It seems X11 does not like creating barriers entirely off the screen,
though the error seems to be a little unreliable (however, off the left
edge was definitely bad).
An imt switcher automatically changes the context's active imt based on
a user specified list of binary inputs. The inputs may be either buttons
(indicated as +button) or cvars (bare name). For buttons, the
pressed/not pressed state is used, and cvars are interpreted as ints
being 0 or not 0. The order of the inputs determines the bit number of
the input, with the first input being bit 0, second bit 1, third bit 2
etc. A default imt is given so large switchers do not need to be fully
configured (the default imt is written to all states).
A context can have any number of switchers attached. The switchers can
wind up fighting over the active imt, but this seems to be something for
the "user" (eg, configuration system) to sort out rather than the
switcher code enforcing anything.
As a result of the inputs being treated as bits, a switcher with N
inputs will have 2**N states, thus there's a maximum of 16 inputs for
now as 65536 states is a lot of configuration.
Using a switcher, setting up a standard strafe/mouse look configuration
is fairly easy.
imt_create key_game imt_mod
imt_create key_game imt_mod_strafe imt_mod
imt_create key_game imt_mod_freelook
imt_create key_game imt_mod_lookstrafe imt_mod_freelook
imt_switcher_create mouse key_game imt_mod_strafe +strafe lookstrafe +mlook freelook
imt_switcher 0 imt_mod 2 imt_mod 4 imt_mod_freelook 8 imt_mod_freelook 12 imt_mod_freelook
imt_switcher 6 imt_mod_lookstrafe 10 imt_mod_lookstrafe 14 imt_mod_lookstrafe
in_bind imt_mod mouse axis 0 move.yaw
in_bind imt_mod mouse axis 1 move.forward
in_bind imt_mod_strafe mouse axis 0 move.side
in_bind imt_mod_lookstrafe mouse axis 0 move.side
in_bind imt_mod_freelook mouse axis 1 move.pitch
This takes advantage of imt chaining and the default imt for the
switcher (there are 8 states that use imt_mod_strafe).
The switcher name must be unique across all contexts, and every imt used
in a switcher must be in the switcher's context.
The listener is invoked when the axis value changes due to IN_UpdateAxis
or IN_ClampAxis updating the axis. This does mean the listener
invocation make be somewhat delayed. I am a tad uncertain about this
design thus it being a separate commit.
Listeners are separate to the main callback as listeners have only
read-only access to the objects, but the main callback is free to modify
the cvar and thus can act as a parser and validator. The listeners are
invoked after the main callback if the cvar is modified. There does not
need to be a main callback for the listeners to be invoked.
This allows id1/qw config files, and to a certain extent scripts, to
work with the new binding system. It does highlight just how limited the
original system was (many keys could not bound).
Mouse axis input does not work yet as that needs a little more work to
support +strafe and +mlook.
I had forgotten that Cmd_Args() preserves quotes, which resulted in
button bindings having excess quotes when used to bind complex commands
(eg, the default quicksave and quickload bindings).
I decided cvars and input buttons/axes need listeners so any changes to
them can be propagated. This will make using cvars in bindings feasible
and I have an idea for automatic imt switching that would benefit from
listeners attached to buttons and cvars.
For now, only the first two axis (mouse X and Y) are supported (XInput
treats the scroll wheel events as axes too, so mice have up to 4!), but
most importantly, this prevents the scroll wheel from being seen as the
X axis. Oops.
It turns out accumulate is not really suitable now that relative axis
accumulation is done in the binding processing, and was never suitable
for absolute inputs (in this context, of course: there are contexts
where accumulate is suitable for absolute inputs).
Combining absolute and relative inputs at the binding does not work well
because absolute inputs generally update only when the physical input
updates, so clearing the axis input each frame results in a brief pulse
from the physical input, but relative inputs must be cleared each frame
(where frame here is each time the axis is read) but must accumulate the
relative updates between frames.
Other than the axis mode being incorrect, this seems to work quite
nicely.
With the old headers removed, X11_SetGamma became a stub and gcc
complained about it wanting the const attribute. On investigation, it
turned out the X_XF86VidModeSetGamma was a holdover from the initial
implementation of hardware gamma support.
UI key presses are still handled by regular X events, but in-game
"button" presses arrive via raw keyboard events. This gives transparent
handling of keyboard repeat (UI keys see repeat, game keys do not),
without messing with the server's settings (yay, that was most annoying
when it came to debugging), and the keyboard is never grabbed, so this
is a fairly user-friendly setup.
At first, I wasn't too keen on capturing them from the root window
(thinking about the user's security), but after a lot of investigation,
I found a post by Peter Hutterer
(http://who-t.blogspot.com/2011/09/whats-new-in-xi-21-raw-events.html)
commenting that root window events were added to XInput2 specifically
for games. Since application focus is tracked and unfocused key events
are dropped very early on, there's no way for code further down the
food-chain to know there even was an event, abusing the access would
require modifying the x11 input code, in which case all bets are off
anyway and any attempt at security anywhere in the code will fail,
meaning that nefarious progs code and the like shouldn't be a problem.
After a lot of thought, it really doesn't make sense to have an option
to block mouse input in x11 (not grabbing or similar does make sense, of
course). Not initializing mouse input made perfect sense in DOS and even
console Linux (SVGA) what with the low level access.
It turns out that if the barriers are set on the app window, and the app
grabs the pointer (even passively), barrier events will no longer be
sent to the app. However, creating the barriers on the root window and
the events are selected on the root window, the barrier events are sent
regardless of the grab state.
The kernel knows nothing about X11 application focus, so we need to take
care of it ourselves.
Device add/remove events are unaffected: the are always passed on.
Other subsystems, especially low-level input drivers, need to know when
the app has input focus. eg, as the evdev driver uses the raw stream
from the kernel, which has no idea about X application focus (in fact,
it seems the events are shared across multiple apps without any issue),
the evdev driver sees all the events thus needs to know when to drop
them.
It turns out to be possible to get a barrier event at the same time as a
configure notify event (which rebuilds the barriers), and trying to
release the pointer at such a time results in a bad barrier error and
program crash. Thus check the event barrier against the currently
existing barriers before attempting to release the pointer.
This does mean that a better mechanism for sequencing window
repositioning and barrier creation may be required.
This should be a much friendlier way of "grabbing" input, though I
suspect that using raw keyboard events will result in a keyboard grab,
which is part of the reason for wanting a friendly grab.
There does seem to be a problem with the mouse sneaking out of the
top-right and bottom-left corners. I currently suspect a bug in the X
server, but further investigation is needed.
This is needed for getting window position info into in_x11 without
exposing more globals, and is likely to be useful for other things,
especially as it doubles as a resize event when that's eventually
supported.
This is the first step in the long-sought goal of allowing the window
size to change, but is required for passing on getting window position
and size information (though size is in viddef, it makes sense to pass
both together).
This is necessary in focus-follows-mouse environments (at least for
openbox, but it wouldn't surprise me if most other WMs behave the same
way) because the WMs don't set focus when the pointer is grabbed (which
XInput does before the WM sees the enter event). This is especially
important when the window is fullscreen on a multi-monitor setup as
there is no border to *maybe* catch the mouse before it enters the
window.
Right now, only raw pointer motion and button events are handled, and
the mouse escapes the window, and there are some issues with focus in
focus-follows-mouse environments. However, this should be a much nicer
setup than DGA.
The current limit is still 32. Dealing with it properly will take some
rather advanced messing with XInput, and will be necessary assuming
non-XInput support is continued.
There's now IN_X11_Preinit, IN_X11_Postinit (both for want of better
names), and in_x11_init. The first two are for taking care of
initialization that needs to be done before window creation and between
window creation and mapping (ie, are very specific to X11 stuff) while
in_x11_init takes care of the setup for the input system. This proved
necessary in my XInput experimentation: a passive enter grab takes
effect only when the pointer enters the window, thus setting up the grab
with the pointer already in the window has no effect until the pointer
leaves the window and returns.
This was always a horrible hack just to get the screen centered on the
window back when we were doing fullscreen badly. With my experiments
with XInput, it has proven to be a liability (I'd forgotten it was even
there until it started imposing a 2s delay to QF's startup).
Input driver can now have an optional init_cvars function. This allows
them to create all their cvars before the actual init pass thus avoiding
some initialization order interdependency issues (in this case, fixing a
segfault when starting x11 clients fullscreen due to the in_dga cvar not
existing yet).
Well... it could be done better, but this works for now assuming it's in
/usr/include (and it's correct for mxe builts). Does need proper
autoconfiscation, though.
Seems to work nicely for keyboard (though key bindings are not
cross-platform). Mouse not tested yet, and I expect there are problems
with it for absolute inputs (yay mouse warp :P).
