;; ASCII Art effect - converts image to ASCII characters
;; @param char_size int [4, 32] default 8
;; @param alphabet string default "standard"
;; @param color_mode string default "color"
;; @param contrast float [1, 3] default 1.5
;; @param background list default (0 0 0)

(define-effect ascii_art
  ((char_size 8) (alphabet "standard") (color_mode "color") (contrast 1.5) (background (list 0 0 0)))
  (let* ((sample (cell-sample frame char_size))
         (colors (nth sample 0))
         (luminances (nth sample 1))
         (chars (luminance-to-chars luminances alphabet contrast)))
    (render-char-grid frame chars colors char_size color_mode background)))