AGE, Another Graphic Engine in .NET

/////////////////////////////////////////////////////////////////////////////////
// MyNeoReport Designer
// --------------------
// Project Copyright (C)    : Fabio Zanetta, email: support@neodatatype.net
// Portions Copyright (C)   : Microsoft Corporation. All Rights Reserved.
// License                  : docs/license.txt
// ------------------------------------------------------------------------------
// File created by          : Fabio Zanetta, email: support@neodatatype.net
// ------------------------------------------------------------------------------
// Please, if you modify some parts of this file mark them as described in
// docs/modify_guidelines.txt
/////////////////////////////////////////////////////////////////////////////////
using System;
using System.Drawing;

namespace NeoDataType.Graphic.Christmas
{
    class StarPainter : Painter
    {
        Point[] _points;

        protected override void OnItemBoundsChanged()
        {
            base.OnItemBoundsChanged();

            Star star = (Star)Item;
            int nPoints = star.SidesCount * 2;

            _points = new Point[nPoints];

            Rectangle bounds = Item.Bounds;

            Point center = new Point(bounds.X + (bounds.Width / 2),
                                     bounds.Y + (bounds.Height / 2));


            Point radius1 = new Point(bounds.Width / 2,
                                      bounds.Height / 2);

            Point radius2 = new Point(bounds.Width / 4,
                                      bounds.Height / 4);

            for (int i = 0; i < nPoints; i++)
            {
                Point radius;
                double d;

                if ((i & 1) != 0)
                    radius = radius2;
                else
                    radius = radius1;
                d = 0;

                _points[i] = GetPointOnCircle(center, radius, Convert.ToInt32((i + d) * (360 / nPoints)));


            }

        }

        private Point GetPointOnCircle(Point center, Point radius, int angle)
        {
            const double pi = Math.PI;
            double r = pi / 180.0;
            Point pt = new Point(Convert.ToInt32(center.X - (Math.Sin(-angle * r) * radius.X)),
                                 Convert.ToInt32(center.Y - (Math.Sin((90 + angle) * r) * radius.Y)));
            return pt;
        }

        protected override void Paint(Graphics g)
        {

            Star star = (Star)Item;
            Pen pen = new Pen(star.ForeColor, (int)((Item.Width + Item.Height) * 0.02));
            SolidBrush brush = new SolidBrush(star.FillColor);


            g.FillPolygon(brush, _points);
            g.DrawPolygon(pen, _points);

            pen.Dispose();
            brush.Dispose();
        }

    }

}