comfortable-motion.vim

Brings physics-based smooth scrolling to the Vim/Neovim world!

This is highly motivated by the lack of a plugin similar to my favorite Emacs package emacs-inertial-scroll.

Scroll with C-d/C-u:

Scroll with C-f/C-b:

Requirements

This plugin depends on the timer API, which requires Vim/Neovim to be at least the following version:

• Vim 7.4.1578 or above
• Neovim 0.1.5 or above

However, currently, this plugin is only tested on Vim 8.0 and Neovim 0.1.7, i.e. my current development environment.

Installation

For example, with vim-plug:

Plug 'yuttie/comfortable-motion.vim'

Configuration

Please note that the following mappings for <C-d> and <C-u> are not ones for you if you expect they scroll a buffer just half a window.

Scrolling Method

This plugin relies on <C-e> and <C-y> by default to actually scroll a window. You can customize these keys to other combinations like j and k as follows:

let g:comfortable_motion_scroll_down_key = "j"
let g:comfortable_motion_scroll_up_key = "k"

This results in:

Please note that you cannot choose complex keys consisting of multiple motions, e.g. $j. This is because the current implementation prepends the number of scroll amount to the keys, e.g. 5$j, and executes it once per simulation tick.

Keys and Mouse Wheel

By default, the following key mappings are defined.

nnoremap <silent> <C-d> :call comfortable_motion#flick(100)<CR>
nnoremap <silent> <C-u> :call comfortable_motion#flick(-100)<CR>

nnoremap <silent> <C-f> :call comfortable_motion#flick(200)<CR>
nnoremap <silent> <C-b> :call comfortable_motion#flick(-200)<CR>

To prevent the plugin from defining those default key mappings, you can set g:comfortable_motion_no_default_key_mappings to 1.

let g:comfortable_motion_no_default_key_mappings = 1

Additionally, if your Vim/NeoVim has mouse support, you can get mouse wheel to scroll a window by the following mappings:

noremap <silent> <ScrollWheelDown> :call comfortable_motion#flick(40)<CR>
noremap <silent> <ScrollWheelUp>   :call comfortable_motion#flick(-40)<CR>

You may need to enable the mouse option for the above to work, for example, by set mouse=a.

Simulation Parameters

There are three configurable parameters:

• g:comfortable_motion_interval [default: 1000.0 / 60]
• g:comfortable_motion_friction [default: 80.0]
• g:comfortable_motion_air_drag [default: 2.0]

For example, with any of the following configurations, you can get <C-u>/<C-d> (with the default impulse value of -100/100) to scroll a window about 25 lines, but tastes are different.

Friction & Air Resistance

let g:comfortable_motion_friction = 80.0
let g:comfortable_motion_air_drag = 2.0

Friction Only

let g:comfortable_motion_friction = 200.0
let g:comfortable_motion_air_drag = 0.0

Air Resistance Only

let g:comfortable_motion_friction = 0.0
let g:comfortable_motion_air_drag = 4.0

Advanced Configurations

If you would like to use scrolling proportional to the window height, you may use settings such as these:

let g:comfortable_motion_no_default_key_mappings = 1
let g:comfortable_motion_impulse_multiplier = 1  " Feel free to increase/decrease this value.
nnoremap <silent> <C-d> :call comfortable_motion#flick(g:comfortable_motion_impulse_multiplier * winheight(0) * 2)<CR>
nnoremap <silent> <C-u> :call comfortable_motion#flick(g:comfortable_motion_impulse_multiplier * winheight(0) * -2)<CR>
nnoremap <silent> <C-f> :call comfortable_motion#flick(g:comfortable_motion_impulse_multiplier * winheight(0) * 4)<CR>
nnoremap <silent> <C-b> :call comfortable_motion#flick(g:comfortable_motion_impulse_multiplier * winheight(0) * -4)<CR>

License

MIT License