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.
* Avoid unnecessary SDL_PumpEvents calls in SDL_WaitEventTimeout
* Add a sentinel event to avoid infinite poll loops
* Move SDL_POLLSENTINEL to new internal event category
* Tweak documentation to indicate SDL_PumpEvents isn't always called
* Avoid shadowing event variable
* Ignore poll sentinel if more (user) events have been added after
Co-authored-by: Sam Lantinga <slouken@libsdl.org>
Instead do an absolute elapsed time check since the start of the wait. If that is exceeded during any iteration the routine exits as the timeout has elapsed.
The observed behavior is that any nonzero timeout value would hang until the device was paused and resumed. And a zero timeout value would always return 0 frames written even when audio fragments could be heard. Making a manual timeout system unworkable.
None of the straightforward systems imply that there's a detectable problem before the call to AAudioStream_write(). And the callback set within AAudioStreamBuilder_setErrorCallback() does not get called as we enter the hang state.
I've found that AAudioStream_getTimestamp() will report an error state from another thread. So this change codifies that behavior a bit until a better fix or more root cause can be found.
David Gow
uyjulian
Sam Lantinga
SDL Wiki Bot
Cacodemon345
James Howard
Sylvain
Ozkan Sezer
DomGries
shaquan-omari
Brick
Rémy Tassoux
Erik Soma
Cameron Cawley