fix(🍏): build on tvOS and visionOS again, and check every Apple SDK in CI

.github/workflows/apple-sdks.yml

@@ -0,0 +1,28 @@
+name: apple-sdks
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    paths:
+      - "packages/webgpu/apple/**"
+      - "packages/webgpu/cpp/**"
+      - "packages/webgpu/package.json"
+      - "packages/webgpu/scripts/check-apple-sdks.sh"
+      - ".github/workflows/apple-sdks.yml"
+jobs:
+  apple-sdks:
+    # Syntax-check only: no yarn install, no pods, no simulator. Only the Dawn
+    # headers are downloaded (about 1 MB out of the package's tarball).
+    runs-on: macos-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v4
+      - name: Download Dawn headers
+        run: |
+          VERSION=$(node -p 'require("./packages/webgpu/package.json").dependencies["react-native-webgpu-dawn"]')
+          mkdir -p "$RUNNER_TEMP/dawn"
+          curl -sfL "https://registry.npmjs.org/react-native-webgpu-dawn/-/react-native-webgpu-dawn-$VERSION.tgz" \
+            | tar xz -C "$RUNNER_TEMP/dawn" package/include
+      - name: Check Apple sources against every SDK
+        run: packages/webgpu/scripts/check-apple-sdks.sh "$RUNNER_TEMP/dawn/package/include"

apps/docs/content/api/canvas.mdx

@@ -141,7 +141,7 @@ To show the views behind the canvas, configure the context with `alphaMode: "pre
 
 ## HDR (extended dynamic range)
 
-`context.configure({ toneMapping: { mode } })` says what happens to values above 1.0 on an `rgba16float` canvas: `"standard"` (the default) clamps them to the display's SDR range, `"extended"` lets them use the display's headroom, as in a browser. On iOS 16 and later the `CAMetalLayer` opts into extended dynamic range content for `"extended"`; the mode is accepted and has no effect on an 8-bit canvas, which cannot hold values above 1.0. Android currently ignores `toneMapping`.
+`context.configure({ toneMapping: { mode } })` says what happens to values above 1.0 on an `rgba16float` canvas: `"standard"` (the default) clamps them to the display's SDR range, `"extended"` lets them use the display's headroom, as in a browser. On iOS 16 and later the `CAMetalLayer` opts into extended dynamic range content for `"extended"`; the mode is accepted and has no effect on an 8-bit canvas, which cannot hold values above 1.0. tvOS has no extended dynamic range for this layer, so `"extended"` behaves like `"standard"` there. Android currently ignores `toneMapping`.
 
 ### Android rendering options
 

packages/webgpu/apple/AppleVideoPlayer.mm

@@ -141,6 +141,15 @@ static int rotationFromTransform(CGAffineTransform t) {
     // The metadata loads asynchronously, so that a remote asset never blocks
     // the calling thread; the getters report 0 until it has.
     AVAsset *asset = item.asset;
+    void (^readVideoTrack)(AVAssetTrack *) = ^(AVAssetTrack *track) {
+      if (track) {
+        CGSize size = track.naturalSize;
+        state->width = static_cast<uint32_t>(size.width);
+        state->height = static_cast<uint32_t>(size.height);
+        state->rotation = rotationFromTransform(track.preferredTransform);
+        state->frameRate = track.nominalFrameRate;
+      }
+    };
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
     [asset
@@ -155,17 +164,18 @@ static int rotationFromTransform(CGAffineTransform t) {
                         }
                         if ([asset statusOfValueForKey:@"tracks" error:nil] ==
                             AVKeyValueStatusLoaded) {
-                          AVAssetTrack *track =
-                              [[asset tracksWithMediaType:AVMediaTypeVideo]
-                                  firstObject];
-                          if (track) {
-                            CGSize size = track.naturalSize;
-                            state->width = static_cast<uint32_t>(size.width);
-                            state->height = static_cast<uint32_t>(size.height);
-                            state->rotation =
-                                rotationFromTransform(track.preferredTransform);
-                            state->frameRate = track.nominalFrameRate;
-                          }
+#if TARGET_OS_VISION
+                          // tracksWithMediaType: is unavailable on visionOS.
+                          [asset loadTracksWithMediaType:AVMediaTypeVideo
+                                       completionHandler:^(
+                                           NSArray<AVAssetTrack *> *tracks,
+                                           NSError * /*error*/) {
+                                         readVideoTrack(tracks.firstObject);
+                                       }];
+#else
+            readVideoTrack(
+                [[asset tracksWithMediaType:AVMediaTypeVideo] firstObject]);
+#endif
                         }
                       }];
 #pragma clang diagnostic pop

packages/webgpu/apple/MetalLayerColorSpace.mm

@@ -54,11 +54,18 @@ void applyCAMetalLayerColorSpace(void *nativeSurface,
   }
   const bool extendedRange =
       isFloat && toneMappingMode == CanvasToneMappingMode::Extended;
-  if (@available(iOS 16.0, tvOS 16.0, *)) {
+  // The property does not exist on tvOS (the SDK marks it unavailable, which
+  // @available cannot work around), so it is compiled only where it exists.
+  // On tvOS "extended" behaves like "standard".
+#if TARGET_OS_IOS || TARGET_OS_OSX || TARGET_OS_VISION
+  if (@available(iOS 16.0, macOS 10.11, visionOS 1.0, *)) {
     if (metalLayer.wantsExtendedDynamicRangeContent != extendedRange) {
       metalLayer.wantsExtendedDynamicRangeContent = extendedRange;
     }
   }
+#else
+  (void)extendedRange;
+#endif
   // The change must be set synchronously so the first present already sees
   // it, and it must reach the render server. On a non-main thread (RN JS or
   // worklet runtime) the property lands in that thread's implicit

packages/webgpu/scripts/check-apple-sdks.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+# Syntax-checks the Apple sources that compile without React headers against
+# every Apple SDK the package can be built for. An API that exists on iOS but
+# is marked unavailable on another platform (wantsExtendedDynamicRangeContent
+# on tvOS, #606) is a compile error that @available cannot hide, and nothing
+# else in CI builds for tvOS or visionOS.
+#
+# Usage: check-apple-sdks.sh [dawn-include-dir]
+# Defaults to the Dawn headers installed in node_modules.
+set -euo pipefail
+
+cd "$(dirname "$0")/.."
+
+DAWN_INCLUDE="${1:-}"
+if [ -z "$DAWN_INCLUDE" ]; then
+  DAWN_INCLUDE="$(dirname "$(node -p 'require.resolve("react-native-webgpu-dawn/package.json")')")/include"
+fi
+
+# The other files under apple/ need React and codegen headers, which only
+# exist after a pod install.
+FILES=(apple/MetalLayerColorSpace.mm apple/AppleVideoPlayer.mm)
+
+# sdk:target pairs, using the podspec's minimum versions.
+TARGETS=(
+  iphoneos:arm64-apple-ios15.1
+  iphonesimulator:arm64-apple-ios15.1-simulator
+  macosx:arm64-apple-macos10.15
+  xros:arm64-apple-xros1.0
+  appletvos:arm64-apple-tvos15.1
+  appletvsimulator:arm64-apple-tvos15.1-simulator
+)
+
+status=0
+for pair in "${TARGETS[@]}"; do
+  sdk="${pair%%:*}"
+  target="${pair#*:}"
+  for file in "${FILES[@]}"; do
+    if xcrun --sdk "$sdk" clang++ -target "$target" -std=c++20 -fobjc-arc \
+      -fsyntax-only -w -x objective-c++ -I "$DAWN_INCLUDE" -I cpp/rnwgpu \
+      -I cpp -I apple "$file"; then
+      echo "✅ $sdk $file"
+    else
+      echo "❌ $sdk $file"
+      status=1
+    fi
+  done
+done
+exit $status