@@ -58,7 +49,7 @@ extern FileToSaveLoad _file_to_saveload;
 void GenerateDefaultSaveName(char *buf, const char *last);
 void SetSaveLoadError(uint16 str);
 const char *GetSaveLoadErrorString();
-SaveOrLoadResult SaveOrLoad(const char *filename, int mode, Subdirectory sb, bool threaded = true);
+SaveOrLoadResult SaveOrLoad(const char *filename, FileOperation fop, DetailedFileType dft, Subdirectory sb, bool threaded = true);
 void WaitTillSaved();
 void ProcessAsyncSaveFinish();
 void DoExitSave();
diff --git a/src/saveload/signs_sl.cpp b/src/saveload/signs_sl.cpp
index 077d34501..132ac181e 100644
--- a/src/saveload/signs_sl.cpp
+++ b/src/saveload/signs_sl.cpp
@@ -60,7 +60,7 @@ static void Load_SIGN()
 		}
 
 		/* Signs placed in scenario editor shall now be OWNER_DEITY */
-		if (IsSavegameVersionBefore(171) && si->owner == OWNER_NONE && _file_to_saveload.filetype == FT_SCENARIO) {
+		if (IsSavegameVersionBefore(171) && si->owner == OWNER_NONE && _file_to_saveload.abstract_ftype == FT_SCENARIO) {
 			si->owner = OWNER_DEITY;
 		}
 	}
diff --git a/src/video/dedicated_v.cpp b/src/video/dedicated_v.cpp
index bfe853e9a..95d40cd00 100644
--- a/src/video/dedicated_v.cpp
+++ b/src/video/dedicated_v.cpp
@@ -142,7 +142,7 @@ static void *_dedicated_video_mem;
 /* Whether a fork has been done. */
 bool _dedicated_forks;
 
-extern bool SafeLoad(const char *filename, int mode, GameMode newgm, Subdirectory subdir, struct LoadFilter *lf = NULL);
+extern bool SafeLoad(const char *filename, FileOperation fop, DetailedFileType dft, GameMode newgm, Subdirectory subdir, struct LoadFilter *lf = NULL);
 
 static FVideoDriver_Dedicated iFVideoDriver_Dedicated;
 
@@ -286,7 +286,7 @@ void VideoDriver_Dedicated::MainLoop()
 		_switch_mode = SM_NONE;
 		/* First we need to test if the savegame can be loaded, else we will end up playing the
 		 *  intro game... */
-		if (!SafeLoad(_file_to_saveload.name, _file_to_saveload.mode, GM_NORMAL, BASE_DIR)) {
+		if (!SafeLoad(_file_to_saveload.name, _file_to_saveload.file_op, _file_to_saveload.detail_ftype, GM_NORMAL, BASE_DIR)) {
 			/* Loading failed, pop out.. */
 			DEBUG(net, 0, "Loading requested map failed, aborting");
 			_networking = false;