/// <summary>
/// Renders the overlay (the drawing that designates selected rectangles, handles and so on) immediately in the current thread.
/// Attention: if there is no cached bitmap, a new bitmap is created, but this must be done in the Gui context, so this can lead to deadlocks.
/// </summary>
private static ImageSource GetImageSourceByRenderingOverlay(GraphController controller, GdiToWpfBitmap bmp, CachedGraphImage cachedGraphImage)
{
if (controller.IsOverlayPaintingRequired)
{
using (var grfx = GetGraphicsContextFromWpfGdiBitmap(bmp))
{
controller.DoPaintOverlay(grfx, cachedGraphImage.ZoomFactor, cachedGraphImage.ViewPortsUpperLeftCornerInGraphCoordinates);
return(bmp.WpfBitmapSource);
}
}
else
{
return(null);
}
}
