Snake Game In Batch Programming

snake.bat

:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
:: SNAKE.BAT - A pure native Windows batch implementation of the classic game
:: ------------------------------------------------------------------------------
:: Written by Sumalya Chatterjee
::
:: The game should work on any Windows machine from XP onward using only batch
:: and native external commands. However, the default configuration will most
:: likely have some screen flicker due to the CLS command issued upon every 
:: screen refresh.
::
:: Note that user preferences and high scores are stored in %USERPROFILE%\Snake
:: User saved games have an implicit .snake.txt "extension", and are saved and
:: loaded from the current directory.
::
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

@echo off
if "%~1" == "startGame" goto :game
if "%~1" == "startController" goto :controller


::---------------------------------------------------------------------
:: setup some global variables used by both the game and the controller

setlocal disableDelayedExpansion
set "toggleVT100="
:getSession
if defined temp (set "tempFileBase=%temp%\") else if defined tmp set "tempFileBase=%tmp%\"
set "tempFileBase=%tempFileBase%Snake%time::=_%"
set "keyFile=%tempFileBase%_key.txt"
set "cmdFile=%tempFileBase%_cmd.txt"
set "gameLock=%tempFileBase%_gameLock.txt"
set "gameLog=%tempFileBase%_gameLog.txt"
set "signal=%tempFileBase%_signal.txt"
set "saveLoc=%userprofile%\Snake"
set "userPref=%saveLoc%\SnakeUserPref.txt"
set "hiFile=%saveLoc%\Snake!size!!growth!Hi"
set "keyStream=9"
set "cmdStream=8"
set "lockStream=7"


::------------------------------------------
:: Lock this game session and launch.
:: Loop back and try a new session if failure.
:: Cleanup and exit when finished

call :launch %lockStream%>"%gameLock%" || goto :getSession
del "%tempFileBase%*"
exit /b


::------------------------------------------
:launch the game and the controller

call :fixLogs
:relaunch
copy nul "%keyFile%" >nul
copy nul "%cmdFile%" >nul
start "" /b cmd /c ^""%~f0" startController %keyStream%^>^>"%keyFile%" %cmdStream%^<"%cmdFile%" 2^>nul ^>nul^"
cmd /c ^""%~f0" startGame %keyStream%^<"%keyFile%" %cmdStream%^>^>"%cmdFile%" ^<nul^"
echo(


::--------------------------------------------------------------
:: Upon exit, wait for the controller to close before returning

:close
2>nul (>>"%keyFile%" call )||goto :close
if "%=exitcode%" equ "00000002" (
  set "toggleVT100=1"
  goto :relaunch
) else if "%=exitcode%" equ "00000001" (
  echo Game play can be improved by installing
  echo(
  echo Alternatively, if your console supports
  echo VT100 escape sequences, then you can
  echo enable VT100 mode within the SNAKE.BAT
  echo Graphic options menu.
  echo(
  echo %cmdcmdline%|find /i "%~f0">nul&&pause
)
exit /b 0


::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
:game
title %~nx0
cls

::---------------------------------------
:: Default playfield size
:: max playing field: (width-2)*(height-2) <= 1365

set "size=Medium"
set "dispWidth=40"   max=99
set "dispHeight=25"  max=99
set "defaultSize=%size%"
set /a "defaultWidth=dispWidth, defaultHeight=dispHeight"

::----------------------------
:: Other default values

set "moveKeys=4"

set "up=W"
set "down=S"
set "left=A"
set "right=D"
set "pause=P"

set "space= "
set "bound=#"
set "food=+"
set "head=@"
set "body=O"
set "death=X"

set "vt0=OFF"
set "vt1=ON"
set "vt=0"

set "growth=1"

::--- sendCmd macro ---
:: sendCmd  command
:::  sends a command to the controller
set "sendCmd=>&%cmdStream% echo"

::---------------------------
:: Load user preferences
if exist "%userPref%" for /f "usebackq delims=" %%V in ("%userPref%") do set "%%V"
call :resize

::---------------------------
:: Variable constants

set "configOptions=diffCode difficulty growth moveKeys up down left right size dispWidth dispHeight"

for %%S in (
 "T Tiny   15 10"
 "S Small  25 15"
 "M Medium 40 25"
 "L Large  47 32"
 "W Wide   82 19"
 "N Narrow 20 40"
) do for /f "tokens=1-4" %%A in (%%S) do (
  set "size%%A=%%B"
  set /a "width%%A=%%C, height%%A=%%D"
)

set "spinner1=-"
set "spinner2=\"
set "spinner3=|"
set "spinner4=/"
set "spinner= spinner1 spinner2 spinner3 spinner4 "

set "delay1=20"
set "delay2=15"
set "delay3=10"
set "delay4=7"
set "delay5=5"
set "delay6=3"

set "desc1=Sluggard"
set "desc2=Crawl"
set "desc3=Slow"
set "desc4=Normal"
set "desc5=Fast"
set "desc6=Insane"

set "spinnerDelay=3"

:: define LF as a Line Feed (newline) character
set ^"LF=^
^" Above empty line is required - do not remove

:: define CR as a Carriage Return character
for /f %%A in ('copy /Z "%~dpf0" nul') do set "CR=%%A"

:: define BS as a BackSpace character
for /f %%A in ('"prompt $H&for %%B in (1) do rem"') do set "BS=%%A"

set "upper=A B C D E F G H I J K L M N O P Q R S T U V W X Y Z"
set "invalid=*~="

::---------------------------
:: define macros

if %vt% equ 1 (
  for /f "delims=" %%E in (
    'forfiles /p "%~dp0." /m "%~nx0" /c "cmd /c echo(0x1B"'
  ) do (
    cls
    <nul set /p "=%%E7"
    set "cls=<nul set /p "=%%E8""
    set "ClearLine=<nul set /p "=%%E[K""
    set "ClearPrev=echo(&echo(%%E[F%%E[K"
    set "Up4=echo(%%E[F%%E[F%%E[F%%E[F%%E[F"
    set "ShowCursor=<nul set /p "=%%E[?25h""
    set "HideCursor=<nul set /p "=%%E[?25l""
    set "exitCode=0"
  )
) else if exist "%~dp0CursorPos.exe" (
  set "cls=CursorPos 0 0"
  set "ClearLine=echo(                                   &CursorPos 0 -1"
  set "ClearPrev=CursorPos 0 -0&echo(                                   "
  set "Up4=CursorPos 0 -4"
  set "ShowCursor="
  set "HideCursor="
  set "exitCode=0"
) else (
  set "cls=cls"
  set "ClearLine="
  set "ClearPrev="
  set "Up4="
  set "ShowCursor="
  set "HideCursor="
  set "exitCode=1"
)

:: define a newline with line continuation
set ^"\n=^^^%LF%%LF%^%LF%%LF%^^"

:: setErr
:::  Sets the ERRORLEVEL to 1
set "setErr=(call)"

:: clrErr
:::  Sets the ERRORLEVEL to 0
set "clrErr=(call )"

:: getKey  [ValidKey]  [ValidKey...]
::: Check for keypress from the controller. Only accept a ValidKey.
::: Token delimiters and poison characters must be quoted.
::: Accept any key if no ValidKey specified.
::: Return result in Key variable. Key is undefined if no valid keypress.
set getKey=%\n%
for %%# in (1 2) do if %%#==2 (%\n%
  set key=%\n%
  set inKey=%\n%
  set keyTest=%\n%
  ^<^&%keyStream% set /p "inKey="%\n%
  if defined inKey (%\n%
    set inKey=!inKey:~0,-1!%\n%
    for %%C in (!args!) do set /a keyTest=1^&if /i !inKey! equ %%~C set key=!inKey!%\n%
  )%\n%
  if not defined keyTest set key=!inKey!%\n%
) else set args=


:: draw
:::  draws the board
set draw=%\n%
set screen=%\n%
for /l %%Y in (0,1,!height!) do set screen=!screen!!line%%Y!!LF!%\n%
set screen=!screen!Speed = !Difficulty! !replay!!LF!Growth Rate = !growth!   HighScore = !hi!!LF!Score = !score!   Time = !m!:!s!%\n%
if defined replay if not defined replayFinished (%\n%
  set screen=!screen!!LF!!LF!Press a key to abort the replay%\n%
)%\n%
%cls%^&echo(!screen!

:: test  X  Y  ValueListVar
:::  tests if value at coordinates X,Y is within contents of ValueListVar
set test=%\n%
for %%# in (1 2) do if %%#==2 (for /f "tokens=1-3" %%1 in ("!args!") do (%\n%
  for %%A in ("!line%%2:~%%1,1!") do if "!%%3:%%~A=!" neq "!%%3!" %clrErr% else %setErr%%\n%
)) else set args=


:: plot  X  Y  ValueVar
:::  places contents of ValueVar at coordinates X,Y
set plot=%\n%
for %%# in (1 2) do if %%#==2 (for /f "tokens=1-3" %%1 in ("!args!") do (%\n%
  set "part2=!line%%2:~%%1!"%\n%
  set "line%%2=!line%%2:~0,%%1!!%%3!!part2:~1!"%\n%
)) else set args=


::--------------------------------------
:: start the game
setlocal enableDelayedExpansion
if not exist "%saveLoc%\" md "%saveLoc%"
set "replay= Aborting... "
set "replayAvailable="
if exist "!gameLog!" set "replayAvailable=R"
call :loadHighScores
call :mainMenu


::--------------------------------------
:: main loop (infinite loop)
for /l %%. in () do (

  %=== check for and process abort signal if in replay mode ===%
  if defined replay if exist "%signal%" (
    del "%signal%"
    set "replayFinished=1"
    %draw%
    echo(
    %ClearLine%
    <nul set /p "=Aborting... "
    findstr "^" >nul <&%keyStream%
    for %%A in (!configOptions!) do set "%%A=!%%ASave!"
    %ShowCursor%
    call :mainMenu
  )

  %=== compute time since last move ===%
  for /f "tokens=1-4 delims=:.," %%a in ("!time: =0!") do set /a "t2=(((1%%a*60)+1%%b)*60+1%%c)*100+1%%d-36610100, tDiff=t2-t1"
  if !tDiff! lss 0 set /a tDiff+=24*60*60*100

  if !tDiff! geq !delay! (
    %=== delay has expired, so time for movement ===%
    set /a t1=t2

    %=== compute game time ===%
    if not defined gameStart set "gameStart=!t2!"
    set /a "gameTime=(t2-gameStart)"
    if !gameTime! lss 0 set /a "gameTime+=24*60*60*100"
    set /a "gameTime=(gameTime-pauseTime)/100, m=gameTime/60, s=gameTime%%60"
    if !m! lss 10 set "m=0!m!"
    if !s! lss 10 set "s=0!s!"

    %=== get keypress ===%
    %getKey% !keys!
    if /i !key! equ !pause! (

      %=== pause game ===%
      echo(
      %ShowCursor%
      call :ask "PAUSED - Press a key to continue..."
      %HideCursor%
      %ClearPrev%
      %sendCmd% go
      for /f "tokens=1-4 delims=:.," %%a in ("!time: =0!") do set /a "t2=(((1%%a*60)+1%%b)*60+1%%c)*100+1%%d-36610100, tDiff=t2-t1"
      if !tDiff! lss 0 set /a tDiff+=24*60*60*100
      set /a pauseTime+=tDiff

    ) else (

      %=== establish direction ===%
      if not defined replay (echo(!key!.) >>"!gameLog!"
      for %%K in (!key!) do if !moveKeys! equ 2 (
        set /a "xDiff=xTurn%%K*!yDiff!, yDiff=yTurn%%K*!xDiff!"
      ) else if "!%%KAxis!" neq "!axis!" (
        set /a "xDiff=xDiff%%K, yDiff=yDiff%%K"
        set "axis=!%%KAxis!"
      )

      %=== erase the tail ===%
      set "TX=!snakeX:~-2!"
      set "TY=!snakeY:~-2!"
      set "snakeX=!snakeX:~0,-2!"
      set "snakeY=!snakeY:~0,-2!"
      %plot% !TX! !TY! space

      %=== compute new head location and attempt to move ===%
      set /a "X=PX+xDiff, Y=PY+yDiff"
      set "X= !X!"
      set "Y= !Y!"
      set "X=!X:~-2!"
      set "Y=!Y:~-2!"
      (%test% !X! !Y! playerSpace) && (

        %=== move successful ===%

        %=== remove the new head location from the empty list ===%
        for %%X in ("!X!") do for %%Y in ("!Y!") do set "empty=!empty:#%%~X %%~Y=!"

        %=== eat any food that may be present ===%
        (%test% !X! !Y! food) && (
          %=== initiate growth ===%
          set /a grow+=growth

          %=== locate and draw new food ===%
          if defined replay (
            <&%keyStream% set /p "F="
          ) else (
            set /a "F=(!random!%%(emptyCnt-1))*6+1"
            (echo !F!) >>"!gameLog!"
          )
          for %%F in (!F!) do (%plot% !empty:~%%F,5! food)
        )

        if !grow! gtr 0 (
          %=== restore the tail ===%
          %plot% !TX! !TY! body
          set "snakeX=!snakeX!!TX!"
          set "snakeY=!snakeY!!TY!"
          set /a emptyCnt-=1

          %=== manage score ===%
          set /a "score+=1, grow-=1"
          if not defined replay if !score! gtr !hi! set /a "hi+=1, newHi=1"

        ) else (
          %=== add the former tail position to the empty list ===%
          set "empty=!empty!#!TX! !TY!"
        )

        %=== draw the new head ===%
        if defined snakeX (%plot% !PX! !PY! body)
        %plot% !X! !Y! head

        %=== Add the new head position to the snake strings ===%
        set "snakeX=!X!!snakeX!"
        set "snakeY=!Y!!snakeY!"
        set "PX=!X!"
        set "PY=!Y!"

        %draw%

      ) || (

        %=== failed move - game over ===%
        set "replayFinished=1"
        %plot% !TX! !TY! body
        call :spinner !PX! !PY! death
        %draw%
        if defined newHi (
          echo(
          echo New High Score - Congratulations^^!
          set "hi!diffCode!=!score!"
          copy "!gameLog!" "%hiFile%!diffCode!.txt" >nul
          >>"%hiFile%!diffCode!.txt" echo ::!score!
        )
        echo(
        %ClearLine%
        %ShowCursor%
        call :ask "Press a key to continue..."
        for %%A in (!configOptions!) do set "%%A=!%%ASave!"
        call :mainMenu
      )
    )
  )
)


::-------------------------------------
:getString  Prompt  Var  MaxLen
:: Prompt for a string with max lengh of MaxLen.
:: Valid keys are alpha-numeric, space, underscore, and dash
:: String is terminated by Enter
:: Backspace works to delete previous character
:: Result is returned in Var
set /a "maxLen=%3"
set "%2="
%sendCmd% prompt
<nul set /p "=%~1 "
call :purge
:getStringLoop
(%getKey% !upper! 0 1 2 3 4 5 6 7 8 9 " " _ - {Enter} !BS!)
if defined key (
  if !key! equ {Enter} (
    echo(
    exit /b
  )
  if !key! neq !BS! if !maxLen! gtr 0 (
    set /a maxLen-=1
    <nul set /p "=.!BS!!key!"
    set "%2=!%2!!key!
  )
  if !key! equ !BS! if defined %2 (
    set /a maxLen+=1
    <nul set /p "=!BS! !BS!"
    set "%2=!%2:~0,-1!"
  )
)
if defined inKey %sendCmd% one
goto :getStringLoop


::-------------------------------------
:ask  Prompt  ValidKey [Validkey]...
:: Prompt for a keypress.
:: Wait until a ValidKey is pressed and return result in Key variable.
:: Token delimiters, ), and poison characters must be quoted.
%sendCmd% prompt
<nul set /p "=%~1 "
(set validKeys=%*)
(set validKeys=!validKeys:%1=!)
call :purge
:getResponse
(%getKey% !validKeys!)
if not defined key (
  if defined inKey %sendCmd% one
  goto :getResponse
)
exit /b


:purge
set "inKey="
for /l %%N in (1 1 1000) do (
  set /p "inKey="
  if "!inKey!" equ "{purged}." exit /b
)<&%keyStream%
goto :purge


::-------------------------------------
:spinner  X  Y  ValueVar
set /a d1=-1000000
for /l %%N in (1 1 5) do for %%C in (%spinner%) do (
  call :spinnerDelay
  %plot% %1 %2 %%C
  %draw%
)
call :spinnerDelay
(%plot% %1 %2 %3)
exit /b


::-------------------------------------
:delay  centiSeconds
setlocal
for /f "tokens=1-4 delims=:.," %%a in ("!time: =0!") do set /a "spinnerDelay=%1, d1=(((1%%a*60)+1%%b)*60+1%%c)*100+1%%d-36610100"
:: fall through to :spinnerDelay

::-------------------------------------
:spinnerDelay
for /f "tokens=1-4 delims=:.," %%a in ("!time: =0!") do set /a "d2=(((1%%a*60)+1%%b)*60+1%%c)*100+1%%d-36610100, dDiff=d2-d1"
if %dDiff% lss 0 set /a dDiff+=24*60*60*100
if %dDiff% lss %spinnerDelay% goto :spinnerDelay
set /a d1=d2
exit /b


::-------------------------------------
:mainMenu
if defined toggleVT100 call :graphicOptions
cls
call :resize
set "loadAvailable="
echo HULK's Game of Snakes
echo(
echo Main Menu:
echo(
echo   N - New game
echo   F - Field size..... !size!
echo   W - groWth rate.... !growth!
echo   C - Control options
echo   G - Graphic options

if defined replayAvailable echo   R - Replay previous game
if defined saveAvailable   echo   S - Save a game
if exist *.snake.txt       echo   L - Load and watch a saved game&set "loadAvailable=L"

echo   Q - Quit
echo(
set "hiAvailable="
for /l %%N in (1 1 6) do if defined hi%%N (
  if not defined hiAvailable (
    echo Replay High Score:
    echo(
  )
  set "desc=!desc%%N!........"
  set "hiAvailable=!hiAvailable! %%N"
  echo   %%N - !desc:~0,8! !hi%%N!
)
if defined hiAvailable echo(
set "keys=N F W C G Q !hiAvailable! !replayAvailable! !saveAvailable! !loadAvailable!"
call :ask ">" !keys!
if /i !key! equ Q (
  %sendCmd% quit
  cls
  exit %exitCode%
) else if /i !key! equ N (
  set "replay="
  set "replayAvailable=R"
  set "saveAvailable=S"
  goto :initialize
) else if /i !key! equ S (
  if defined replayAvailable (
    call :ask "HighScore # or P for Previous:" !hiAvailable! P
  ) else (
    call :ask "HighScore #:" !hiAvailable!
  )
  echo !key!
  if /i !key! equ P (set "src=!gameLog!") else set "src=%hiFile%!key!.txt"
  call :getString "Save file name:" file 20
  copy "!src!" "!file!.snake.txt"
  call :ask "Press a key to continue..."
) else if /i !key! equ L (
  call :getString "Load file name:" file 20
  if exist "!file!.snake.txt" (
    set "replay=!file!.snake.txt"
    goto :initialize
  )
  echo Error: File "!file!.snake.txt" not found
  call :ask "Press a key to continue..."
) else if /i !key! equ R (
  set "replay=!gameLog!"
  goto :initialize
) else if /i !key! equ C (
  call :controlOptions
) else if /i !key! equ G (
  call :graphicOptions
) else if /i !key! equ F (
  call :sizeOptions
) else if /i !key! equ W (
  call :ask "Press a digit for growth rate (0 = 10)" 0 1 2 3 4 5 6 7 8 9
  if !key! equ 0 set "key=10"
  set "growth=!key!"
  call :loadHighScores
) else if !key! geq 1 if !key! leq 6 (
  set "replay=%hiFile%!key!.txt"
  goto :initialize
)
goto :mainMenu


::-------------------------------------
:sizeOptions
cls
set "keys=T S M L W N"
echo Field Size Options:
echo(
echo   T - Tiny   15 x 10
echo   S - Small  30 x 20
echo   M - Medium 40 x 25
echo   L - Large  47 x 32
echo   W - Wide   82 x 19
echo   N - Narrow 15 x 40
echo(
call :ask ">" !keys!
set "size=!size%key%!"
set /a "dispWidth=!width%key%!, dispHeight=!height%key%!"
call :loadHighScores
goto :saveUserPrefs
exit /b


::-------------------------------------
:controlOptions
cls
set "keys={Enter} T L R P"
if !moveKeys! equ 4 set "keys=!keys! U D"
                    echo Control Options:
                    echo(
                    echo   T - Type... = !moveKeys! keys
                    echo(
                    echo   L - Left... = !left!
                    echo   R - Right.. = !right!
if !moveKeys! equ 4 echo   U - Up..... = !up!
if !moveKeys! equ 4 echo   D - Down... = !down!
                    echo(
                    echo   P - Pause.. = !pause!
                    echo(
                    echo   {Enter} - Return to Main Menu
                    echo(
call :ask ">" !keys!
if !key! equ {Enter} goto :saveUserPrefs
if /i !key! equ T (
  if !moveKeys! equ 2 (set "moveKeys=4") else set "moveKeys=2"
  goto :controlOptions
)
set "option= LLeft RRight UUp DDown PPause"
for /f %%O in ("!option:* %key%=!") do (
  call :ask "Press a key for %%O:"
  for %%K in (0 1 2) do if "!key!" equ "!invalid:~%%K,1!" goto :controlOptions
  for %%C in (!upper!) do set "key=!key:%%C=%%C!"
  set "%%O=!key!"
)
goto :controlOptions


::-------------------------------------
:graphicOptions
set "toggleVT100="
cls
echo Graphic Options:
echo(
echo   B - Border...... = !bound!
echo   E - Empty space. = !space!
echo   H - snake Head.. = !head!
echo   S - Snake body.. = !body!
echo   F - Food........ = !food!
echo   D - Death....... = !death!
echo(
echo   V - VT100 mode.. = !vt%vt%!
echo(
echo   {Enter} - Rturn to Main Menu
echo(
call :ask ">" B E H S F D V {Enter}
if !key! equ {Enter} goto :saveUserPrefs
if /i !key! equ V (
  set /a "vt=^!vt"
  call :saveUserPrefs
  %sendCmd% quit
  exit 2
) else (
  set "option=-BBorder:bound:-EEmpty Space:space:-HSnake Head:head:-SSnake Body:body:-FFood:food:-DDeath:death:"
  for /f "tokens=1,2 delims=:" %%A in ("!option:*-%key%=!") do (
    call :ask "Press a key for %%A"
    for %%K in (0 1 2) do if "!key!" equ "!invalid:~%%K,1!" goto :graphicOptions
    set "%%B=!key!"
  )
)
goto :graphicOptions


::------------------------------------
:saveUserPrefs
(for %%V in (moveKeys up down left right space bound food head body death pause growth vt size dispWidth dispHeight) do echo %%V=!%%V!) >"%userPref%"
exit /b


::-------------------------------------
:initialize
cls
if defined replay (
  echo Replay Speed Options:
) else (
  echo Speed Options:
)
echo                       delay
echo    #   Description  (seconds)
echo   ---  -----------  ---------
for /l %%N in (1 1 6) do (
  set "delay=0!delay%%N!"
  set "desc=!desc%%N!           "
  echo    %%N   !desc:~0,11!    0.!delay:~-2!
)
echo(
call :ask "Pick a speed (1-6):" 1 2 3 4 5 6
set "difficulty=!desc%key%!"
set "delay=!delay%key%!"
set "diffCode=%key%"
echo %key% - %difficulty%
echo(
<nul set /p "=Initializing."
for %%A in (!configOptions!) do set "%%ASave=!%%A!"
if defined replay (
  %sendCmd% replay
  %sendCmd% !replay!
  call :waitForSignal
  set "replay=(REPLAY at !difficulty!)"
  set "size=%defaultSize%"
  set /a "dispWidth=defaultWidth, dispHeight=defaultHeight"
  :loadReplayConfig
  <&%keyStream% set /p "ln="
  if "!ln!" neq "END" set "!ln!" & goto :loadReplayConfig
  call :resize
)
set "axis=X"
set "xDiff=+1"
set "yDiff=+0"
set "empty="
set /a "PX=1, PY=height/2, FX=width/2+1, FY=PY, score=0, emptyCnt=0, t1=-1000000"
set "gameStart="
set "m=00"
set "s=00"
set "snakeX= %PX%"
set "snakeY= %PY%"
set "snakeX=%snakeX:~-2%"
set "snakeY=%snakeY:~-2%"
for /l %%Y in (0 1 %height%) do (
  <nul set /p "=."
  set "line%%Y="
  for /l %%X in (0,1,%width%) do (
    set "cell="
    if %%Y equ 0        set "cell=%bound%"
    if %%Y equ %height% set "cell=%bound%"
    if %%X equ 0        set "cell=%bound%"
    if %%X equ %width%  set "cell=%bound%"
    if %%X equ %PX% if %%Y equ %PY% set "cell=%head%"
    if not defined cell (
      set "cell=%space%"
      set "eX= %%X"
      set "eY= %%Y"
      set "empty=!empty!#!eX:~-2! !eY:~-2!"
      set /a emptyCnt+=1
    )
    if %%X equ %FX% if %%Y equ %FY% set "cell=%food%"
    set "line%%Y=!line%%Y!!cell!"
  )
)
set "replayFinished="
if defined replay (
  set "keys="
  set "hi=0"
  for /f "delims=:" %%A in ('findstr "^::" "%hiFile%!diffCode!.txt" 2^>nul') do set "hi=%%A"
  %HideCursor%
  cls
  (%draw%)
  call :delay 100
) else (
  if defined hi%diffCode% (set "hi=!hi%diffCode%!") else set "hi=0"
  cls
  (%draw%)
  >"!gameLog!" ( 
    for %%A in (!configOptions!) do (echo %%A=!%%A!)
    (echo END)
  )
  echo(
  if !moveKeys! equ 4 (
    echo Controls: !up!=up !down!=down !left!=left !right!=right !pause!=pause
  ) else (
    echo Controls: !left!=left !right!=right !pause!=pause
  )
  echo Avoid running into yourself (!body!!body!!head!^) or wall (!bound!^)
  echo Eat food (!food!^) to grow.
  echo(
  call :ask "Press a key to start..."
  %HideCursor%
  %sendCmd% go
)
set "pauseTime=0"
set "xDiff!up!=+0"
set "xDiff!down!=+0"
set "xDiff!left!=-1"
set "xDiff!right!=+1"
set "yDiff!up!=-1"
set "yDiff!down!=+1"
set "yDiff!left!=+0"
set "yDiff!right!=+0"
set "!up!Axis=Y"
set "!down!Axis=Y"
set "!left!Axis=X"
set "!right!Axis=X"
set "xTurn!left!=1"
set "xTurn!right!=-1"
set "yTurn!left!=-1"
set "yTurn!right!=1"
set "playerSpace=!space!!food!"
set ^"keys="!left!" "!right!" "!pause!"^"
set "newHi="
set "grow=0"
if !moveKeys! equ 4 set ^"keys=!keys! "!up!" "!down!"^"
if defined Up4 if not defined replay (
  %Up4%
  for /l %%N in (1 1 5) do (echo(                                             )
)
exit /b


::-------------------------------------
:waitForSignal
if not exist "%signal%" goto :waitForSignal
del "%signal%"
exit /b


::-------------------------------------
:loadHighScores
set "saveAvailable="
for /l %%N in (1 1 6) do (
  set "hi%%N="
  for /f "delims=:" %%A in ('findstr "^::" "%hiFile%%%N.txt" 2^>nul') do (
    set "hi%%N=%%A"
    set "saveAvailable=S"
  )
)
exit /b


::----------------------------
:resize the console window
set /a cols=dispWidth+1, lines=dispHeight+10, area=(dispWidth-2)*(dispHeight-2)
if %area% gtr 1365 (
  echo ERROR: Playfield area too large
  %sendCmd% quit
  exit
)
if %lines% lss 25 set lines=25
if %cols% lss 46 set cols=46
mode con: cols=%cols% lines=%lines%
set /a "width=dispWidth-1, height=dispHeight-1"
set "resize="
exit /b


::-------------------------------------
:fixLogs
setlocal enableDelayedExpansion
for %%F in (*.snake) do (
  ren "%%F" "%%F.txt"
  call :fixLog "%%F.txt"
)
pushd "%SaveLoc%"
for /f "delims=" %%F in ('dir /b SnakeHi*.txt 2^>nul') do (
  set "file=%%~nF"
  set "file=Snake1Hi!file:~-1!.txt"
  ren "%%F" "!file!"
  call :fixLog "!file!"
)
for /f "tokens=1* delims=eE" %%A in (
  'dir /b Snake*Hi*.txt ^| findstr /i "^Snake[0-9]"'
) do ren "Snake%%B" "SnakeMedium%%B"
popd
exit /b

:fixLog  filePath
>"%~1.new" (
  <"%~1" (
    for %%A in (diffCode difficulty moveKeys up down left right) do (
      set /p "val="
      (echo %%A=!val!)
    )
  )
  (echo growth=1)
  (echo END)
  more +7 "%~1"
)
move /y "%~1.new" "%~1" >nul
exit /b


::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
:controller
:: Detects keypresses and sends the information to the game via a key file.
:: The controller has various modes of input that are activated by commands sent
:: from the game via a cmd file.
::
:: Modes:
::
::   hold   - No input, wait for command
::
::   go     - Continuously get/send key presses
::
::   prompt - Send {purged} marker to allow game to purge input buffer, then
::            get/send a single key press and hold
::
::   one    - Get/send a single key press and hold
::
::   replay - Copy a game log to the key file. The next line in cmd file
::            specifies name of log file to copy. During replay, the controller
::            will send an abort signal to the game if a key is pressed.
::
::   quit   - Immediately exit the controller process
::
:: As written, this routine incorrectly reports ! as ), but that doesn't matter
:: since we don't need that key. Both <CR> and Enter key are reported as {Enter}.
:: An extra character is appended to the output to preserve any control chars
:: when read by SET /P.

setlocal enableDelayedExpansion
for /f %%a in ('copy /Z "%~dpf0" nul') do set "CR=%%a"
set "cmd=hold"
set "inCmd="
set "key="
for /l %%. in () do (
  if "!cmd!" neq "hold" (
    for /f "delims=" %%A in ('xcopy /w "%~f0" "%~f0" 2^>nul') do (
      if not defined key set "key=%%A"
    )
    set "key=!key:~-1!"
    if !key! equ !CR! set "key={Enter}"
  )
  <&%cmdStream% set /p "inCmd="
  if defined inCmd (
    if !inCmd! equ quit exit
    set "cmd=!inCmd!"
    if !inCmd! equ replay (
      <&%cmdStream% set /p "file="
      type "!file!" >&%keyStream%
      copy nul "%signal%"
    )
    set "inCmd="
  )
  if defined key (
    if "!cmd!" equ "prompt" (echo {purged}.)
    if "!cmd!" equ "replay" (
      copy nul "%signal%" >nul
      set "cmd=go"
    ) else (echo(!key!.)
    if "!cmd!" neq "go" set "cmd=hold"
    set "key="
  )>&%keyS