A port of the ANGLE library (OpenGL ES 2.0 for Direct3D) to WinRT, via https://github.com/stammen/angleproject, is used as a base.
To enable, clone 'angleproject' into the directory one above where SDL/WinRT is, open the file SDL/include/SDL_config_winrt.h, and uncomment the #defines that begin with 'SDL_VIDEO_OPENGL'. From there, apps can create an OpenGL capable SDL_Window via the flag, SDL_WINDOW_OPENGL, and an OpenGL ES 2 context via SDL_GL_CreateContext. The Direct3D 11.1 renderer cannot be used alongside SDL_WINDOW_OPENGL. Only Windows 8/8.1 is supported for now. Shaders may need to be precompiled, in some (all?) cases.
This can break builds of existing SDL/WinRT apps. To fix, remove the reference to SDL_winrt_main.cpp, then add a reference to the renamed file, SDL_winrt_main_NonXAML.cpp. If you get a build error about a missing .winmd file, enable the /ZW compiler flag for that one file (at minimum).
1. remove references to SDL's project files from the Visual Studio Solution. To note, these project files have been renamed, and will show up in Visual Studio with the text, "load failed".
2. add the SDL project files back into the Visual Studio Solution
3. for each project that should link to SDL, add a reference to it. This can be done by right-clicking on it in Visual Studio, selecting "References...", clicking "Add New Reference", checking the box next to the SDL project, then closing each dialog by clicking OK.
SDL_mixer, SDL_ttf, and SDL_image for WinRT have been updated, and will be pushed to my Bitbucket repos with these changes having been made. If you do not pull in these changes, be sure to re-add to them the reference to the SDL project, as described above.
XAudio2 2.8's header file, xaudio2.h, doesn't compile in plain C code for WinRT
apps, not automatically at least. Initially, this file was adapted to compile
as C++, however these changes are now deprecated in favor of some preprocessor
based hacks that should get xaudio2.h to compile (while making sure XAudio2
still works).
- moved SDL_WinRTApp.* from src/video/windowsrt/ to src/core/winrt/, and renamed them to SDL_winrtapp.* (to mimick case-sensitivity used elsewhere in SDL)
- renamed all "windowsrt" directories (in src) to "winrt", as the shorthand name is used more often (and, IMO, "WinRT" != "Windows RT", not entirely at least)
David Ludwig