// Copyright (c) 2021 homuler
//
// Use of this source code is governed by an MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT.

namespace Mediapipe.Unity
{
  public class MaskAnnotationController : AnnotationController<MaskAnnotation>
  {
    private int _maskWidth;
    private int _maskHeight;

    private ImageFrame _currentTarget;
    private float[] _maskArray;

    public void InitScreen(int maskWidth, int maskHeight)
    {
      _maskWidth = maskWidth;
      _maskHeight = maskHeight;
      _maskArray = new float[_maskWidth * _maskHeight];
      annotation.Init(_maskWidth, _maskHeight);
    }

    public void DrawNow(ImageFrame target)
    {
      _currentTarget = target;
      UpdateMaskArray(_currentTarget);
      SyncNow();
    }

    public void DrawLater(ImageFrame target)
    {
      UpdateCurrentTarget(target, ref _currentTarget);
      UpdateMaskArray(_currentTarget);
    }

    private void UpdateMaskArray(ImageFrame imageFrame)
    {
      if (imageFrame != null)
      {
        // NOTE: assume that the image is transformed properly by calculators.
        var _ = imageFrame.TryReadChannelNormalized(0, _maskArray);
      }
    }

    protected override void SyncNow()
    {
      isStale = false;
      annotation.Draw(_currentTarget == null ? null : _maskArray, _maskWidth, _maskHeight);
    }
  }
}