Implementing base directory populating on init

After initialization, we get following base directories list (in priority order):

* Writable preference path
* User defined paths (cmd-line and configuration)
* Platform defined paths (such as /usr/share/Descent3 on Linux or Steam installation paths on all platforms (TBD))
* Directory of executable

Removing `-setdir` and `-useexedir` as redundant (both can be replaced with `-additionaldir` option).

CMakeLists.txt

@@ -103,6 +103,12 @@ if(FORCE_PORTABLE_INSTALL)
   set(CMAKE_INSTALL_LIBDIR ".")
   set(CMAKE_INSTALL_DATADIR ".")
   set(CMAKE_INSTALL_DOCDIR ".")
+
+  set(D3_DATADIR "${CMAKE_INSTALL_DATADIR}")
+else()
+  set(CMAKE_INSTALL_DATADIR "${CMAKE_INSTALL_DATADIR}/Descent3")
+  # On system install files will go into /usr/share/Descent3
+  set(D3_DATADIR "${CMAKE_INSTALL_FULL_DATADIR}/Descent3")
 endif()
 
 # Get info about multi-config environment

Descent3/CMakeLists.txt

@@ -294,6 +294,12 @@ if(WIN32)
   )
 endif()
 
+configure_file(
+  ${CMAKE_SOURCE_DIR}/lib/d3_platform_path.h.in
+  ${CMAKE_BINARY_DIR}/lib/d3_platform_path.h
+  @ONLY
+)
+
 if(UNIX AND NOT APPLE)
   set(PLATFORM_LIBS m ${CMAKE_DL_LIBS})
 endif()

Descent3/init.cpp

@@ -921,6 +921,7 @@
 #include "init.h"
 #include "config.h"
 #include "3d.h"
+#include "d3_platform_path.h"
 #include "hlsoundlib.h"
 #include "manage.h"
 #include "bitmap.h"
@@ -1004,6 +1005,9 @@ bool Running_editor = false; // didn't we have a variable like this somewhere
 
 static bool Init_in_editor = false;
 
+// Base directory from configuration path
+std::filesystem::path config_base_directory;
+
 // used to update load bar.
 static void SetInitMessageLength(const char *c, float amount); // portion of total bar to fill (0 to 1)
 extern void UpdateInitMessage(float amount);                   // amount is 0 to 1
@@ -1196,6 +1200,9 @@ void SaveGameSettings() {
     Database->write("Default_pilot", Default_pilot.c_str(), strlen(Default_pilot.c_str()) + 1);
   else
     Database->write("Default_pilot", " ", 2);
+
+  Database->write("GAME_base_directory", config_base_directory.u8string().c_str(),
+                  strlen(config_base_directory.u8string().c_str()) + 1);
 }
 
 /*
@@ -1258,6 +1265,11 @@ void LoadGameSettings() {
     }
   }
 
+  templen = TEMPBUFFERSIZE;
+  if (Database->read("GAME_base_directory", tempbuffer, &templen)) {
+    config_base_directory = tempbuffer;
+  }
+
   templen = TEMPBUFFERSIZE;
   if (Database->read("RS_gamma", tempbuffer, &templen)) {
     Render_preferred_state.gamma = strtod(tempbuffer, &stoptemp);
@@ -1392,45 +1404,58 @@ void LoadGameSettings() {
         I/O systems initialization
 */
 void InitIOSystems(bool editor) {
-  ddio_init_info io_info;
+  // Read in stuff from the registry
+  INIT_MESSAGE(("Reading settings."));
+  LoadGameSettings();
 
-  // Set the writable base directory
-  int dirarg = FindArg("-setdir");
-  int exedirarg = FindArg("-useexedir");
-  std::filesystem::path writable_base_directory;
-  if (dirarg) {
-    writable_base_directory = GameArgs[dirarg + 1];
-  } else if (exedirarg) {
-    char exec_path[_MAX_PATH];
-    memset(exec_path, 0, sizeof(exec_path));
-    // Populate exec_path with the executable path
-    if (!ddio_GetBinaryPath(exec_path, sizeof(exec_path))) {
-      Error("Failed to get executable path\n");
-    } else {
-      std::filesystem::path executablePath(exec_path);
-      writable_base_directory = executablePath.parent_path();
-      LOG_INFO << "Using working directory of " << writable_base_directory;
-    }
-  } else {
-    writable_base_directory = std::filesystem::current_path();
+  /*
+   * Populate base directories. In result, we have the following list of directories (in priority order):
+   * - Writable preference path
+   * - User defined paths (cmd-line and configuration)
+   * - Platform defined paths (such as /usr/share/Descent3 on Linux or Steam installation paths)
+   * - Directory of executable
+   */
+
+  // Writable preference path
+  std::filesystem::path pref_path = ddio_GetPrefPath(D3_PREF_ORG, D3_PREF_APP);
+  if (pref_path.empty()) {
+    Error("Failed to get preference path!");
   }
+  LOG_INFO << "Setting writable preference path " << pref_path;
+  cf_AddBaseDirectory(pref_path);
 
-  ddio_SetWorkingDir(writable_base_directory.u8string().c_str());
-  cf_AddBaseDirectory(writable_base_directory);
-
-  // Set any additional base directories
-  auto additionaldirarg = 0;
+  // Additional paths
+  int 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.";
+    if (dir_to_add == nullptr) {
+      LOG_WARNING << "-additionaldir requires directory path as value.";
       break;
     } else {
-      cf_AddBaseDirectory(std::filesystem::path(dir_to_add));
+      cf_AddBaseDirectory(dir_to_add);
       additionaldirarg += 2;
     }
   }
+  // Path from configuration
+  if (!config_base_directory.empty()) {
+    cf_AddBaseDirectory(config_base_directory);
+  }
+
+  // Platform dependent paths
+  std::filesystem::path platform_dir = std::filesystem::canonical(D3_DATADIR);
+  cf_AddBaseDirectory(platform_dir);
+  // TODO: add Steam/registry locations
+
+  // Add path of executable
+  std::filesystem::path exec_path = ddio_GetBasePath();
+  // Populate exec_path with the executable path
+  if (exec_path.empty() || exec_path == platform_dir) {
+    LOG_DEBUG << "Skipping adding executable path (empty or redundant path).";
+  } else {
+    cf_AddBaseDirectory(exec_path);
+  }
+
+  LOG_INFO << "Base directories: " << cf_LocateMultiplePaths("");
 
   Descent->set_defer_handler(D3DeferHandler);
 
@@ -1447,6 +1472,7 @@ void InitIOSystems(bool editor) {
 #endif
 
   //	do io init stuff
+  ddio_init_info io_info{};
   io_info.obj = Descent;
 
   INIT_MESSAGE(("Initializing DDIO systems."));
@@ -1461,10 +1487,6 @@ void InitIOSystems(bool editor) {
                   RTI_MATCENFRAMETIME);
   RTP_ENABLEFLAGS(RTI_OBJFRAMETIME | RTI_AIFRAMETIME | RTI_PROCESSKEYTIME);
 
-  //	Read in stuff from the registry
-  INIT_MESSAGE(("Reading settings."));
-  LoadGameSettings();
-
   // Setup temp directory
   INIT_MESSAGE(("Setting up temp directory."));
   SetupTempDirectory();

cfile/cfile.cpp

@@ -54,13 +54,10 @@ struct library {
   FILE *file = nullptr; // pointer to file for this lib, if no one using it
 };
 
-/* The "root" directories of the D3 file tree
- *
- * Directories that come later in the list override directories that come
- * earlier in the list. For example, if Base_directories[0] / "d3.hog" exists
- * and Base_directories[1] / "d3.hog" also exists, then the one in
- * Base_directories[1] will get used. The one in Base_directories[0] will be
- * ignored.
+/*
+ * List of base directories of the D3 file tree.
+ * Directories at the top of the list have higher priority.
+ * First entry should be a writable directory.
  */
 std::vector<std::filesystem::path> Base_directories = {};
 
@@ -82,7 +79,7 @@ const char *eof_error = "Unexpected end of file";
  * from this module.
  */
 void cf_AddBaseDirectory(const std::filesystem::path &base_directory) {
-  if (std::filesystem::exists(base_directory)) {
+  if (std::filesystem::exists(base_directory) && std::filesystem::is_directory(base_directory)) {
     Base_directories.push_back(base_directory);
   } else {
     LOG_WARNING << "Ignoring nonexistent base directory: " << base_directory;

lib/d3_platform_path.h.in

@@ -0,0 +1,28 @@
+/*
+ * Descent 3
+ * Copyright (C) 2024 Descent Developers
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+// Platform-specific compile-time defined location of data files
+#define D3_DATADIR "@D3_DATADIR@"
+
+// Part of preference path (organization)
+#define D3_PREF_ORG "Outrage Entertainment"
+
+// Part of preference path (application)
+#define D3_PREF_APP "Descent 3"

linux/CMakeLists.txt

@@ -19,6 +19,7 @@ target_include_directories(linux PUBLIC
   $<BUILD_INTERFACE:
   ${PROJECT_SOURCE_DIR}/linux
   >
+  ${PROJECT_BINARY_DIR}/lib
   ${SDL3_INCLUDE_DIRS}
 )
 target_link_libraries(linux PRIVATE

linux/lnxdata.cpp

@@ -55,6 +55,8 @@
 #endif
 
 #include "appdatabase.h"
+#include "d3_platform_path.h"
+#include "ddio.h"
 #include "linux/lnxdatabase.h"
 #include "log.h"
 #include "pserror.h"
@@ -68,13 +70,12 @@ oeLnxAppDatabase::oeLnxAppDatabase() {
   // Open up the database file, for reading, read in all data and keep it in memory
   // then close the database
 
-  const char* prefPath = SDL_GetPrefPath("Outrage Entertainment", "Descent 3");
-  if (prefPath == nullptr) {
+  std::filesystem::path prefPath = ddio_GetPrefPath(D3_PREF_ORG, D3_PREF_APP);
+  if (prefPath.empty()) {
     LOG_FATAL << "Couldn't find preference directory!";
     exit(43);
   }
-  std::filesystem::path fileName = std::filesystem::path(prefPath) / REGISTRY_FILENAME;
-  SDL_free((void *)prefPath);
+  std::filesystem::path fileName = prefPath / REGISTRY_FILENAME;
 
   database = new CRegistry(fileName.u8string().c_str());
   database->Import();