/// <summary>
/// Called by `ViewController.OnFrameCaptured` once per frame with the buffer processed by the image-processing pipeline in
/// `VideoCaptureDelegate.DidOutputSampleBuffer`
/// </summary>
/// <param name="buffer">The captured video frame.</param>
public void OnFrameCaptured(CVPixelBuffer buffer)
{
// Run the tracker
var request = new VNTrackObjectRequest(trackedRectangle, ObjectTracked);
request.TrackingLevel = VNRequestTrackingLevel.Accurate;
NSError error;
var requests = new[] { request };
overlay.InvokeOnMainThread(() => overlay.Clear());
trackingHandler.Perform(requests, buffer, out error);
if (error != null)
{
InvokeOnMainThread(() => overlay.Message = error.ToString());
}
}
private void RectangleDetected(CGPoint[] normalizedQuadrilateral)
{
overlay.InvokeOnMainThread(() =>
{
// Note conversion from inverted coordinate system!
var rotatedQuadrilateral = normalizedQuadrilateral.Select(pt => new CGPoint(pt.X, 1.0 - pt.Y)).ToArray();
overlay.AddQuad(rotatedQuadrilateral);
});
}