Windows Scroll / Typing Performance has significant delay in maximized mode

markhagemann commented 3 years ago

Describe the bug

When running WezTerm (nightly and latest release), if the terminal isn't maximized, the performance is almost identical to Windows Terminal Preview (I can't fault it).

If WezTerm is maximized, the typing and scroll delay is significantly worse. This is shown most clearly in vim / neovim (even with plugins disabled).

I have experimented with front_end and prefer_egl and found the same results.

Environment (please complete the following information):

OS: Windows with WSL2
Version: wezterm 20210517-072856-bf032062
The active keyboard layout name: English (United States)

To Reproduce

Load up a large file in vim without WezTerm being on maximized, scroll up and down and note the performance.
Maximize WezTerm and compare scrolling performance from before

Configuration

local wezterm = require 'wezterm';

return {
    colors = {
        background = "#202734",
        foreground = "#CBCCC6",
        cursor_fg = "#fff",
        cursor_bg = "#42546e",
        cursor_border = "#42546e",
    },
    default_prog = {"wsl.exe", "~", "--exec", "tmux", "-l"},
    font = wezterm.font("CaskaydiaCove Nerd Font"),
    font_size = 12,
    hide_tab_bar_if_only_one_tab = true,
    initial_cols = 160,
    initial_rows = 40,
    window_close_confirmation = "NeverPrompt",
    window_padding = {
        left = 10,
        right = 5,

        top = 5,
        bottom = 5,
    }
}

Expected behavior

Minimal difference between maximized mode and standard mode.

Session Recording

wezterm windows recording.zip

wez commented 3 years ago

What are the window dimensions when maximized?

markhagemann commented 3 years ago

1920 x 1150 (50px for the windows taskbar - max res on laptop is 1920 x 1200 - Dell Precision 5550).

I have attached a video (via zip file) using OBS, doesn't seem to capture it properly... I may have to wait and see if anyone else experiences.

I will try this out on my desktop PC rather than work laptop and see if I can reproduce it again.

wez commented 3 years ago

Even though #817 is newer than this, it has the same root cause; the render cost is O(window area), so I'm closing this issue in favor of that one.

github-actions[bot] commented 1 year ago

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues. If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.

wez / wezterm