// Copyright 2005, 2006 - Morten Nielsen (www.iter.dk)

//

// This file is part of SharpMap.

// SharpMap is free software; you can redistribute it and/or modify

// it under the terms of the GNU Lesser General Public License as published by

// the Free Software Foundation; either version 2 of the License, or

// (at your option) any later version.

//

// SharpMap is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

// GNU Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public License

// along with SharpMap; if not, write to the Free Software

// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

using System;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Text;

namespace SharpMap.CoordinateSystems

{

/// <summary>

/// Base interface for all coordinate systems.

/// </summary>

/// <remarks>

/// <para>A coordinate system is a mathematical space, where the elements of the space

/// are called positions. Each position is described by a list of numbers. The length

/// of the list corresponds to the dimension of the coordinate system. So in a 2D

/// coordinate system each position is described by a list containing 2 numbers.</para>

/// <para>However, in a coordinate system, not all lists of numbers correspond to a

/// position - some lists may be outside the domain of the coordinate system. For

/// example, in a 2D Lat/Lon coordinate system, the list (91,91) does not correspond

/// to a position.</para>

/// <para>Some coordinate systems also have a mapping from the mathematical space into

/// locations in the real world. So in a Lat/Lon coordinate system, the mathematical

/// position (lat, long) corresponds to a location on the surface of the Earth. This

/// mapping from the mathematical space into real-world locations is called a Datum.</para>

/// </remarks>

public abstract class CoordinateSystem : Info, ICoordinateSystem

{

/// <summary>

/// Initializes a new instance of a coordinate system.

/// </summary>

/// <param name="name">Name</param>

/// <param name="authority">Authority name</param>

/// <param name="authorityCode">Authority-specific identification code.</param>

/// <param name="alias">Alias</param>

/// <param name="abbreviation">Abbreviation</param>

/// <param name="remarks">Provider-supplied remarks</param>

internal CoordinateSystem(string name, string authority, long authorityCode, string alias, string abbreviation, string remarks)

: base (name,authority,authorityCode,alias,abbreviation,remarks)

{

}

#region ICoordinateSystem Members

/// <summary>

/// Dimension of the coordinate system.

/// </summary>

public int Dimension

{

get { return _AxisInfo.Count; }

}

/// <summary>

/// Gets the units for the dimension within coordinate system.

/// Each dimension in the coordinate system has corresponding units.

/// </summary>

public abstract IUnit GetUnits(int dimension);

private Collection<AxisInfo> _AxisInfo;

internal Collection<AxisInfo> AxisInfo

{

get { return _AxisInfo; }

set { _AxisInfo = value; }

}

/// <summary>

/// Gets axis details for dimension within coordinate system.

/// </summary>

/// <param name="dimension">Dimension</param>

/// <returns>Axis info</returns>

public AxisInfo GetAxis(int dimension)

{

if (dimension >= _AxisInfo.Count || dimension < 0)

throw new ArgumentException("AxisInfo not available for dimension " + dimension.ToString());

return _AxisInfo[dimension];

}

private SharpMap.Geometries.BoundingBox _DefaultEnvelope;

/// <summary>

/// Gets default envelope of coordinate system.

/// </summary>

/// <remarks>

/// Coordinate systems which are bounded should return the minimum bounding box of their domain.

/// Unbounded coordinate systems should return a box which is as large as is likely to be used.

/// For example, a (lon,lat) geographic coordinate system in degrees should return a box from

/// (-180,-90) to (180,90), and a geocentric coordinate system could return a box from (-r,-r,-r)

/// to (+r,+r,+r) where r is the approximate radius of the Earth.

/// </remarks>

public SharpMap.Geometries.BoundingBox DefaultEnvelope

{

get { return _DefaultEnvelope; }

set { _DefaultEnvelope = value; }

}

#endregion

}

}