simple crossword grid in eml

gistfile1.hs

import Dict

side = 30
n = 15
x0 = side * n 

-- coordinates
toScreen (x, y) = (side * x - x0, side * (n - y))
fromScreen (x, y) = (div (x + x0) side, n - div y side)

-- square

data Square = Black | White Char

sqColor s = case s of
              Black -> black
              White _ -> white

sqLetter s = case s of
               Black -> '#'
               White c -> c

renderCell square = layers 
  [ sqr <| sqColor square 
  , container side side middle <| plainText [ sqLetter square ]
  ]

-- grid

getSq grid x y =
  case (Dict.lookup (x, y) grid) of
    Just s -> s
    Nothing -> White ' '

sqr c = collage side side [
             square side |> filled c
           , square side |> outlined (solid black)
          ]

crsr = opacity 0.5 <| collage side side [ square side |> filled green ]

sq grid x y =
  let (px, py) = toScreen (x, y)
      cell = getSq grid x y
  in renderCell cell |> toForm |> move (px, py)

renderCursor state =
  let (px, py) = toScreen state.cursor
  in  crsr |> toForm |> move (px, py)

renderGrid state =
  concatMap (\x -> map (sq state.grid x) [1 .. n]) [1 .. n]

renderAll state = concat [renderGrid state, [renderCursor state]]

start = [((1, 1), Black), ((1, 3), White 'A')]

main = 
  let grid = Dict.fromList start 
      state = { grid = grid, cursor = (1, 1) }
  in
  collage 1200 1200 <| renderAll state