hello:
i’d like to report one thing about the implementation of SDL_getenv in
Win32 environment… its implemented in a manner that can cause two
subsequent calls to SDL_getenv can cause the 1st value to be stomped over
by the 2nd.
For example the code in SDL_dx5video.c (approx line 1179) - will never set
SD_windowx and SDL_windowy if both SDL_VIDEO_WINDOW_POS & SDL_VIDEO_CENTER
are specified.
if ( !SDL_windowX && !SDL_windowY ) {
window = SDL_getenv(“SDL_VIDEO_WINDOW_POS”);
center = SDL_getenv(“SDL_VIDEO_CENTERED”);
if ( window ) {
if ( SDL_sscanf(window, “%d,%d”, &x, &y) == 2 ) {
SDL_windowX = x;
SDL_windowY = y;
}
if ( SDL_strcmp(window, “center”) == 0 ) {
center = window;
}
}
}
Consider the case where i’ve set SDL_VIDEO_WINDOW_POS as “100,100” and
SDL_VIDEO_CENTERED as “yes”. In this case, the value of window after the
2nd SDL_getenv call will become “yes”. This is 'cause SDL_getenv returns a
fixed pointer which is only allocated if the current buffer is not large
enough to take the value of the environment variable.
So, the above code will work with slight rearrangment (though I’d prefer
that SDL_getenv be fixed!)
if ( !SDL_windowX && !SDL_windowY ) {
window = SDL_getenv(“SDL_VIDEO_WINDOW_POS”);
if ( window ) {
if ( SDL_sscanf(window, “%d,%d”, &x, &y) == 2 ) {
SDL_windowX = x;
SDL_windowY = y;
}
if ( SDL_strcmp(window, “center”) == 0 ) {
center = window;
}
}
if (!center) /* assuming that SDL_VIDEO_WINDOW_POS specification of
"center" overrides SDL_VIDEO_CENTERED */
center = SDL_getenv(“SDL_VIDEO_CENTERED”);
}
Hope that helps…
BTW: these env vars don’t seem to do anything in Win32 ?? (i’ll post this
separately)–
Sheshadri Mantha | Principal Software Engineer