/// <summary>
/// Views the did load.
/// </summary>
public override void ViewDidLoad()
{
base.ViewDidLoad();
// Hide no camera label
NoCamera.Hidden = ThisApp.CameraAvailable;
// Attach to camera view
ThisApp.Recorder.DisplayView = CameraView;
// Set min and max values
Offset.MinValue = ThisApp.CaptureDevice.MinExposureTargetBias;
Offset.MaxValue = ThisApp.CaptureDevice.MaxExposureTargetBias;
Duration.MinValue = 0.0f;
Duration.MaxValue = 1.0f;
ISO.MinValue = ThisApp.CaptureDevice.ActiveFormat.MinISO;
ISO.MaxValue = ThisApp.CaptureDevice.ActiveFormat.MaxISO;
Bias.MinValue = ThisApp.CaptureDevice.MinExposureTargetBias;
Bias.MaxValue = ThisApp.CaptureDevice.MaxExposureTargetBias;
// Create a timer to monitor and update the UI
SampleTimer = new Timer(5000);
SampleTimer.Elapsed += (sender, e) => {
// Update position slider
Offset.BeginInvokeOnMainThread(() => {
Offset.Value = ThisApp.Input.Device.ExposureTargetOffset;
});
Duration.BeginInvokeOnMainThread(() => {
var newDurationSeconds = CMTimeGetSeconds(ThisApp.Input.Device.ExposureDuration);
var minDurationSeconds = Math.Max(CMTimeGetSeconds(ThisApp.CaptureDevice.ActiveFormat.MinExposureDuration), ExposureMinimumDuration);
var maxDurationSeconds = CMTimeGetSeconds(ThisApp.CaptureDevice.ActiveFormat.MaxExposureDuration);
var p = (newDurationSeconds - minDurationSeconds) / (maxDurationSeconds - minDurationSeconds);
Duration.Value = (float)Math.Pow(p, 1.0f / ExposureDurationPower);
});
ISO.BeginInvokeOnMainThread(() => {
ISO.Value = ThisApp.Input.Device.ISO;
});
Bias.BeginInvokeOnMainThread(() => {
Bias.Value = ThisApp.Input.Device.ExposureTargetBias;
});
};
// Watch for value changes
Segments.ValueChanged += (object sender, EventArgs e) => {
// Lock device for change
if (ThisApp.CaptureDevice.LockForConfiguration(out Error))
{
// Take action based on the segment selected
switch (Segments.SelectedSegment)
{
case 0:
// Activate auto exposure and start monitoring position
Duration.Enabled = false;
ISO.Enabled = false;
ThisApp.CaptureDevice.ExposureMode = AVCaptureExposureMode.ContinuousAutoExposure;
SampleTimer.Start();
Automatic = true;
break;
case 1:
// Lock exposure and allow the user to control the camera
SampleTimer.Stop();
ThisApp.CaptureDevice.ExposureMode = AVCaptureExposureMode.Locked;
Automatic = false;
Duration.Enabled = false;
ISO.Enabled = false;
break;
case 2:
// Custom exposure and allow the user to control the camera
SampleTimer.Stop();
ThisApp.CaptureDevice.ExposureMode = AVCaptureExposureMode.Custom;
Automatic = false;
Duration.Enabled = true;
ISO.Enabled = true;
break;
}
// Unlock device
ThisApp.CaptureDevice.UnlockForConfiguration();
}
};
// Monitor position changes
Duration.ValueChanged += (object sender, EventArgs e) => {
// If we are in the automatic mode, ignore changes
if (Automatic)
{
return;
}
// Calculate value
var p = Math.Pow(Duration.Value, ExposureDurationPower);
var minDurationSeconds = Math.Max(CMTimeGetSeconds(ThisApp.CaptureDevice.ActiveFormat.MinExposureDuration), ExposureMinimumDuration);
var maxDurationSeconds = CMTimeGetSeconds(ThisApp.CaptureDevice.ActiveFormat.MaxExposureDuration);
var newDurationSeconds = p * (maxDurationSeconds - minDurationSeconds) + minDurationSeconds;
// Update Focus position
if (ThisApp.CaptureDevice.LockForConfiguration(out Error))
{
ThisApp.CaptureDevice.LockExposure(CMTime.FromSeconds(p, 1000 * 1000 * 1000), ThisApp.CaptureDevice.ISO, null);
ThisApp.CaptureDevice.UnlockForConfiguration();
}
};
ISO.ValueChanged += (object sender, EventArgs e) => {
// If we are in the automatic mode, ignore changes
if (Automatic)
{
return;
}
// Update Focus position
if (ThisApp.CaptureDevice.LockForConfiguration(out Error))
{
ThisApp.CaptureDevice.LockExposure(ThisApp.CaptureDevice.ExposureDuration, ISO.Value, null);
ThisApp.CaptureDevice.UnlockForConfiguration();
}
};
Bias.ValueChanged += (object sender, EventArgs e) => {
// If we are in the automatic mode, ignore changes
// if (Automatic) return;
// Update Focus position
if (ThisApp.CaptureDevice.LockForConfiguration(out Error))
{
ThisApp.CaptureDevice.SetExposureTargetBias(Bias.Value, null);
ThisApp.CaptureDevice.UnlockForConfiguration();
}
};
}
