Turn Base_directory into an std::filesystem::path

Before this change, Base_directory was a char array. In general, it’s
better to use an std::filesystem::path to represent paths. Here’s why:

• char arrays have a limited size. If a user creates a file or directory
that has a very long path, then it might not be possible to store that
path in a given char array. You can try to make the char array long
enough to store the longest possible path, but future operating systems
may increase that limit. With std::filesystem::paths, you don’t have
to worry about path length limits.

• char arrays cannot necessarily represent all paths. We try our best to
use UTF-8 for all char arrays [1], but unfortunately, it’s possible to
create a path that cannot be represent using UTF-8 [2]. With an
std::filesystem::paths, stuff like that is less likely to happen because
std::filesystem::path::value_type is platform-specific.

• char arrays don’t have any built-in mechanisms for manipulating paths.
Before this commit, the code would work around this problem in two
different ways:

  1. It would use Descent 3–specific functions that implement path
  operations on char arrays/pointers (for example, ddio_MakePath()).
  Once all paths use std::filesystem::path, we’ll be able to simplify
  the code by removing those functions.

  2. It would temporarily convert Base_directory into an
  std::filesystem::path. This commit simplifies the code by removing
  those temporary conversions because they are no longer necessary.

[1]: 7cd7902 (Merge pull request DescentDevelopers#494 from Jayman2000/encoding-improvements, 2024-07-20)
[2]: <rust-lang/rust#12056>

Descent3/Game2DLL.cpp

@@ -567,7 +567,7 @@ bool InitGameModule(const char *name, module *mod) {
   char dll_name[_MAX_PATH * 2];
   char tmp_dll_name[_MAX_PATH * 2];
   // Make the hog filename
-  ddio_MakePath(lib_name, Base_directory, "netgames", name, NULL);
+  ddio_MakePath(lib_name, Base_directory.u8string().c_str(), "netgames", name, NULL);
   strcat(lib_name, ".d3m");
 // Make the dll filename
 #if defined(WIN32)
@@ -580,7 +580,7 @@ bool InitGameModule(const char *name, module *mod) {
 
   // Open the hog file
   if (!cf_OpenLibrary(lib_name)) {
-    ddio_MakePath(tmp_dll_name, Base_directory, "netgames", name, NULL);
+    ddio_MakePath(tmp_dll_name, Base_directory.u8string().c_str(), "netgames", name, NULL);
     strcat(tmp_dll_name, ".d3m");
     Multi_game_dll_name[0] = '\0';
     goto loaddll;

Descent3/ambient.cpp

@@ -293,7 +293,7 @@ void WriteAmbientData() {
   CFILE *ofile;
 
 #ifndef NEWEDITOR
-  ddio_MakePath(filename, Base_directory, "data", "misc", AMBIENT_FILE_NAME, NULL);
+  ddio_MakePath(filename, Base_directory.u8string().c_str(), "data", "misc", AMBIENT_FILE_NAME, NULL);
 #else
   ddio_MakePath(filename, D3HogDir, "data", "misc", AMBIENT_FILE_NAME, NULL);
 #endif

Descent3/demofile.cpp

@@ -360,7 +360,7 @@ void DemoToggleRecording() {
     if (stricmp(szfile + (strlen(szfile) - 4), ".dem") != 0) {
       strcat(szfile, ".dem");
     }
-    Demo_fname = std::filesystem::path(Base_directory) / "demo" / szfile;
+    Demo_fname = Base_directory / "demo" / szfile;
     mprintf(0, "Saving demo to file: %s\n", Demo_fname.u8string().c_str());
     // Try to create the file
     Demo_cfp = cfopen(Demo_fname, "wb");
@@ -1423,7 +1423,7 @@ bool LoadDemoDialog() {
   //	return false;
   // #else
 
-  std::filesystem::path file = std::filesystem::path(Base_directory) / "demo";
+  std::filesystem::path file = Base_directory / "demo";
 
   if (DoPathFileDialog(false, file, TXT_VIEWDEMO, {"*.dem"}, PFDF_FILEMUSTEXIST)) {
     Demo_fname = file;

Descent3/descent.h

@@ -182,7 +182,7 @@ extern bool Descent_overrided_intro;
 #define MSN_NAMELEN 32
 
 // The "root" directory of the D3 file tree
-extern char Base_directory[];
+extern std::filesystem::path Base_directory;
 
 // Variable to preserve current path. TODO: redundant?
 extern std::filesystem::path orig_pwd;

Descent3/game.cpp

@@ -1298,7 +1298,7 @@ void DoScreenshot() {
   count = 1;
   while (!done) {
     snprintf(str, sizeof(str), "Screenshot%.3d.png", count);
-    ddio_MakePath(filename, Base_directory, str, NULL);
+    ddio_MakePath(filename, Base_directory.u8string().c_str(), str, NULL);
     infile = (CFILE *)cfopen(filename, "rb");
     if (infile == NULL) {
       done = 1;

Descent3/gamesave.cpp

@@ -350,7 +350,7 @@ void QuickSaveGame() {
     i = Quicksave_game_slot;
 
     snprintf(filename, sizeof(filename), "saveg00%d", i);
-    ddio_MakePath(pathname, Base_directory, "savegame", filename, NULL);
+    ddio_MakePath(pathname, Base_directory.u8string().c_str(), "savegame", filename, NULL);
 
     fp = fopen(pathname, "rb");
     if (fp) {
@@ -393,7 +393,7 @@ void SaveGameDialog() {
 #endif
 
   // setup paths.
-  ddio_MakePath(savegame_dir, Base_directory, "savegame", NULL);
+  ddio_MakePath(savegame_dir, Base_directory.u8string().c_str(), "savegame", NULL);
   //	ddio_MakePath(pathname, savegame_dir, "*.sav", NULL); -unused
 
   // create savegame directory if it didn't exist before.
@@ -545,7 +545,7 @@ void __cdecl LoadGameDialogCB(newuiTiledWindow *wnd, void *data)
 
     mprintf(0, "savegame slot=%d\n", id - SAVE_HOTSPOT_ID);
 
-    ddio_MakePath(savegame_dir, Base_directory, "savegame", NULL);
+    ddio_MakePath(savegame_dir, Base_directory.u8string().c_str(), "savegame", NULL);
     snprintf(filename, sizeof(filename), "saveg00%d", (id - SAVE_HOTSPOT_ID));
     ddio_MakePath(pathname, savegame_dir, filename, NULL);
 
@@ -588,7 +588,7 @@ bool LoadGameDialog() {
   }
 
   // setup paths.
-  ddio_MakePath(savegame_dir, Base_directory, "savegame", NULL);
+  ddio_MakePath(savegame_dir, Base_directory.u8string().c_str(), "savegame", NULL);
   ddio_MakePath(pathname, savegame_dir, "*.sav", NULL);
 
   // create savegame directory if it didn't exist before.

Descent3/init.cpp

@@ -1025,7 +1025,7 @@ static bool Title_bitmap_init = false;
 uint8_t Use_motion_blur = 0;
 
 // The "root" directory of the D3 file tree
-char Base_directory[_MAX_PATH];
+std::filesystem::path Base_directory;
 
 extern int Min_allowed_frametime;
 
@@ -1399,8 +1399,7 @@ void InitIOSystems(bool editor) {
   int dirarg = FindArg("-setdir");
   int exedirarg = FindArg("-useexedir");
   if (dirarg) {
-    strncpy(Base_directory, GameArgs[dirarg + 1], sizeof(Base_directory) - 1);
-    Base_directory[sizeof(Base_directory) - 1] = '\0';
+    Base_directory = GameArgs[dirarg + 1];
   } else if (exedirarg) {
     char exec_path[_MAX_PATH];
     memset(exec_path, 0, sizeof(exec_path));
@@ -1409,16 +1408,14 @@ void InitIOSystems(bool editor) {
       Error("Failed to get executable path\n");
     } else {
       std::filesystem::path executablePath(exec_path);
-      std::string baseDirectoryString = executablePath.parent_path().string();
-      strncpy(Base_directory, baseDirectoryString.c_str(), sizeof(Base_directory) - 1);
-      Base_directory[sizeof(Base_directory) - 1] = '\0';
+      Base_directory = executablePath.parent_path();
       mprintf(0, "Using working directory of %s\n", Base_directory);
     }
   } else {
-    ddio_GetWorkingDir(Base_directory, sizeof(Base_directory));
+    Base_directory = std::filesystem::current_path();
   }
 
-  ddio_SetWorkingDir(Base_directory);
+  ddio_SetWorkingDir(Base_directory.u8string().c_str());
 
   Descent->set_defer_handler(D3DeferHandler);
 
@@ -2048,7 +2045,7 @@ void SetupTempDirectory(void) {
     exit(1);
   }
   // restore working dir
-  ddio_SetWorkingDir(Base_directory);
+  ddio_SetWorkingDir(Base_directory.u8string().c_str());
 }
 
 void DeleteTempFiles() {

Descent3/mmItem.cpp

@@ -331,7 +331,7 @@ void mmInterface::Create() {
     static_menu_background = true;
   } else {
     char filename[_MAX_PATH];
-    ddio_MakePath(filename, Base_directory, "movies", "mainmenu", NULL);
+    ddio_MakePath(filename, Base_directory.u8string().c_str(), "movies", "mainmenu", NULL);
     m_movie = StartMovie(filename, true);
 
     if (!m_movie) //[ISB] Didn't find the menu movie?

Descent3/multi.cpp

@@ -8077,23 +8077,23 @@ char *GetFileNameFromPlayerAndID(int16_t playernum, int16_t id) {
     break;
   case NETFILE_ID_SHIP_TEX:
     if (NetPlayers[playernum].ship_logo[0])
-      ddio_MakePath(rval, Base_directory, "custom", "graphics", NetPlayers[playernum].ship_logo, NULL);
+      ddio_MakePath(rval, Base_directory.u8string().c_str(), "custom", "graphics", NetPlayers[playernum].ship_logo, NULL);
     break;
   case NETFILE_ID_VOICE_TAUNT1:
     if (NetPlayers[playernum].voice_taunt1[0])
-      ddio_MakePath(rval, Base_directory, "custom", "sounds", NetPlayers[playernum].voice_taunt1, NULL);
+      ddio_MakePath(rval, Base_directory.u8string().c_str(), "custom", "sounds", NetPlayers[playernum].voice_taunt1, NULL);
     break;
   case NETFILE_ID_VOICE_TAUNT2:
     if (NetPlayers[playernum].voice_taunt2[0])
-      ddio_MakePath(rval, Base_directory, "custom", "sounds", NetPlayers[playernum].voice_taunt2, NULL);
+      ddio_MakePath(rval, Base_directory.u8string().c_str(), "custom", "sounds", NetPlayers[playernum].voice_taunt2, NULL);
     break;
   case NETFILE_ID_VOICE_TAUNT3:
     if (NetPlayers[playernum].voice_taunt3[0])
-      ddio_MakePath(rval, Base_directory, "custom", "sounds", NetPlayers[playernum].voice_taunt3, NULL);
+      ddio_MakePath(rval, Base_directory.u8string().c_str(), "custom", "sounds", NetPlayers[playernum].voice_taunt3, NULL);
     break;
   case NETFILE_ID_VOICE_TAUNT4:
     if (NetPlayers[playernum].voice_taunt4[0])
-      ddio_MakePath(rval, Base_directory, "custom", "sounds", NetPlayers[playernum].voice_taunt4, NULL);
+      ddio_MakePath(rval, Base_directory.u8string().c_str(), "custom", "sounds", NetPlayers[playernum].voice_taunt4, NULL);
     break;
   default:
     mprintf(0, "Unknown id (%d) passed to GetFileNameFromPlayerAndID()\n", id);

Descent3/multi_dll_mgr.cpp

@@ -526,7 +526,7 @@ void GetMultiAPI(multi_api *api) {
   api->vp[2] = (int *)&Game_is_master_tracker_game;
   api->vp[3] = (int *)&Game_mode;
   api->vp[4] = (int *)NULL; // Current_pilot; no longer a struct
-  api->vp[5] = (int *)Base_directory;
+  api->vp[5] = (int *)&Base_directory;
   api->vp[6] = (int *)&MultiDLLGameStarting;
   api->vp[7] = (int *)MTPilotinfo;
   api->vp[8] = (int *)&Num_network_games_known;
@@ -596,7 +596,7 @@ int LoadMultiDLL(const char *name) {
   if (MultiDLLHandle.handle)
     FreeMultiDLL();
 
-  std::filesystem::path dll_path_name = std::filesystem::path(Base_directory) / "online";
+  std::filesystem::path dll_path_name = Base_directory / "online";
   ddio_DoForeachFile(dll_path_name, std::regex(".+\\.tmp"), [](const std::filesystem::path& path, ...) {
     std::error_code ec;
     std::filesystem::remove(path, ec);
@@ -606,7 +606,7 @@ int LoadMultiDLL(const char *name) {
   });
 
   // Make the hog filename
-  ddio_MakePath(lib_name, Base_directory, "online", name, NULL);
+  ddio_MakePath(lib_name, Base_directory.u8string().c_str(), "online", name, NULL);
   strcat(lib_name, ".d3c");
 // Make the dll filename
 #if defined(WIN32)
@@ -619,7 +619,7 @@ int LoadMultiDLL(const char *name) {
 
   // Open the hog file
   if (!cf_OpenLibrary(lib_name)) {
-    ddio_MakePath(tmp_dll_name, Base_directory, "online", name, NULL);
+    ddio_MakePath(tmp_dll_name, Base_directory.u8string().c_str(), "online", name, NULL);
     strcat(tmp_dll_name, ".d3c");
     Multi_conn_dll_name[0] = 0;
     goto loaddll;

Descent3/multi_ui.cpp

@@ -441,7 +441,7 @@ int MainMultiplayerMenu() {
 
   std::vector<std::string> dllnames;
 
-  ddio_DoForeachFile(std::filesystem::path(Base_directory) / "online", std::regex(".*\\.d3c"),
+  ddio_DoForeachFile(Base_directory / "online", std::regex(".*\\.d3c"),
                      [&dllnames](const std::filesystem::path &path) {
                        std::string filename = path.stem().string();
 
@@ -988,15 +988,15 @@ void DoMultiAllowed(void) {
 }
 
 void MultiDoConfigSave() {
-  std::filesystem::path file = std::filesystem::path(Base_directory) / "custom" / "settings";
+  std::filesystem::path file = Base_directory / "custom" / "settings";
   if (DoPathFileDialog(true, file, TXT_MULTISAVESET, {"*.mps"}, 0)) {
     file.replace_extension(".mps");
     MultiSaveSettings(file);
   }
 }
 
 void MultiDoConfigLoad() {
-  std::filesystem::path file = std::filesystem::path(Base_directory) / "custom" / "settings";
+  std::filesystem::path file = Base_directory / "custom" / "settings";
   if (DoPathFileDialog(false, file, TXT_MULTILOADSET, {"*.mps"}, PFDF_FILEMUSTEXIST))
     MultiLoadSettings(file);
 }

Descent3/pilot.cpp

@@ -1583,7 +1583,7 @@ bool PltDelete(pilot *Pilot) {
   std::string pfilename = Pilot->get_filename();
   std::error_code ec;
   if (!pfilename.empty()) {
-    return std::filesystem::remove(std::filesystem::path(Base_directory) / pfilename, ec);
+    return std::filesystem::remove(Base_directory / pfilename, ec);
   } else {
     Int3(); // this is odd
 
@@ -1597,7 +1597,7 @@ bool PltDelete(pilot *Pilot) {
     PltMakeFNValid(pname);
 
     pfilename = std::string(pname) + PLTEXTENSION;
-    return std::filesystem::remove(std::filesystem::path(Base_directory) / pfilename, ec);
+    return std::filesystem::remove(Base_directory / pfilename, ec);
   }
 }
 
@@ -1636,7 +1636,7 @@ void PltReadFile(pilot *Pilot, bool keyconfig, bool missiondata) {
     return;
 
   // open and process file
-  std::filesystem::path filename = std::filesystem::path(Base_directory) / pfilename;
+  std::filesystem::path filename = Base_directory / pfilename;
   try {
     file = cfopen(filename, "rb");
     if (!file)
@@ -3311,7 +3311,7 @@ void _ReadOldPilotFile(pilot *Pilot, bool keyconfig, bool missiondata) {
   std::string pfilename = Pilot->get_filename();
 
   // open and process file
-  std::filesystem::path filename = std::filesystem::path(Base_directory) / pfilename;
+  std::filesystem::path filename = Base_directory / pfilename;
   CFILE *file = cfopen(filename, "rb");
   if (!file)
     return;

Descent3/pilot_class.cpp

@@ -416,7 +416,7 @@ int pilot::flush(bool new_file) {
   }
 
   CFILE *file;
-  std::filesystem::path real_filename = std::filesystem::path(Base_directory) / filename;
+  std::filesystem::path real_filename = Base_directory / filename;
 
   if (new_file && cfexist(real_filename)) {
     // the file already exists, we can't write out
@@ -498,7 +498,7 @@ int pilot::read(bool skip_config, bool skip_mission_data) {
   }
 
   CFILE *file;
-  std::filesystem::path real_filename = std::filesystem::path(Base_directory) / filename;
+  std::filesystem::path real_filename = Base_directory / filename;
 
   if (!cfexist(real_filename)) {
     // the file already exists, we can't write out

editor/MainFrm.cpp

@@ -1460,7 +1460,7 @@ void InitCScripts() {
   CreateNewMine();
 
   //	Setup include directories for OSIRIS
-  ddio_MakePath(path, Base_directory, "data", "levels", NULL);
+  ddio_MakePath(path, Base_directory.u8string().c_str(), "data", "levels", NULL);
 }
 
 // Copied from winmain.cpp

editor/editor_lighting.cpp

@@ -870,7 +870,7 @@ void DoRadiosityForRooms() {
 
   if (save_after_bsp) {
     char filename[_MAX_PATH];
-    ddio_MakePath(filename, Base_directory, "BSPSave.D3L", NULL);
+    ddio_MakePath(filename, Base_directory.u8string().c_str(), "BSPSave.D3L", NULL);
 
     // Save the level to
     SaveLevel(filename);
@@ -1140,7 +1140,7 @@ void DoRadiosityForRooms() {
   SqueezeLightmaps(0, -1);
 
   char filename[_MAX_PATH + 1];
-  ddio_MakePath(filename, Base_directory, "LightSave.D3L", NULL);
+  ddio_MakePath(filename, Base_directory.u8string().c_str(), "LightSave.D3L", NULL);
 
   // Save the level to disk
   SaveLevel(filename);

editor/gameeditor.cpp

@@ -612,7 +612,7 @@ void GameToEditor(bool set_viewer_from_player) {
   if (Temp_level_saved) {
     char filename[_MAX_PATH];
 
-    ddio_MakePath(filename, Base_directory, "GameSave.D3L", NULL); // make explicit path
+    ddio_MakePath(filename, Base_directory.u8string().c_str(), "GameSave.D3L", NULL); // make explicit path
     LoadLevel(filename);
     Temp_level_saved = 0;
   }
@@ -752,7 +752,7 @@ void EditorToGame() {
   //	set game working directory
   bool set_size = false;
   ddio_GetWorkingDir(Editor_dir, sizeof(Editor_dir));
-  ddio_SetWorkingDir(Base_directory);
+  ddio_SetWorkingDir(Base_directory.u8string().c_str());
 
   Osiris_ResetAllTimers();
 

manage/manage.cpp

@@ -672,8 +672,13 @@ int mng_LoadTableFiles(int show_progress) {
 // This is for initting tables on STAND_ALONE, if the network is down, or if
 // the user doesn't want network support
 int mng_InitLocalTables() {
-  // Set the local table directory from the base directory
-  strcpy(LocalD3Dir, Base_directory);
+  // Set the local table directory from the base directory.
+  auto base_directory_string = Base_directory.u8string();
+  strncpy(LocalD3Dir, base_directory_string.c_str(), sizeof LocalD3Dir);
+  LocalD3Dir[sizeof LocalD3Dir - 1] = '\0';
+  if (strlen(LocalD3Dir) != strlen(base_directory_string.c_str())) {
+    mprintf(0, "Warning: Base_directory is too long to fit in LocalD3Dir, so LocalD3Dir was truncated.");
+  }
   mprintf(1, "Local dir:%s\n", LocalD3Dir);
 
   // Make the CFILE system first look at our local directories.  If the goods aren't