# Main Command: Go
# Maze by Guy Walker
# www.logoarts.co.uk

to new
  # set default screen, pen and turtle 
  ResetAll SetScreenSize [400 400] HideTurtle 
  SetSC Black SetPC Green SetPS 1 PenUp 
end

to init
  # global values
  GlobalMake "Order 27 
  GlobalMake "Width 378
  GlobalMake "Side :Width/:Order
  GlobalMake "OffSet (:Side/2 - :Width/2) 
  GlobalMake "Filled 1
end

to gridd :m :n
  # return X Y screen position
  Make "X (:N*:Side) + :OffSet
  Make "Y (:M*:Side) + :OffSet
  Output List :X :Y
end

to drawpath
  # pick a heading and move forward if OK
  While [Not :Headings = [ ] ] [
  SetH Pick :Headings
  If (Item 2 (FindColor TestPos)) = 0 [ 
    SetPos TestPos
    Make "Headings [0 90 180 270]
  Make "Filled :Filled + 1] [
  Make "Headings Remove Heading :Headings]
  DrawPath]
end

to randomplace
  SetPos Gridd Random :Order Random :Order
end

to testpos
  Output List ((First Pos)+:Side*(Sin Heading)) ((Last Pos)+:Side*(Cos Heading))
end

to border
  # fill screen edge
  SetPC [0 1 0] SetPW 10 SetXY 196 196 SetH 270
  PenDown Repeat 4 [Forward :Width+15 Left 90] PenUp
end

to ends
  SetPC Red SetPW :Side/1.5
  Dot Gridd 0 0 
  Dot Gridd :Order-1 :Order-1 
end

to drawmaze
  If :Filled = 1 [RandomPlace Dot Pos] [
  While [Not ((Item 2 (FindColor Pos)) = 255) ] [RandomPlace] ]
  Make "Headings [0 90 180 270]
  PenDown DrawPath
  PenUp SetPC [0 254 0] Dot Pos SetPC Green
end

to go
  New Init Border Ends SetPW :Side/3 SetPC Green
  While [:Filled < Power :Order 2] [DrawMaze]
end