Bryan Cain
Using any SDL application with the Wayland backend under Weston, if the application sets a cursor with SDL_SetCursor, the cursor will work until the mouse pointer leaves the window. When the pointer re-enters the window, there will be no cursor displayed at all.
I did some digging, and the reason for this is that SDL attaches the buffer to the cursor surface only once (during cursor creation) and assumes that it will stay attached. This is not how Wayland works, though - once the compositor is done rendering the buffer, it will release it, so it is no longer attached to the surface. When the cursor re-enters the window a second time, SDL sets the cursor to the same surface with no buffer attached, so no cursor is displayed.
This is fixed by the attached patch, which makes SDL attach the buffer to the surface when the cursor is set, not when it is created.
Bryan Cain
Wayland_CreateSystemCursor tries to load a cursor named "wait" for two of the system cursor categories. This causes a segmentation fault when one of these cursors is used, because "wait" is not an actual cursor name in X11/Wayland cursor themes.
I can't attach my patch since I'm on a mobile right now, but I can confirm that simply replacing "wait" with "watch" for both of its uses in Wayland_CreateSystemCursor (in SDL_waylandmouse.c) fixes the bug.
Sylvain
Someone provided a patch for this, recently on the mailing list :
-----
Hi,
it is possible to skip the bug in libX11 by using the defaults for
XNResourceName and XNResourceClass in `XCreateIC' (the table for the
"Input Context Values" [1] in libX11-doc shows that a default is
provided if it is not set).
diff -ur SDL2-2.0.3~/src/video/x11/SDL_x11window.c SDL2-2.0.3/src/video/x11/SDL_x11window.c
--- SDL2-2.0.3~/src/video/x11/SDL_x11window.c 2014-04-04 17:09:40.764307181 +0200
+++ SDL2-2.0.3/src/video/x11/SDL_x11window.c 2014-04-04 17:10:23.887765046 +0200
@@ -239,8 +239,7 @@
data->ic =
X11_XCreateIC(videodata->im, XNClientWindow, w, XNFocusWindow, w,
XNInputStyle, XIMPreeditNothing | XIMStatusNothing,
- XNResourceName, videodata->classname, XNResourceClass,
- videodata->classname, NULL);
+ NULL);
}
#endif
data->created = created;
Tito Latini
[1] http://www.x.org/releases/X11R7.7-RC1/doc/libX11/libX11/libX11.html#Input_Context_Values
Changes included:
- adding support for a few, additional, VirtualKey constants
- removing accesses to 'windows_scancode_table', as the table's contents
don't line up with WinRT virtual keys. Using Windows older VK_* constants
may, however, be a good alternative in a future update.
