To active new functions of tinygl (sharders), you need new SDL2 (TinyGL53 branch), actually i working on it... (I test and I give feedback to bigfoot)

I rebuild R6 with my SDL2 beta, i see some errors with shaders but ARB2 is available...
i reactive SDL_SetWindowGrab and i dont see any problem with that here (G5 X800)

Need more test i think...