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.
Also fix a bug where despite supporting 32 buttons, only 18 were actually
supported, and a similar issue for the number of axes.
My saitek x52 has 34 buttons and 10 axes. Whee.
First, this completely smashes joystick input: it will not work (though it
doesn't crash). This is because there is, as of yet, no means to configure
the system.
Each joystick axis has:
- per-axis amplification (both pre and post).
- per-axis offset (offset applied after pre-amp but before post amp)
- selectable destination:
- linear delta: position and angles (as before)
- axis button: if the value crosses the threshold, the given key is
pressed or released as appropriate.
The axis amplification still uses joy_amp and joy_pre_amp (and
in_amp/in_pre_amp), but now also has the per-axis settings.
The per-axis offset is most useful for axis buttons. For example, the xbox
360 controller triggers are analong but go "all the way to negative on 0
state". Offsetting the input keeps axis button thresholds simple.
Amplification and offset is applied before anything is done with the axis
value. The formula is:
joy_amp * in_amp * axis-amp *
(offset + value * joy_pre_amp * in_pre_amp * axis-pre_amp)
Axis button thresholds are very simple: if the sign of the value is the
same as the sign of the threshold and abs(value) >= abs(threshold), the
button is pressed. While multiple thresholds and keys can be placed on an
axis, only one can be pressed at a time. The threshold furthest from 0
wins.
