Snake.bat

@echo off

 color rgb(0,255,0)

 if "%~1" == "startGame" goto :game

 if "%~1" == "startController" goto :controller





 ::------------------------------------------------------------

 :: verify existence of CHOICE command

 :: set up a macro appropriately depending on available version



 set "choice="

 2>nul >nul choice /c:yn /t 0 /d y

 if errorlevel 1 if not errorlevel 2 set "choice=choice /cs"

 if not defined choice (

   2>nul >nul choice /c:yn /t:y,1

   if errorlevel 1 if not errorlevel 2 set "choice=choice /s"

 )

 if not defined choice (

   echo ERROR: This game requires the CHOICE command, but it is missing.

   echo Game aborted. :(

   echo(

   echo A 16 bit port of CHOICE.EXE from FREEDOS is available at

   echo http://winsupport.org/utilities/freedos-choice.html

   echo(

   echo A 32 bit version from ??? suitable for 64 bit machines is available at

   echo http://hp.vector.co.jp/authors/VA007219/dkclonesup/choice.html

   echo(

   exit /b

 )





 ::---------------------------------------------------------------------

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



 set "keys=ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"

 set "keyFile=key.txt"

 set "cmdFile=cmd.txt"





 ::------------------------------------------

 :: launch the game and the controller



 copy nul "%keyFile%" >nul

 start "" /b "%~f0" startController 9^>^>%keyFile% 2^>nul ^>nul

 cmd /c "%~f0" startGame 9^<%keyFile% ^<nul

 echo(



 ::--------------------------------------------------------------------------------

 :: Upon exit, wait for the controller to close before deleting the temp input file



 :close

 2>nul (>>"%keyFile%" call )||goto :close

 del "%keyFile%"

 exit /b





 ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

 :game

 setlocal disableDelayedExpansion

 title akila_malliya(??)

 cls



 ::----------------------------

 :: user configurable options



 set "up=W"

 set "down=S"

 set "left=A"

 set "right=D"



 set "width=40"   max=99

 set "height=25"  max=99

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



 ::----------------------------

 :: resize the console window



 set /a cols=width+1, lines=height+10, area=(width-2)*(height-2)

 if %area% gtr 1365 (

   echo ERROR: Playfield area too large

   >"%cmdFile%" (echo quit)

   exit

 )

 if %lines% lss 14 set lines=14

 if %cols% lss 46 set cols=46

 mode con: cols=%cols% lines=%lines%



 ::----------------------------

 :: define variables



 set "spinner1=-"

 set "spinner2=\"

 set "spinner3=|"

 set "spinner4=/"

 set "spinner= spinner1 spinner2 spinner3 spinner4 "



 set "space= "

 set "bound=#"

 set "food=$"

 set "head=A"

 set "body=0"

 set "death=X"

 set "playerSpace=%space%%food%"



 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 "delay1=20"

 set "delay2=15"

 set "delay3=10"

 set "delay4=7"

 set "delay5=5"

 set "delay6=3"

 set "delay0=0"



 set "desc1=Sluggard"

 set "desc2=Crawl"

 set "desc3=Slow"

 set "desc4=Normal"

 set "desc5=Fast"

 set "desc6=Insane"

 set "desc0=Unplayable"



 set "spinnerDelay=3"



 set /a "width-=1, height-=1"





 ::---------------------------

 :: define macros



 ::define a Line Feed (newline) string (normally only used as !LF!)

 set LF=^





 ::Above 2 blank lines are required - do not remove



 ::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  ValidKeys

 ::: Check for keypress. Only accept keys listed in ValidKeys

 ::: Return result in Key variable. Key is undefined if no valid keypress.

 set getKey=%\n%

 for %%# in (1 2) do if %%#==2 (for /f "eol= delims= " %%1 in ("!args!") do (%\n%

   set "validKeys=%%1"%\n%

   set "key="%\n%

   ^<^&9 set /p "key="%\n%

   if defined key if "!key!" neq ":" (%\n%

     set /a key-=1%\n%

     for %%K in (!key!) do set "key=!keys:~%%K,1!"%\n%

   )%\n%

   for %%K in (!key!) do if "!validKeys:%%K=!" equ "!validKeys!" set "key="%\n%

 )) else set args=





 :: draw

 :::  draws the board

 set draw=%\n%

 cls%\n%

 for /l %%Y in (0,1,%height%) do echo(!line%%Y!%\n%

 echo Speed=!Difficulty!%\n%

 echo Score=!score!





 :: 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

 call :initialize





 ::--------------------------------------

 :: main loop (infinite loop)

 for /l %%. in (1 0 1) do (



   %=== 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 ===%



     %=== establish direction ===%

     %getKey% ASDW

     for %%K in (!key!) do 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=!"



       (%test% !X! !Y! food) && (

         %=== moving to food - eat it ===%



         %=== restore the tail ===%

         %plot% !TX! !TY! body

         set "snakeX=!snakeX!!TX!"

         set "snakeY=!snakeY!!TY!"



         %=== increment score and locate and draw new food ===%

         set /a "score+=1, F=(!random!%%(emptyCnt-=1))*6+1"

         for %%F in (!F!) do (%plot% !empty:~%%F,5! food)



       ) || (

         %=== moving to empty space ===%



         %=== 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 ===%

       %plot% !TX! !TY! body

       call :spinner !PX! !PY! death

       %draw%

       echo(

       call :ask "Would you like to play again? (Y/N)" YN

       if /i "!key!" equ "N" (

         >"%cmdFile%" (echo quit)

         exit

       ) else (

         call :initialize

       )

     )



     set /a t1=t2

   )

 )



 :ask  Prompt  ValidKeys

 :: Prompt for a keypress. ValidKeys is a list of acceptable keys

 :: Wait until a valid key is pressed and return result in Key variable

 >"%cmdFile%" (echo prompt)

 <nul set /p "=%~1 "

 :purge

 (%getKey% :)

 if not defined key goto :purge

 :getResponse

 (%getKey% %2)

 if not defined key (

   >"%cmdFile%" (echo one)

   goto :getResponse

 )

 exit /b





 :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



 :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





 ::-------------------------------------

 :initialize

 cls



 echo Speed Options:

 echo                       delay

 echo    #   Description  (seconds)

 echo   ---  -----------  ---------

 echo    1   Sluggard        0.20

 echo    2   Crawl           0.15

 echo    3   Slow            0.10

 echo    4   Normal          0.07

 echo    5   Fast            0.05

 echo    6   Insane          0.03

 echo    0   Unplayable      none

 echo(

 call :ask "Pick a speed (1-6, 0):" 1234560

 set "difficulty=!desc%key%!"

 set "delay=!delay%key%!"

 echo %key% - %difficulty%

 echo(

 <nul set /p "=Initializing."

 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 "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!"

   )

 )

 (%draw%)

 echo(

 echo Movement keys: %up%=up %down%=down %left%=left %right%=right

 echo Avoid running into yourself (%body%%body%%head%) or wall (%bound%)

 echo Eat food (%food%) to grow.

 echo(

 call :ask "Press any alpha-numeric key to start..." %keys%

 >"%cmdFile%" (echo go)

 exit /b





 ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

 :controller



 setlocal enableDelayedExpansion

 set "cmd=hold"

 set "key="

 for /l %%. in (1 0 1) do (

   if "!cmd!" neq "hold" (

     %choice% /n /c:!keys!

     set "key=!errorlevel!"

   )

   if exist "%cmdFile%" (

     <"%cmdFile%" set /p "cmd="

     del "%cmdFile%"

   )

   if "!cmd!" equ "quit" exit

   if defined key (

     if "!cmd!" equ "prompt" >&9 (echo :)

     >&9 (echo !key!)

     if "!cmd!" neq "go" set "cmd=hold"

     set "key="

   )

 )