/// <summary>

        /// Generate seal bitmap

        /// </summary>

        /// <returns></returns>

        public Bitmap TextOnPathBitmap()

        {

            // Create bitmap and graphics

            Bitmap bit = new Bitmap( _rect.Width, _rect.Height );

            Graphics g = Graphics.FromImage( bit );

             // Compute string length in graphics

            float[] fCharWidth = new float[_text.Length];

            float fTotalWidth = ComputeStringLength( _text, g, fCharWidth, _letterspace, _chardirect );

             // Compute arc's start-angle and end-angle

            double fStartAngle, fSweepAngle;

            fSweepAngle = fTotalWidth * 360 / ( _rectcircle.Width * Math.PI );

            fStartAngle = 270 - fSweepAngle / 2;

             // Compute every character's position and angle

            PointF[] pntChars = new PointF[ _text.Length ];

            double[] fCharAngle = new double[ _text.Length ];

            ComputeCharPos( fCharWidth, pntChars, fCharAngle, fStartAngle );

             g.SmoothingMode = SmoothingMode.HighQuality;

            g.CompositingQuality = CompositingQuality.HighQuality;

            g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;

             DrawSealBase( g );

             // Draw every character

            for( int i = 0; i < _text.Length; i++ )

             DrawRotatedText( g, _text[i].ToString(), (float)(fCharAngle[i] + _degree), pntChars[i] );

             g.Dispose();

             // Return bitmap

            return bit;

        }

         /// <summary>

        /// Draw seal base

        /// </summary>

        /// <param name="g"></param>

        private void DrawSealBase( Graphics g )

        {

            // Draw background

            g.FillRectangle( Brushes.Black, _rect );

            g.FillEllipse( new SolidBrush( _fillcolor ),

                new Rectangle( 1,1, _rect.Width - 2, _rect.Height - 2 ) );

            g.FillEllipse( Brushes.White,

                new Rectangle( 4, 4, _rect.Width - 8, _rect.Height - 8 ) );

             // Draw start signal

            StringFormat sf = new StringFormat();

            string strStar = "★";

            Font fnt = new Font( _font.FontFamily, _font.Size * 3 );

            sf.Alignment = StringAlignment.Center;

            sf.LineAlignment = StringAlignment.Center;

            SizeF siz = g.MeasureString( strStar, fnt );

            g.DrawString( strStar, fnt, new SolidBrush( _fillcolor ),

                new RectangleF( _rect.Width / 2 - siz.Width / 2,

                _rect.Height / 2 - siz.Height/ 2,

                siz.Width, siz.Height ), sf );

             // Draw base string

            float[] fCharWidth = new float[_basestring.Length];

            float fTotalWidths = ComputeStringLength( _basestring, g, fCharWidth, 0,

                Char_Direction.Center );

            float fLeftPos = ( _rect.Width - fTotalWidths ) / 2;

            PointF pt;

            for( int i = 0; i < _basestring.Length; i++ )

            {

                pt = new PointF( fLeftPos + fCharWidth[i] / 2,

                    _rect.Height / 2 + siz.Height / 2 + 10 );

                DrawRotatedText( g, _basestring[i].ToString(), 0, pt );

                fLeftPos += fCharWidth[i];

            }

        }