Jonas Fackelmeyer Project · Personal project
Illuminate
A menu-bar app that brightens everyday content on XDR displays by up to twice the current SDR white – no hardware tricks, only public macOS APIs. Finished and in my daily use.
- Organisation
- Personal project
- Role
- Concept and implementation
- Period
- 2026
- Team
- solo
- Status
- Finished, in daily use
- Stack
- Swift 6.2 · AppKit · Metal · Core Animation · CoreGraphics
Last updated:
Problem
On a MacBook Pro with a Liquid Retina XDR display, macOS caps desktop content at 500–600 nits, although the panel sustains 1000 nits full-screen.
Solution
Illuminate asks WindowServer for EDR headroom and lifts SDR content into it, by up to twice the current SDR white. The boost follows the system brightness slider and is capped at 60 % of the available headroom.
The decision: two techniques
- Overlay (default): a click-through window per display with a
CAMetalLayerin extended colour space and a multiply filter. If the app crashes, the window disappears with it; no system state is left behind. - Gamma table: scales the display’s captured transfer table, so calibration is preserved. Colours stay exact, but HDR video clips. It is disabled on M5 Pro and M5 Max, where macOS ignores gamma tables.
Robustness
A per-display state machine waits for headroom before applying any gain; a display that refuses EDR never affects another one. The boost pauses for the screen saver, lock screen and sleep, on battery below 20 % and in Low Power Mode. The gamma table is restored at exit, on signals, and at the next launch after a crash.
The core logic lives in its own module without AppKit and is fully unit-tested.