C:/Users/Andreas Schiffler/Desktop/SVN/NewGamePhysics/NewGamePhysics/Mathematics/EquirectangularProjection.cs

//-----------------------------------------------------------------------------
// EquirectangularProjection.cs
// (A. Schiffler, 2009)
//-----------------------------------------------------------------------------

namespace NewGamePhysics.Mathematics
{
    using System;

    public class EquirectangularProjection
    {
        public static double lonToX(double lon)
        {
            if ((lon < 0) || (lon > 360.0))
            {
                throw new ArgumentOutOfRangeException("lon");
            }

            return lon / 360.0;
        }

        public static double latToY(double lat)
        {
            if ((lat < -90.0) || (lat > 90.0))
            {
                throw new ArgumentOutOfRangeException("lat");
            }

            return (lat / 90.0 + 1.0) / 2.0;
        }

        public static double xToLon(double x)
        {
            if ((x < 0.0) || (x > 1.0))
            {
                throw new ArgumentOutOfRangeException("lon");
            }

            return x * 360.0;
        }

        public static double yToLat(double y)
        {
            if ((y < 0.0) || (y > 1.0))
            {
                throw new ArgumentOutOfRangeException("lon");
            }

            return y * 180.0 - 90.0;
        }
    }
}

---