Optional Dependencies ===================== jack - if you want to use JACK for audio output, install jack and set JACK=yes in the environment before building xroar. If JACK audio has x-runs, try 'setcap cap_ipc_lock,cap_sys_nice=ep /usr/games/xroar'. Environment Variables ===================== GTKGLEXT - If you have gtkglext installed, but don't want to build xroar with it, export GTKGLEXT=no [1] [2]. SDL2 - If you don't want to build xroar with SDL2, export SDL2=no [2]. This will remove the "-ui sdl" option, which is probably of no consequence since the SDL user interface isn't very featureful. OSS - use OSS for audio? Default is "no", export OSS="yes" to enable. Most users won't need this. PULSE - use PulseAudio? Default is "yes", export PULSE="no" to disable. Notes ===== [1]: Yes, gtkglext is optional, despite being listed in REQUIRES in the .info file. I made it a hard dependency because the SDL user interface has no real GUI features, while the gtkglext UI acts like a proper GUI application. Users who just take the defaults will end up with the usable UI. If you're reading this, you're welcome to ignore the REQUIRES="gtkglext" and build with SDL2 only, if you have a reason to want to. [2]: At least one of SDL2 or gtkglext is required, so you can't build with SDL2=no GTKGLEXT=no. If you want to be super-pedantic, yes, it *is* possible to build xroar without either gtkglext or SDL2, but the result is that xroar won't display anything at all. This is useless and confusing, nobody wants it, and I'm not willing to support it.