This includes moving the related cvars from botn nq and qw into the
client hud code. In addition, the hud code supports update and
update-once function components. The update component is for updates
that occur every frame, but update-once components (not used yet) are
for one-shot updates (eg, when a value updates very infrequently).
Much of the nq/qw HUD system is quite broken, but the basic status bar
seems to be working nicely. As is the console (both client and server).
Possibly the biggest benefit is separating the rendering of HUD elements
from the updating of them, and much less traversing of invisible views
whose only purpose is to control the positioning of the visible views.
The view flow tests are currently disabled until I adapt the flow code
to ECS.
There seems to be a problem with view resizing in that some gravities
don't follow resizing correctly.
And use it for hud_scoreboard_gravity. Putting the enum def in view made
the most sense as view does own the base type and the enum is likely to
be by useful for other settings.
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.
They've been near-identical for years, now they're only one. It proved
necessary to start merging the HUD code which for now is just a few cvar
declarations (not even init), but that should be a separate set of
commits.
