;;; -*- lexical-binding: t -*-
;;
;; --------------------------------------------------------------------------

(require 'cl-lib)
(cl-pushnew "." load-path :test #'string=)
(require 'luki-lisp)

;; --------------------------------------------------------------------------

(-> 'bad-box) ; NOTE: OK
(-> 'bad-color)
(-> 'bad-elem)
(-> 'bad-move)

;; --------------------------------------------------------------------------

(let ((step-def 0.05))

  (cl-defmethod bad-advance ((e elem) &optional step)
    (or step (setq step step-def))
    (unless (z step)
      (~ (prox) e
         (let ((mn 0.0)
               (mx 1.0))
           (if (< prox mn)
               (setf prox mn)
             (when (< mx prox)
               (setf prox mx)))
           (let* ((pos (< 0 step))
                  (stp 1)
                  (mve (if pos stp (- stp))))
             (when (or (& (! pos) (< mn prox))
                       (&    pos  (< prox mx)))
               (bad-add-row e mve)
               (bad-add-col e mve)
               (++ prox step)
               (bad-compute-actual-fg e)
               (bad-update e)))))))

  (cl-defmethod bad-retreat ((e elem) &optional step)
    (or step (setq step step-def))
    (bad-advance e (- step))))

(declare-function bad-advance nil)
(declare-function bad-retreat nil)

;; --------------------------------------------------------------------------

(cl-defmethod bad-compute-actual-fg ((e elem) &optional verbose)
  (~ (dist-fg actual-fg fg prox) e
     (unless dist-fg
       (setf dist-fg our-black-b))
     (unless fg
       (setf fg our-white-b))
     (when (or (!n prox) (< 1.0 prox))
       (setf prox 1.0))
     (when (< prox 0.0)
       (setf prox 0.0))
     (setf actual-fg (bad-color-norm (col+ (col* (- 1.0 prox) dist-fg)
                                           (col*        prox       fg))
                                     'to-str))
     (when verbose
       ($ "prox: %.2f  ( fg %s | distant %s | actual %s )" prox fg dist-fg actual-fg))))

;; --------------------------------------------------------------------------

(<- 'bad-proximity)