Add -aditionaldir option

Before this change, Descent 3 would look for all of its game data files
in a single directory. This change allows users to spread out Descent
3’s game data over multiple directories.

Building Descent 3 produces multiple files that can be freely
redistributed (Descent3, d3-linux.hog, online/Direct TCP~IP.d3c, etc.).
Running Descent 3 requires those files and several additional files that
cannot be freely redistributed. Before this change, the files that were
redistributable had to be in the same directory as the files that were
not redistributable. This change makes it so that they can be in
separate directories.

The main motivation behind this change is to allow people to package
Descent 3 for Linux in a reasonable manner. For the most part, binary
packages for Descent 3 will contain all of the freely redistributable
components. Package managers will copy those components into system
directories that are owned by root and that users probably shouldn’t
edit manually. Users will then create a new directory and copy the game
data from their copy of Descent 3 into that new directory. Users will
then be able to run:

  Descent3 -setdir <path-to-proprietary-files> -additionaldir <path-to-open-source-files>

The -additionaldir option can also be used to support more complicated
scenarios. For example, if the user is using Debian’s
game-data-packager [1], then they would do something like this:

  Descent3 -setdir <path-to-writable-directory> -additionaldir <path-to-gdp-directory> -additionaldir <path-to-open-source-files>

The -additionaldir option can also be used to load a mod that replaces
.hog files:

  Descent3 -setdir <path-to-base-game-data> -additionaldir <path-to-mod-files>

[1]: <#373 (comment)>

Descent3/Game2DLL.cpp

@@ -573,8 +573,7 @@ bool InitGameModule(const char *name, module *mod) {
 
   // Open the hog file
   if (!cf_OpenLibrary(lib_name)) {
-    tmp_dll_name = Base_directory / "netgames" / name;
-    tmp_dll_name.replace_extension(".d3m");
+    tmp_dll_name = cf_LocatePath(lib_name).u8string().c_str();
     Multi_game_dll_name.clear();
     goto loaddll;
   }

Descent3/ambient.cpp

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

Descent3/demofile.cpp

@@ -359,7 +359,7 @@ void DemoToggleRecording() {
     if (stricmp(szfile + (strlen(szfile) - 4), ".dem") != 0) {
       strcat(szfile, ".dem");
     }
-    Demo_fname = Base_directory / "demo" / szfile;
+    Demo_fname = cf_GetWritableBaseDirectory() / "demo" / szfile;
     LOG_INFO.printf("Saving demo to file: %s", Demo_fname.u8string().c_str());
     // Try to create the file
     Demo_cfp = cfopen(Demo_fname, "wb");
@@ -1408,7 +1408,7 @@ bool LoadDemoDialog() {
   //	return false;
   // #else
 
-  std::filesystem::path file = Base_directory / "demo";
+  std::filesystem::path file = cf_GetWritableBaseDirectory() / "demo";
 
   if (DoPathFileDialog(false, file, TXT_VIEWDEMO, {"*.dem"}, PFDF_FILEMUSTEXIST)) {
     Demo_fname = file;

Descent3/game.cpp

@@ -1279,7 +1279,7 @@ void DoScreenshot() {
   count = 1;
   while (!done) {
     snprintf(str, sizeof(str), "Screenshot%.3d.png", count);
-    ddio_MakePath(filename, Base_directory.u8string().c_str(), str, NULL);
+    ddio_MakePath(filename, cf_GetWritableBaseDirectory().u8string().c_str(), str, NULL);
     infile = (CFILE *)cfopen(filename, "rb");
     if (infile == NULL) {
       done = 1;

Descent3/gamesave.cpp

@@ -348,7 +348,7 @@ void QuickSaveGame() {
     i = Quicksave_game_slot;
 
     snprintf(filename, sizeof(filename), "saveg00%d", i);
-    ddio_MakePath(pathname, Base_directory.u8string().c_str(), "savegame", filename, NULL);
+    ddio_MakePath(pathname, cf_GetWritableBaseDirectory().u8string().c_str(), "savegame", filename, NULL);
 
     fp = fopen(pathname, "rb");
     if (fp) {
@@ -391,7 +391,7 @@ void SaveGameDialog() {
 #endif
 
   // setup paths.
-  ddio_MakePath(savegame_dir, Base_directory.u8string().c_str(), "savegame", NULL);
+  ddio_MakePath(savegame_dir, cf_GetWritableBaseDirectory().u8string().c_str(), "savegame", NULL);
   //	ddio_MakePath(pathname, savegame_dir, "*.sav", NULL); -unused
 
   // create savegame directory if it didn't exist before.
@@ -543,7 +543,7 @@ void __cdecl LoadGameDialogCB(newuiTiledWindow *wnd, void *data)
 
     LOG_DEBUG.printf("savegame slot=%d", id - SAVE_HOTSPOT_ID);
 
-    ddio_MakePath(savegame_dir, Base_directory.u8string().c_str(), "savegame", NULL);
+    ddio_MakePath(savegame_dir, cf_GetWritableBaseDirectory().u8string().c_str(), "savegame", NULL);
     snprintf(filename, sizeof(filename), "saveg00%d", (id - SAVE_HOTSPOT_ID));
     ddio_MakePath(pathname, savegame_dir, filename, NULL);
 
@@ -586,7 +586,7 @@ bool LoadGameDialog() {
   }
 
   // setup paths.
-  ddio_MakePath(savegame_dir, Base_directory.u8string().c_str(), "savegame", NULL);
+  ddio_MakePath(savegame_dir, cf_GetWritableBaseDirectory().u8string().c_str(), "savegame", NULL);
   ddio_MakePath(pathname, savegame_dir, "*.sav", NULL);
 
   // create savegame directory if it didn't exist before.

Descent3/init.cpp

@@ -1390,12 +1390,12 @@ void LoadGameSettings() {
 void InitIOSystems(bool editor) {
   ddio_init_info io_info;
 
-  // Set the base directory
+  // Set the writable base directory
   int dirarg = FindArg("-setdir");
   int exedirarg = FindArg("-useexedir");
-  std::filesystem::path initial_base_directory;
+  std::filesystem::path writable_base_directory;
   if (dirarg) {
-    initial_base_directory = GameArgs[dirarg + 1];
+    writable_base_directory = GameArgs[dirarg + 1];
   } else if (exedirarg) {
     char exec_path[_MAX_PATH];
     memset(exec_path, 0, sizeof(exec_path));
@@ -1404,15 +1404,28 @@ void InitIOSystems(bool editor) {
       Error("Failed to get executable path\n");
     } else {
       std::filesystem::path executablePath(exec_path);
-      initial_base_directory = executablePath.parent_path();
-      LOG_INFO << "Using working directory of " << Base_directory;
+      writable_base_directory = executablePath.parent_path();
+      LOG_INFO << "Using working directory of " << writable_base_directory;
     }
   } else {
-    initial_base_directory = std::filesystem::current_path();
+    writable_base_directory = std::filesystem::current_path();
   }
 
-  cf_SetBaseDirectory(initial_base_directory);
-  ddio_SetWorkingDir(Base_directory.u8string().c_str());
+  ddio_SetWorkingDir(writable_base_directory.u8string().c_str());
+  cf_AddBaseDirectory(writable_base_directory);
+
+  // Set any additional base directories
+  auto additionaldirarg = 0;
+  while (0 != (additionaldirarg = FindArg("-additionaldir", additionaldirarg))) {
+    const auto dir_to_add = GetArg(additionaldirarg + 1);
+    if (dir_to_add == NULL) {
+      LOG_WARNING << "-additionaldir was at the end of the argument list. It should never be at the end of the argument list.";
+      break;
+    } else {
+      cf_AddBaseDirectory(std::filesystem::path(dir_to_add));
+      additionaldirarg += 2;
+    }
+  }
 
   Descent->set_defer_handler(D3DeferHandler);
 
@@ -2015,7 +2028,7 @@ void SetupTempDirectory(void) {
     exit(1);
   }
   // restore working dir
-  ddio_SetWorkingDir(Base_directory.u8string().c_str());
+  ddio_SetWorkingDir(cf_GetWritableBaseDirectory().u8string().c_str());
 }
 
 void DeleteTempFiles() {

Descent3/menu.cpp

@@ -1061,51 +1061,55 @@ bool ProcessCommandLine() {
 #define TRAINING_MISSION_NAME "Pilot Training"
 
 /**
- * Count singleplayer missions in directory. Mission should have .mn3 extension.
- * @param missions_directory where to search missions. Should be a valid directory.
+ * Count singleplayer missions in directories. Mission should have .mn3 extension.
+ * @param missions_directories where to search missions. Should be a list of valid directories.
  * @return count of found missions
  */
-static inline int count_missions(const std::filesystem::path &missions_directory) {
+static inline int count_missions(const std::vector<std::filesystem::path> &missions_directories) {
   int c = 0;
 
-  ddio_DoForeachFile(missions_directory, std::regex(".*\\.mn3"), [&c](const std::filesystem::path &path) {
-    if (stricmp(path.filename().u8string().c_str(), "d3_2.mn3") == 0)
-      return;
-    LOG_DEBUG.printf("Mission path: %s", path.u8string().c_str());
-    tMissionInfo msninfo{};
-    GetMissionInfo(path.filename().u8string().c_str(), &msninfo);
+  for (const auto &missions_directory : missions_directories) {
+    ddio_DoForeachFile(missions_directory, std::regex(".*\\.mn3"), [&c](const std::filesystem::path &path) {
+      if (stricmp(path.filename().u8string().c_str(), "d3_2.mn3") == 0)
+        return;
+      LOG_DEBUG.printf("Mission path: %s", path.u8string().c_str());
+      tMissionInfo msninfo{};
+      GetMissionInfo(path.filename().u8string().c_str(), &msninfo);
 
-    if (msninfo.name[0] && msninfo.single) {
-      LOG_DEBUG.printf("Name: %s", msninfo.name);
-      c++;
-      if (!(c % 2))
-        DoWaitMessage(true);
-    } else {
-      LOG_DEBUG.printf("Illegal or multiplayer mission: %s", path.u8string().c_str());
-    }
-  });
+      if (msninfo.name[0] && msninfo.single) {
+        LOG_DEBUG.printf("Name: %s", msninfo.name);
+        c++;
+        if (!(c % 2))
+          DoWaitMessage(true);
+      } else {
+        LOG_DEBUG.printf("Illegal or multiplayer mission: %s", path.u8string().c_str());
+      }
+    });
+  }
 
   return c;
 }
 
 static inline int generate_mission_listbox(newuiListBox *lb, int n_maxfiles, char **filelist,
-                                           const std::filesystem::path &missions_directory) {
+                                           const std::vector<std::filesystem::path> &missions_directories) {
   int c = 0;
-  ddio_DoForeachFile(
-      missions_directory, std::regex(".*\\.mn3"), [&c, &lb, &n_maxfiles, &filelist](const std::filesystem::path &path) {
-        tMissionInfo msninfo{};
-        if (c < n_maxfiles) {
-          if (stricmp(path.filename().u8string().c_str(), "d3_2.mn3") == 0)
-            return;
-          if (GetMissionInfo(path.filename().u8string().c_str(), &msninfo) && msninfo.name[0] && msninfo.single) {
-            filelist[c] = mem_strdup(path.filename().u8string().c_str());
-            lb->AddItem(msninfo.name);
-            c++;
-            if (!(c % 2))
-              DoWaitMessage(true);
+  for (const auto &missions_directory : missions_directories) {
+    ddio_DoForeachFile(
+        missions_directory, std::regex(".*\\.mn3"), [&c, &lb, &n_maxfiles, &filelist](const std::filesystem::path &path) {
+          tMissionInfo msninfo{};
+          if (c < n_maxfiles) {
+            if (stricmp(path.filename().u8string().c_str(), "d3_2.mn3") == 0)
+              return;
+            if (GetMissionInfo(path.filename().u8string().c_str(), &msninfo) && msninfo.name[0] && msninfo.single) {
+              filelist[c] = mem_strdup(path.filename().u8string().c_str());
+              lb->AddItem(msninfo.name);
+              c++;
+              if (!(c % 2))
+                DoWaitMessage(true);
+            }
           }
-        }
-      });
+        });
+  }
 
   return c;
 }
@@ -1182,8 +1186,9 @@ bool MenuNewGame() {
   // add mission names to listbox
   // count valid mission files.
   // add a please wait dialog here.
+  auto missions_directories = cf_LocateMultiplePaths("missions");
   n_missions = 0;
-  n_missions += count_missions(D3MissionsDir);
+  n_missions += count_missions(missions_directories);
   if (n_missions) {
     // allocate extra mission slot because of check below which adds a name to the filelist.
     filelist = (char **)mem_malloc(sizeof(char *) * (n_missions + 1));
@@ -1196,7 +1201,7 @@ bool MenuNewGame() {
     goto missions_fail;
   }
   // generate real listbox now.
-  generate_mission_listbox(msn_lb, n_missions, filelist, D3MissionsDir);
+  generate_mission_listbox(msn_lb, n_missions, filelist, missions_directories);
   // #ifdef RELEASE
   int k;
   for (k = 0; k < n_missions; k++) {

Descent3/multi.cpp

@@ -8010,23 +8010,23 @@ 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.u8string().c_str(), "custom", "graphics", NetPlayers[playernum].ship_logo, NULL);
+      ddio_MakePath(rval, cf_GetWritableBaseDirectory().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.u8string().c_str(), "custom", "sounds", NetPlayers[playernum].voice_taunt1, NULL);
+      ddio_MakePath(rval, cf_GetWritableBaseDirectory().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.u8string().c_str(), "custom", "sounds", NetPlayers[playernum].voice_taunt2, NULL);
+      ddio_MakePath(rval, cf_GetWritableBaseDirectory().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.u8string().c_str(), "custom", "sounds", NetPlayers[playernum].voice_taunt3, NULL);
+      ddio_MakePath(rval, cf_GetWritableBaseDirectory().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.u8string().c_str(), "custom", "sounds", NetPlayers[playernum].voice_taunt4, NULL);
+      ddio_MakePath(rval, cf_GetWritableBaseDirectory().u8string().c_str(), "custom", "sounds", NetPlayers[playernum].voice_taunt4, NULL);
     break;
   default:
     LOG_FATAL.printf("Unknown id (%d) passed to GetFileNameFromPlayerAndID()", id);

Descent3/multi_dll_mgr.cpp

@@ -520,14 +520,17 @@ void GetMultiAPI(multi_api *api) {
   api->fp[109] = (int *)GetRankIndex;
   api->fp[110] = (int *)CheckGetD3M;
   api->fp[111] = (int *)ddio_DoForeachFile;
+  api->fp[112] = (int *)cf_LocatePath;
+  api->fp[113] = (int *)cf_LocateMultiplePaths;
+  api->fp[114] = (int *)cf_GetWritableBaseDirectory;
 
   // Variable pointers
   api->vp[0] = (int *)&Player_num;
   api->vp[1] = (int *)Tracker_id;
   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 *)NULL; // Base_directory; no longer exists
   api->vp[6] = (int *)&MultiDLLGameStarting;
   api->vp[7] = (int *)MTPilotinfo;
   api->vp[8] = (int *)&Num_network_games_known;
@@ -598,7 +601,7 @@ int LoadMultiDLL(const char *name) {
   if (MultiDLLHandle.handle)
     FreeMultiDLL();
 
-  std::filesystem::path dll_path_name = Base_directory / "online";
+  std::filesystem::path dll_path_name = cf_GetWritableBaseDirectory() / "online";
   ddio_DoForeachFile(dll_path_name, std::regex(".+\\.tmp"), [](const std::filesystem::path& path, ...) {
     std::error_code ec;
     std::filesystem::remove(path, ec);
@@ -616,7 +619,7 @@ int LoadMultiDLL(const char *name) {
 
   // Open the hog file
   if (!cf_OpenLibrary(lib_name)) {
-    tmp_dll_name = Base_directory / "online" / name;
+    tmp_dll_name = std::filesystem::path("online") / name;
     tmp_dll_name.replace_extension(".d3c");
     Multi_conn_dll_name.clear();
     goto loaddll;

Descent3/multi_ui.cpp

@@ -442,11 +442,12 @@ int MainMultiplayerMenu() {
 
   std::vector<std::string> dllnames;
 
-  ddio_DoForeachFile(Base_directory / "online", std::regex(".*\\.d3c"),
-                     [&dllnames](const std::filesystem::path &path) {
-                       std::string filename = path.stem().string();
+  for (const auto &online_directory : cf_LocateMultiplePaths("online")) {
+    ddio_DoForeachFile(online_directory, std::regex(".*\\.d3c"),
+                       [&dllnames](const std::filesystem::path &path) {
+                         std::string filename = path.stem().string();
 
-                       std::replace(filename.begin(), filename.end(), '~', '/');
+                         std::replace(filename.begin(), filename.end(), '~', '/');
 
                        // Place PXO_NAME first in list
                        if (stricmp(filename.c_str(), PXO_NAME) == 0) {
@@ -455,6 +456,7 @@ int MainMultiplayerMenu() {
                          dllnames.push_back(filename);
                        }
                      });
+  }
 
   for (auto const &name : dllnames) {
     lists->AddItem(name.c_str());
@@ -989,15 +991,15 @@ void DoMultiAllowed(void) {
 }
 
 void MultiDoConfigSave() {
-  std::filesystem::path file = Base_directory / "custom" / "settings";
+  std::filesystem::path file = cf_GetWritableBaseDirectory() / "custom" / "settings";
   if (DoPathFileDialog(true, file, TXT_MULTISAVESET, {"*.mps"}, 0)) {
     file.replace_extension(".mps");
     MultiSaveSettings(file);
   }
 }
 
 void MultiDoConfigLoad() {
-  std::filesystem::path file = Base_directory / "custom" / "settings";
+  std::filesystem::path file = cf_GetWritableBaseDirectory() / "custom" / "settings";
   if (DoPathFileDialog(false, file, TXT_MULTILOADSET, {"*.mps"}, PFDF_FILEMUSTEXIST))
     MultiLoadSettings(file);
 }