holedeep

focus, or be devoured.

A pomodoro timer for macOS where break time is enforced by a black hole. When your focus session ends, a Schwarzschild black hole spawns over your live desktop and gravitationally lenses your work into oblivion — photon ring, accretion disk, chromatic aberration and all — until the break is over and it evaporates.

Built with Tauri 2 + React + WebGL2.

How it works

1. The Rust side runs a real work/break timer (tray icon included).
2. At break start it screenshots every monitor (xcap) for an instant first frame, opens a borderless always-on-top overlay window per monitor, then starts a ScreenCaptureKit stream (scap) per display — excluding the overlays themselves so the hole doesn't capture itself. The overlay polls ~15 fps, so the desktop stays live while being devoured.
3. The overlay renders the desktop through a WebGL2 fragment shader that integrates null geodesics through the Schwarzschild metric per pixel — the shadow, lensing, and photon ring emerge from the physics, they are not painted on.
4. Break ends → the hole collapses → overlays close → back to work.

The screen is never actually locked: hold Esc for 2.5 s to skip a break.

Development

npm install
npm run tauri dev

The overlay has a browser demo mode with a synthetic desktop: run npm run dev and open http://localhost:1420/overlay.html — useful for shader work without triggering real breaks.

On first break, macOS will ask for the Screen Recording permission (System Settings → Privacy & Security). Without it the black hole renders over deep space instead of your desktop.

Credits

The shader is a WebGL2 port of blackhole.glsl by s13k (MIT), itself after Eric Bruneton's Real-time High-Quality Rendering of Non-Rotating Black Holes. The original terminal shader had no state, so it faked its pomodoro with wall-clock arithmetic; here the timer is real and the shader just gets told how hungry to be. The pristine original lives in shaders/reference/.