GCTD — Game Crosshair To Desktop

A GNOME Shell extension that draws a crosshair over your desktop for games (or apps) that don't have their own — plus a one-click Gamemode for the rest of your setup.

What it does

• Crosshair overlay. Shows a scope/reticle centered on your screen, above every window and full-screen game. Pick from a few built-in styles or add your own PNG. Adjust size, opacity, and offset from center to line it up with your game's actual aim point.
• Panel indicator. A quick switch in the top panel to toggle the crosshair and Gamemode without digging into settings.
• Keyboard shortcut. Bind any key combo to toggle the crosshair from anywhere, including full-screen games.
• Gamemode. One switch that can, all optionally:
  • silence notification banners,
  • flatten mouse acceleration to 1:1,
  • stop the screen from blanking or locking,
  • disable hot corners so a stray mouse movement doesn't throw you into the Activities overview,
  • and, if the GameMode daemon is installed, register itself with it so your CPU governor switches to performance mode while you play.
• Everything Gamemode changes is restored to exactly what you had before — nothing is left in a weird state when you turn it off.
• The crosshair and Gamemode both remember whether they were on when you log out, and switch back on automatically next time.

Requirements

• GNOME Shell 48, 49, or 50. (Other versions may work but aren't tested.)
• libadwaita, which ships with GNOME Shell's extension preferences on any current GNOME install — nothing to install separately.
• (Optional) GameMode by Feral Interactive, if you want Gamemode's "performance CPU governor" toggle to actually do something. Without it, that switch simply has no effect — everything else works either way.

Installation

From source:

git clone https://github.com/VenerisAsgard/GCTD.git
cd GCTD
cp -r "GCTD@dev.va_icloud.com" ~/.local/share/gnome-shell/extensions/

Then log out and back in (Wayland requires a full re-login; on X11 you can instead reload GNOME Shell with Alt+F2, r, Enter).

Enable it with the Extensions app, or from a terminal:

gnome-extensions enable "GCTD@dev.va_icloud.com"

Using it

Open the extension's preferences (via the panel indicator's Preferences entry, or the Extensions app) to:

• pick or add a crosshair image, and tune its size, opacity, and position (Appearance),
• choose exactly which tweaks Gamemode applies (Gamemode),
• set a keyboard shortcut and notification/indicator preferences (General).

For developers

Regenerate the translation template:

find . -name "*.js" -exec xgettext --from-code=UTF-8 --output=po/GCTD@dev.va_icloud.com.pot {} +

Pack the extension (compiles schemas and translations):

gnome-extensions pack --podir=po "GCTD@dev.va_icloud.com/"

Thanks

• Just Perfection
• ExposedCat