A GPS tracer application for Windows Mobile CE 5

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Drawing.Text;
using System.Drawing;
using System.IO;



namespace GpsTracer
{

    class Mapper
    {

        private List<Point> m_points;
        private Point m_center;

        int m_drawded = 1;
        private Graphics m_g;
        private Rectangle m_clip;

        static private Pen m_bgPen = new Pen(Color.LightBlue);
        static private Pen m_gridPen = new Pen(Color.LightGray);
        static private Brush m_bgBrush = new SolidBrush(m_bgPen.Color);
        static private Pen m_linePen = new Pen(Color.MediumBlue);
        static private Pen m_pointPen = new Pen(Color.Blue);
        static private Pen m_lastPointPen = new Pen(Color.Red);
        static private Font m_font = new Font("Tahoma", 8, FontStyle.Regular);
        static private Brush m_fontBrush = new SolidBrush(Color.Blue);
        
        public Mapper(Graphics g, int x, int y, int width, int height)
        {
            m_points = new List<Point>();
            m_center = new Point(x + width / 2, y + height / 2);
            m_g = g;
            m_clip = new Rectangle(x, y, width, height);
            m_g.Clip = new Region(m_clip);
            clearAndDraw();
        }


        public void parseAndDraw(string s)
        {
            string[] Words = s.Split(',');

            m_g.FillRectangle(m_bgBrush, new Rectangle(m_clip.X, m_clip.Y + 5, m_clip.Width, 15));
            m_g.DrawString(s, m_font,m_fontBrush, new RectangleF(m_clip.X , m_clip.Y + 5, m_clip.Width, 15));

            switch (Words[0])
            {
                case "$GPRMC":// $GPRMC,170111,A,4338.5810,N,07015.1010,W,000.0,360.0,060199,017.5,W*73
                    // RMC - Recommended minimum specific GPS/Transit data

                    if (Words[3].Length > 0 && Words[5].Length > 0)
                    {
                        drawLatLong(Words[3], Words[5]);
                    }
                    break;
                case "$GPGSV":// $GPGSV,2,1,08,03,17,171,42,06,21,047,44,14,28,251,45,16,25,292,44*71
                    // GSV - Satellites in view
                    break;
                case "$GPGSA":// $GPGGA,170111,4338.581,N,07015.101,W,1,00,2.0,1.1,M,-31.8,M,,*71
                    //GSA - GPS dilution of precision and active satellites
                    break;
                default:
                    break;
            }
        }

        public void drawLatLong(string latitude, string longitude)
        {

            Point aPoint = new Point();

            aPoint.X = (Convert.ToInt32(latitude.Substring(latitude.Length - 4, 4)));
            aPoint.Y = (Convert.ToInt32(longitude.Substring(longitude.Length - 4, 4)));

            aPoint.X += (Convert.ToInt32(latitude.Substring(latitude.Length - 7, 2))) * 60;
            aPoint.Y += (Convert.ToInt32(longitude.Substring(longitude.Length - 7, 2))) * 60;

            aPoint.X += (Convert.ToInt32(latitude.Substring(latitude.Length - 9, 2))) * 3600;
            aPoint.Y += (Convert.ToInt32(longitude.Substring(longitude.Length - 9, 2))) * 3600;

            m_points.Add(aPoint);
            draw();
        }

        public void draw()
        {
            float xTo = 0;
            float xFrom = 0;
            float yTo = 0;
            float yFrom = 0;
                       

            for (int i = m_drawded; i < m_points.Count; i++)
            {
                xTo = (m_points[i].X - m_points[0].X) / m_scale + m_center.X;
                xFrom = (m_points[i - 1].X - m_points[0].X) / m_scale + m_center.X;
                yTo = (m_points[i].Y - m_points[0].Y) / m_scale + m_center.Y;
                yFrom = (m_points[i - 1].Y - m_points[0].Y) / m_scale + m_center.Y;
                m_g.DrawLine(m_linePen, (int)xTo, (int)yTo, (int)xFrom, (int)yFrom);
                m_g.DrawEllipse(m_pointPen, new Rectangle((int)xFrom - 2, (int)yFrom - 2, 4, 4));
            }
            m_g.DrawEllipse(m_lastPointPen, new Rectangle((int)xTo - 2, (int)yTo - 2, 4, 4));
            m_drawded++;
        }

        private float m_scale = 10;

        public float Scale
        {
            get { return m_scale; }
            set { m_scale = value; }
        }

        public void clearAndDraw()
        {
            m_g.FillRectangle(m_bgBrush, m_clip);
            m_drawded = 1;
            draw();
        }


        public void moveCenter(int x, int y)
        {
            m_center.X -= x;
            m_center.Y -= y;
        }

        public void centerInTheMiddle()
        {
            int n =m_points.Count;
            m_center.X = (int)((m_points[n - 1].X - m_points[0].X) / m_scale);
            m_center.Y = (int)((m_points[n - 1].Y -m_points[0].Y) / m_scale);
                        
            clearAndDraw();
        }

        public void loatPath(String filename)
        {
            StreamReader sr = new StreamReader(filename);

            m_points.Clear();
            int n = 0;
            Point p = new Point();
            while (!sr.EndOfStream)
            {

                String readed = sr.ReadLine();
                p.X = Convert.ToInt32(readed);
                readed = sr.ReadLine();
                p.Y = Convert.ToInt32(readed);
                m_points.Add(p);
                n++;
            }
            m_drawded = 1;
            sr.Close();
            clearAndDraw();
        }

        public void savePath(String filename)
        {
            StreamWriter sw = new StreamWriter(filename);

            foreach (Point p in m_points)
            {
                sw.WriteLine(Convert.ToString(p.X));
                sw.WriteLine(Convert.ToString(p.Y));
            }

            sw.Flush();
            sw.Close();
        }
    }
}