UI-For-UWP/Controls/Map/Map.UWP/SpatialReference.cs

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using System;
using Telerik.Geospatial;
using Telerik.UI.Drawing;
using Windows.Foundation;

namespace Telerik.UI.Xaml.Controls.Map
{
    /// <summary>
    /// The OGC Spatial Reference requirements.
    /// </summary>
    public class SpatialReference : ISpatialReference
    {
        /// <summary>
        /// Half of PI.
        /// </summary>
        public const double HalfPI = 0.159154943091895;

        /// <summary>
        /// Degrees of one radiant.
        /// </summary>
        public const double RadiansToDegrees = 57.2957795130823;

        /// <summary>
        /// Gets or sets the measurement units used to define the angles of a spheroid or ellipse associated with a specific datum.
        /// The datum is WGS 1984 and the unit of measurement is a degree.
        /// </summary>
        public double AngularUnitOfMeasurement
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the authority body that defines the standards for the spatial reference parameters.
        /// The Spatial Reference is WGS 1984 and the authority is EPSG:4326.
        /// </summary>
        public string Authority
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the line of longitude at the center of a map projection generally used as the basis for constructing the projection.
        /// </summary>
        public double CentralMeridian
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the horizontal datum,
        /// which corresponds to the procedure used to measure positions on the surface of the Earth.
        /// </summary>
        public string Datum
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the horizontal datum,
        /// which corresponds to the procedure used to measure positions on the surface of the Earth.
        /// </summary>
        public string DatumAuthority
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets value added to all "x" values in the rectangular coordinate for a map projection. 
        /// This value frequently is assigned to eliminate negative numbers.
        /// Expressed in the unit of measure identified in Planar Coordinate Units.
        /// </summary>
        public double FalseEasting
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets value added to all "y" values in the rectangular coordinates for a map projection. 
        /// This value frequently is assigned to eliminate negative numbers. 
        /// Expressed in the unit of measure identified in Planar Coordinate Units.
        /// </summary>
        public double FalseNorthing
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets coordinate system based on latitude and longitude.
        /// Some geographic coordinate systems are Latitude/Longitude, and some are Longitude/Latitude.
        /// You can find out which this is by examining the axes. 
        /// You should also check the angular units, since not all geographic coordinate systems use degrees.
        /// </summary>
        public string GeoGcs
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the latitude chosen as the origin of rectangular coordinate for a map projection.
        /// </summary>
        public double LatitudeOfOrigin
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets logical X offset to centre of earth.
        /// </summary>
        public double OffsetX
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets logical Y offset to centre of earth.
        /// </summary>
        public double OffsetY
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the meridian used to take longitude measurements from. 
        /// The units of the longitude must be inferred from the context.
        /// </summary>
        public double Primem
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the meridian used to take longitude measurements from. 
        /// The units of the longitude must be inferred from the context.
        /// </summary>
        public string PrimemAuthority
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets a projection from geographic coordinates to projected coordinates.
        /// </summary>
        public string ProjectionAuthority
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the real world coordinate scale at a given longitude.
        /// </summary>
        public double ScaleX
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the real world coordinate scale at a given latitude.
        /// </summary>
        public double ScaleY
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets a spheroid, which is an approximation of the Earth's surface as a squashed sphere.
        /// </summary>
        public double SpheroidRadius
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets a spheroid, which is an approximation of the Earth's surface as a squashed sphere.
        /// </summary>
        public double SpheroidFlattening
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets a spheroid, which is an approximation of the Earth's surface as a squashed sphere.
        /// </summary>
        public string SpheroidAuthority
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the line of constant latitude at which the surface of the Earth
        /// and the plane or developable surface intersect.
        /// </summary>
        public double StandardParallel
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the authority body that defines the unit of measurement i.e. European Petroleum Survey Group (EPSG).
        /// The unit of measurement is usually degrees and the authority for the datum the map uses, WGS 1984 is EPSG:4326.
        /// </summary>
        public string UnitAuthority
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the minimum Latitude this tile source supports.
        /// </summary>
        public double MinLatitude
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the maximum Latitude this tile source supports.
        /// </summary>
        public double MaxLatitude
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the minimum Longitude this tile source supports.
        /// </summary>
        public double MinLongitude
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets the maximum Longitude this tile source supports.
        /// </summary>
        public double MaxLongitude
        {
            get;
            set;
        }

        /// <summary>
        /// Converts a geographical coordinate (Longitude, Latitude) to a logical Point (0->1).
        /// </summary>
        /// <param name="geographicPoint">The geographical coordinate (Longitude, Latitude).</param>
        /// <returns>The logical Point.</returns>
        public virtual DoublePoint ConvertGeographicToLogicalCoordinate(Location geographicPoint)
        {
            double d = Math.Sin(geographicPoint.Latitude * this.AngularUnitOfMeasurement);

            DoublePoint point = new DoublePoint()
                {
                    X = (geographicPoint.Longitude * this.AngularUnitOfMeasurement * this.ScaleX) + this.OffsetX,
                    Y = (0.5 * Math.Log((1.0 + d) / (1.0 - d)) * this.ScaleY) + this.OffsetY
                };

            if (point.Y > 1)
            {
                point.Y = 1;
            }

            return point;
        }

        /// <summary>
        /// Converts a logical Point (0->1) to a geographical coordinate (Longitude, Latitude).
        /// </summary>
        /// <param name="logicalPoint">The logical Point.</param>
        /// <returns>The geographical coordinate (Longitude, Latitude).</returns>
        public virtual Location ConvertLogicalToGeographicCoordinate(DoublePoint logicalPoint)
        {
            return new Location(
                Math.Atan(Math.Sinh((logicalPoint.Y - this.OffsetY) / this.ScaleY)) * RadiansToDegrees,
                (logicalPoint.X - this.OffsetX) * RadiansToDegrees / this.ScaleX);
        }
    }
}