Impossible to disable vsync glcore

[roig]

Hello, I found that is impossible to disable vsync (at least when using GLCORE):

In sapp_desc I put swap_interval to 0 but this line is defaulting it to 1:
res.swap_interval = _sapp_def(res.swap_interval, 1);

Maybe I'm not understanding swap_interval correctly.
But I think _sapp.wgl.SwapIntervalEXT(0); disables vsync so the _sapp_def to 1 when is 0 seems wrong.

[floooh]

Yes, disabling vsync altogether isn't supported by sokol_app.h, but not for the '0 vs 1' situation you stumbled over.

Implementing this across all backends would be a non-trivial job (e.g. AFAIK it's completely impossible on web with requestAnimationFrame, and on macOS/iOS with MTKView it's also only possible by not using the 'canonical' way to drive the frame loop).

The current swap_interval thing also isn't very useful in practice and will eventually be replaced by something like a target-frame-rate, but this still will be vsync-throttled.

[floooh]

I'll close this as duplicate of #1053 and #292