What works on iOS sim now:
- pure-UIKit boot via UIApplicationMain (no SDL3 on iOS)
- SxGLView (CAEAGLLayer) + EAGLContext(GLES3) + CADisplayLink
- GLES3 shader path in modules/ui/renderer.sx (was wasm-only; now
wasm-OR-ios)
- UITouch -> ui.Event translation (mouse_down/moved/up) on touchesBegan/
Moved/Ended/Cancelled. Verified by tapping the chess board: the
expected pawn highlights and its legal moves show as green dots.
- chdir to NSBundle.mainBundle.resourcePath inside UIKitPlatform.init so
the game's relative fopen("assets/...") calls resolve.
Required restructuring to fix four problems discovered along the way:
1. GL context + load_gl must happen BEFORE UIApplicationMain so the
game's pipeline.init (which compiles shaders) doesn't crash on null
function pointers. Pulled EAGLContext creation + load_gl out of
didFinishLaunching: into UIKitPlatform.init via uikit_create_gl_context.
2. UIScreen.nativeScale returns CGFloat (=double on 64-bit Apple).
Reading it through a `(*void, *void) -> f32` msgSend signature
clobbers the value to 0 — the upper 32 bits of d0 land where the f32
reads from. Replaced msg_f with msg_d returning f64 (and added
msg_odbl for setContentScaleFactor: which takes CGFloat).
3. `xx <f64-call-result>` directly assigned to an f32 field through a
sema path lowers as `sitofp` (integer→float) on the double — LLVM
verification rejects it. Workaround: hoist into an `f64` local first.
4. The renderer was selecting the GLSL 330 core shader on every non-wasm
target, including iOS GLES3 where it silently fails to compile and
no quads render. Added OS == .ios to the GLES branch.
Game changes:
- main.sx: g_plat is now a boxed `Platform` (not concrete *SdlPlatform).
Backend chosen per-target via `inline if OS == .ios { ... }`. The
ESC-to-stop handling is OS-guarded (mobile apps don't quit on key
press, and SDL_Keycode references would force-link SDL on iOS).
- build.sx: iOS no longer adds SDL3; it adds UIKit + OpenGLES +
QuartzCore instead.
- delta_time and viewport dims are now mirrored to free globals so the
dock subsystem (`g_dock_delta_time = @g_delta_time`) and build_ui
layout decisions don't need a pointer through the boxed protocol.
Other:
- Added `stop()` to the Platform protocol (no-op on UIKitPlatform).
- examples/66-uikit-platform.sx updated: taps advance the clear color
(red → green → blue) — smoke test for the touch IMP wiring.
- shutdown() on UIKitPlatform is a no-op (mobile apps don't tear down).
Outstanding for next session:
- The Dynamic Island notch overlaps the top of the board because we
haven't read UIView.safeAreaInsets yet (CGRect/UIEdgeInsets struct
returns require a different msgSend ABI than we currently express).
- Keyboard observer (UIKeyboardWillChangeFrameNotification + animation
duration) — the load-bearing iOS feature.
- Real-device codesigning workflow for the new build.
Two more sx compiler bugs to file out of this work:
- xx(f64 call result) → f32 emits sitofp (problem #3 above).
- Inline `#import` inside `inline if` fails to parse (we worked around
by importing both backends unconditionally; the unused-backend's
Obj-C calls are gated by `inline if OS == .ios`).
End-to-end on iOS sim: UIKitPlatform boots an SxAppDelegate, installs
an SxGLView (UIView subclass overriding +layerClass to return
CAEAGLLayer) as the root view controller's view, sets the drawable
properties (EAGLColorFormatRGBA8, non-retained backing — looked up by
dlsym so pointer-identity-checked constants match), creates an
EAGLContext (GLES3), and registers a CADisplayLink that invokes the
user's frame closure on every vsync. end_frame presents the
renderbuffer via [EAGLContext presentRenderbuffer:].
The renderbuffer is allocated lazily in -[SxGLView layoutSubviews] once
the layer has its real on-screen bounds — allocating earlier (e.g. in
didFinishLaunching) failed with INCOMPLETE_ATTACHMENT because the
SxGLView's frame was still zero at that point. Setting the SxGLView
as the VC's `view` (via setView:) lets the standard VC layout pipeline
size it to the window without us having to read CGRect struct returns
from objc_msgSend.
EAGL drawableProperties dict keys/values are dlsym'd from OpenGLES —
the framework checks them by pointer identity, so synthesized NSString
literals with the same contents don't work.
examples/66-uikit-platform.sx — runnable smoke test that cycles the
screen color (red → green → blue every 30 frames) so you can confirm
the display-link tick and present pipeline.
modules/opengl.sx gains glGenFramebuffers, glGenRenderbuffers,
glBindFramebuffer, glBindRenderbuffer, glFramebufferRenderbuffer,
glGetRenderbufferParameteriv, glCheckFramebufferStatus — needed for
the iOS GLES FBO-to-renderbuffer setup. They're wired into load_gl
so SDL and the iOS dlsym loader both pick them up.
Compiles cleanly on macOS / WASM / iOS-sim. Non-iOS targets never
reference the unresolved UIKit/QuartzCore/OpenGLES symbols because
every Obj-C touch lives inside `inline if OS == .ios`.
Game's iOS path still goes through SDL3 for now. Touch events + game
wire-up + keyboard observer = next steps.
