0.2.0

[0.2.0] - 2026-10-09

iOS 26 and iOS 27 capture APIs, a rebuilt logging layer, and a round of capture, session and accessibility fixes. Building now requires Xcode 27 (Swift 6.4, iOS 27 SDK); the deployment target stays iOS 18, and every new API is availability-gated. Breaking changes are marked in Changed.

Added

• Priority modes and variable aperture (iOS 27): PRMExposureValue, PRMExposureAxes, setExposure(aperture:shutterSeconds:iso:), setShutterPriority(seconds:), setISOPriority(_:), setAperturePriority(_:), setAutoApertureRateLimit(_:), exposurePriorityAxes; device helpers prm_setExposure(aperture:shutterSeconds:iso:completion:), prm_supportsExposure(...), prm_lensApertureRange, prm_autoExposureAxes, prm_setAutoApertureRateLimit(_:). State lensAperture, autoExposureAxes; device apertureRange, recommendedApertureStops.
• Exposure signals (iOS 27): PRMExposureSignal, setExposureSignals(_:), prm_setExposureSignals(_:), prm_activeExposureSignals; state activeExposureSignals, device supportedExposureSignals.
• Lens lock (iOS 27): lockLens(_:), prm_lockPrimaryConstituent(to:), prm_isPrimaryConstituentLocked; state isPrimaryConstituentLocked, device supportsPrimaryConstituentLock.
• Focus and exposure rects of interest (iOS 26): setFocusAndExposure(focusMode:exposureMode:in:monitorSubjectAreaChange:), defaultFocusRect(for:), prm_setFocusAndExposure(focusMode:exposureMode:in:monitorSubjectAreaChange:), prm_defaultFocusRect(for:), prm_setExposurePointOfInterest(_:mode:); device supportsFocusRectOfInterest, supportsExposureRectOfInterest.
• Calibrated white balance presets (iOS 26): PRMWhiteBalancePreset.temperatureAndTint.
• Nominal focal lengths (iOS 26): PRMLens.FocalLengthSource / focalLengthSource, prm_nominalFocalLength35mm.
• Subject tracking (iOS 27): setContinuousAutoFocusTrackingEnabled(_:), setContinuousAutoFocusTrackingBias(_:), prm_setContinuousAutoFocusTracking(_:), prm_setContinuousAutoFocusTrackingBias(_:retargetingAt:) and the prm_isContinuousAutoFocusTracking… / prm_continuousAutoFocusTrackingBias properties; state for enabled, subject acquired and bias; device supportsContinuousAutoFocusTracking.
• Detected objects: PRMDetectedObject, PRMMetadataRouter (with lastFocusTrackedObject), detectedObjectsStream(), setMetadataObjectTypes(_:), PRMCameraConfiguration.includesMetadataOutput and metadataObjectTypes.
• Cinematic Video (iOS 26): setCinematicVideoEnabled(_:targetPhotoOutputAttached:), PRMCameraConfiguration.enableCinematicVideo, PRMCinematicFocusMode, PRMCinematicFocusRequest with setCinematicFocus(_:) / prm_setCinematicFocus(_:), setCinematicSimulatedAperture(_:), PRMSceneMonitoringStatus / prm_cinematicSceneStatuses, format prm_cinematicFrameRateRange and prm_simulatedApertureRange, and on iOS 27 PRMCinematicMetadataCapture with setCinematicMetadataCapture(_:). State isCinematicVideoCaptureEnabled, cinematicSimulatedAperture, cinematicSceneStatuses, isCinematicVideoMetadataCaptureEnabled; device supportsCinematicVideo, cinematicVideoDeviceType, cinematicZoomRange, simulatedApertureRange, cinematicFrameRateRange, and PRMCameraDevice.cinematicVideoDeviceType(at:). Which cameras run Cinematic Video depends on the iPhone (Apple documents the back Dual Wide and front TrueDepth cameras; an iPhone 18 Pro Max runs it on the back wide camera), never the Triple camera Pro iPhones open by default: enabling switches to a camera that supports it and disabling switches back, switchCamera(to:) lands on the new position's Cinematic camera while it's on, and enableCinematicVideo opens that camera at configure. Enabling it is refused while the 48MP format is wanted. Apps driving PRMCameraSession directly call reapplyCinematicVideoCaptureIfNeeded() after a camera switch (PRMCamera does it for you).
• Focus safety: PRMCamera.setFocusMode(_:) and PRMCameraSession.withVideoDevice(_:), which checks Cinematic Video and writes to the device in one step (AVFoundation raises on focus-mode changes while Cinematic Video is on). setFocusAndExposure(focusMode:exposureMode:at:monitorSubjectAreaChange:), its rect variant and prm_setFocusAndExposure take a nil exposure mode to focus without touching exposure, so a tap keeps a manual exposure.
• Session health: PRMDeferredStart / PRMCameraConfiguration.deferredStart (iOS 26), lensSmudgeDetectionInterval, setLensSmudgeDetection(interval:), PRMLensSmudgeStatus and prm_lensSmudgeStatus (iOS 26), PRMLowLightVideoNoiseReduction with setLowLightVideoNoiseReduction(_:) (iOS 27), enableBluetoothHighQualityRecording (iOS 26), PRMSystemPressure; state lensSmudgeStatus, isLowLightVideoNoiseReductionActive, systemPressure, interruptionReason; device supportsLensSmudgeDetection, supportsLowLightVideoNoiseReduction.
• Dynamic aspect ratio and Smart Framing (iOS 26): PRMAspectRatio, PRMVideoDimensions, PRMFraming, setDynamicAspectRatio(_:), supportedFramings(), setSmartFraming(enabledFramings:), framingRecommendationStream() (the current recommendation first, then changes), applyFraming(_:), prm_dynamicAspectRatio, prm_dynamicDimensions, prm_setDynamicAspectRatio(_:timeout:); state dynamicAspectRatio, dynamicDimensions; device supportedDynamicAspectRatios, supportsSmartFraming.
• AirPods Camera Control (iOS 26): PRMCaptureSound, PRMCaptureEventHelper.primarySound / secondarySound / usesCustomCaptureSounds.
• Capture orientation: PRMPhotoSettings.rotationAngle(_:) rotates the saved photo; pass PRMRotationCoordinator.currentCaptureRotationAngle so landscape shots save upright.
• Session controls: PRMCameraSession.setZoom(_:), rampZoom(to:rate:), setFrameRate(_:allowFormatChange:), resetFrameRate(), enableDepthFormat(), setHighResolutionPhotoFormat(_:) and setStabilization(_:), each checked and applied in one step; attachDepthDataOutput(delegate:queue:filteringEnabled:) / detachDepthDataOutput() for a live depth stream the session keeps across reconfigures; wantsRunning and restartAfterMediaServicesReset().
• Errors: PRMSessionError.captureFailed(_:) carries AVFoundation's AVError (so its code, such as -11872, survives), plus .exposureCombinationUnsupported and .unsupportedConfiguration(_:); PRMBurstInterruptedError.
• Device helpers: prm_withConfigurationLock(_:), prm_supportsCustomLensPosition, prm_supportsManualExposureCapture, prm_setLensPosition(_:completion:); the waiting variants of prm_setLensPosition, prm_setCustomExposure and prm_lockWhiteBalance take a timeout.
• PrismUI accessibility: VoiceOver labels and states on the settings drawer and rows (the drawer is modal while open and closes with the escape gesture), mode-aware shutter labels with press-and-hold offered as custom actions, a localized level reading, Dynamic Type in the drawer and rows, and opt-in hapticsEnabled on PRMShutterButton and PRMLevelIndicatorView. PrismUI's strings are localizable.
• Night mode: PRMNightModeOptions, PRMNightPlan, PRMNightProgress, PRMNightPhoto, PRMNightModeCapture.plan(_:) (the plan a capture would use, for an "AUTO 3s" label), and PRMCameraSession.isExclusiveCaptureActive.
• Portrait readiness: PRMPortraitReadiness and PRMPortraitReadinessMonitor, which tell whether a Portrait capture gets its depth effect right now (subject distance from a live depth stream, face and body detections, light) for a "NATURAL LIGHT" style indicator.
• Frame orientation: PRMRotationCoordinator.portraitFrameRotation(connectionAngle:) and frameRotation(uprightAngle:connectionAngle:) give the rotation a view still has to apply to video-data frames, with PRMCameraSession.videoDataRotationAngle and isVideoDataMirrored. A connection's default rotation isn't always 0: on the Center Stage front camera of iPhone 17 and later it is 270°, so drawing frames by the coordinator's angle alone leaves that preview sideways.
• Other: PRMCameraConfiguration.enableCameraSensorOrientationCompensation (iOS 26), PRMRotationCoordinator.videoRotationAngle(relativeTo:) (iOS 27), PRMCameraSession.defaultVideoDeviceType(at:), .lowLatency stabilization (iOS 26), and PRMCameraDevice.supportedExposureModes, supportedWhiteBalanceModes and supportedFocusModes (with AVCaptureDevice.prm_supportedExposureModes and friends, and each mode's prm_name) so a UI offers only the modes a camera runs: iPhone cameras have no one-shot auto white balance. PRMCameraDevice.supportsLowLightBoost and supportsVideoHDR (active format) gate those controls the same way. PRMCameraDevice.depthDeviceType(at:) names the camera that streams depth, for when the current one has no depth format (enableDepthFormat() returns false): an iPhone 14 Pro's Triple camera has none on iOS 18.
• Logging (PRMLog): six levels (debug to fault, PRMLogLevel) under the subsystem dev.luminoid.prism, categories Session, Capture, Filter, Preview and General. PRMLog.minimumLevel sets the threshold at runtime (default .info; errors and faults are always written); PRMLog.handler forwards every written PRMLogEntry. Message text is public; file paths and full error descriptions are private.
• Always-on log lines: a notice summary after configure, start, stop and every device switch; isRunning changes; interruptions with their reason; thermal state and system pressure changes; photo and recording outcomes, where a photo smaller than the size it asked for says why when that's known (manual exposure and locked white balance capture at 12 MP; 24 MP needs auto-deferred photo delivery); permission results. Every error sent to errorStream() is logged.
• Example app: iOS 26 / 27 drawer sections in Studio with telemetry badges and detection overlays, and the iOS 26 / 27 flags in Configuration Lab. Settings that can't run together follow one rule: the newest wins, turning the others off with a toast and a log line that say what changed and why; only what the camera can't do, or a recording would have to stop for, is refused.

Changed

• Breaking: building requires Xcode 27 (swift-tools-version: 6.4).
• Breaking: PRMLogger and PRMLogCategory are removed, replaced by PRMLog. PRMLogger.isVerboseTracingEnabled = true becomes PRMLog.minimumLevel = .debug. The subsystem changes from com.luminoid.Prism to dev.luminoid.prism, so update Console filters and log predicates.
• Breaking: PRMSessionError has three new cases (captureFailed, exposureCombinationUnsupported, unsupportedConfiguration), which break exhaustive switch statements. AVFoundation capture and recording errors now arrive as captureFailed instead of photoCaptureFailed / videoRecordingFailed strings.
• Breaking: PRMPhotoCapture.output and PRMVideoRecorder.output are optional: nil for a session-based wrapper before its first capture, instead of an empty placeholder output.
• Breaking: device setters throw when the device lacks the mode instead of returning silently: prm_setExposureMode, prm_setCustomExposure, prm_setWhiteBalanceMode, prm_lockWhiteBalance, prm_setTorch, prm_setFocusMode, prm_setLensPosition, and prm_setVideoHDR / prm_setLowLightBoost when turning the feature on. The matching PRMCamera setters report it on errorStream().
• Breaking: captureBurst throws PRMBurstInterruptedError (with the photos already captured) when a shot after the first fails.
• Switching cameras, changing the frame rate or format, entering a depth format, removing the movie output and reconfiguring are refused while recording, with PRMSessionError.unsupportedConfiguration.
• setHighResolutionPhotoFormat(true) is refused while a movie output is attached (the 48MP format would replace the video format), and turning it off then only drops the choice (allowed while recording). PRMCamera.setHighResolutionPhotoFormat(_:) returns whether it applied.
• Photo settings are checked against the photo output at capture time: quality prioritization above the output's maximum is lowered to it, and maxDimensions the active format doesn't offer falls back to the largest one that fits.
• Breaking: PRMNightModeCapture is rebuilt for brighter, cleaner Night photos. init(session:context:) and capture(_:progress:) returning PRMNightPhoto replace init(capture:context:) and capture(frameCount:perFrameDuration:iso:codec:didCaptureFrame:), and session replaces the capture and context properties. It picks the exposure from how dark the scene is, gathers frames from the live stream for 1 to 3 seconds (up to 10 when the phone is stable), aligns them, leaves out what moved, and brightens the result by up to 3 EV. It needs a physical camera: on a virtual multi-camera device it throws virtualDeviceManualControlUnsupported, so switch to .builtInWideAngleCamera first. During a capture, camera switches, format and frame-rate changes, zoom, focus, exposure and white-balance changes are refused.
• The live preview no longer gets the requested stabilization mode, which on video formats could delay it by up to a second (.auto picks cinematic stabilization there). The video data output runs unstabilized in photo modes and with iOS 26's low-latency stabilization while a movie output is attached; recordings keep the requested mode, and PRMCameraState.activeStabilizationMode reports the recording connection when there is one.
• The video data output's sampleBufferDelegate is Prism's frame router, which forwards every callback to the delegate passed to setVideoDataOutputDelegate(_:).
• A PRMPhotoSettings.manualExposureOverride on a camera that can't take a manual exposure (virtual multi-camera devices) captures at the camera's own exposure and leaves the EXIF alone.
• PRMAspectRatioMaskView.cropRect(in:) orients the ratio to the bounds: 4:3 in a portrait view is a 3:4 crop.
• PRMCameraSession.isRunning reflects the capture session itself, and the session restarts on its own after a media-services reset if the app wanted it running.
• The 48MP photo format choice and Live Photo's on/off state carry across camera switches.
• stateStream() emits only when the state changed and delivers the newest state to slow subscribers.
• lockWhiteBalance(preset:) locks to Apple's calibrated values on iOS 26 and later (every preset except .flash); PRMWhiteBalancePreset.temperature keeps the nominal Kelvin.
• PRMLens.focalLength35mm reports nominal focal lengths on iOS 26 and later; snapping() leaves nominal values unchanged.
• setFrameRate, resetFrameRate and enableDepthFormat refresh PRMCamera.device, since the active format (and with it most capability flags) can change.
• PRMPreviewView stops redrawing while frames aren't arriving and flushes its texture cache on memory warnings.
• PRMImage.jpegData(from:compressionQuality:context:) encodes in sRGB, like the metadata-preserving encoders (an extended-range color space from a capture made it return nil), and returns nil for an infinite extent.
• Deprecated: withConfigurationLock(_:) (use prm_withConfigurationLock(_:)), prm_setLensPositionAsync (use prm_setLensPosition(_:completion:)), PRMPhotoSettings.livePhoto (ignored; use captureLivePhoto), PRMPhotoSettings.makeAVSettings() (use makeAVSettings(for:)), PRMDepthCapture.addDepthDataOutput(to:delegate:queue:) (use PRMCameraSession.attachDepthDataOutput).

Fixed

• After AVFoundation stopped the session (a runtime error or media-services reset), start() did nothing and the preview stayed black.
• Switching cameras in video or slow-motion mode with Live Photo configured froze the preview for a full session rebuild and ended any recording.
• Manual-exposure stills crashed on iOS 27 when the camera was a virtual multi-camera device (Triple or Dual Camera).
• Captures could crash the app: a quality prioritization above the output's maximum, a manual exposure outside the active format's ISO or shutter range, and maxDimensions the output couldn't deliver.
• Starting a recording while the previous one was finalizing left the new one impossible to stop (start() now throws until the previous recording finishes), and cancel() left the recorder in .recording.
• A capture could hang when a deferred photo came back empty or a Live Photo's movie never arrived.
• captureBurst discarded every photo already captured when a later shot failed.
• setLensPosition never returned while the session was stopped or interrupted.
• Shutter speeds at the ends of the range could round outside it and crash; fractional frame rates such as 29.97 fps were truncated.
• Auto torch crashed on devices without it; manual exposure turned automatic video HDR back on after an explicit setVideoHDR(_:); enableDepthFormat() left geometric distortion correction off for good.
• Lens zoom labels on dual (wide + telephoto) cameras read the wide lens as 0.5×.
• Video stabilization was lost after a camera switch, and the video output's pixel format was forced back to BGRA after a format change.
• A refused manual exposure, white-balance lock, or exposure or white-balance mode change kept showing the requested values, and a tap-to-focus left manual ISO and shutter pinned.
• PRMPortraitBokehFilter's depth mode crashed, the blur filters darkened the frame edges, and filters that move the image rendered offset in the live chain.
• Replacing the active filter renderer could race the frame being rendered.
• PRMPreviewView.texturePoint(fromViewPoint:) and viewPoint(fromTexturePoint:) mirrored 90° and 270° rotations and ignored the fill crop and fit letterbox.
• PRMLevelIndicatorView hid the tilt with Reduce Motion on, and took over a shared motion manager's handler.
• A late subscriber to a stream with a current value could end up with a stale one.
• PRMVideoRecorder.start() could hang forever when recording failed (or was stopped) before it began.
• PRMVideoRecorder.stop() returned a PRMRecording with a duration of 0.
• setHighResolutionPhotoFormat(true) could pick the video-range (420v) twin of the 48MP format, which has fewer tonal steps than the full-range one.
• resetFrameRate() restored the photo preset without the 48MP format, so after a custom frame rate photos came back at 12MP while setHighResolutionPhotoFormat(true) was still in effect.
• Filtered frames from a camera format that carries color primaries but no color space were rendered in device RGB, which could shift colors; the color space is now built from the format's primaries and transfer function.
• HEIC photos from the filter pass and PRMImage.heifDataPreservingMetadata stored an alpha channel the photo didn't have, so files were larger and took twice the memory to decode.