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| author | Po Lu <luangruo@yahoo.com> | 2021-12-03 13:55:39 +0800 |
|---|---|---|
| committer | Po Lu <luangruo@yahoo.com> | 2021-12-03 14:04:04 +0800 |
| commit | 1afa295aed81357fddf9694bfe68ed0e6d159a2d (patch) | |
| tree | bf770c1e7919cfdf48b4f91d5b948a6f536a809e /lisp/pixel-scroll.el | |
| parent | c66eb524537f98667507024e5f21e0b24038c964 (diff) | |
| download | emacs-1afa295aed81357fddf9694bfe68ed0e6d159a2d.tar.gz | |
Improve velocity calculation in momentum scrolling
* lisp/pixel-scroll.el
(pixel-scroll-precision-momentum-factor): Remove option.
(pixel-scroll-precision-initial-velocity-factor)
(pixel-scroll-precision-momentum-min-velocity): New user
options.
(pixel-scroll-accumulate-velocity): Clear velocity ring
if sign is different.
(pixel-scroll-calculate-velocity): Use current time.
(pixel-scroll-start-momentum): Use better algorithm.
Diffstat (limited to 'lisp/pixel-scroll.el')
| -rw-r--r-- | lisp/pixel-scroll.el | 74 |
1 files changed, 49 insertions, 25 deletions
diff --git a/lisp/pixel-scroll.el b/lisp/pixel-scroll.el index 3c764ff65ab..1c2d95613e5 100644 --- a/lisp/pixel-scroll.el +++ b/lisp/pixel-scroll.el @@ -121,8 +121,14 @@ This is only effective if supported by your mouse or touchpad." :type 'float :version "29.1") -(defcustom pixel-scroll-precision-momentum-factor 0.95 - "Factor by which to reduce scroll velocity on each momentum scroll" +(defcustom pixel-scroll-precision-momentum-min-velocity 10.0 + "The minimum scrolled pixels per second before momentum scrolling starts." + :group 'mouse + :type 'float + :version "29.1") + +(defcustom pixel-scroll-precision-initial-velocity-factor 0.25 + "Factor applied to the initial velocity before momentum scrolling begins." :group 'mouse :type 'float :version "29.1") @@ -524,8 +530,13 @@ It is a vector of the form [ VELOCITY TIME ]." (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 (and time (> (- (float-time) time) 0.5)) + (when (or (and time (> (- (float-time) time) 0.5)) + (and (not (ring-empty-p ring)) + (not (eq (< delta 0) + (< (cdr (ring-ref ring 0)) + 0))))) (aset state 0 (make-ring 10))) (ring-insert (aref state 0) (cons (aset state 1 (float-time)) @@ -538,8 +549,7 @@ It is a vector of the form [ VELOCITY TIME ]." (total 0)) (dolist (tem elts) (setq total (+ total (cdr tem)))) - (/ total (* (- (caar elts) - (caar (last elts))) + (/ total (* (- (float-time) (caar elts)) 100)))) (defun pixel-scroll-start-momentum (event) @@ -555,26 +565,40 @@ It is a vector of the form [ VELOCITY TIME ]." (while-no-input (unwind-protect (progn (aset state 0 (pixel-scroll-calculate-velocity state)) - (let ((velocity (/ (aref state 0) 3)) - (time-spent 0)) - (if (> velocity 0) - (while (and (> velocity 0.2) - (<= time-spent pixel-scroll-precision-momentum-seconds)) - (pixel-scroll-precision-scroll-up (ceiling velocity)) - (setq velocity (* velocity pixel-scroll-precision-momentum-factor)) - (redisplay t) - (sit-for pixel-scroll-precision-momentum-tick) - (setq time-spent (+ time-spent - pixel-scroll-precision-momentum-tick)))) - (while (and (< velocity -0.4) - (<= time-spent - pixel-scroll-precision-momentum-seconds)) - (pixel-scroll-precision-scroll-down (floor (abs velocity))) - (setq velocity (* velocity pixel-scroll-precision-momentum-factor)) - (redisplay t) - (sit-for pixel-scroll-precision-momentum-tick) - (setq time-spent (+ time-spent - pixel-scroll-precision-momentum-tick))))) + (when (> (abs (aref state 0)) + pixel-scroll-precision-momentum-min-velocity) + (let* ((velocity (* (aref state 0) + pixel-scroll-precision-initial-velocity-factor)) + (original-velocity velocity) + (time-spent 0)) + (if (> velocity 0) + (while (and (> velocity 0) + (<= time-spent + pixel-scroll-precision-momentum-seconds)) + (when (> (round velocity) 0) + (pixel-scroll-precision-scroll-up (round velocity))) + (setq velocity (- velocity + (/ original-velocity + (/ pixel-scroll-precision-momentum-seconds + pixel-scroll-precision-momentum-tick)))) + (redisplay t) + (sit-for pixel-scroll-precision-momentum-tick) + (setq time-spent (+ time-spent + pixel-scroll-precision-momentum-tick)))) + (while (and (< velocity 0) + (<= time-spent + pixel-scroll-precision-momentum-seconds)) + (when (> (round (abs velocity)) 0) + (pixel-scroll-precision-scroll-down (round + (abs velocity)))) + (setq velocity (+ velocity + (/ (abs original-velocity) + (/ pixel-scroll-precision-momentum-seconds + pixel-scroll-precision-momentum-tick)))) + (redisplay t) + (sit-for pixel-scroll-precision-momentum-tick) + (setq time-spent (+ time-spent + pixel-scroll-precision-momentum-tick)))))) (aset state 0 (make-ring 10)) (aset state 1 nil)))))))) |