system: resolve user-facing paths against the app root so a macOS bundle keeps them beside the .app

include/rex/filesystem.h

@@ -36,6 +36,14 @@ std::filesystem::path GetExecutablePath();
 // Get executable folder.
 std::filesystem::path GetExecutableFolder();
 
+// Get the application's root folder: the executable folder, or, when the
+// executable lives inside a macOS application bundle
+// ("<root>/<name>.app/Contents/MacOS/<exe>"), the folder containing the
+// bundle. User-facing files (config, game data, saves, DLC, logs) resolve
+// against this so a bundled app keeps them beside the bundle rather than
+// inside it.
+std::filesystem::path GetAppRootFolder();
+
 // Get user folder.
 std::filesystem::path GetUserFolder();
 

src/core/filesystem_posix.cpp

@@ -95,6 +95,21 @@ std::filesystem::path GetExecutableFolder() {
   return GetExecutablePath().parent_path();
 }
 
+std::filesystem::path GetAppRootFolder() {
+  auto folder = GetExecutableFolder();
+#if REX_PLATFORM_MAC
+  // <root>/<name>.app/Contents/MacOS/<exe> -> <root>
+  if (folder.filename() == "MacOS") {
+    const auto contents = folder.parent_path();
+    const auto bundle = contents.parent_path();
+    if (contents.filename() == "Contents" && bundle.extension() == ".app") {
+      return bundle.parent_path();
+    }
+  }
+#endif
+  return folder;
+}
+
 std::filesystem::path GetUserFolder() {
   // get preferred data home
   char* home = std::getenv("XDG_DATA_HOME");

src/core/filesystem_win.cpp

@@ -65,6 +65,12 @@ std::filesystem::path GetExecutableFolder() {
   return GetExecutablePath().parent_path();
 }
 
+std::filesystem::path GetAppRootFolder() {
+  // Application bundles are a macOS concept; the executable folder is the
+  // application root everywhere else.
+  return GetExecutableFolder();
+}
+
 std::filesystem::path GetUserFolder() {
   std::filesystem::path result;
   PWSTR path;

src/input/sdl/sdl_input_driver.cpp

@@ -16,6 +16,7 @@
 #include <rex/assert.h>
 #include <rex/chrono/clock.h>
 #include <rex/cvar.h>
+#include <rex/filesystem.h>
 #include <rex/input/flags.h>
 #include <rex/input/sdl/sdl_input_driver.h>
 #include <rex/logging.h>
@@ -96,18 +97,23 @@ void SDLInputDriver::OnWindowAvailable(rex::ui::Window* window) {
       }
       SDL_Gamepad_initialized_ = true;
 
-      // Load custom controller mappings if available
+      // Load custom controller mappings if available. A relative path is
+      // resolved against the application root rather than the working
+      // directory, which is undefined when launched from a bundle/Finder.
       if (!REXCVAR_GET(hid_mappings_file).empty()) {
         std::filesystem::path mappings_path(REXCVAR_GET(hid_mappings_file));
+        if (mappings_path.is_relative()) {
+          mappings_path = rex::filesystem::GetAppRootFolder() / mappings_path;
+        }
         if (!std::filesystem::exists(mappings_path)) {
           REXLOG_WARN("SDL GameControllerDB: file '{}' does not exist.",
-                      REXCVAR_GET(hid_mappings_file));
+                      mappings_path.string());
         } else {
           auto mappings_result =
-              SDL_AddGamepadMappingsFromFile(REXCVAR_GET(hid_mappings_file).c_str());
+              SDL_AddGamepadMappingsFromFile(mappings_path.string().c_str());
           if (mappings_result < 0) {
             REXLOG_ERROR("SDL GameControllerDB: error loading file '{}': {}.",
-                         REXCVAR_GET(hid_mappings_file), mappings_result);
+                         mappings_path.string(), mappings_result);
           } else {
             REXLOG_INFO("SDL GameControllerDB: loaded {} mappings.", mappings_result);
           }

src/ui/rex_app.cpp

@@ -312,7 +312,9 @@ bool ReXApp::OnInitialize() {
 }
 
 bool ReXApp::SetupEnvironment() {
-  auto exe_dir = rex::filesystem::GetExecutableFolder();
+  // App root, not executable folder: inside a macOS .app bundle the config
+  // and logs stay next to the bundle, where users can find them.
+  auto exe_dir = rex::filesystem::GetAppRootFolder();
   auto config_path = exe_dir / (std::string(GetName()) + ".toml");
 
   // Load config before resolving cvar-backed paths such as game_data_root.