SDL_APP_WILLENTERBACKGROUND is now sent as soon as the app is told that it is
about to go to the background. SDL_APP_DIDENTERBACKGROUND is sent via a WinRT
'deferral operation', which is how WinRT gives apps a bit of extra time
(multiple seconds worth) to prepare for an app-backgrounding.
The distinction may be important as the deferral operation's code is always run
in a separate thread. For Direct3D-only apps, this means that between the
two SDL app-backgrounded events, SDL_APP_WILLENTERBACKGROUND will be the only
one run from the main thread. Given that some WinRT operations can only be done
on the main thread (operations to the CoreWindow fall into this category), this
could be important.
It is important to note that pre-deferral code may only have a very short bit of
time to execute code, less so than code run in the deferral operation (where
SDL_APP_DIDENTERBACKGROUND is sent from), which usually gets several seconds to
run.
SDL/WinRT did have support for OpenGL ES 2 via an older version of ANGLE/WinRT,
however its API changed a few months ago, and SDL/WinRT would crash when trying
to use it. It would also occasionally crash when using the older version.
This changeset should make SDL/WinRT work with the latest version, as
available via MS Open Tech's git repository of it at
https://github.com/msopentech/angle
Older versions of ANGLE/WinRT (from either https://github.com/stammen/angleproject
or https://bitbucket.org/DavidLudwig/angleproject) will need to be updated to
MS Open Tech's latest version.
It's been hardcoded out forever now, but I've now forcibly removed it with
the preprocessor so static analysis doesn't complain about it for now.
Eventually I want to rewrite or remove this code.
This is actually a false-positive, in this case, since Clang doesn't know
that SDL_SetError() only ever returns -1. Feature request to improve that,
with explanation about these specific SDL patches, is here:
http://llvm.org/bugs/show_bug.cgi?id=19208
Rotation detection and handling should now work across all, publicly-released,
WinRT-based platforms (Windows 8.0, Windows 8.1, and Windows Phone 8.0).
This changeset prevents IDXGISwapChain::ResizeBuffers from being invoked on
Windows Phone 8, a function that isn't available on the platform (but is
available on other Windows platforms). The call would fail, which ultimately
led to a crash.
This changeset also attempts to make sure that the D3D11 swap chain is created
at the correct size, when using Windows Phone 8.
Still TODO: make sure rotation-querying works across relevant Windows
platforms (that support Direct3D 11.x).
