This fixes the weird slug when running nq on windows. It turns out it
was the "friendly neighbor" sleep code activating due to bitrot. In
addition, there are cvars for enabling unfocused sleep (defaults off)
and disabling minimized sleep (defaults on).
The event handling changes take care of VagueLobster's segfaults on
startup for all renderers (vulkan will still be iffy depending on his
hardware: it dies on my GTX 965 M, probably due to memory and QF's
shadows). One nice side effect is it takes care of the broken CD audio
event handling (does anyone even care, though?).
I never liked it, but with C2x coming out, it's best to handle bools
properly. I haven't gone through all the uses of int as bool (I'll leave
that for fixing when I encounter them), but this gets QF working with
both c2x (really, gnu2x because of raw strings).
This is an extremely extensive patch as it hits every cvar, and every
usage of the cvars. Cvars no longer store the value they control,
instead, they use a cexpr value object to reference the value and
specify the value's type (currently, a null type is used for strings).
Non-string cvars are passed through cexpr, allowing expressions in the
cvars' settings. Also, cvars have returned to an enhanced version of the
original (id quake) registration scheme.
As a minor benefit, relevant code having direct access to the
cvar-controlled variables is probably a slight optimization as it
removed a pointer dereference, and the variables can be located for data
locality.
The static cvar descriptors are made private as an additional safety
layer, though there's nothing stopping external modification via
Cvar_FindVar (which is needed for adding listeners).
While not used yet (partly due to working out the design), cvars can
have a validation function.
Registering a cvar allows a primary listener (and its data) to be
specified: it will always be called first when the cvar is modified. The
combination of proper listeners and direct access to the controlled
variable greatly simplifies the more complex cvar interactions as much
less null checking is required, and there's no need for one cvar's
callback to call another's.
nq-x11 is known to work at least well enough for the demos. More testing
will come.
It turns out the dd and dib "driver" code is very specific to the
software renderer. This does not fix the segfault on changing video
mode, but I do know where the problem lies: the window is being
destroyed and recreated without recreating the buffers. I suspect a
clean solution to this will allow for window resizing in X as well.
