for i=1 to n
  disable_ints
  erase_block
  enable_ints
  nop
  disable_ints
  write_block
  enable_ints
next i

' A pay thy, Ci0sss
r a rt X
I)y Ns223,3 (Ftit(1w(wo =r cv( g
r=1n )nsad
Local integer i,j

xstart = 50
Print gfx$ "C" 0,0,sw,sh
Print gfx$ "I" 0,0,255,4
For i = 1 To 40
  For j = 1 To 40
    If w(i,j) And 1 Then
      Print gfx$ "A" xs+10*i,ys+10*j,xs+6+10*i,ys+6+10*j,0,0
    EndIf
  Next j
Next i

End Sub

End

' A short test program to play the Game of Life, invented
' by John Conway. Unfortunately, Covid19 took John's life
' on April 11, 2020. His legacy lives on in the coutless
' people inspired by his invention of the cellular automaton
' called the Game of Life and his other works.
'
' Written by vegipete, April 22, 2020 for use with GFXTerm.

Option DEFAULT INTEGER
Dim INTEGER i,j,count
Dim INTEGER xs,ys
Dim INTEGER sw,sh

Dim string GFX$
Dim float w(41,41)

GFX$ = Chr$(16)

Print GFX$ "?"  ' request size of GFXTerm Window
Input sw,sh ' grab dimensions - width and height

Print Chr$(27)+"[2J";   ' esc sequence to erase the text screen
Print "Thank you John Conway. Rest in Peace."

xs = 100: ys = 20

' clear the world to start
For i = 0 To 41
For j = 0 To 41
  w(i,j) = 0
Next j
Next i

' seed the world
w(19,31) = 3 : w(20,31) = 3 : w(21,31) = 3
w(19,32) = 3 : w(21,32) = 3
w(19,33) = 3 : w(21,33) = 3
w(20,34) = 3
w(17,35) = 3 : w(19,35) = 3 : w(20,35) = 3: w(21,35) = 3
w(18,36) = 3 : w(20,36) = 3 : w(22,36) = 3
w(20,37) = 3 : w(23,37) = 3
w(19,38) = 3 : w(21,38) = 3
w(19,39) = 3 : w(21,39) = 3

showWorld
Pause 2000

For i = 0 To 1000
ConwayLife
showWorld
Next i

End

' Calculate a new generation of life, using the classic rules
Sub ConwayLife
Local integer i,j,count

' wrap the corners
w(0,0) = w(40,40) : w(41,41) = w(1,1)
w(0,41) = w(40,1) : w(41,0) = w(1,40)

' wrap the edges
For i = 1 To 40
  w(0,i) = w(40,i) ' left
  w(41,i) = w(1,i) ' right
  w(i,0) = w(i,40) ' top
  w(i,41) = w(i,1) ' bottom
Next i

' move most recent generation to previous and clear new geneartion
For i = 1 To 40
  For j = 1 To 40
    w(i,j) = w(i,j) << 1
  Next j
Next i

' calculate new generation
For i = 1 To 40
  For j = 1 To 40
    count = Neighbours(i,j)

    If (w(i,j) And 2) Then  ' was cell alive last generation?
      ' yes so test if it stays alive
      If (count = 2) Or (count = 3) Then
        w(i,j) = w(i,j) + 1 ' cell remains alive for new generation
      EndIf
    Else
      ' no so test if it gets born
      If count = 3 Then
        w(i,j) = w(i,j) + 1 ' cell becomes alive for new generation
      EndIf
    EndIf

  Next j
Next i


End Sub

' return number of neighbours around given point
Function Neighbours(x,y)
Local count

count = 0

If (w(x-1,y-1) And 2) Then count = count + 1
If (w(x+0,y-1) And 2) Then count = count + 1
If (w(x+1,y-1) And 2) Then count = count + 1
If (w(x-1,y+0) And 2) Then count = count + 1
If (w(x+1,y+0) And 2) Then count = count + 1
If (w(x-1,y+1) And 2) Then count = count + 1
If (w(x+0,y+1) And 2) Then count = count + 1
If (w(x+1,y+1) And 2) Then count = count + 1

Neighbours = count

End Function

' display the current world
Sub showWorld
Local integer i,j

xstart = 50
Print gfx$ "C" 0,0,sw,sh
Print gfx$ "I" 0,0,255,4
For i = 1 To 40
  For j = 1 To 40
    If w(i,j) And 1 Then
      Print gfx$ "A" xs+10*i,ys+10*j,xs+6+10*i,ys+6+10*j,0,0
    EndIf
  Next j
Next i

End Sub

End