Data directories
This page describes the current proposal for how data / config / save files should be located (see also https://github.com/arx/ArxLibertatis/issues/88):
The game will recognize two different directories, a data directory and a user directory.
- The data directory holds read-only asset data and possibly a cfg_default.ini. The data directory can be empty to only load data from the user directory.
- The user directory holds save games, cfg.ini, screenshots, but can also hold asset data that takes priority over that from the data directory (like user-installed mods).
This should allow the game run either from all files in the current directory or from a system-wide installation with per-user config and save files.
Goals
- Starting from a local directory should be as simple as possibly and store saves/settings in that directory. This is for compatibility with the current way arx-libertatis is run and to allow easier testing.
- Windows installers should be able to specify the directories in the registry.
- By default, linux installations should look in the directories specified by the XDG Base Directory Specification
Directory detection procedure
Data directory
1. If a --data-dir=...
command-line option is given, always use that data directory.
2. If a --no-data-dir
command-line option is given, don't use a separate data directory.
3. (windows-only) If the HKEY_CURRENT_USER\Software\ArxLibertatis\DataDir
registry keys exists, use it's value.
4. (windows-only) If the HKEY_LOCAL_MACHINE\Software\ArxLibertatis\DataDir
registry keys exists, use it's value.
5. If a cmake -DDATA_DIR
and -DDATA_DIR_PREFIXES
options are given and DATA_DIR
is a relative path after expanding environment variables, interpret DATA_DIR_PREFIXES
as a colon-separated list (after expanding environment variables) and search for DATA_DIR
in each entry. Use the first match found.
- default value is 'arx'
- (linux-only) default value for DATA_DIR_PREFIXES is '${CMAKE_INSTALL_PREFIX}/share:$XDG_DATA_DIRS'
6. If a cmake -DDATA_DIR
option was given, use it after expanding environment variables.
If a data directory was found but does not exist, clear it. If no data directory was found, that's ok - the user directory can contain all required files.
User directory
1. If a --user-dir=...
command-line option is given, always use that user directory.
3. (windows-only) If the HKEY_CURRENT_USER\Software\ArxLibertatis\UserDir
registry keys exists, use it's value.
4. (windows-only) If the HKEY_LOCAL_MACHINE\Software\ArxLibertatis\UserDir
registry keys exists, use it's value.
5. If a cmake -DUSER_DIR
and -DUSER_DIR_PREFIXES
options are given and USER_DIR
is a relative path after expanding environment variables, interpret USER_DIR_PREFIXES
as a colon-separated list (after expanding environment variables) and search for USER_DIR
in each entry. Use the first match found.
- default value is 'arx'
- (linux-only) default value for
USER_DIR_PREFIXES
is '$XDG_DATA_HOME
' - (windows-only) default value for
USER_DIR_PREFIXES
is '%USERPROFILE%/My Documents/Games
'
6. If a cmake -DUSER_DIR
option was given, use it after expanding environment variables.
7. If a data directory has been found but not user directory and the preconditions for step 5 hold, create USER_DIR
in the first directory of USER_DIR_PREFIXES
that already exists. If none of the directories in USER_DIR_PREFIXES
exist, create the first entry.
8. If a data directory has been found but not user directory and the preconditions for step 6 hold, create USER_DIR
.
9. Otherwise, use the current working directory as the user directory.
If no user directory was found or could be created, quit.