using System;

using System.Collections.Generic;

using System.Drawing;

using System.Web;

using System.Web.UI;

using SharpMap;

using GeoAPI.CoordinateSystems;

using GeoAPI.CoordinateSystems.Transformations;

using SharpMap.Data.Providers;

using GeoAPI.Geometries;

using SharpMap.Layers;

using SharpMap.Web;

using Point=GeoAPI.Geometries.Coordinate;

using ProjNet.CoordinateSystems;

using ProjNet.CoordinateSystems.Transformations;

public partial class Transformation : Page

{

private ICoordinateSystem datacoordsys;

private Map myMap;

protected void Page_Load(object sender, EventArgs e)

{

//Set up the map. We use the method in the App_Code folder for initializing the map

myMap = InitializeMap(new Size((int) imgMap.Width.Value, (int) imgMap.Height.Value));

if (Page.IsPostBack)

{

//Page is post back. Restore center and zoom-values from viewstate

myMap.Center = (Point) ViewState["mapCenter"];

myMap.Zoom = (double) ViewState["mapZoom"];

}

else

{

//This is the initial view of the map. Zoom to the extents of the map:

myMap.Zoom = 80;

myMap.Center = new Point(-95, 37);

//Create the map

GenerateMap();

}

}

protected void imgMap_Click(object sender, ImageClickEventArgs e)

{

//Set center of the map to where the client clicked

myMap.Center = myMap.ImageToWorld(new System.Drawing.Point(e.X, e.Y));

//Set zoom value if any of the zoom tools were selected

if (rblMapTools.SelectedValue == "0") //Zoom in

myMap.Zoom = myMap.Zoom*0.5;

else if (rblMapTools.SelectedValue == "1") //Zoom out

myMap.Zoom = myMap.Zoom*2;

//Create the map

GenerateMap();

}

/// <summary>

/// Creates the map, inserts it into the cache and sets the ImageButton Url

/// </summary>

private void GenerateMap()

{

//Save the current mapcenter and zoom in the viewstate

ViewState.Add("mapCenter", myMap.Center);

ViewState.Add("mapZoom", myMap.Zoom);

ViewState.Add("currentProj", ddlProjection.SelectedValue);

//Render the map

Image img = myMap.GetMap();

string imgID = Caching.InsertIntoCache(1, img);

imgMap.ImageUrl = "getmap.aspx?ID=" + HttpUtility.UrlEncode(imgID);

litEnvelope.Text = myMap.Envelope.MinX.ToString("#.##") + "," + myMap.Envelope.MinY.ToString("#.##") + " -> " +

myMap.Envelope.MaxX.ToString("#.##") + "," + myMap.Envelope.MaxY.ToString("#.##") +

" (Projected coordinate system)";

}

protected void ddlProjection_SelectedIndexChanged(object sender, EventArgs e)

{

//Transform current view to new coordinate system and zoom to the transformed box

string PreviousProj = ViewState["currentProj"].ToString();

string SelectedProj = ddlProjection.SelectedValue;

//Points defining the current view

Point left = new Point(myMap.Envelope.MinX, myMap.Center.Y);

Point right = new Point(myMap.Envelope.MaxX, myMap.Center.Y);

Point center = myMap.Center;

if (PreviousProj != "Pseudo")

{

//Transform current view back to geographic coordinates

ICoordinateTransformation trans = GetTransform(PreviousProj);

left = GeometryTransform.TransformCoordinate(new Point(myMap.Envelope.MinX, myMap.Center.Y),

trans.MathTransform.Inverse());

right = GeometryTransform.TransformCoordinate(new Point(myMap.Envelope.MaxX, myMap.Center.Y),

trans.MathTransform.Inverse());

center = GeometryTransform.TransformCoordinate(myMap.Center, trans.MathTransform.Inverse());

}

//If both PreviousSRID and SelectedSRID are projected coordsys, first transform to geographic

if (SelectedProj == "Pseudo")

{

myMap.Center = center;

myMap.Zoom = Math.Abs(right.X - left.X);

}

else //Project coordinates to new projection

{

//Transform back to geographic and over to new projection

ICoordinateTransformation trans = GetTransform(SelectedProj);

left = GeometryTransform.TransformCoordinate(left, trans.MathTransform);

right = GeometryTransform.TransformCoordinate(right, trans.MathTransform);

center = GeometryTransform.TransformCoordinate(center, trans.MathTransform);

myMap.Center = center;

myMap.Zoom = Math.Abs(right.X - left.X);

var envelopeGcs = GeometryTransform.TransformBox(myMap.Envelope, trans.MathTransform.Inverse());

litEnvelopeLatLong.Text = envelopeGcs.ToString();

}

GenerateMap();

}

public Map InitializeMap(Size size)

{

HttpContext.Current.Trace.Write("Initializing map...");

//Initialize a new map of size 'imagesize'

Map map = new Map(size);

//Set up the countries layer

VectorLayer layCountries = new VectorLayer("Countries");

//Set the datasource to a shapefile in the App_data folder

ShapeFile datasource = new ShapeFile(HttpContext.Current.Server.MapPath(@"~\App_data\USA\states.shp"), true);

layCountries.DataSource = datasource;

datacoordsys = datasource.CoordinateSystem;

//Set fill-style to green

layCountries.Style.Fill = new SolidBrush(Color.Green);

//Set the polygons to have a black outline

layCountries.Style.Outline = Pens.Black;

layCountries.Style.EnableOutline = true;

layCountries.CoordinateTransformation = GetTransform(ddlProjection.SelectedValue);

if (layCountries.CoordinateTransformation != null)

{

litInputCoordsys.Text = layCountries.CoordinateTransformation.TargetCS.WKT;

litCoordsys.Text = layCountries.CoordinateTransformation.SourceCS.WKT;

litTransform.Text = layCountries.CoordinateTransformation.MathTransform.WKT;

}

else

{

litInputCoordsys.Text = datasource.CoordinateSystem.WKT;

litCoordsys.Text = "None";

litTransform.Text = "None";

}

VectorLayer layGrid = new VectorLayer("Grid");

//Set the datasource to a shapefile in the App_data folder

layGrid.DataSource = new ShapeFile(HttpContext.Current.Server.MapPath(@"~\App_data\USA\latlong.shp"), true);

layGrid.CoordinateTransformation = layCountries.CoordinateTransformation;

layGrid.Style.Line = new Pen(Color.FromArgb(127, 255, 0, 0), 1);

//Add the layers to the map object.

map.Layers.Add(layCountries);

map.Layers.Add(layGrid);

map.BackColor = Color.LightBlue;

HttpContext.Current.Trace.Write("Map initialized");

return map;

}

public ICoordinateTransformation GetTransform(string name)

{

switch (name)

{

case "Mercator":

return Transform2Mercator(datacoordsys);

case "Albers":

return Transform2Albers(datacoordsys);

case "Lambert":

return Transform2Lambert(datacoordsys);

default:

return null;

}

}

public static ICoordinateTransformation Transform2Albers(ICoordinateSystem source)

{

if (source == null)

throw new ArgumentException("Source coordinate system is null");

if (!(source is IGeographicCoordinateSystem))

throw new ArgumentException("Source coordinate system must be geographic");

CoordinateSystemFactory cFac = new CoordinateSystemFactory();

List<ProjectionParameter> parameters = new List<ProjectionParameter>();

parameters.Add(new ProjectionParameter("central_meridian", -95));

parameters.Add(new ProjectionParameter("latitude_of_origin", 50));

parameters.Add(new ProjectionParameter("standard_parallel_1", 29.5));

parameters.Add(new ProjectionParameter("standard_parallel_2", 45.5));

parameters.Add(new ProjectionParameter("false_easting", 0));

parameters.Add(new ProjectionParameter("false_northing", 0));

IProjection projection = cFac.CreateProjection("Albers_Conic_Equal_Area", "albers", parameters);

IProjectedCoordinateSystem coordsys = cFac.CreateProjectedCoordinateSystem("Albers_Conic_Equal_Area",

source as IGeographicCoordinateSystem,

projection, ProjNet.CoordinateSystems.LinearUnit.Metre,

new AxisInfo("East",

AxisOrientationEnum.East),

new AxisInfo("North",

AxisOrientationEnum.

North));

return new CoordinateTransformationFactory().CreateFromCoordinateSystems(source, coordsys);

}

public static ICoordinateTransformation Transform2Mercator(ICoordinateSystem source)

{

CoordinateSystemFactory cFac = new CoordinateSystemFactory();

List<ProjectionParameter> parameters = new List<ProjectionParameter>();

parameters.Add(new ProjectionParameter("latitude_of_origin", 0));

parameters.Add(new ProjectionParameter("central_meridian", 0));

parameters.Add(new ProjectionParameter("false_easting", 0));

parameters.Add(new ProjectionParameter("false_northing", 0));

IProjection projection = cFac.CreateProjection("Mercator", "Mercator_2SP", parameters);

IProjectedCoordinateSystem coordsys = cFac.CreateProjectedCoordinateSystem("Mercator",

source as IGeographicCoordinateSystem,

projection, ProjNet.CoordinateSystems.LinearUnit.Metre,

new AxisInfo("East",

AxisOrientationEnum.East),

new AxisInfo("North",

AxisOrientationEnum.

North));

return new CoordinateTransformationFactory().CreateFromCoordinateSystems(source, coordsys);

}

public static ICoordinateTransformation Transform2Lambert(ICoordinateSystem source)

{

if (source == null)

throw new ArgumentException("Source coordinate system is null");

if (!(source is IGeographicCoordinateSystem))

throw new ArgumentException("Source coordinate system must be geographic");

CoordinateSystemFactory cFac = new CoordinateSystemFactory();

List<ProjectionParameter> parameters = new List<ProjectionParameter>();

parameters.Add(new ProjectionParameter("latitude_of_origin", 50));

parameters.Add(new ProjectionParameter("central_meridian", -95));

parameters.Add(new ProjectionParameter("standard_parallel_1", 33));

parameters.Add(new ProjectionParameter("standard_parallel_2", 45));

parameters.Add(new ProjectionParameter("false_easting", 0));

parameters.Add(new ProjectionParameter("false_northing", 0));

IProjection projection = cFac.CreateProjection("Lambert Conformal Conic 2SP", "lambert_conformal_conic_2sp",

parameters);

IProjectedCoordinateSystem coordsys = cFac.CreateProjectedCoordinateSystem("Lambert Conformal Conic 2SP",

source as IGeographicCoordinateSystem,

projection, ProjNet.CoordinateSystems.LinearUnit.Metre,

new AxisInfo("East",

AxisOrientationEnum.East),

new AxisInfo("North",

AxisOrientationEnum.

North));

return new CoordinateTransformationFactory().CreateFromCoordinateSystems(source, coordsys);

}

}