Pressing the hardware back button on a Windows Phone 8 device will now cause SDL to emit a pair of key-down and key-up events, with the SDL scancode, SDL_SCANCODE_AC_BACK.
By default, if WinRT's native back-button-press events are not explicitly marked as 'handled', then Windows Phone will terminate the app. More details on Microsoft's reasoning behind this can be found on MSDN, at http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj247550(v=vs.105).aspx
To mark back-button-press events as 'handled', set SDL_HINT_WINRT_HANDLE_BACK_BUTTON to 1. Setting it to anything else will cause these events to not be marked as 'handled'.
Due to limitations in Windows Phone's APIs, SDL will emit a virtual key-up event immediately after the back button's key-down event is registered. Unfortunately, Windows Phone 8 only allows one to register for back-button-press events, and not back-button-release events.
This change is only relevant for Windows 8, 8.1, and RT apps, and only for those that are network-enabled. Such apps must feature a link to a privacy policy, which must be displayed via the Windows Settings charm. This is needed to pass Windows Store app-certification.
Using SDL_SetHint, along with SDL_HINT_WINRT_PRIVACY_POLICY_URL and optionally SDL_HINT_WINRT_PRIVACY_POLICY_LABEL, will cause SDL/WinRT to create a link inside the Windows Settings charm, as invoked from within an SDL-based app.
Network-enabled Windows Phone apps do not need to set this hint, and should provide some sort of in-app means to display their privacy policy. Microsoft does not appear to provide an OS-integrated means for displaying such on Windows Phone.
SDL 2.x recently accepted patches to enable OpenGL ES 2 support via Google's ANGLE library. The thought is to try to eventually merge SDL/WinRT's OpenGL code with SDL-official's.
This bumps the build SDK level to 12 (up from 10). Runtime requirements remain
the same (at API level < 12 joystick support is disabled).
Also enables building SDL for armv7 and x86.
To enable the Debug Layer, set the hint, SDL_HINT_RENDER_DIRECT3D11_DEBUG to '1'.
The Debug Layer will be turned off by default, both in Release and Debug builds (of SDL).
If the app is in landscape mode and the user presses the power button, a pause
is followed immediately by a surfaceChanged event because the lock screen
is shown in portrait mode. This triggers a "false" resume.
So, we just pause and resume following the onWindowFocusChanged events.
Also, wait for SDL_APP_WILLENTERBACKGROUND and SDL_APP_DIDENTERBACKGROUND before
blocking the event pump.