used variables
- environment variable HOME
- environment variable XBLASTDIR
- macro GAME_DATADIR (Makefile, configure --with-otherdatadir)

userPath
= ./user (if $HOME undefined)
= $HOME/.xblast-tnt (otherwise)

general search paths for all files/dirs except sounds on x11
1 - userPath
2 - XBLASTDIR (if defined in Makefile)
3 - .
4 - /

sound search path on x11
1 - XBLASTDIR
2 - GAME_DATADIR/
3 - .

config directories (config, central, demo)
- are created in userPath at start

data directory image (package: images)
- GAME_DATADIR/image/block
- GAME_DATADIR/image/explosion
- GAME_DATADIR/image/misc
- GAME_DATADIR/image/score

data directory image/sprite (package: models)
- GAME_DATADIR/image/sprite

data directory level (package: levels)
- GAME_DATADIR/level

data directory sounds (package: sounds)
- sounds -> general search path (w32), sound search path (x11)