react-native-vision-camera/package/ios/CameraView+Focus.swift
2023-10-06 14:30:12 +02:00

94 lines
2.8 KiB
Swift

//
// CameraView+Focus.swift
// mrousavy
//
// Created by Marc Rousavy on 19.02.21.
// Copyright © 2021 mrousavy. All rights reserved.
//
import Foundation
extension CameraView {
private func convertPreviewCoordinatesToCameraCoordinates(_ point: CGPoint) -> CGPoint {
return previewView.captureDevicePointConverted(fromLayerPoint: point)
}
func focus(point: CGPoint, promise: Promise) {
withPromise(promise) {
guard let device = self.videoDeviceInput?.device else {
throw CameraError.session(SessionError.cameraNotReady)
}
if !device.isFocusPointOfInterestSupported {
throw CameraError.device(DeviceError.focusNotSupported)
}
// in {0..1} system
let normalizedPoint = convertPreviewCoordinatesToCameraCoordinates(point)
do {
try device.lockForConfiguration()
defer {
device.unlockForConfiguration()
}
// Set Focus
if device.isFocusPointOfInterestSupported {
device.focusPointOfInterest = normalizedPoint
device.focusMode = .autoFocus
}
// Set Exposure
if device.isExposurePointOfInterestSupported {
device.exposurePointOfInterest = normalizedPoint
device.exposureMode = .autoExpose
}
// Remove any existing listeners
NotificationCenter.default.removeObserver(self,
name: NSNotification.Name.AVCaptureDeviceSubjectAreaDidChange,
object: nil)
// Listen for focus completion
device.isSubjectAreaChangeMonitoringEnabled = true
NotificationCenter.default.addObserver(self,
selector: #selector(subjectAreaDidChange),
name: NSNotification.Name.AVCaptureDeviceSubjectAreaDidChange,
object: nil)
return nil
} catch {
throw CameraError.device(DeviceError.configureError)
}
}
}
@objc
func subjectAreaDidChange(notification _: NSNotification) {
guard let device = videoDeviceInput?.device else {
invokeOnError(.session(.cameraNotReady))
return
}
do {
try device.lockForConfiguration()
defer {
device.unlockForConfiguration()
}
// Reset Focus to continuous/auto
if device.isFocusPointOfInterestSupported {
device.focusMode = .continuousAutoFocus
}
// Reset Exposure to continuous/auto
if device.isExposurePointOfInterestSupported {
device.exposureMode = .continuousAutoExposure
}
// Disable listeners
device.isSubjectAreaChangeMonitoringEnabled = false
} catch {
invokeOnError(.device(.configureError))
}
}
}