This is pretty trivial, but also quite annoying due to details like
mismatching eglGetProcAddress() function signature (most callers just
cast the function pointer), and ARM/Linux hacks. So move them all to one
place.
Preparation for the following commits. Since at least theoretically the
config selection depends on the context type (EGL_RENDERABLE_TYPE has
separate bits for ES 2, ES 3, and desktop GL), doing it any other way
would be too painful.
For X11 garbage we have to pass some annoying parameters to EGL context
creation. Add some sort of extensible API, so that adding a new
parameter doesn't break all callers. We still want to keep it as a
single function, because it's so nice isolating all the EGL nonsense API
boilerplate like this. (Did I mention yet that X11 and EGL are garbage?)
Also somewhat simplifies the vo_flags mess in the helper internals.
Add a function to egl_helpers.c for creating an EGL context and make
context_x11egl.c use it. This is meant to be generic, and should work
with other windowing APIs as well. The other EGL-using code in mpv can
be switched to it.
Until now, we've used system-specific API (GLX, EGL, etc.) to retrieve
the depth of the default framebuffer. (We equal this to display depth
and use the determined depth for dithering.)
We can actually retrieve this value through standard GL API, and it
works everywhere (except GLES 2 of course). This simplifies everything a
great deal.
egl_helpers.c is empty now. But I expect that some EGL boilerplate will
be moved to it, so don't remove it yet.
This is used for dithering, although I'm not aware of anyone who got
higher than 8 bit depth support to work on Linux.
Also put this into egl_helpers.c. Since EGL is pseudo-portable at best I
have no hope that the EGL context creation code in all the backends can
be fully shared. But some self-contained functionality can definitely be
shared.
wm4