vimpad
======

vimpad is a utility for controlling vim with a Linux-compatible gamepad. It
was developed on an X-box controller, but should be compatible with any
gamepad that works with Linux and has two analogue sticks.

vimpad depends on qjoypad and vim.

Install: place vimpad.vim into ~/.vim/after/ and vimpad.lyt into ~/.qjoypad3/.

From within vim, call GamepadOn. To exit, call GamepadOff.

TODO:
    * Swap d and u? I feel that u is currently easier to reach and I use it
      more often.
    * Improve documentation.  Better diagram?
    * Better packaging?

Normal mode mapping:
--------------------

          ____________________________              __
         / [__??__]          [__??__] \               |
        / [__Ctrl__]        [_Shift _] \              | Front Triggers
     __/________________________________\__         __|
    /     d                            _   \          |
   /      /\           __             (n)   \         |
  /       ||       _  | /|  ___    _       _ \        | Main Pad
 |   r<===DP===>a |;|      |Esc|  (v) -|- Bkp |       |
  \       ||    ___          ___       _     /        |
  /\      \/   / w \        / k \     Ent   /\      __|
 /  \_____u__ |q   e| ____ |h   l| ________/  \       |
|         /  \ \_p_/ /    \ \_j_/ /  \         |      | Control Sticks
|        /    \_____/      \_____/    \        |    __|
|       /                              \       |
 \_____/                                \_____/

     |________|______|    |______|___________|
       D-Pad    Left       Right   Action Pad
               Stick       Stick

                 |_____________|
                    Menu Pad

Diagram from Linux foundation documentation by David Herrmann,
https://www.kernel.org/doc/html/latest/input/gamepad.html.

Insert/command-line mode mapping:
---------------------------------

In insert and command-line mode, keypad.vim defines two functions that
remap pairs of keystrokes into individual ASCII characters available on a
standard keyboard. To avoid complicating things, characters that already have
an assignment on the left and right sticks can be accessed by doubling it:
e.g. e is mapped to ee (left stick --> right). All other characters are
accessed by a direction on one stick then a direction on a different stick.

The two analogue sticks are used to enter letters, with assignments based on 
letter frequency:

e  ee
t  eh
a  el
r  ej
i  ek
o  qh
n  ql
s  qj
h  hh
d  qk
l  ll
u  ph
w  ww
m  pl
f  pj
c  pk
g  wh
y  wl
p  pp
b  wj
k  kk
v  wk
j  jj
x  he
q  qq
z  hq

Note the recurring patterns of eqpw and hljk.

We have still not used up all the right stick ones: only two combinations out
of 16. We may as well make the remaining 12 numeric:

-  hp
=  hw
1  le
2  lq
3  lp
4  lw
5  je
6  jq
7  jp
8  jw
9  ke
0  kq
Space kw

kp and kw are spare, I can't think of obvious mappings.

Special keys

Space ; (The Back key. It was cumbersome as a combo. ; can be accessed with
the uu combo, or Down-Down on the D-pad.)

The D-pad signals a special key:

,     rr
.     aa
Del   dd
`     dr
\     ru    
]     ar
[     ra
Tab   da
PgUp  ud
PgDn  du

'     ak
#     al
;     uu

And finally, the arrow keys:

Up    rk
Down  rh
Left  rj
Right rl