Windows Phone does not appear to allow VSync to be turned off. Doing so appears
to either result in content not getting drawn (when the D3D debug runtime is
turned off), or forcing VSync back on and logging an error (when the D3D debug
runtime is turned on).
VSync had been getting turned on anyways, this change just notes such:
- via the WinRT README
- by always setting the SDL_RENDERER_PRESENTVSYNC flag when creating an
SDL_Renderer on Windows Phone
Jonas Kulla
The configure script didn't differentiate between Linux and Android, unconditionally compiling in the unix implementation of SDL_sysfilesystem.c.
I'm probably one of the very few people building SDL for android using classic configure + standalone toolchain, so this has gone undetected all along.