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Simple DirectMedia Layer for Windows

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OpenGL ES 2.x support

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SDL has support for OpenGL ES 2.x under Windows via two alternative 

implementations. 

The most straightforward method consists in running your app in a system with 

a graphic card paired with a relatively recent (as of November of 2013) driver 

which supports the WGL_EXT_create_context_es2_profile extension. Vendors known 

to ship said extension on Windows currently include nVidia and Intel.

The other method involves using the ANGLE library (https://code.google.com/p/angleproject/)

If an OpenGL ES 2.x context is requested and no WGL_EXT_create_context_es2_profile

extension is found, SDL will try to load the libEGL.dll library provided by

ANGLE.

To obtain the ANGLE binaries, you can either compile from source from

https://chromium.googlesource.com/angle/angle or copy the relevant binaries from

a recent Chrome/Chromium install for Windows. The files you need are:

    * libEGL.dll

    * libGLESv2.dll

    * d3dcompiler_46.dll (supports Windows Vista or later, better shader compiler)

    or...

    * d3dcompiler_43.dll (supports Windows XP or later)

If you compile ANGLE from source, you can configure it so it does not need the

d3dcompiler_* DLL at all (for details on this, see their documentation). 

However, by default SDL will try to preload the d3dcompiler_46.dll to

comply with ANGLE's requirements. If you wish SDL to preload d3dcompiler_43.dll (to

support Windows XP) or to skip this step at all, you can use the 

SDL_HINT_VIDEO_WIN_D3DCOMPILER hint (see SDL_hints.h for more details).

Known Bugs:

    * SDL_GL_SetSwapInterval is currently a no op when using ANGLE. It appears

      that there's a bug in the library which prevents the window contents from

      refreshing if this is set to anything other than the default value.