Function: zone-pgm-drip

zone-pgm-drip is a byte-compiled function defined in zone.el.gz.

Signature

(zone-pgm-drip &optional FRET-P PANCAKE-P)

Source Code

;; Defined in /usr/src/emacs/lisp/play/zone.el.gz
(defun zone-pgm-drip (&optional fret-p pancake-p)
  (let* ((ww (1- (window-width)))
         (wh (window-height))
         (mc 0)                         ; miss count
         (total (* ww wh))
         (fall-p nil)
         wbeg wend c)
    (zone-fill-out-screen ww wh)
    (setq wbeg (window-start)
          wend (window-end))
    (catch 'done
      (while (not (input-pending-p))
        (setq mc 0 wend (window-end))
        ;; select non-ws character, but don't miss too much
        (goto-char (+ wbeg (random (- wend wbeg))))
        (while (looking-at "[ \n\f]")
          (if (= total (setq mc (1+ mc)))
              (throw 'done 'sel)
            (goto-char (+ wbeg (random (- wend wbeg))))))
        ;; character animation sequence
        (let ((p (point)))
          (when fret-p (zone-fret wbeg p))
          (goto-char p)
          (setq c (zone-cpos p)
                fall-p (zone-fall-through-ws c wbeg wend)))
        ;; assuming current-column has not changed...
        (when (and pancake-p
                   fall-p
                   (< (count-lines (point-min) (point))
                      wh))
          (let ((cw (ceiling (char-width (aref c 0)))))
            (zone-replace-char cw   1 c ?@) (zone-park/sit-for wbeg 0.137)
            (zone-replace-char cw nil c ?*) (zone-park/sit-for wbeg 0.137)
            (zone-replace-char cw nil c ?_)))))))