public void RenderVariationMarker(Vector2f center, float diameter, bool active)
 {
     float radius = diameter / 2;
     Pen pen;
     if (active)
         pen = new Pen(RawColor.Blue, 2);
     else
         pen = new Pen(RawColor.Blue);
     Graphics.DrawCircle(pen, center, radius);
 }
 public abstract void DrawRectangle(Pen pen, RectangleF rect);
 public abstract void DrawPolygon(Pen pen, params Vector2f[] points);
 public abstract void DrawLine(Pen pen, Vector2f p1, Vector2f p2);
 public abstract void DrawCircle(Pen pen, Vector2f center, float radius);