C# Identicons

using System;
using System.Drawing;
using System.Security.Cryptography;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public sealed class Identicon : Control
    {
        public enum HashAlgorithms
        {
            MD5,
            SHA1,
            SHA256,
            SHA384,
            SHA512,
            RIPEMD160
        }

        private string Identity = string.Empty;
        private HashAlgorithms HashType = HashAlgorithms.SHA256;
        private Double Margin = .08;

        public Identicon()
        {
            if (string.IsNullOrEmpty(this.Identity))
            {
                this.Identity = Guid.NewGuid().ToString();
            }
        }

                protected override void OnPaint(PaintEventArgs e)
        {
            var hash = this.HashString(this.Identity, this.HashType);
            var size = (this.Size.Width < this.Size.Height) ? this.Size.Width : this.Size.Height;
            var margin = Math.Floor(size*this.Margin);
            var cell = Math.Floor((size - (margin * 2)) / 5);

            var b = new Bitmap(this.Size.Width, this.Size.Height);
            var g = Graphics.FromImage(b);

            var hsl = new HSLColor(
                (Convert.ToInt32(hash.Substring(hash.Length - 7), 16) / 0xfffffff),
                .5,
                .7);

            var rgb = (Color)hsl;

            var bg = this.BackColor;
            var fg = rgb;

            for (var i = 0; i < 15; i++)
            {
                var color = (Convert.ToInt32(hash[i].ToString(), 16) % 2) == 1 ? bg : fg;

                if (i < 5)
                {
                    Rectangle(2 * cell + margin, i * cell + margin, cell, cell, new SolidBrush(color), g);
                }
                if (i < 10)
                {
                    this.Rectangle(1 * cell + margin, (i - 5) * cell + margin, cell, cell, new SolidBrush(color), g);
                    this.Rectangle(3 * cell + margin, (i - 5) * cell + margin, cell, cell, new SolidBrush(color), g);
                }
                if (i < 15)
                {
                    this.Rectangle(0 * cell + margin, (i - 10) * cell + margin, cell, cell, new SolidBrush(color), g);
                    this.Rectangle(4 * cell + margin, (i - 10) * cell + margin, cell, cell, new SolidBrush(color), g);
                }
            }

            e.Graphics.DrawImage(b, new Point(0, 0));

            base.OnPaint(e);
        }

        private void Rectangle(double x, double y, double w, double h, SolidBrush color, Graphics g)
        {
            g.FillRectangle(color, new RectangleF((float)x, (float)y + ((this.Size.Width < this.Size.Height) ? this.Size.Width : this.Size.Height * 9 / 100), (float)w, (float)h));
        }

        private string HashString(string str, HashAlgorithms Algorithm)
        {
            var hasher = HashAlgorithm.Create(Algorithm.ToString());
            var strBytes = Encoding.UTF8.GetBytes(str);

            var hashed = hasher.ComputeHash(strBytes);
            var sb = new StringBuilder();

            for (var i = 0; i < hashed.Length; i++)
            {
                sb.Append(hashed[i].ToString("x2"));
            }

            return sb.ToString();
        }

    }

}