' Maze formed from Truchet Tiles
' This is basically the same algorithm as the famous
' Commodore Pet '10Print' one-line maze.
' Rev 1.0.0 William M Leue 4/1/2021
option default integer
option base 1

const TSIZE = 30
CORNERS = 0

do
 cls
 ncols = MM.HRES\TSIZE
 nrows = MM.VRES\TSIZE
 for row = 1 to nrows+1
   y = (row-1)*TSIZE
   for col = 1 to ncols+1
     x = (col-1)*TSIZE
     DrawTruchetTile x, y, rnd()
   next col
 next row
 box 0,0,MM.HRES,MM.VRES
 pixel fill ncols*TSIZE/2,nrows*TSIZE/2,rgb(blue)
 circle ncols*TSIZE/2,nrows*TSIZE/2,TSIZE/4,0,1,,rgb(red)
 do : k$ = inkey$ : loop until k$ <> ""
 if k$ = "1" then CORNERS = 1
 if k$ = "0" then CORNERS = 0
loop until k$ = chr$(27)
end

sub DrawTruchetTile x, y, r as float
 if CORNERS then
   if r < 0.5 then
     line x + TSIZE/2, y, x + TSIZE, y + TSIZE/2
     line x, y + TSIZE/2, x + TSIZE/2, y + TSIZE
   else
     line x + TSIZE/2, y, x, y + TSIZE/2
     line x + TSIZE, y + TSIZE/2, x + TSIZE/2, y + TSIZE
   end if
 else
   if r < 0.5 then
     arc x, y + TSIZE, TSIZE/2,, 0, 93
     arc x + TSIZE, y, TSIZE/2,, 180, 273
   else
     arc x, y, TSIZE/2,, 87, 180
     arc x + TSIZE, y + TSIZE, TSIZE/2,, -93, 0
   end if
 end if
end sub