These two options were mutually exclusive, and both were doing the same
thing -- switching to EGL on desktop GL, or switching away from EGL on
GLES. That made all logic vastly more complicated than it should be, and
unfortunately it took me half a decade to realize that. The new logic is
significantly simpler everywhere.
As usual, the old options are still recognized by CMake on a deprecated
build (with a warning), and are still exposed both as CMake variables
and a preprocessor define. But the logic for them was quite complicated,
so I don't guarantee all cases are covered.
I also tried to clean up the dependent CMake options to allow building
GLX and WGL apps on GLES independently of whether EGL is used, but it's
quite a mess due to the limitations of CMake < 3.22. Build directories
that have the options switched randomly over a long time might start
misbehaving, but the initial build should work well.