Function: pixel-scroll-accumulate-velocity

pixel-scroll-accumulate-velocity is a byte-compiled function defined in pixel-scroll.el.gz.

Signature

(pixel-scroll-accumulate-velocity DELTA)

Documentation

Accumulate DELTA into the current window's kinetic scroll state.

Source Code

;; Defined in /usr/src/emacs/lisp/pixel-scroll.el.gz
(defun pixel-scroll-accumulate-velocity (delta)
  "Accumulate DELTA into the current window's kinetic scroll state."
  (let* ((state (pixel-scroll-kinetic-state))
         (ring (aref state 0))
         (time (aref state 1)))
    (when (or (and time (> (- (float-time) time) 0.5))
              (and (not (ring-empty-p ring))
                   (not (eq (< delta 0)
                            (aref state 2)))))
      (aset state 0 (make-ring 30)))
    (aset state 2 (< delta 0))
    (ring-insert (aref state 0)
                 (cons (aset state 1 (float-time))
                       delta))))