ElevationProfile.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using ZedGraph;
using GMap.NET;
using System.Xml;
using MissionPlanner.Utilities; // GE xml alt reader

namespace MissionPlanner
{
    public partial class ElevationProfile : Form
    {
        List<PointLatLngAlt> gelocs = new List<PointLatLngAlt>();
        List<PointLatLngAlt> srtmlocs = new List<PointLatLngAlt>();
        List<PointLatLngAlt> planlocs = new List<PointLatLngAlt>();
        PointPairList list1 = new PointPairList();
        PointPairList list2 = new PointPairList();
        PointPairList list3 = new PointPairList();

        PointPairList list4terrain = new PointPairList();
        int distance = 0;
        double homealt = 0;
        GCSViews.FlightPlanner.altmode altmode = GCSViews.FlightPlanner.altmode.Relative;

        public ElevationProfile(List<PointLatLngAlt> locs, double homealt, GCSViews.FlightPlanner.altmode altmode)
        {
            InitializeComponent();

            this.altmode = altmode;

            planlocs = locs;

            for (int a = 0; a < planlocs.Count; a++)
            {
                if (planlocs[a] == null || planlocs[a].Tag != null && planlocs[a].Tag.Contains("ROI"))
                {
                    planlocs.RemoveAt(a);
                    a--;
                }
            }

            if (planlocs.Count <= 1)
            {
                CustomMessageBox.Show("Please plan something first", Strings.ERROR);
                return;
            }

            // get total distance
            distance = 0;
            PointLatLngAlt lastloc = null;
            foreach (PointLatLngAlt loc in planlocs)
            {
                if (loc == null)
                    continue;

                if (lastloc != null)
                {
                    distance += (int) loc.GetDistance(lastloc);
                }
                lastloc = loc;
            }

            this.homealt = homealt/CurrentState.multiplierdist;

            Form frm = Common.LoadingBox("Loading", "using srtm data"); //Downloading Google Earth Data

            gelocs = getGEAltPath(planlocs);

            srtmlocs = getSRTMAltPath(planlocs);

            frm.Close();

            MissionPlanner.Utilities.Tracking.AddPage(this.GetType().ToString(), this.Text);
        }

        private void ElevationProfile_Load(object sender, EventArgs e)
        {
            if (planlocs.Count <= 1)
            {
                this.Close();
                return;
            }
            // GE plot
            double a = 0;
            double increment = (distance/(float)(gelocs.Count - 1));

            foreach (PointLatLngAlt geloc in gelocs)
            {
                if (geloc == null)
                    continue;

                list2.Add(a, geloc.Alt);

                Console.WriteLine("GE " + geloc.Lng + "," + geloc.Lat + "," + geloc.Alt);

                a += increment;
            }

            // Planner Plot
            a = 0;
            int count = 0;
            PointLatLngAlt lastloc = null;
            foreach (PointLatLngAlt planloc in planlocs)
            {
                if (planloc == null)
                    continue;

                if (lastloc != null)
                {
                    a += planloc.GetDistance(lastloc);
                }

                // deal with at mode
                if (altmode == GCSViews.FlightPlanner.altmode.Terrain)
                {
                    list1 = list4terrain;
                    break;
                }
                else if (altmode == GCSViews.FlightPlanner.altmode.Relative)
                {
                    // already includes the home alt
                    list1.Add(a, (planloc.Alt/CurrentState.multiplierdist), 0, planloc.Tag);
                }
                else
                {
                    // abs
                    // already absolute
                    list1.Add(a, (planloc.Alt/CurrentState.multiplierdist), 0, planloc.Tag);
                }

                lastloc = planloc;
                count++;
            }
            // draw graph
            CreateChart(zg1);
        }

        List<PointLatLngAlt> getSRTMAltPath(List<PointLatLngAlt> list)
        {
            List<PointLatLngAlt> answer = new List<PointLatLngAlt>();

            PointLatLngAlt last = null;

            double disttotal = 0;

            foreach (PointLatLngAlt loc in list)
            {
                if (loc == null)
                    continue;

                if (last == null)
                {
                    last = loc;
                    continue;
                }

                double dist = last.GetDistance(loc);

                int points = (int) (dist/10) + 1;

                double deltalat = (last.Lat - loc.Lat);
                double deltalng = (last.Lng - loc.Lng);

                double steplat = deltalat/points;
                double steplng = deltalng/points;

                PointLatLngAlt lastpnt = last;

                for (int a = 0; a <= points; a++)
                {
                    double lat = last.Lat - steplat*a;
                    double lng = last.Lng - steplng*a;

                    var newpoint = new PointLatLngAlt(lat, lng, srtm.getAltitude(lat, lng).alt, "");

                    double subdist = lastpnt.GetDistance(newpoint);

                    disttotal += subdist;

                    // srtm alts
                    list3.Add(disttotal, newpoint.Alt/CurrentState.multiplierdist);

                    // terrain alt
                    list4terrain.Add(disttotal, (newpoint.Alt - homealt + loc.Alt)/CurrentState.multiplierdist);

                    lastpnt = newpoint;
                }

                answer.Add(new PointLatLngAlt(loc.Lat, loc.Lng, srtm.getAltitude(loc.Lat, loc.Lng).alt, ""));

                last = loc;
            }

            return answer;
        }

        List<PointLatLngAlt> getGEAltPath(List<PointLatLngAlt> list)
        {
            double alt = 0;
            double lat = 0;
            double lng = 0;

            int pos = 0;

            List<PointLatLngAlt> answer = new List<PointLatLngAlt>();

            //http://code.google.com/apis/maps/documentation/elevation/
            //http://maps.google.com/maps/api/elevation/xml
            string coords = "";

            foreach (PointLatLngAlt loc in list)
            {
                if (loc == null)
                    continue;

                coords = coords + loc.Lat.ToString(new System.Globalization.CultureInfo("en-US")) + "," +
                         loc.Lng.ToString(new System.Globalization.CultureInfo("en-US")) + "|";
            }
            coords = coords.Remove(coords.Length - 1);

            if (list.Count < 2 || coords.Length > (2048 - 256))
            {
                CustomMessageBox.Show("Too many/few WP's or to Big a Distance " + (distance/1000) + "km", Strings.ERROR);
                return answer;
            }

            try
            {
                using (
                    XmlTextReader xmlreader =
                        new XmlTextReader("http://maps.google.com/maps/api/elevation/xml?path=" + coords + "&samples=" +
                                          (distance/100).ToString(new System.Globalization.CultureInfo("en-US")) +
                                          "&sensor=false"))
                {
                    while (xmlreader.Read())
                    {
                        xmlreader.MoveToElement();
                        switch (xmlreader.Name)
                        {
                            case "elevation":
                                alt = double.Parse(xmlreader.ReadString(), new System.Globalization.CultureInfo("en-US"));
                                Console.WriteLine("DO it " + lat + " " + lng + " " + alt);
                                PointLatLngAlt loc = new PointLatLngAlt(lat, lng, alt, "");
                                answer.Add(loc);
                                pos++;
                                break;
                            case "lat":
                                lat = double.Parse(xmlreader.ReadString(), new System.Globalization.CultureInfo("en-US"));
                                break;
                            case "lng":
                                lng = double.Parse(xmlreader.ReadString(), new System.Globalization.CultureInfo("en-US"));
                                break;
                            default:
                                break;
                        }
                    }
                }
            }
            catch
            {
                CustomMessageBox.Show("Error getting GE data", Strings.ERROR);
            }

            return answer;
        }

        public void CreateChart(ZedGraphControl zgc)
        {
            GraphPane myPane = zgc.GraphPane;

            // Set the titles and axis labels
            myPane.Title.Text = "Elevation above ground";
            myPane.XAxis.Title.Text = "Distance (m)";
            myPane.YAxis.Title.Text = "Elevation (m)";

            LineItem myCurve;

            myCurve = myPane.AddCurve("Planner", list1, Color.Red, SymbolType.None);
            myCurve = myPane.AddCurve("GE", list2, Color.Green, SymbolType.None);
            myCurve = myPane.AddCurve("SRTM", list3, Color.Blue, SymbolType.None);

            foreach (PointPair pp in list1)
            {
                // Add a another text item to to point out a graph feature
                TextObj text = new TextObj((string) pp.Tag, pp.X, pp.Y);
                // rotate the text 90 degrees
                text.FontSpec.Angle = 90;
                text.FontSpec.FontColor = Color.White;
                // Align the text such that the Right-Center is at (700, 50) in user scale coordinates
                text.Location.AlignH = AlignH.Right;
                text.Location.AlignV = AlignV.Center;
                // Disable the border and background fill options for the text
                text.FontSpec.Fill.IsVisible = false;
                text.FontSpec.Border.IsVisible = false;
                myPane.GraphObjList.Add(text);
            }

            // Show the x axis grid
            myPane.XAxis.MajorGrid.IsVisible = true;

            myPane.XAxis.Scale.Min = 0;
            myPane.XAxis.Scale.Max = distance;

            // Make the Y axis scale red
            myPane.YAxis.Scale.FontSpec.FontColor = Color.Red;
            myPane.YAxis.Title.FontSpec.FontColor = Color.Red;
            // turn off the opposite tics so the Y tics don't show up on the Y2 axis
            myPane.YAxis.MajorTic.IsOpposite = false;
            myPane.YAxis.MinorTic.IsOpposite = false;
            // Don't display the Y zero line
            myPane.YAxis.MajorGrid.IsZeroLine = true;
            // Align the Y axis labels so they are flush to the axis
            myPane.YAxis.Scale.Align = AlignP.Inside;
            // Manually set the axis range
            //myPane.YAxis.Scale.Min = -1;
            //myPane.YAxis.Scale.Max = 1;

            // Fill the axis background with a gradient
            //myPane.Chart.Fill = new Fill(Color.White, Color.LightGray, 45.0f);

            // Calculate the Axis Scale Ranges
            try
            {
                zg1.AxisChange();
            }
            catch
            {
            }
        }
    }
}