{*
** John Conway's Game of Life, written in ACE BASIC.
**
** Author: David J Benn
**   Date: 24th-26th December 1994
**
** Future enhancements: Circular world option; speed increase;
**			Life projects (shell and Wb args);
**			variable grid size.
**
** Try evolving the following pattern anywhere on the Life grid:
**
**	x
**	 x
**     xxx
**
** Try also loading and evolving the file "GliderGun.pat".
*}

DEFINT a-z

STRING version SIZE 26
version = "$VER: Life 1.0 (26.12.94)"
 
{*
** General constants.
*}
CONST true 	= -1&
CONST false 	= 0&
CONST null	= 0&
CONST scrWidth	= 640
CONST scrHeight	= 200
	
{*
** Life constants.
*}
CONST maxX 	= 40
CONST maxY 	= 15
CONST cellX	= 14&
CONST cellY	= 7&
CONST dead 	= 0&
CONST alive 	= 1&

{*
** Color constants.
*}
CONST black	= 0
CONST white	= 1
CONST red	= 2
CONST green	= 3
CONST blue	= 4

{*
** Menu constants.
*}
CONST sDisable	= 0
CONST sEnable	= 1
CONST sCheck	= 2

CONST mProject	= 1
CONST iProject	= 0
CONST iLoad	= 1
CONST iStore	= 2
CONST iModify	= 3
CONST iGenerate	= 4
CONST iRandom	= 5
CONST iClear	= 6
CONST iSep1.1	= 7
CONST iAbout	= 8
CONST iQuit	= 9

{*
** Global variable declarations.
*}
'..Main and auxillary life matrices.
DIM L(maxX,maxY), X(maxX,maxY)

'..Modes.
Modifying = true
Generating = false

'..Other globals.
GenCount = 0
Changed = false
xOff = (scrWidth - (maxX*cellX + 3*cellX)) \ 2
yOff = (scrHeight - (maxY*cellY + 5*cellY)) \ 2

{*
** Enable event trapping.
*}
ON MENU GOSUB handle_menu
MENU ON

{*
** Library function declarations.
*}
CONST leave = -1&
LIBRARY "intuition.library"
DECLARE FUNCTION SetWindowTitles(wdw&,wdw_title$,scr_title$) LIBRARY intuition

{*
** Subprogram definitions.
*}
SUB SetupMenus
  MENU mProject,iProject,sEnable,	"Project"
  MENU mProject,iLoad,sEnable,		"  Load..."
  MENU mProject,iStore,sEnable,		"  Store..."
  MENU mProject,iModify,sEnable,	"  Modify Grid Contents", 	"M"
  MENU mProject,iGenerate,sEnable,	"  Evolve Life Pattern",	"E"
  MENU mProject,iRandom,sEnable,	"  Create Random Pattern",	"R"
  MENU mProject,iClear,sEnable,		"  Clear Grid",			"C"
  MENU mProject,iSep1.1,sDisable,	"------------------------------"
  MENU mProject,iAbout,sEnable,		"  About..."
  MENU mProject,iQuit,sEnable,		"  Quit",			"Q"
END SUB

SUB SetMode(SHORTINT Mode)
SHARED Modifying, Generating
  IF Mode = iModify THEN
	Modifying = true
	MENU mProject,iModify,sCheck 
	Generating = false
	MENU mProject,iGenerate,sEnable	
	EXIT SUB
  END IF
  IF Mode = iGenerate THEN
  	Generating = true 
	MENU mProject,iGenerate,sCheck	
	Modifying = false			
	MENU mProject,iModify,sEnable 
	EXIT SUB
  END IF
END SUB

SUB DrawGridLines
SHARED xOff, yOff
  COLOR blue
  '..Vertical lines.
  FOR i=1 TO maxX+1
    LINE (i*cellX+xOff,cellY+yOff)-(i*cellX+xOff,maxY*cellY+cellY+yOff)
  NEXT
  '..Horizontal lines.
  FOR i=1 TO maxY+1
    LINE (cellX+xOff,i*cellY+yOff)-(maxX*cellX+cellX+xOff,i*cellY+yOff)
  NEXT
END SUB

SUB ShowGenCount
SHARED GenCount
STRING wdwTitle SIZE 81
  wdwTitle = "The Game of Life"+SPACE$(17)+"Generation:"+STR$(GenCount)    
  SetWindowTitles(WINDOW(7),wdwTitle,leave)
END SUB

SUB ClearGrid
SHARED X, L
SHARED GenCount, Changed
SHARED xOff, yOff
  MENU mProject,iProject,sDisable
  FOR i=1 TO maxX
    FOR j=1 TO maxY
      X(i,j) = dead
      L(i,j) = dead
      LINE (i*cellX+1+xOff,j*cellY+1+yOff)- ~
	   (i*cellX+(cellX-1)+xOff,j*cellY+(cellY-1)+yOff),black,bf
    NEXT j
  NEXT i
  Changed = false
  GenCount = 0
  ShowGenCount
  MENU mProject,iProject,sEnable
END SUB

SUB Msg(STRING theMsg)
  SetWindowTitles(WINDOW(7),"The Game of Life",leave)
  MSGBOX theMsg, "Continue"
  ShowGenCount
END SUB

SUB LoadPattern
SHARED X, L
SHARED GenCount
SHARED Changed
SHARED xOff, yOff
STRING theFile SIZE 80
  theFile = FILEBOX$("Load Life Pattern...")
  IF theFile = "" THEN
    Msg("No file selected.")
  ELSE
    OPEN "I",#1,theFile
    IF HANDLE(1) = null THEN
      Msg("Unable to open "+theFile+".")
    ELSE
      IF EOF(1) THEN
	Msg(theFile+" is empty!")
   	CLOSE #1
      ELSE
      	INPUT #1,x$
      	IF x$ <> "#LIFE PATTERN#" THEN
	  Msg("Incorrect file format.")
   	  CLOSE #1
        ELSE
    	  ClearGrid
    	  GenCount = 0
    	  ShowGenCount
	  Changed = true
	  IF EOF(1) THEN 
	    Msg("Unexpected end of file.")
	  ELSE	    
	    INPUT #1,columns,rows
	    WHILE NOT EOF(1)
	      INPUT #1,a,b
	      IF a >= 1 AND a <= columns AND b >= 1 AND b <= rows THEN
	        X(a,b) = alive : L(a,b) = alive
	        LINE (a*cellX+1+xOff,b*cellY+1+yOff)- ~
	       	     (a*cellX+(cellX-1)+xOff,b*cellY+(cellY-1)+yOff),red,bf
	      ELSE
	        Msg("Invalid Coordinate: ("+STR$(a)+","+STR$(b)+" )")
	      END IF
	    WEND
	    CLOSE #1
      	    Msg(theFile+" loaded.")
	  END IF
	END IF
      END IF
    END IF
  END IF
END SUB

SUB StorePattern
SHARED L
STRING theFile SIZE 80
  theFile = FILEBOX$("Store Life Pattern...")
  IF theFile = "" THEN
    Msg("No file selected.")
  ELSE
    OPEN "O",#1,theFile
    IF HANDLE(1) = null THEN
      Msg("Unable to open "+theFile+".")
    ELSE
      WRITE #1,"#LIFE PATTERN#"
      WRITE #1,maxX,maxY
      FOR i=1 TO maxX
        FOR j=1 TO maxY
	  IF L(i,j) = alive THEN WRITE #1,i,j
        NEXT j
      NEXT i
      CLOSE #1
      SetWindowTitles(WINDOW(7),"The Game of Life",leave)
      Msg("Pattern stored in "+theFile+".")
      ShowGenCount
    END IF
  END IF
END SUB

SUB ModifyGrid
SHARED X, L
SHARED Modifying, Generating
SHARED GenCount
SHARED xOff, yOff

 GenCount = 0
 ShowGenCount

  WHILE Modifying
    '..Await left mouse button press.
    WHILE Modifying AND NOT MOUSE(0):SLEEP:WEND
    IF Modifying THEN
      mouseX = MOUSE(1) - xOff
      mouseY = MOUSE(2) - yOff
      IF mouseX > cellX AND mouseX < maxX*cellX+cellX AND ~
         mouseY > cellY AND mouseY < maxY*cellY+cellY THEN
        i = mouseX\cellX
        j = mouseY\cellY
        IF X(i,j) = dead THEN
	  L(i,j) = alive
	  X(i,j) = alive
	  LINE (i*cellX+1+xOff,j*cellY+1+yOff)- ~
	       (i*cellX+(cellX-1)+xOff,j*cellY+(cellY-1)+yOff),red,bf
        ELSE
	  L(i,j) = dead
	  X(i,j) = dead
	  LINE (i*cellX+1+xOff,j*cellY+1+yOff)- ~
	       (i*cellX+(cellX-1)+xOff,j*cellY+(cellY-1)+yOff),black,bf
        END IF
      END IF
      '..Await left mouse button release.
      WHILE Modifying AND MOUSE(0):SLEEP:WEND
    END IF
  WEND
END SUB

SUB GenerateLife
SHARED X, L
SHARED Generating
SHARED GenCount, Changed
SHARED xOff, yOff

 REPEAT
  Changed = false

  i=1
  WHILE i <= maxX
    j=1
    WHILE j <= maxY

      '..Reset neighbour counter.
      s = 0

      '..Compute effect of 8 neighbours.
      '..Ignore cells that are off the grid.
      IF i-1 >= 1 AND j-1 >= 1 THEN s = s+L(i-1,j-1)
      IF i+1 <= maxX AND j+1 <= maxY THEN s = s+L(i+1,j+1)
      IF i-1 >= 1 AND j+1 <= maxY THEN s = s+L(i-1,j+1)
      IF i+1 <= maxX AND j-1 >= 1 THEN s = s+L(i+1,j-1)
      IF i-1 >= 1 THEN s = s+L(i-1,j)
      IF j-1 >= 1 THEN s = s+L(i,j-1)
      IF i+1 <= maxX THEN s = s+L(i+1,j)
      IF j+1 <= maxY THEN s = s+L(i,j+1)

      '..Determine life/death status of cell.
      IF L(i,j) = alive THEN
	IF s <> 2 AND s <> 3 THEN
	  X(i,j) = dead
	  Changed = true
	END IF
      ELSE
	IF s = 3 THEN
	  X(i,j) = alive
	  Changed = true
 	END IF
      END IF  

      ++j
    WEND

    ++i
  WEND

  '..Don't allow pattern to be modified/stored until
  '..the Life matrix is in a consistent state.
  MENU mProject,iModify,sDisable
  MENU mProject,iStore,sDisable

  '..Refresh main life matrix and display 
  '..current generation.
  FOR i=1 TO maxX
    FOR j=1 TO maxY
      L(i,j) = X(i,j)
      IF L(i,j) = alive THEN colr = red ELSE colr = black 
      LINE (i*cellX+1+xOff,j*cellY+1+yOff)- ~
	   (i*cellX+(cellX-1)+xOff,j*cellY+(cellY-1)+yOff),colr,bf
    NEXT j 
  NEXT i

  '..Increment generation counter.
  IF Changed THEN
    ++GenCount 
    ShowGenCount
  END IF

  '..Allow pattern to be modified/stored now that
  '..the Life matrix is in a consistent state.
  MENU mProject,iModify,sEnable
  MENU mProject,iStore,sEnable
 UNTIL NOT Generating OR NOT Changed

 '..Switch generation mode off.
 MENU mProject,iGenerate,sEnable
 Generating = false
END SUB

SUB RandomPattern
SHARED X, L
SHARED GenCount, Changed
SHARED xOff, yOff
  MENU mProject,iProject,sDisable
  FOR i=1 TO maxX
    FOR j=1 TO maxY
      IF RND <= .1 THEN status = alive ELSE status = dead
      X(i,j) = status
      L(i,j) = status
      IF L(i,j) = alive THEN colr = red ELSE colr = black 
      LINE (i*cellX+1+xOff,j*cellY+1+yOff)- ~
	   (i*cellX+(cellX-1)+xOff,j*cellY+(cellY-1)+yOff),colr,bf
    NEXT j
  NEXT i
  Changed = true
  GenCount = 0
  ShowGenCount
  MENU mProject,iProject,sEnable
END SUB

SUB AboutLife
  SetWindowTitles(WINDOW(7),"Life - written in ACE BASIC",leave)
  MsgBox "Version 1.0 by David Benn, 12/94", "Continue"
  ShowGenCount
END SUB

{*
** Main.
*}
RANDOMIZE TIMER
SCREEN 1,scrWidth,scrHeight,3,2
WINDOW 1,"",(0,0)-(scrWidth,scrHeight),0,1
PALETTE black,0,0,0
PALETTE white,1,1,1
PALETTE red,1,0,0
PALETTE green,0,1,0
PALETTE blue,0,0,1
SetupMenus
ClearGrid
DrawGridLines
SetMode(iModify)
ModifyGrid
HavingFun = true
WHILE HavingFun
  SLEEP
WEND
END

{*
** Event handlers.
*}
handle_menu:
  theMenu = MENU(0)
  theItem = MENU(1)
  IF theMenu = mProject THEN
    CASE
      theItem = iLoad	    : LoadPattern

      theItem = iStore	    : StorePattern

      theItem = iModify     : IF NOT Modifying THEN
				SetMode(iModify)
				ModifyGrid
		    	      ELSE
				Modifying = false			
				MENU mProject,iModify,sEnable
		    	      END IF

      theItem = iGenerate   : IF NOT Generating THEN
				SetMode(iGenerate)
				GenerateLife
		    	      ELSE
				Generating = false
				MENU mProject,iGenerate,sEnable
		    	      END IF


      theItem = iRandom	    : RandomPattern

      theItem = iClear 	    : ClearGrid

      theItem = iAbout	    : AboutLife

      theItem = iQuit 	    : WINDOW CLOSE 1:SCREEN CLOSE 1:STOP
    END CASE
  END IF
RETURN