So if Gnome/KDE/etc have a keyboard shortcut or titlebar decoration to
make any window go fullscreen (with the _NET_WM_FULLSCREEN flag on the
_NET_WM_STATE property), we update the SDL window flag.
Fixes#5390.
This makes sure the window doesn't have outdated values if you try to access
them (or call something that does, like SDL_SetWindowMinimumSize).
Fixes#5233.
The functions can go south if other operations are in progress, like
X11_SetWindowBordered, which might be doing something traumatic behind the
scenes of the window manager.
We can't make these tasks totally synchronous, which would fix the problem,
because not only can the window manager block however long it wants, it might
also decide to deny our requests without any notification, so we'd be waiting
forever for a window change that isn't coming. :(
Fixes#5274.
This fixes a compile warning — and possible invalid memory read —
introduced in 9c03d255 ("Add back X11 legacy WM_NAME encodings"), which
was part of PR #5029, fixing Bug #4924.
The issue is with one of the added warnings in X11_GetWindowTitle().
Basically, the "title" variable passed to SDL_LogError() hasn't been
initialised yet: we could pass propdata in directly, but it's better to
move the SDL_LogError() call until after title is set, IMHO.
This fixes the following warning from gcc (SUSE Linux) 11.2.1:
In file included from /home/david/Development/SDL/src/video/x11/../../SDL_internal.h:45,
from /home/david/Development/SDL/src/video/x11/SDL_x11window.c:21:
/home/david/Development/SDL/src/video/x11/SDL_x11window.c: In function 'X11_GetWindowTitle':
/home/david/Development/SDL/src/video/x11/../../dynapi/SDL_dynapi_overrides.h:33:22: warning: '%s' directive argument is null [-Wformat-overflow=]
33 | #define SDL_LogDebug SDL_LogDebug_REAL
/home/david/Development/SDL/src/video/x11/SDL_x11window.c:720:13: note: in expansion of macro 'SDL_LogDebug'
720 | SDL_LogDebug(SDL_LOG_CATEGORY_VIDEO, "Failed to convert WM_NAME title expecting UTF8! Title: %s", title);
| ^~~~~~~~~~~~
Closes#4924.
Based on patches of the past, such as this work by James Cloos in July
2010:
d7d98751b7,
as well as code comments in the Perl module X11::Protocol::WM
(https://metacpan.org/pod/X11::Protocol::WM) and even the code to Xlib
itself, which taught me that we should never have been using
`XStoreName`, all it does is call `XChangeProperty`, hardcoded to
`XA_STRING`!
What can I say, when the task is old school, the sources are too 😂
This API and implementation comes from the Unreal Engine branch of SDL, which
originally called this "SDL_ConfineCursor".
Some minor cleanup and changes for consistency with the rest of SDL_video, but
there are two major changes:
1. The coordinate system has been changed so that `rect` is _window_ relative
and not _screen_ relative, making it easier to implement without having
global access to the display.
2. The UE version unset all rects when passing `NULL` as a parameter for
`window`, this has been removed as it was an unused feature anyhow.
Currently this is only implemented for X, but can be supported on Wayland and
Windows at minimum too.
This can give some performance boost, and save some resources, as there's no
reason to keep a copy of an SDL window's contents on the server: most SDL
apps are redrawing completely every frame, and the API allows for expose
events to tell an app a redraw is needed anyhow.
(And compositors are free to ignore this setting if it makes sense to do so,
according to the Xlib docs.)
Reference Issue #3776.
This adds SDL_SetWindowKeyboardGrab(), SDL_GetWindowKeyboardGrab(),
SDL_SetWindowMouseGrab(), SDL_GetWindowMouseGrab(), and new
SDL_WINDOW_KEYBOARD_GRABBED flag. It also updates the test harness to exercise
this functionality and makes a minor fix to X11 that I missed in
https://hg.libsdl.org/SDL/rev/02a2d609369b
To fit in with this new support, SDL_WINDOW_INPUT_CAPTURE has been renamed to
SDL_WINDOW_MOUSE_CAPTURE with the old name remaining as an alias for backwards
compatibility with older code.
This gives us flexibility to add others hints to control keyboard grab behavior
without having to touch all of the backends. It also allows us to possibly
expose keyboard grab separately from mouse grab for applications that want to
manage those independently.
Wait up to 100 milliseconds, since the window manager might alter or
outright veto the window change...or not respond at all.
In a well-functioning system, though, this should help make sure
that SDL_SetWindowPosition's results match reality.
Fixes Bugzilla #4646.
Martin Fiedler
To be precise, this is about *desktop OpenGL* on X11. For OpenGL ES, EGL is already used (as it's the only way to get an OpenGL ES context), as Sylvain noted above.
To shine some light on why this is needed:
In 99% of all cases, using GLX on X11 is fine, even though it's effectively deprecated in favor of EGL [1]. However, there's at least one use case that *requires* the OpenGL context being created with EGL instead of GLX, and that's DRM_PRIME interoperability: The function glEGLImageTargetTexture2DOES simply doesn't work with GLX. (Currently, Mesa actually crashes when trying that.)
Some example code:
https://gist.github.com/kajott/d1b29c613be30893c855621edd1f212e
Runs on Intel and open-source AMD drivers just fine (others unconfirmed), but with #define USE_EGL 0 (i.e. forcing it to GLX), it crashes. The same happens when using SDL for window and context creation.
The good news is that most of the pieces for EGL support on X11 are already in place: SDL_egl.c is pretty complete (and used for desktop OpenGL on Wayland, for example), and SDL_x11opengl.c has the aforementioned OpenGL-ES-on-EGL support. However, when it comes to desktop OpenGL, it's hardcoded to fall back to GLX.
I'm not advocating to make EGL the default for desktop OpenGL on X11; don't fix what ain't broken. But something like an SDL_HINT_VIDEO_X11_FORCE_EGL would be very appreciated to make use cases like the above work with SDL.
[1] source: Eric Anholt, major Linux graphics stack developer, 7 years ago already - see last paragraph of https://www.phoronix.com/scan.php?page=news_item&px=MTE3MTI
Solra Bizna
I have written a program that, in the event that the user requests more MSAA samples than their hardware supports, attempts to gracefully fall back to the best MSAA available. This code works with my conventional OpenGL renderer, but if I change nothing about the code except to make it request an OpenGL ES profile instead, Xlib kills the program with an error that looks like:
X Error of failed request: BadWindow (invalid Window parameter)
Major opcode of failed request: 4 (X_DestroyWindow)
Resource id in failed request: 0x5c00008
Serial number of failed request: 188
Current serial number in output stream: 193
To trigger the bug, attempt to create a window with the SDL_WINDOW_OPENGL flag, with SDL_GL_CONTEXT_PROFILE_MASK set to SDL_GL_CONTEXT_PROFILE_ES, and with SDL_GL_MULTISAMPLESAMPLES set to any unsupported value. SDL_CreateWindow properly returns NULL, but at this point the program is already doomed. Xlib will shortly terminate the program with an error. Calling SDL_CreateWindow again will immediately trigger this termination.
I have attached a skeletal program that reproduces this bug for me. Replacing SDL_GL_CONTEXT_PROFILE_ES with SDL_GL_CONTEXT_PROFILE_COMPATIBILITY avoids the bug (but, obviously, doesn't create an OpenGL ES context).
As I suspected, the problem was with XDestroyWindow being called twice on the same window. The X11_CreateWindow function in src/video/x11/SDL_x11window.c calls SetupWindowData. If initialization fails after that point, XDestroyWindow gets called on the window by a subsequent call to X11_DestroyWindow. But, later in the same function, iff a GLES context is requested and initializing it fails, X11_XDestroyWindow (which wraps XDestroyWindow) is manually called. Shortly after, the intended call to X11_DestroyWindow occurs, which attempts to destroy the same window again. Boom.
(The above confusing summary involves three separate, similarly-named functions: XDestroyWindow, X11_DestroyWindow, X11_XDestroyWindow)
I have attached a simple patch that removes the redundant X11_XDestroyWindow calls. I've tested that XDestroyWindow still gets called for the windows in question, and that it only gets called once.