On Sun, Sep 10, 2017 at 09:37:58AM +0100, Alan Third wrote:
> How about instead of using the default font height, I provide a
> variable that the user can use to set a ‘line height’ of their own
> choosing? i.e. ‘(setq ns-touchpad-scroll-line-height 1)’ for one
> pixel.

Updated patch attached.

I’ve modified mousewheel scrolling so it also makes use of macOS’s
built‐in mousewheel acceleration. My thinking was that if we turn off
Emacs progressive scrolling for touchpad, then mousewheels can feel
awfully slow. ns-use-system-mwheel-acceleration allows you to turn it
off if you don’t like the new behaviour, but it has no effect on
touchpad scrolling.

If anyone gives the patch a try, please let me know what you think.
-- 
Alan Third