private void OnPairedPreviewCanvasInvalidated(object sender, SKPaintSurfaceEventArgs e)
{
var canvas = e.Surface.Canvas;
canvas.Clear();
if (_viewModel.PreviewFrame != null)
{
var bitmap = _viewModel.DecodeBitmapAndCorrectOrientation(_viewModel.PreviewFrame, true);
if (bitmap != null)
{
float secondaryRatio;
if (bitmap.Width < bitmap.Height) //portrait
{
secondaryRatio = bitmap.Height / (1f * bitmap.Width);
}
else //landscape
{
secondaryRatio = bitmap.Width / (1f * bitmap.Height);
}
// when portrait, the wider side sets the height for both
// when landscape, fill width
double height;
double width;
if (bitmap.Height > bitmap.Width) // portrait
{
height = canvas.DeviceClipBounds.Width * _viewModel.PreviewAspectRatio;
width = height / secondaryRatio;
}
else //landscape
{
width = canvas.DeviceClipBounds.Width;
height = width / secondaryRatio;
}
var zoomDirection = _viewModel.Settings.FovPrimaryCorrection > _viewModel.Settings.FovSecondaryCorrection; // true means zoom out on secondary, false means zoom in
var zoomAmount = zoomDirection
? 1 / (1 + _viewModel.Settings.FovPrimaryCorrection)
: 1 + _viewModel.Settings.FovSecondaryCorrection;
var zoomedWidth = width * zoomAmount;
var zoomedHeight = height * zoomAmount;
var newX = (canvas.DeviceClipBounds.Width - zoomedWidth) / 2;
var newY = (canvas.DeviceClipBounds.Height - zoomedHeight) / 2f;
canvas.DrawBitmap(bitmap,
new SKRect(0, 0, bitmap.Width, bitmap.Height),
new SKRect(
(float)newX,
(float)newY,
(float)(newX + zoomedWidth),
(float)(newY + zoomedHeight)));
}
}
_viewModel.BluetoothOperatorBindable.RequestPreviewFrame();
}
