( K E Y B O A R D )
1 const ^ESC
15 const ^TAB
28 const ^ENTER
29 const ^CTRL
51 const ^<
52 const ^>
56 const ^ALT
57 const ^SPACE
72 const ^UP
75 const ^LEFT
77 const ^RIGHT
80 const ^DOWN

: wait-key ( k -- ) begin dup key-pressed not while suspend repeat drop ;
: udelta ( u u -- u )
  2dup u> if
    swap -1 swap - + 1 +
  else
    swap -
  then ;

( M O U S E )
var prevbutton
: tick-debounce
  mousebuttons prevbutton ! ;

1 const MOUSEL
2 const MOUSER
: mousedown ( button -- bool ) mousebuttons & ;
: clicked ( button -- bool )
  dup mousedown not swap
  prevbutton @ & and ;