This causes lots of spam in test automation and it's not clear it's useful to developers. If we need this level of validation, we should add a log category for it.
A racing reader could read from our fd between SDL_IOReady()/X11_Pending()
and our call to XNextEvent() which will cause XNextEvent() to block for
more data. Avoid this by using XCheckIfEvent() which will never block.
This also fixes a bug where we could poll() for data, even when events were
already read and pending in the queue. Unlike the Wayland implementation,
this isn't totally thread-safe because nothing prevents a racing reader
from reading events into the queue between our XCheckIfEvent() and
SDL_IOReady() calls, but I think this is the best we can do with Xlib.
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.
In this case we'll get WM_KILLFOCUS when the child window is focused, but we'll retain focus on the top level window, but when we Alt-Tab away, we won't get another WM_KILLFOCUS or WM_NCACTIVATE, we get WM_ACTIVATE instead, so we need to check for focus updates in response to that as well.
Add a new flag to avoid suppressing EINTR in SDL_IOReady(). Pass the
flag in WaitEventTimeout() to ensure that a SIGINT will wake up
SDL_WaitEvent() without another event coming in.
We can have spurious wakeups in WaitEventTimeout() due to Wayland events
that don't end up causing us to generate an SDL event. Fortunately for us,
SDL_WaitEventTimeout_Device() handles this situation properly by calling
WaitEventTimeout() again with an adjusted timeout.
Wayland provides the prepare_read()/read_events() family of APIs for
reading from the display fd in a deadlock-free manner across multiple
threads in a multi-threaded application. Let's use those instead of
trying to roll our own solution using a mutex.
This fixes an issue where a call to SDL_GL_SwapWindow() doesn't swap
buffers if it happens to collide with SDL_PumpEvents() in the main
thread. It also allows coexistence with other code or toolkits in
our process that may want read and dispatch events themselves.
Instead of taking a direct copy of the mouse cursor surface, and then
premultiplying on every BO upload (using the custom
legacy_alpha_premultiply_ARGB8888 function), use the new
SDL_PremultiplySurfaceAlphaToARGB8888() function, which converts a whole
surface at a time, once and save the result.
The already-premultiplied data is then copied from that to the BO on
each upload, adjusting for the stride (which the previous implementation
required to be equal to the width), thereby making the extra copy
slightly useful..
This also adds support for non-SDL_PIXELFORMAT_ARGB8888 surfaces.
It turns out that Wayland's WL_SHM_FORMAT_ARGB8888 format (and, indeed,
all wayland RGBA formats) should be treated as premultiplied. SDL
surfaces tend not to be premultiplied, and this is assumed by other
backends when dealing with cursors.
This change premultiplies the cursor surface in Wayland_CreateCursor()
using the new SDL_PremultiplySurfaceAlphaToARGB8888(). In so doing, it
also adds support for a wider range of input surfaces, including those
with non-ARGB8888 pixel formats, and those which don't have
pitch==width.
This should fix#4856
A number of video backends need to get ARGB8888 formatted surfaces with
premultiplied alpha, typically for mouse cursors. Add a new function to
do this, based loosely on legacy_alpha_premultiply_ARGB8888() from the
KMSDRM backend.
The new function, SDL_PremultiplySurfaceAlphaToARGB8888() takes two
arguments:
- src: an SDL_Surface to be converted.
- dst: a buffer which is filled with premultiplied ARGB8888 data of the
same size as the surface (assuming pitch = w).
This is not heavily optimised: it just repeatedly calls SDL_GetRGBA() to
do the conversion, but should do for now.
This fixes a specific issue seen on macOS 10.14.6 where a DELL E248WFP
Display connected to a 2014 Mac Mini with a scaled 1920x1080 resolution
selected and SDL_Init(SDL_INIT_VIDEO) failed with the error: "The video
driver did not add any displays".
The underlying cause was that the current 1080p display mode did not
have the flag kDisplayModeSafeFlag, the check for which was added in
a963e36, with the idea that certain display modes should not be
candidates for switching to in fullscreen exclusive mode. That may well
be the right thing to do for filtering down a list of candidate modes,
but it doesn't pay to be so picky about the current mode. After all,
this current mode was set by System Preferences, the picture does appear
correctly on screen, and other non-SDL based applications launch and run
correctly in this mode.
Therefore the fix is to have GetDisplayMode only filter out a mode based
on flags if it's part of a candidate list, but if it's the current mode
and it can possibly be converted to an SDL_DisplayMode, do so.
