internal void Zoom(float factor)
{
var size = ClientSize;
PointT center = ToShapeSpace(new PointT(size.Width / 2, size.Height / 2));
_scrollZoom.Translate(center.X, center.Y);
_scrollZoom.Scale(factor, factor);
_scrollZoom.Translate(-center.X, -center.Y);
MatrixChanged();
}
void MatrixChanged()