Create a window as transparent background and top most and unclickable window form.
i think its more performance then directx about sprites and circle or rectange
and also you can draw text with outline color easly.
you can find more example in:
https://www.sfml-dev.org/tutorials/2.4/graphics-shape.php
Download SFML Library:
https://www.sfml-dev.org/download.php
sf::RenderWindow window;
sf::ContextSettings settings;
settings.antialiasingLevel = 8;
window.create(sf::VideoMode(screen_width, screen_height), "Amiral Router", sf::Style::None, settings);
window.setFramerateLimit(120);
window.setVerticalSyncEnabled(false);
HWND hWnd = window.getSystemHandle();
SetWindowLong(hWnd, GWL_EXSTYLE, WS_EX_TRANSPARENT | WS_EX_LAYERED);
SetLayeredWindowAttributes(hWnd, 0, 255, LWA_ALPHA);
MARGINS margin = { -1 };
DwmExtendFrameIntoClientArea(hWnd, &margin);
::SetWindowPos(hWnd, HWND_TOPMOST, 1,1, screen_width, screen_height, SWP_SHOWWINDOW);
UpdateWindow(hWnd);