: blah
  ' seremit task-emit !
  ' log-emit task-echo ! ;

: start-repl activate blah
  s" .:: J O R T H ( jean forth) ::." type cr
  begin receive loadstring s" ok" type cr again ;
task const REPL
REPL start-repl

1 const ^ESC
28 const ^ENTER
29 const ^CTRL
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 ;
: sleep ( count -- )
  ticks swap begin over ticks udelta over u< while suspend repeat drop drop ;

defer tick
defer draw

: defentity var 2 cells allot ;
: entity.x ;
: entity.y cell + ;
: entity.dir 2 cells + ;

0 const W
1 const E
2 const N
3 const S

: defsprite ( s n e w ) b, b, b, b, here 4 - const ;
: sprindex ( sprite dir ) + b@ ;

3 1 0 2 defsprite s_car

defentity player

100 player entity.x !
100 player entity.y !

: tick-player
  0 ^LEFT key-down if 3 - W player entity.dir ! then
  ^RIGHT key-down if 3 + E player entity.dir ! then
  player entity.x +!
  0 ^UP key-down if 3 - N player entity.dir ! then
  ^DOWN key-down if 3 + S player entity.dir ! then
  player entity.y +! ;

: draw-player
  player entity.x @
  player entity.y @
  s_car player entity.dir @ sprindex
  draw-sprite ;

: full-draw
  player entity.x @ 152 -
  player entity.y @ 92 -
  scroll

  draw-player
  50 50 0 draw-sprite
  600 600 2 draw-sprite
  draw-screen ;

' tick-player is tick
' full-draw is draw