Matthew
Its possible to set SDL_CaptureMouse() so you continue receiving mouse input while the mouse is outside your window. This works however There is then a gap where no messages send, which is when the mouse is hovering the title bar and the window edges.
X11 seemed to be confused by the broad definition, so WEIGHT_NAME,
SLANT and SETWIDTH_NAME were defined, thus fixing the font lookup
on some systems (tested on Mageia 6 with X11 1.19.1).
Fixes bug 3571.
Mark Callow
The attached patch does the following for the X11 and Windows platforms, the only ones where SDL attempts to use context_create_es_profile:
- Adds SDL_HINT_OPENGL_ES_DRIVER by which the application can
say to use the OpenGL ES driver & EGL rather than the Open GL
driver. (For bug #2570)
- Adds code to {WIN,X11}_GL_InitExtensions to determine the maximum
OpenGL ES version supported by the OpenGL driver (for bug #3145)
- Modifies the test that determines whether to use the OpenGL
driver or the real OpenGL ES driver to take into account the
hint, the requested and supported ES version and whether ES 1.X
is being requested. (For bug #2570 & bug #3145)
- Enables the testgles2 test for __WINDOWS__ and __LINUX__ and adds
the test to the VisualC projects.
With the fix in place I have run testdraw2, testgl and testgles2 without any issues and have run my own apps that use OpenGL, OpenGL ES 3 and OpenGL ES 1.1.
Mark Logan 2015-08-24 15:57:50 UTC
In SDL_windowsopengles.c, WIN_GLES_SetSwapInterval is as follows:
WIN_GLES_SetSwapInterval(_THIS, int interval)
{
/* FIXME: This should call SDL_EGL_SetSwapInterval, but ANGLE has a bug that prevents this
* from working if we do (the window contents freeze and don't swap properly). So, we ignore
* the request for now.
*/
SDL_Log("WARNING: Ignoring SDL_GL_SetSwapInterval call due to ANGLE bug");
return 0;
}
With a recent version of ANGLE (early July) calling SDL_EGL_SetSwapInterval with a D3D11 backend appears to work just fine. I am working on testing this with D3D9.
--
Alex Szpakowski
I found the bug, it was fixed in 2013. https://bugs.chromium.org/p/angleproject/issues/detail?id=481
In my opinion it should be safe to unconditionally use SetSwapInterval now. Anyone who encounters the bug should update their ANGLE to a version less than 3 years old, especially since they'd be using a SDL version that's 3+ years newer than their ANGLE version.
For example, if sR is 0 and dR is 255, we will get -255*sA casted to an unsigned value. Basically results are quite large numbers instead of the expected 0-255 range.
Ryan C. Gordon
Kristian says you can't do it with Wayland, and that going forward, it'll just handle whatever you throw at it anyhow.
https://twitter.com/hoegsberg/status/816148272402165761
So I say we mark it SDL_PIXELFORMAT_RGB888, which is what my X11 display currently reports, and leave it at that.
kaisyu
In case of OpenGLES, the sequences of loading and unloading driver library should be like that:
SDL_Init
...
SDL_GL_LoadLibrary
SDL_EGL_LoadLibrary
...
SDL_Quit
...
SDL_GL_UnloadLibrary
SDL_EGL_UnloadLibrary
...
However, according to my test results, the varible '_this->gl_config.driver_loaded' does not allow 'SDL_GL_UnloadLibrary' to call 'SDL_EGL_UnloadLibrary'.
Intellectual Kitty
In SDL_video.c, on line #1756, in SDL_SetWindowPosition (from today's distribution, 12-31-2016, https://hg.libsdl.org/SDL/shortlog/bf19e0c84483):
if (displayIndex > _this->num_displays) {
should be:
if (displayIndex >= _this->num_displays) {
felix
Compiling even a simple SDL2 'hello world' program with gcc -Wstrict-prototypes (GCC 6.2.1) results in warnings like:
/usr/include/SDL2/SDL_gamecontroller.h:143:1: attention : function declaration isn't a prototype [-Wstrict-prototypes]
extern DECLSPEC int SDLCALL SDL_GameControllerNumMappings();
^~~~~~
It seems there is a missing 'void' between the parentheses.
Ozkan Sezer
This adds the name 'ad' to two unnamed unions in edid.h
and adjusts edid-parse.c for it. Nameless unions are not supported in
ancient gcc, which I happened to use on one of my ancient setups.
Diego
I was previously unaware that rotating the device to a different orientation when the keyboard is shown causes a keyboardWillHide followed by a keyboardWillShow notification. The previous patch would then mistakenly StopTextInput when rotating. This patch fixes that by checking if the device is rotating before stopping text input.
Ozkan Sezer
With rev. 10651, i.e. http://hg.libsdl.org/SDL/rev/747a6a795b21 ,
SDL2 - OS X builds fail to run on 10.6 (my setup: i686 / 10.6.8)
because the symbol _IOPMAssertionCreateWithDescription is missing.
The SDK listing it for 10.7+ does seem correct. Reverting r10651
and rebuilding makes it to function again.
Simon Hug
The SDL_BlitScaled function runs into an access violation for specific blit coordinates and surface sizes. The attached testcase blits a 800x600 surface to a 1280x720 surface at the coordinates -640,-345 scaled to 1280x720. The blit function that moves the data then runs over and reads after the pixel data from the src surface causing an access violation.
I can't say where exactly it goes wrong, but I think it could have something to do with the rounding in SDL_UpperBlitScaled. final_src.y is 288 and final_src.h is 313. Together that's 601, which I believe is one too much, but I just don't know the code enough to make sure that's the problem.
Sylvain
I think this patch fix the issue, but maybe it's worth re-writing "SDL_UpperBlitScaled" using SDL_FRect.
The non-deprecated approach (IOPMAssertion) already exists in SDL, and is
available in Mac OS X 10.6 and later (although it was incorrectly listed as
10.7 and later in SDL). Since SDL now requires 10.6 or later, this is no
longer conditionally used.
realitix
SDL2 allows to create widow and to get information through SDL_SysWMinfo.
But it misses something, with Vulkan, you need the HWND and HINSTANCE of the window for Win32 system.
Sadly, SDL2 provides only HWND but not HINSTANCE.
In some context, it can be difficult to get the HINSTANCE, indeed, I'm using pySDL2 (Python) and I can only access properties that SDL2 gives me.
I have to use a dirty trick like that to get the HINSTANCE: (https://raw.githubusercontent.com/bglgwyng/pyVulkan/master/examples/win32misc.py)
felix
Building SDL 2.0.5, or even the Mercurial snapshot (r10608) with GCC 6.2.1 and --enable-video-directfb generates a number of compiler diagnostics and fails.
Ozkan Sezer
On systems with old glibc, such mine with glibc-2.8, the following warning
is issued and is fixed easily by defining _GNU_SOURCE:
/home/me/SDL2-2.0.5/src/video/x11/SDL_x11modes.c: In function 'CalculateXRandRRefreshRate':
/home/me/SDL2-2.0.5/src/video/x11/SDL_x11modes.c:263: warning: implicit declaration of function 'round'
/home/me/SDL2-2.0.5/src/video/x11/SDL_x11modes.c:263: warning: incompatible implicit declaration of built-in function 'round'
x414e54
I have implemented Drag and Drop and Clipboard support for Wayland.
Drag and dropping files from nautilus to the testdropfile application seems to work and also copy and paste.
Alex Baines
I realized overnight that my patch probably broke text input events with UIM, and I confirmed that it does. Can't believe I overlooked that... I've been making stupid mistakes in these patches recently, sorry.
Anyway, *this* one seems to fix it properly. Knowing my luck it probably breaks something else.
Patch uses XkbFreeKeyboard to free the memory returned by XkbGetMap.
Earlier implementation called XkbFreeClientMap which frees all the maps
but not data->xkb structure itself, XkbFreeKeyboard will free maps and
the structure.
/home/fedora/SDL2-2.0.5/src/video/SDL_blit_N.c: In function 'calc_swizzle32':
/home/fedora/SDL2-2.0.5/src/video/SDL_blit_N.c:127:5: error: ISO C90 forbids mixed declarations and code [-Werror=declaration-after-statement]
const vector unsigned char plus = VECUINT8_LITERAL(0x00, 0x00, 0x00, 0x00,
^
Kai Sterker
Apparently, SDL2 on Haiku does not generate SDL_TEXTINPUT events.
Attached is a patch that adds this functionality.
Tested with SDLs own checkkeys program and different keymaps as well as my own SDL application and German keyboard layout to verify it generates the expected input.
Albert Casals
On a RaspberryPI, it might become convenient to specify the Dispmanx layer SDL uses.
Currently, it is hardcoded to be 10000 to sit above most applications.
This can be specially useful when integrating other graphical apps and frameworks like OMXplayer, QT5 etc.. in order to have more flexibility on their Z-order.
Eric Wasylishen
The patch makes StartTextInput/StopTextInput call Xutf8ResetIC ( https://www.x.org/releases/X11R7.5/doc/man/man3/XmbResetIC.3.html ) on the XIC of all SDL windows.
This fixes my use case in Quakespasm (Ubuntu 16.04, system keyboard layout set to German. Type the '^' dead key, which opens Quakespasm's developer console and calls SDL_StartTextInput, then press 'e'. I expect the dead key to be ignored.)
Also, here is a patch for sdl2's "checkkeys" for testing this: https://bugzilla-attachments.libsdl.org/attachment.cgi?id=2451
Olav Sorensen
After a drag and drop event, any following mouse button input (down/up) doesn't generate an event. Clicking any mouse button a *second* time generates an event like it should.
Further investigation shows that the new SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH logic also causes this issue in other cases, like the first time you open the program and click the mouse.
Robert Folland
When running this little test program with SDL2 on Wayland it often crashes in SDL_Init.
From a backtrace it is apparent that there is a race condition in creating a xkb_context_ref. Sometimes it is 0x0.
By moving the relevant lines higher up in Wayland_VideoInit (in SDL2-2.0.4/src/video/wayland/SDL_waylandvideo.c:302) this seems to get fixed.
I moved the call to WAYLAND_xkb_context_new() up to before the call to WAYLAND_wl_display_connect().
Here is the test program (just a loop of init and quit), and a backtrace from gdb:
#include <cstdio>
#include <stdlib.h>
#include <SDL2/SDL.h>
#include <unistd.h>
#include <iostream>
int main(int argc, char **argv)
{
int count = atoi(argv[1]);
for (int i = 0; i < count; i++) {
std::cout << "Init " << i << std::endl;
if (SDL_Init(SDL_INIT_VIDEO) < 0) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"Couldn't initialize SDL: %s\n",
SDL_GetError());
return 1;
}
std::cout << "Quit" << std::endl;
SDL_Quit();
}
return 0;
}
Init 12
Quit
Init 13
Program received signal SIGSEGV, Segmentation fault.
xkb_context_ref (ctx=ctx@entry=0x0) at src/context.c:156
156 ctx->refcnt++;
(gdb) bt
#0 xkb_context_ref (ctx=ctx@entry=0x0) at src/context.c:156
#1 0x00007ffff5e1cd4c in xkb_keymap_new (ctx=0x0, format=XKB_KEYMAP_FORMAT_TEXT_V1, flags=flags@entry=XKB_KEYMAP_COMPILE_NO_FLAGS) at src/keymap-priv.c:65
#2 0x00007ffff5e1c6cc in xkb_keymap_new_from_buffer (ctx=<optimized out>,
buffer=0x7ffff7fd5000 "xkb_keymap {\nxkb_keycodes \"(unnamed)\" {\n\tminimum = 8;\n\tmaximum = 255;\n\t<ESC>", ' ' <repeats 16 times>, "= 9;\n\t<AE01>", ' ' <re
peats 15 times>, "= 10;\n\t<AE02>", ' ' <repeats 15 times>, "= 11;\n\t<AE03>", ' ' <repeats 15 times>, "= 12;\n\t<AE04>", ' ' <repeats 12 times>..., length=48090,
format=<optimized out>, flags=<optimized out>) at src/keymap.c:191
#3 0x00007ffff7b8ea4e in keyboard_handle_keymap (data=0x6169b0, keyboard=<optimized out>, format=<optimized out>, fd=5, size=48091)
at /home/vlab/abs/sdl2/src/SDL2-2.0.4/src/video/wayland/SDL_waylandevents.c:269
#4 0x00007ffff64501f0 in ffi_call_unix64 () from /usr/lib/libffi.so.6
#5 0x00007ffff644fc58 in ffi_call () from /usr/lib/libffi.so.6
#6 0x00007ffff665be3e in wl_closure_invoke (closure=closure@entry=0x61f000, flags=flags@entry=1, target=<optimized out>, target@entry=0x616d20,
opcode=opcode@entry=0, data=<optimized out>) at src/connection.c:949
#7 0x00007ffff6658be0 in dispatch_event (display=<optimized out>, queue=<optimized out>) at src/wayland-client.c:1274
#8 0x00007ffff6659db4 in dispatch_queue (queue=0x617398, display=0x6172d0) at src/wayland-client.c:1420
#9 wl_display_dispatch_queue_pending (display=0x6172d0, queue=0x617398) at src/wayland-client.c:1662
#10 0x00007ffff665a0cf in wl_display_roundtrip_queue (display=0x6172d0, queue=0x617398) at src/wayland-client.c:1085
#11 0x00007ffff7b8faa0 in Wayland_VideoInit (_this=<optimized out>) at /home/vlab/abs/sdl2/src/SDL2-2.0.4/src/video/wayland/SDL_waylandvideo.c:302
#12 0x00007ffff7b7aed6 in SDL_VideoInit_REAL (driver_name=<optimized out>, driver_name@entry=0x0) at /home/vlab/abs/sdl2/src/SDL2-2.0.4/src/video/SDL_video.c:513
#13 0x00007ffff7ae0ee7 in SDL_InitSubSystem_REAL (flags=16416) at /home/vlab/abs/sdl2/src/SDL2-2.0.4/src/SDL.c:173
#14 0x0000000000400b24 in main (argc=2, argv=0x7fffffffebb8) at vplay-init.cpp:13
(gdb)
Eric wing
Sometimes an SDL_assert triggers at RPI_WarpMouseGlobal
src/video/raspberry/SDL_rpimouse.c:232 'update'.
It doesn't always reproduce, but it seems to happen when you really bog down the system and the event loop can't update for awhile.
The first time I hit this, I wasn't even using the mouse. I don't call any warp mouse functions either.
I can usually reproduce with a simple program that runs an expensive blocking CPU series of functions which blocks the main loop until complete (can be up to 10 seconds).
Sometimes this assertion gets triggered after that. I'm not sure if
they are related or coincidental.
Disabling the SDL_asserts when compiling SDL will avoid this problem. I actually haven't seen any problems with the mouse when I do this.
On a Raspberry Pi 2 running Raspbian Jessie.
Daniel Gibson
Ok, I followed the simple approach of just making SDL_PIXELFORMAT_RGBA32 an alias of SDL_PIXELFORMAT_RGBA8888/SDL_PIXELFORMAT_ABGR8888, depending on endianess. And I did the same for SDL_PIXELFORMAT_ARGB32, .._BGRA, .._ABGR.
SDL_GetPixelFormatName() will of course return SDL_PIXELFORMAT_RGBA8888 (or SDL_PIXELFORMAT_ABGR8888) instead of SDL_PIXELFORMAT_RGBA32, but as long as that's mentioned in the docs it shouldn't be a problem.
Weitian Leung
Just moved ibus direct call to SDL_IME_* related functions, and adds fcitx IME support (uses DBus, too),
enable with env: SDL_IM_MODULE=fcitx (ibus still the default one)
x414e54
Wayland will sometimes send empty resize events (0 width and 0 height) to the client. I have not worked out the exact conditions a client would receive these but I can assume it might be if the window is offscreen or not mapped yet.
This causes issues with some SDL clients as they receive the 0x0 event and unexpected resize event or might not request to resize back to the correct size.
As per the wl_shell Wayland spec configure events are only a suggestion and the client is free to ignore or pick a different size (this is how min/max and fixed aspect ratio is supped to be implemented).
A patch is attached but is just the first iteration and I will fix any issues such as checking for FULLSCREEN/MAXIMIZED or RESIZABLE flags unless someone else fixes this first.
I have update to take into account non resizable and fullscreen windows. Also adding in maximize/restore and title functions for Wayland.
Darren Kulp
The dummy video driver is not available on Mac OS X if SDL_VIDEO_OPENGL is set at library compilation time.
In src/video/SDL_video.c, there is a compile-time check in SDL_CreateWindow() for (SDL_VIDEO_OPENGL && __MACOSX__). When it succeeds, SDL_WINDOW_OPENGL is always requested. Since the dummy video driver does not supply an OpenGL implementation, the error "No OpenGL support in video driver" is supplied to the user, and SDL_CreateWindow() is exited early.
Daniel Gibson
Currently, SDL_CreateRGBSurface() and SDL_CreateRGBSurfaceFrom() take Uint32 masks for RGBA to "describe" the Pixelformat of the surface.
Internally those value are only used to map to one of the SDL_PIXELFORMAT_* enum values that are used for further processing.
I think it would be both handy and more efficient to be able to specify SDL_PIXELFORMAT_* yourself without using SDL_PixelFormatEnumToMasks() to create masks first, so I implemented functions that do that:
SDL_CreateRGBSurfaceWithFormat() and SDL_CreateRGBSurfaceWithFormatFrom() which are like the versions without "WithFormat" but instead of taking 4 Uint32s for R/G/B/A masks, they take one for a SDL_PIXELFORMAT_* enum value.
Together with https://bugzilla.libsdl.org/show_bug.cgi?id=2923 creating a SDL_Surface* from RGBA data (e.g. from stb_image) is as easy as
surf = SDL_SDL_CreateRGBSurfaceWithFormat(0, w, h, bppToUse*8, SDL_PIXELFORMAT_RGBA32);
Jan Hellwig
On Windows, you are able to navigate between the buttons on a MessageBox that was created using SDL_ShowMessageBox using the arrow keys. However, if you press the left arrow key, the selection jumps to the button on the right of the currently selected one (and vice versa).
This can be fixed by reversing the order in which the buttons are added to the dialog.
The attached patch files fixes this problem. However the first press of an arrow key leads to the selection of the leftmost or rightmost button on the MessageBox, not to the selection of the button left/right of the one that is selected by default.
Jonas Kulla
At startup time, the single android window is assigned a "windowed" (window->windowed.{w,h}) size based on the current orientation of the mobile device; this size is never updated throughout the lifetime of the app.
This becomes problematic when the app is paused and then resumed in an orientation that it did not start up in. Eventually, 'SDL_OnWindowRestored()' is called, which calls 'SDL_UpdateFullscreenMode()'. This function is very problematic because it is written with a desktop monitor in mind: it tries to find a matching display mode for the windowed size, doesn't find any, and finally applies the windowed size as the fullscreen one. In the end, the windowed size is reported in a RESIZED event, which doesn't correspond to the actual surface size.
To see this in action: Start an orientation aware SDL app in eg. portrait mode, suspend the app, put the device into landscape orientation and resume the app. It will erroneously render in portrait mode (until the device is rotated again).
Tim McDaniel
Using checkkeys test app:
* Press and hold Caps Lock key.
* checkkeys reports a CapsLock key pressed event and a CapsLock key released event.
* Release Caps Lock key.
* checkkeys reports no further events.
This patch fixes OSX Caps Lock up/down event detection by installing a HID callback.
John Wordsworth
While attempting to integrate CEF (Browser) into an SDL application, we noticed that there were problems on OS X where approximately 50% of the input events were essentially being lost - even when we were using off-screen rendering in CEF and passing through input events manually.
It appears that this problem has been around for a while (see: http://www.magpcss.org/ceforum/viewtopic.php?f=6&t=11141).
Please consider the following patch that fixes this issue. Instead of processing events directly after calling [NSApp nextEventMatchingMask:...] we now pass these events down to NSApp, for processing by an overloaded sendEvent: method. Chromium also forwards events to NSApp in the same way, which means we don't miss events, even if they were originally dequeued by CEF.
Michael
In SDL_x11modes.c the CalculateXRandRRefreshRate() function performs integer math on values that may return fractional results. This causes a value that would be calculated as 59.99972... to be returned as 59. In Linux the xrandr command returns 60Hz for this particular display mode yet SDL returns 59Hz.
I suggest this function be updated to correctly round the result of the calculation instead of truncating the result.
Patrick Gutlich
The mouse cursor gets corrupted when the mouse moves over the screen edges (right and bottom) a weird type of scaling seems to occur and you end up with a blank square.
Fritzor
Source Suface is ABGR and Destination Surface is ABGR. We use software blending. In the Switch-Case statement for SDL_COPY_BLEND (Line 126) the alpha-channel is not calculated like in every SDL_blit_auto - function. So if the destination Surface has alpha - channel of zero the resulting surface has zero as well.
Add: ?dstA = srcA + ((255 - srcA) * dstA) / 255;? to code and everything is okay.
Evgeny Vrublevsky
Original code in the video/windows/SDL_windowsevents.c registers obsolete WNDCLASS (not WNDCLASSEX). As the result only one icon size is used as the small and normal icons. Also original code doesn't specify required size of an icon. As the result when 256x256 icon is available, the program uses it as a default icon, and it looks ugly.
We have to use WNDCLASSEX and load icons with proper sizes which we can get using GetSystemMetrics.
Better idea. We could use the first icon from resources, like the Explorer does. Patch is included. It also correctly loads large and small icons, so it will look nice everywhere.
Diego
The keyboard on iPads has a dismiss button that hides the keyboard. When the keyboard was hidden using that button, instead of the return key, SDL was still reporting IsTextInputActive as true. This patch adds an extra SDL_StopTextInput when iOS reports the keyboard will hide.
Eric Wasylishen
The bug here is that a dead keys pressed before calling SDL_StartTextInput() carries over into future text input, so the next key pressed will have the deadkey applied to it.
This in undesirable, imho, and doesn't occur on OS X (haven't check Linux or elsewhere). It's causing a problem for Quakespasm on German keyboard layouts, where we use the ^ deadkey to toggle the console (which enables/disables text input), and ^ characters are showing up in the TEXTINPUT events.
Simon Hug
The current SDL_SaveBMP_RW function that saves surfaces to a BMP uses an old bitmap header which doesn't officially support alpha channels. Applications just ignore the byte where the alpha is stored. This can easily be extended by using a newer header version and setting the alpha mask.
The attached patch has these changes:
- Extending the description of the function in the SDL_surface.h header with the supported formats.
- Refining when surfaces get stored to a 32-bit BMP. (Must have bit depth of 8 or higher and must have an alpha mask or colorkey.)
- Fixing a small bug that saves 24-bit BGR surfaces with a colorkey in a 24-bit BMP.
- Adding code that switches to the bitmap header version 4 if the surface has an alpha mask or colorkey. (I chose version 4 because Microsoft didn't lose its documentation behind a file cabinet like they did with version 3.)
- Adding a hint that can disable the use of the version 4 header. This is for people that need the legacy header or like the old behavior better. (I'm not sure about the hint name, though. May need changing if there are any rules to that.)
Simon Hug
When the SDL_Blit_Slow function compares the pixel to the color key it does so without removing the alpha component from the pixel value and the key. This is different from the optimized 32-bit blitters which create a rgb mask and apply it to both to filter the alpha out. SDL_Blit_Slow will only skip the pixels with the exact alpha value of the key instead of all pixels with the same color.
The attached test case blits a surface with a color key and prints the pixel values to the console. The third row is expected to be skipped.
The Apple TV remote is currently exposed as a joystick with its touch surface treated as two axes. Key presses are also generated when its buttons and touch surface are used.
A new hint has been added to help deal with deciding whether to background the app when the remote's menu button is pressed: SDL_HINT_APPLE_TV_CONTROLLER_UI_EVENTS.
Previously when the canvas was scaled up and the pointer was locked,
motion corresponding to less than one pixel was lost. Therefore,
slow mouse motion resulted in no motion. This fixes that.
Browsers don't have the functionality to fully support the generic
SDL_ShowMessageBox(), but this handles the likely most-common case.
Without this, you'd return immediately with a proper error result and no UI,
but probably no one checks that for SDL_ShowSimpleMessageBox. And if they
did: what would they do to handle this anyhow?
We'd need to lobby for an HTML spec of some sort that allows customizable
message boxes--that block!--to properly support SDL message boxes on
Emscripten, but this is probably Good Enough for now.
Generate the C protocol files from the protocol XML files installed by
wayland-protocols, and use them to implement support for relative pointer
motions and pointer locking.
Note that at the time, the protocol is unstable and may change in the future.
Any future breaking changes will, however, fail gracefully and result in no
regressions compared to before this patch.
Since we are loading shared objects dynamically, build our own version of the
core protocol symbols, so that we in the future can include protocol
extensions.
This will be used by Wayland compositors to match the application ID and
.desktop file to the SDL window(s).
Applications can set the SDL_VIDEO_WAYLAND_WMCLASS environemnt variable
early in the process to override using the binary name as a fallback.
Note that we also support the SDL_VIDEO_X11_WMCLASS in the Wayland
backend so that if a program correctly associated the desktop file with
the window under X11, only a newer SDL would be needed for it to work
under Wayland.
https://bugzilla.libsdl.org/show_bug.cgi?id=3376
The repro steps were this:
1. run an sdl2 winrt/uwp app, on Win10, v10.0.10586.0 or higher
2. hide the cursor, via a call to SDL_ShowCursor(0)
3. make the Win10 game bar appear, by pressing the Windows + G hotkey
4. observe that the mouse cursor appears, in order to interact with the
game bar (this is expected behavior)
5. make the Win10 game bar disappear, either by pressing the Windows + G hotkey
again, or clicking somewhere in the app
EXPECTED RESULT: cursor disappears, as game bar disappears
ACTUAL RESULT: cursor didn't always disappear
