(local tiledraw (require :editor.tiledraw))

(fn map-bitxy-tile [x y]
  (when (and (>= x 0) (< x 16) (>= y 0) (< y 16))
    (local ibyte (if (< x 8) y (+ y 16)))
    (local ibit
      (if (= x 0) 7
          (< x 8) (- x 1)
                  (- x 8)))
    (values ibyte ibit 1)))

(fn map-bitxy-portrait [x y]
  (local quadrant (+ (if (>= x 16) 2 0) (if (>= y 16) 1 0)))
  (local tilex
    (if (or (= x 0) (= x 30))  0
        (or (= x 1) (= x 31))  15
        (< x 16)               (- x 1)
                               (- x 15)))
  (local tiley (% y 16))
  (local (ibyte ibit) (map-bitxy-tile tilex tiley))
  (values (+ ibyte (* quadrant 32)) ibit 1))

{:map-bitxy (fn [self x y w] (if (> w 16) (map-bitxy-portrait x y) (map-bitxy-tile x y)))
 :pixel-color (fn [self b _ ibit]
   (if (= ibit 7) (tiledraw.pal-from-bit (= b 1))
       (= b 1)    [255 255 255]
                  [0 0 0]))
 :draw-off  (fn [self]   (set self.bit nil))
 :draw-on   (fn [self b] (when (= self.bit nil) (set self.bit (if (= b 1) 0 1))))
 :draw-bits (fn [self] self.bit)
 :pixel-storage-divisor #8
}