SDL environment variables ========================= last updated: 27 Sept 2001 The following applies to the CVS SDL (the 1.2 branch). This is unofficial, and the semantics may vary, and some variables might go away. AUDIODEV The audio device to use, if SDL_PATH_DSP isn't set. SDL_AUDIODRIVER Selects the audio driver for SDL to use. Possible values, in the order they are tried if this variable is not set: openbsd (OpenBSD) dsp (OSS /dev/dsp: Linux, Solaris, BSD etc) alsa (Linux) audio (Unix style /dev/audio: SunOS, Solaris etc) AL (Irix) artsc (ARTS audio daemon) esd (esound audio daemon) nas (NAS audio daemon) dma (OSS /dev/dsp, using DMA) dsound (Win32 DirectX) waveout (Win32 WaveOut) baudio (BeOS) sndmgr (MacOS SoundManager) paud (AIX) AHI (Amiga) disk (all; output to file) SDL_CDROM A colon-separated list of CD-ROM devices to use, in addition to the standard devices (typically /dev/cdrom, platform-dependant). SDL_DEBUG If set, causes every call to SDL_SetError() to also print an error message on stderr. SDL_DISKAUDIOFILE The name of the output file for the "disk" audio driver. If not set, the name "sdlaudio.raw" is used. SDL_DISKAUDIODELAY For the "disk" audio driver, how long to wait (in ms) before writing a full sound buffer. The default is 150 ms. SDL_DSP_NOSELECT For some audio drivers (alsa, paud, dma and dsp), don't use select() but a timed method instead. May cure some audio problems, or cause others. SDL_ELO_MIN_X SDL_ELO_MIN_Y SDL_ELO_MAX_X SDL_ELO_MAX_Y Calibration values for the fbcon driver, for the Elographics touchscreen controller. Default values are 400, 500, 3670, 3540 respectively. SDL_FBACCEL If set to 0, disable hardware acceleration in the linux fbcon driver. SDL_FBDEV Frame buffer device to use in the linux fbcon driver, instead of /dev/fb0 SDL_FULLSCREEN_UPDATE In the ps2gs driver, sets the SDL_ASYNCBLIT flag on the display surface. SDL_JOYSTICK_DEVICE Joystick device to use in the linux joystick driver, in addition to the usual: /dev/js*, /dev/input/event*, /dev/input/js* SDL_LINUX_JOYSTICK Special joystick configuration string for linux. The format is "name numaxes numhats numballs" where name is the name string of the joystick (possibly in single quotes), and the rest are the number of axes, hats and balls respectively. SDL_MOUSE_RELATIVE If set to 0, do not use mouse relative mode in X11. The default is to use it if the mouse is hidden and input is grabbed. SDL_MOUSEDEV The mouse device to use for the linux fbcon driver. If not set, SDL first tries to use GPM in repeater mode, then various other devices (/dev/pcaux, /dev/adbmouse, /dev/mouse etc). SDL_MOUSEDEV_IMPS2 If set, SDL will not try to auto-detect the IMPS/2 protocol of a PS/2 mouse but use it right away. For the fbcon and ps2gs drivers. SDL_MOUSEDRV For the linux fbcon driver: if set to ELO, use the ELO touchscreen controller as a pointer device SDL_NO_RAWKBD For the libvga driver: If set, do not attempt to put the keyboard in raw mode. SDL_NOMOUSE If set, the linux fbcon driver will not use a mouse at all. SDL_PATH_DSP The audio device to use. If not set, SDL tries AUDIODEV and then a platform-dependent default value (/dev/audio on Solaris, /dev/dsp on Linux etc). SDL_VIDEODRIVER Selectes the video driver for SDL to use. Possible values, in the order they are tried if this variable is not set: x11 dga (the XFree86 DGA2) nanox (Linux) fbcon (Linux) directfb (Linux) ps2gs (Playstation 2) ggi vgl (BSD) svgalib (Linux) aalib directx (Win32) windib (Win32) bwindow (BeOS) toolbox (MacOS Classic) DSp (MacOS Classic) Quartz (MacOS X) CGX (Amiga) photon (QNX) epoc (Epoc) dummy SDL_VIDEO_CENTERED If set, tries to center the SDL window when running in X11 windowed mode, or using the CyberGrafix driver. SDL_VIDEO_GL_DRIVER The openGL driver (shared library) to use for X11. Default is libGL.so.1 SDL_VIDEO_X11_DGAMOUSE With XFree86, enables use of DGA mouse if set. SDL_VIDEO_X11_MOUSEACCEL For X11, sets the mouse acceleration. The value should be a string on the form: n/d/t where n and d are the acceleration numerator/denumerators (so mouse movement is accelerated by n/d), and t is the threshold above which acceleration applies (counted as number of pixels the mouse moves at once). SDL_VIDEO_X11_NODIRECTCOLOR If set, don't attempt to use DirectColor visuals even if they are present. (SDL will use them otherwise for gamma correction). This is needed with older X servers when using the XVideo extension. SDL_VIDEO_X11_VISUALID ID of an X11 visual to use, overriding SDL's default visual selection algorithm. It can be in decimal or in hex (prefixed by 0x). SDL_VIDEO_YUV_DIRECT If set, display YUV overlay directly on the video surface if possible, instead of on the surface passed to SDL_CreateYUVOverlay(). SDL_VIDEO_YUV_HWACCEL If not set or set to a nonzero value, SDL will attempt to use hardware YUV acceleration for video playback. SDL_WINDOWID For X11 or Win32, contains the ID number of the window to be used by SDL instead of creating its own window. Either in decimal or in hex (prefixed by 0x).