Vim fixed side scrolling

fixscroll.vim

function! s:FixScroll()
    if &wrap
        return 0
    elseif col(".") - wincol() - &fdc + &number * &numberwidth ==# 0
        return 0
    endif

    let l:targetcol = winwidth(0) - &sidescrolloff

    if wincol() < l:targetcol
        let l:move_amount = l:targetcol - wincol()
        exe 'normal! ' . l:move_amount . 'zh'
    endif
endfunction

" Run fixscroll command on cursor move
autocmd CursorMoved,CursorMovedI * call <SID>FixScroll()