I want to draw a vertical text on the Chart. Here is the code of the INPaintCallback implementation:

public void OnAfterPaint(NPanel panel, NPanelPaintEventArgs eventArgs)
{

string label = "test";
var yStyle = new NTextStyle(new Font("Arial", 12), Color.Red);
yStyle.Orientation = 90;
eventArgs.Graphics.PaintText(label, yStyle, new NPointF(100,100));
}


But text rendered horizontal. How can I rotate it?