public class LambertConformalProjection
    {
        private double n;
        private double F;
        private double rho;
        private double earthRadiusTimesF;
        private double lon0Degrees;
        private double lat0;
        private double lon0;
        private double par1;
        private double par2;
        private double falseEasting;
        private double falseNorthing;

        public LambertConformalProjection(double centerPtLat, double standardLon, double trueLat1, double trueLat2)
            : this(centerPtLat, standardLon, trueLat1, trueLat2, 0.0D, 0.0D)
        {

        }

        public LambertConformalProjection(double centerPtLat, double standardLon, double trueLat1, double trueLat2, double falseEast, double falseNorth)
        {
            this.lat0 = this.ToRadians(centerPtLat);
            this.lon0 = this.ToRadians(standardLon);
            this.par1 = trueLat1;
            this.par2 = trueLat2;
            double d = 1.0D;
            if (Double.IsNaN(falseEast))
            {
                falseEast = 0.0D;
            }

            if (Double.IsNaN(falseNorth))
            {
                falseNorth = 0.0D;
            }

            int i = (falseEast != 0.0D) || (falseNorth != 0.0D) ? 1 : 0;
            if (i != 0)
            {
                d = 1.0D;
            }

            this.falseEasting = (d * falseEast);
            this.falseNorthing = (d * falseNorth);
            this.Precalculate();
        }

        private double ToRadians(double degrees)
        {
            return degrees * Math.PI / 180.0;
        }

        private double ToDegrees(double radians)
        {
            return radians * 180.0 / Math.PI;
        }

        private void Precalculate()
        {
            if (Math.Abs(this.lat0 - 1.570796326794897D) < 1.0E-006D)
            {
                throw new ArgumentException("LambertConformal lat0 = 90");
            }

            if (Math.Abs(this.lat0 + 1.570796326794897D) < 1.0E-006D)
            {
                throw new ArgumentException("LambertConformal lat0 = -90");
            }

            if (Math.Abs(this.par1 - 90.0D) < 1.0E-006D)
            {
                throw new ArgumentException("LambertConformal par1 = 90");
            }

            if (Math.Abs(this.par1 + 90.0D) < 1.0E-006D)
            {
                throw new ArgumentException("LambertConformal par1 = -90");
            }

            if (Math.Abs(this.par2 - 90.0D) < 1.0E-006D)
            {
                throw new ArgumentException("LambertConformal par2 = 90");
            }

            if (Math.Abs(this.par2 + 90.0D) < 1.0E-006D)
            {
                throw new ArgumentException("LambertConformal par2 = -90");
            }

            double d1 = this.ToRadians(this.par1);
            double d2 = this.ToRadians(this.par2);
            double d3 = Math.Tan(0.7853981633974483D + d1 / 2.0D);
            double d4 = Math.Tan(0.7853981633974483D + d2 / 2.0D);

            if (Math.Abs(this.par2 - this.par1) < 1.0E-006D)
            {
                this.n = Math.Sin(d1);
            }
            else
            {
                this.n = (Math.Log(Math.Cos(d1) / Math.Cos(d2)) / Math.Log(d4 / d3));
            }

            double d5 = Math.Pow(d3, this.n);
            this.F = (Math.Cos(d1) * d5 / this.n);
            this.earthRadiusTimesF = (6371.2290000000003D * this.F) * 1000;
            double d6 = Math.Pow(Math.Tan(0.7853981633974483D + this.lat0 / 2.0D), this.n);
            this.rho = (6371.2290000000003D * 1000 * this.F / d6);
            this.lon0Degrees = this.ToDegrees(this.lon0);
        }

        public void LatLonToProj(double[] inLonLatOutXY)
        {
            var xy = this.LatLonToProj(new CoordinateLatLon() { Lon = inLonLatOutXY[0], Lat = inLonLatOutXY[1] });
            inLonLatOutXY[0] = xy.X;
            inLonLatOutXY[1] = xy.Y;
        }

        public CoordinateXY LatLonToProj(double paramDouble1, double paramDouble2, CoordinateXY paramCoordinateXY)
        {
            double d3 = paramDouble1;
            double d4 = paramDouble2;
            d3 = this.ToRadians(d3);
            double d5 = CoordinateLatLon.LonNormal(d4 - this.lon0Degrees);
            double d6 = this.n * this.ToRadians(d5);
            double d7 = Math.Pow(Math.Tan(0.7853981633974483D + d3 / 2.0D), this.n);
            double d8 = this.earthRadiusTimesF / d7;
            double d1 = d8 * Math.Sin(d6);
            double d2 = this.rho - d8 * Math.Cos(d6);
            paramCoordinateXY.X = ((float)(d1 + this.falseEasting));
            paramCoordinateXY.Y = ((float)(d2 + this.falseNorthing));
            return paramCoordinateXY;
        }

        public CoordinateXY LatLonToProj(CoordinateLatLon paramCoordinateLatLon)
        {
            double d3 = paramCoordinateLatLon.Lat;
            double d4 = paramCoordinateLatLon.Lon;
            d3 = this.ToRadians(d3);
            double d5 = CoordinateLatLon.LonNormal(d4 - this.lon0Degrees);
            double d6 = this.n * this.ToRadians(d5);
            double d7 = Math.Pow(Math.Tan(0.7853981633974483D + d3 / 2.0D), this.n);
            double d8 = this.earthRadiusTimesF / d7;
            double d1 = d8 * Math.Sin(d6);
            double d2 = this.rho - d8 * Math.Cos(d6);
            return new CoordinateXY() { X = (d1 + this.falseEasting), Y = (d2 + this.falseNorthing) };
        }

        public CoordinateLatLon ProjToLatLon(CoordinateXY paramCoordinateXY)
        {
            CoordinateLatLon localCoordinateLatLon = new CoordinateLatLon();
            return ProjToLatLon(localCoordinateLatLon, paramCoordinateXY.X, paramCoordinateXY.Y);
        }

        public CoordinateLatLon ProjToLatLon(CoordinateLatLon paramCoordinateLatLon, double paramFloat1, double paramFloat2)
        {
            double d3 = paramFloat1 - this.falseEasting;
            double d4 = paramFloat2 - this.falseNorthing;
            double d5 = this.rho;

            if (this.n < 0.0D)
            {
                d5 *= -1.0D;
                d3 *= -1.0D;
                d4 *= -1.0D;
            }

            double d6 = d5 - d4;
            double d7 = Math.Atan2(d3, d6);
            double d8 = Math.Sqrt(d3 * d3 + d6 * d6);

            if (this.n < 0.0D)
            {
                d8 *= -1.0D;
            }

            double d2 = this.ToDegrees(d7 / this.n + this.lon0);
            double d1;
            if (Math.Abs(d8) < 1.0E-006D)
            {
                d1 = this.n < 0.0D ? -90.0D : 90.0D;
            }
            else
            {
                double d9 = Math.Pow(6371.2290000000003D * this.F / d8, 1.0D / this.n);
                d1 = this.ToDegrees(2.0D * Math.Atan(d9) - 1.570796326794897D);
            }

            paramCoordinateLatLon.Lat = d1;
            paramCoordinateLatLon.Lon = d2;
            return paramCoordinateLatLon;
        }
    }

    public struct CoordinateXY
    {
        public double X;
        public double Y;
    }

    public struct CoordinateLatLon
    {
        public double Lat;
        public double Lon;

        public static double LonNormal(double paramDouble)
        {
            if ((paramDouble < -180.0D) || (paramDouble > 180.0D))
            {
                return Math.IEEERemainder(paramDouble, 360.0D);
            }

            return paramDouble;
        }
    }