The raylib examples, on an iPhone, from Clojure

Who owns thread 0

UIKit insists its window work happens on the main thread, so the whole design turns on who owns it. Here the answer is our own executable, and the loop is handed back to us on the thread UIKit wants.

flowchart LR
  main["Chez owns main()
thread 0"]
  run["SDL_UIKitRunApp
:blocking FFI call"]
  uikit["UIApplicationMain
SDLUIKitDelegate"]
  cb["our :collect-safe callback
= SDL_main"]
  loop["the raylib loop
InitWindow · BeginDrawing · EndDrawing"]
  main --> run --> uikit -->|"postFinishLaunch, on thread 0"| cb --> loop
  loop -->|"EndDrawing pumps CFRunLoop
so a blocking loop is legal"| uikit
    

A blocking while loop is normally wrong on iOS. It works here only because EndDrawing reaches SDL_PumpEvents, which spins the run loop, so UIKit gets its turn every frame.

The gallery

Every scene is pure .cljc that runs on a build host with no raylib, no SDL and no device, which is how they are tested. Three come from the Jolt Android experiment, identical apart from namespace names and whitespace, and written for a different platform entirely, along with three more namespaces carrying the scene contract itself. The other hundred and thirty-four are ports from raylib-jolt-demo's demos (originally raylib-jlt's).

generative 6 · fractals 3 · toys 5 · games 1 · three of them identical to the Android originals apart from names and whitespace. Every one came off the phone unattended, the moving ones recorded from a live iPhone Mirroring window. Nobody touched the device for any of them: Flappy Bird is flapped by a loop running inside the app, started from the nREPL. The bezel is the mirror's own.