feat(apple): Improve presenter

feat(apple): add cursor capture on iPad

clients/apple/Tests/PunktfunkKitTests/MetalPresenterTests.swift

@@ -1,11 +1,13 @@
 import XCTest
 
 #if canImport(Metal)
+import CoreVideo
 import Metal
+import QuartzCore
 @testable import PunktfunkKit
 
 final class MetalPresenterTests: XCTestCase {
-    /// `MetalVideoPresenter.init?()` compiles the runtime Metal shaders (the BT.709/BT.2020 YUV→RGB
+    /// `MetalVideoPresenter.make()` compiles the runtime Metal shaders (the BT.709/BT.2020 YUV→RGB
     /// fragment shaders plus the Catmull-Rom luma sampler). A `nil` result on a GPU-equipped host
     /// means a shader failed to compile — this catches a malformed shader before it silently
     /// degrades stage-2 to a stage-1 fallback on device.
@@ -14,8 +16,54 @@ final class MetalPresenterTests: XCTestCase {
             throw XCTSkip("no Metal device available in this environment")
         }
         XCTAssertNotNil(
-            MetalVideoPresenter(),
+            MetalVideoPresenter.make(),
             "stage-2 Metal shaders failed to compile (presenter init returned nil)")
     }
+
+    /// The HDR fix: `configure(hdr:)` must put the layer into the BT.2020-PQ EDR configuration with a
+    /// reference-white anchor (`edrMetadata`) — the missing anchor was what made HDR render "too
+    /// bright". SDR must use the plain 8-bit path with EDR off and no metadata. A mid-session flip is a
+    /// per-mode reconfigure, so the round trip back to SDR must fully restore the SDR config.
+    func testConfigureHDRSetsEDRAnchor() throws {
+        guard let presenter = MetalVideoPresenter.make() else {
+            throw XCTSkip("no Metal device available in this environment")
+        }
+        presenter.configure(hdr: true)
+        XCTAssertEqual(presenter.layer.pixelFormat, .rgba16Float, "HDR uses an EDR-capable drawable")
+        XCTAssertNotNil(presenter.layer.colorspace, "HDR layer must be tagged (itur_2100_PQ)")
+        XCTAssertTrue(
+            presenter.layer.wantsExtendedDynamicRangeContent, "EDR must be requested on all platforms")
+        XCTAssertNotNil(
+            presenter.layer.edrMetadata,
+            "HDR must anchor reference white via edrMetadata (the fix for 'too bright')")
+
+        // Mid-session HDR→SDR flip: the 8-bit path, EDR off, no metadata.
+        presenter.configure(hdr: false)
+        XCTAssertEqual(presenter.layer.pixelFormat, .bgra8Unorm, "SDR uses the plain 8-bit drawable")
+        XCTAssertFalse(presenter.layer.wantsExtendedDynamicRangeContent)
+        XCTAssertNil(presenter.layer.edrMetadata)
+    }
+
+    /// `render` with a freshly-allocated NV12 buffer must present without crashing or hanging — the
+    /// main-thread present path is the highest-risk part of the stage-2 rewrite. (A headless CI with no
+    /// display can still allocate a drawable from a CAMetalLayer; if it can't, render returns false,
+    /// which is also a valid non-crashing outcome.)
+    func testRenderDoesNotCrashOnNV12Frame() throws {
+        guard let presenter = MetalVideoPresenter.make() else {
+            throw XCTSkip("no Metal device available in this environment")
+        }
+        presenter.configure(hdr: false)
+        var pb: CVPixelBuffer?
+        let attrs: [CFString: Any] = [kCVPixelBufferMetalCompatibilityKey: true]
+        let status = CVPixelBufferCreate(
+            kCFAllocatorDefault, 256, 256, kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange,
+            attrs as CFDictionary, &pb)
+        guard status == kCVReturnSuccess, let pixelBuffer = pb else {
+            throw XCTSkip("could not allocate a test pixel buffer")
+        }
+        // Just asserting it returns (true or false) without trapping — the layer may have no drawable
+        // source headless, so a false return is acceptable.
+        _ = presenter.render(pixelBuffer, isHDR: false)
+    }
 }
 #endif

clients/apple/Tests/PunktfunkKitTests/Stage444Tests.swift

@@ -0,0 +1,68 @@
+// 4:4:4 decode-path coverage: the hardware-capability probe is stable/cached, and a real 4:4:4 HEVC
+// keyframe decodes through VideoDecoder to a biplanar 4:4:4 pixel buffer. Reuses the same synthetic
+// 4:4:4 blobs the runtime probe ships with.
+
+import CoreVideo
+import VideoToolbox
+import XCTest
+@testable import PunktfunkKit
+
+private final class FrameBox: @unchecked Sendable {
+    let lock = NSLock()
+    var frame: ReadyFrame?
+    var error: OSStatus?
+}
+
+final class Stage444Tests: XCTestCase {
+    /// The capability probe is device-static and cached — reading it twice must return the same value
+    /// (and must never crash, including where 4:4:4 is unsupported → false).
+    func testProbeIsStableAndCached() {
+        XCTAssertEqual(Stage444Probe.hwDecode444_8bit, Stage444Probe.hwDecode444_8bit)
+        XCTAssertEqual(Stage444Probe.hwDecode444_10bit, Stage444Probe.hwDecode444_10bit)
+    }
+
+    /// A real 8-bit 4:4:4 HEVC keyframe (the embedded probe blob) decodes through `VideoDecoder` with
+    /// `setChroma444(true)` to a 256×256 biplanar 4:4:4 (`444v`/`444f`) buffer classified SDR.
+    /// (4:4:4 sessions require a hardware decoder — skip where there isn't one, which is exactly where
+    /// the client wouldn't advertise 4:4:4 anyway.)
+    func testVideoDecoderDecodes444() throws {
+        try XCTSkipUnless(
+            Stage444Probe.hwDecode444_8bit, "no hardware 4:4:4 decode on this device")
+        let data = Data(Probe444Blobs.au444_8bit)
+        let format = try XCTUnwrap(
+            AnnexB.formatDescription(fromIDR: data), "the 4:4:4 blob must yield a format description")
+        let au = AccessUnit(data: data, ptsNs: 7_000_000, frameIndex: 0, flags: 0)
+
+        let box = FrameBox()
+        let done = DispatchSemaphore(value: 0)
+        let decoder = VideoDecoder(
+            onDecoded: { f in box.lock.lock(); box.frame = f; box.lock.unlock(); done.signal() },
+            onDecodeError: { s in box.lock.lock(); box.error = s; box.lock.unlock(); done.signal() })
+        decoder.setChroma444(true)
+
+        XCTAssertTrue(decoder.decode(au: au, format: format), "4:4:4 frame submit should succeed")
+        XCTAssertEqual(done.wait(timeout: .now() + 10), .success, "the decode callback must fire")
+        decoder.reset()
+
+        box.lock.lock(); let frame = box.frame; let error = box.error; box.lock.unlock()
+        XCTAssertNil(error.map { "decode error \($0)" })
+        let ready = try XCTUnwrap(frame, "a 4:4:4 ReadyFrame must be delivered")
+        XCTAssertEqual(CVPixelBufferGetWidth(ready.pixelBuffer), 256)
+        XCTAssertEqual(CVPixelBufferGetHeight(ready.pixelBuffer), 256)
+        let pf = CVPixelBufferGetPixelFormatType(ready.pixelBuffer)
+        XCTAssertTrue(
+            pf == kCVPixelFormatType_444YpCbCr8BiPlanarVideoRange
+                || pf == kCVPixelFormatType_444YpCbCr8BiPlanarFullRange,
+            "expected a biplanar 4:4:4 8-bit buffer, got \(fourCCString(pf))")
+        XCTAssertFalse(ready.isHDR, "an 8-bit BT.709 4:4:4 stream is SDR")
+        // The chroma plane (plane 1) must be FULL resolution for 4:4:4 (vs half for 4:2:0) — this is
+        // what lets the unchanged shader sample chroma at the luma UV.
+        XCTAssertEqual(CVPixelBufferGetWidthOfPlane(ready.pixelBuffer, 1), 256)
+        XCTAssertEqual(CVPixelBufferGetHeightOfPlane(ready.pixelBuffer, 1), 256)
+    }
+
+    private func fourCCString(_ t: OSType) -> String {
+        let b = [UInt8(t >> 24 & 0xff), UInt8(t >> 16 & 0xff), UInt8(t >> 8 & 0xff), UInt8(t & 0xff)]
+        return String(bytes: b, encoding: .ascii) ?? "\(t)"
+    }
+}