I’m using SDL-2.0.10 (default apt install version with Ubuntu-20.04) in docker env, here is my main Dockerfile libraries setup:
# try setup Xvfb+mesa headless X env: xorg xorg-dev?
RUN apt-get update && apt-get install -y mesa-utils xvfb libglvnd-dev libgl1-mesa-dev libegl1-mesa-dev libgles2-mesa-dev libgbm-dev mesa-utils-extra
# install gstreamer for X app window capture:
RUN apt-get update && apt-get install -y libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev libgstreamer-plugins-bad1.0-dev gstreamer1.0-plugins-base gstreamer1.0-plugins-good gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly gstreamer1.0-libav gstreamer1.0-doc gstreamer1.0-tools gstreamer1.0-x gstreamer1.0-alsa gstreamer1.0-gl gstreamer1.0-gtk3 gstreamer1.0-qt5 gstreamer1.0-pulseaudio
# SDL2 & other deps:
RUN apt-get update && apt-get install -y libsdl2-dev libfreetype-dev libharfbuzz-dev libglib2.0-dev libpng-dev libunwind-dev libfontconfig1-dev libicu-dev libcurl4-openssl-dev libssl-dev
My SDL2 test code init is:
const int windowWidth = 1280;
const int windowHeight = 720;
if (SDL_Init(SDL_INIT_EVERYTHING) < 0) {
printf("Init SDL failed '%s' !\n", SDL_GetError());
return 0;
}
SDL_Window *window = SDL_CreateWindow("test", SDL_WINDOWPOS_CENTERED
, SDL_WINDOWPOS_CENTERED, windowWidth, windowHeight, SDL_WINDOW_ALLOW_HIGHDPI);
if (NULL == window) {
printf("SDL could not create window with error: %s\n", SDL_GetError());
return 0;
}
...
My cmd is: xvfb-run ./test which auto creates a Display and set DISPLAY env var.
However, app frequently reports:
error: XDG_RUNTIME_DIR not set in the environment.
Init SDL failed 'No available video device' !
I’ve tracked to X11_CreateDevice function:
static SDL_VideoDevice *
X11_CreateDevice(int devindex)
{
SDL_VideoDevice *device;
SDL_VideoData *data;
const char *display = NULL; /* Use the DISPLAY environment variable */
if (!SDL_X11_LoadSymbols()) {
return NULL;
}
/* Need for threading gl calls. This is also required for the proprietary
nVidia driver to be threaded. */
X11_XInitThreads();
/* Initialize all variables that we clean on shutdown */
device = (SDL_VideoDevice *) SDL_calloc(1, sizeof(SDL_VideoDevice));
if (!device) {
SDL_OutOfMemory();
return NULL;
}
data = (struct SDL_VideoData *) SDL_calloc(1, sizeof(SDL_VideoData));
if (!data) {
SDL_free(device);
SDL_OutOfMemory();
return NULL;
}
device->driverdata = data;
data->global_mouse_changed = SDL_TRUE;
/* FIXME: Do we need this?
if ( (SDL_strncmp(X11_XDisplayName(display), ":", 1) == 0) ||
(SDL_strncmp(X11_XDisplayName(display), "unix:", 5) == 0) ) {
local_X11 = 1;
} else {
local_X11 = 0;
}
*/
data->display = X11_XOpenDisplay(display);
#ifdef SDL_VIDEO_DRIVER_X11_DYNAMIC
/* On some systems if linking without -lX11, it fails and you get following message.
* Xlib: connection to ":0.0" refused by server
* Xlib: XDM authorization key matches an existing client!
*
* It succeeds if retrying 1 second later
* or if running xhost +localhost on shell.
*/
if (data->display == NULL) {
SDL_Delay(1000);
data->display = X11_XOpenDisplay(display);
}
#endif
if (data->display == NULL) {
SDL_free(device->driverdata);
SDL_free(device);
SDL_SetError("Couldn't open X11 display");
return NULL;
}
Since there is no SDL_OutOfMemory() related error message, i doubt the root cause is in SDL_X11_LoadSymbols…
Can anyone here help? thanks.