void SaveFrame(int framerate)
{
float rateTime = 1.0f / framerate;
if (_frameTime + rateTime < Time.TotalUnscaledf)
{
_frameTime = Time.TotalUnscaledf;
_frameSurface.GetColors(ref buffer);
Directory.CreateDirectory(folder);
Stream writer = new FileStream($"{folder}/image{_frameIndex:D4}.bmp", FileMode.Create);
WriteBitmap(writer, _frameSurface.Width, _frameSurface.Height, buffer);
writer.Close();
_frameIndex += 1;
}
}