Fullscreen in game overlays, on screen display software and tools.

• Playclaw can draw these types of overlay : text, web browser, web cam, hardware stats etc...
  Text can be read from file, at 0.5 seconds interval, supports webcam input from obs virtual cam plugin.
  SDK for version 6 - https://github.com/CyberDemonLord/playclaw6-sdk

• Rivatuner provides shared memory interface to draw text overlay.
  repo - https://github.com/upgradeQ/RTSSSharedMemoryPythonNET

Dual monitor/screen/display based overlay

OBS Studio supports sending preview to another monitor, so you can grab fullscreen application,
typically a game, compose a scene with overlays, then send it RMB > Fullscreen project > Some monitor.
This also can be used with single monitors, but its requires setting up a virtual(fake) monitor,
for windows required steps described https://superuser.com/questions/62051/is-there-a-way-to-fake-a-dual-second-monitor
http://dualmonitortool.sourceforge.net/ this software has these features:

• send current application to second monitor - http://dualmonitortool.sourceforge.net/dmt_swapscreen.html
• lock mouse in one monitor - dualmonitortool.sourceforge.net/dmt_cursor.html
  To maximize preview performance, go to Settings > Video > FPS and set the Integral value to double your monitor's refresh rate (Hz).

Directory listing

• /osu - Check osu on how to play flashlight + hidden with overlaying transparent normal replay video.
• /cheatengine - Output health value to txt file repeatedly and then using OBS scripting to set level of opacity filter according to HP value,cheatengine
• pygame_overlay.py - overlay for game OpenSpades running in windowed mode
• overlay.ahk - ahk script to set any window to be non clickable
• x11_pyqt_overlay.py - creates overlay from any window on X11.
• obs-desktop-hud.lua - dwm based overlay for Windows 11