Building ambient desktop particles for macOS with CAEmitterLayer

I recently shipped a free macOS app called Wisp — a menu bar utility that adds gentle, glowing particles between your wallpaper and your desktop icons. Nothing revolutionary, just a visual texture I missed. But building it turned into a tour of some underused Apple APIs I want to share. 🌐 wisp.gruffix.ru · 💾 GitHub · MIT The challenge I wanted ~1,000 particles drifting smoothly on a 4K display at roughly 1 % CPU idle. A naive approach — a Timer that loops over particle structs and draws into a C