/// <summary>
/// Draw centred text
/// </summary>
/// <param name="context">The graphics context to draw on</param>
/// <param name="text">The text to draw</param>
/// <param name="point">The point to centre the text around</param>
protected void DrawCentredText(IDrawContext context, string text, Point point)
{
var extents = context.GetTextExtents(text);
double x = point.X - (extents.Width / 2 + extents.X);
double y = point.Y - (extents.Height / 2 + extents.Y);
context.MoveTo(x, y);
context.ShowText(text);
}