//============================================================================
//PointPairBase Class
//Copyright © 2006  Jerry Vos & John Champion
//
//This library 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 2.1 of the License, or (at your option) any later version.
//
//This library 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 this library; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//=============================================================================

using System;
using System.Drawing;
using System.Runtime.Serialization;
using System.Security.Permissions;
using IComparer = System.Collections.IComparer;

namespace ZedGraph
{
	/// <summary>
	/// This is a base class that provides base-level functionality for a data point consisting
	/// of an (X,Y) pair of double values.
	/// </summary>
	/// <remarks>
	/// This class is typically a base class for actual <see cref="PointPair" /> type implementations.
	/// </remarks>
	/// 
	/// <author> Jerry Vos modified by John Champion </author>
	/// <version> $Revision: 1.4 $ $Date: 2007/04/16 00:03:02 $ </version>
	[Serializable]
	public class PointPairBase : ISerializable
	{

	#region Member variables

		/// <summary>
		/// Missing values are represented internally using <see cref="System.Double.MaxValue"/>.
		/// </summary>
		public const double Missing = Double.MaxValue;

		/// <summary>
		/// The default format to be used for displaying point values via the
		/// <see cref="ToString()"/> method.
		/// </summary>
		public const string DefaultFormat = "G";

		/// <summary>
		/// This PointPair's X coordinate
		/// </summary>
		public double X;

		/// <summary>
		/// This PointPair's Y coordinate
		/// </summary>
		public double Y;

	#endregion

	#region Constructors

		/// <summary>
		/// Default Constructor
		/// </summary>
		public PointPairBase()
			: this( 0, 0 )
		{
		}

		/// <summary>
		/// Creates a point pair with the specified X and Y.
		/// </summary>
		/// <param name="x">This pair's x coordinate.</param>
		/// <param name="y">This pair's y coordinate.</param>
		public PointPairBase( double x, double y )
		{
			this.X = x;
			this.Y = y;
		}

		/// <summary>
		/// Creates a point pair from the specified <see cref="PointF"/> struct.
		/// </summary>
		/// <param name="pt">The <see cref="PointF"/> struct from which to get the
		/// new <see cref="PointPair"/> values.</param>
		public PointPairBase( PointF pt )
			: this( pt.X, pt.Y )
		{
		}

		/// <summary>
		/// The PointPairBase copy constructor.
		/// </summary>
		/// <param name="rhs">The basis for the copy.</param>
		public PointPairBase( PointPairBase rhs )
		{
			this.X = rhs.X;
			this.Y = rhs.Y;
		}

	#endregion

	#region Serialization

		/// <summary>
		/// Current schema value that defines the version of the serialized file
		/// </summary>
		public const int schema = 11;

		/// <summary>
		/// Constructor for deserializing objects
		/// </summary>
		/// <param name="info">A <see cref="SerializationInfo"/> instance that defines the serialized data
		/// </param>
		/// <param name="context">A <see cref="StreamingContext"/> instance that contains the serialized data
		/// </param>
		protected PointPairBase( SerializationInfo info, StreamingContext context )
		{
			// The schema value is just a file version parameter.  You can use it to make future versions
			// backwards compatible as new member variables are added to classes
			int sch = info.GetInt32( "schema" );

			X = info.GetDouble( "X" );
			Y = info.GetDouble( "Y" );
		}

		/// <summary>
		/// Populates a <see cref="SerializationInfo"/> instance with the data needed to serialize the target object
		/// </summary>
		/// <param name="info">A <see cref="SerializationInfo"/> instance that defines the serialized data</param>
		/// <param name="context">A <see cref="StreamingContext"/> instance that contains the serialized data</param>
		[SecurityPermissionAttribute( SecurityAction.Demand, SerializationFormatter = true )]
		public virtual void GetObjectData( SerializationInfo info, StreamingContext context )
		{
			info.AddValue( "schema", schema );
			info.AddValue( "X", X );
			info.AddValue( "Y", Y );
		}

	#endregion

	#region Properties

		/// <summary>
		/// Readonly value that determines if either the X or the Y
		/// coordinate in this PointPair is a missing value.
		/// </summary>
		/// <returns>true if either value is missing</returns>
		public bool IsMissing
		{
			get { return this.X == PointPairBase.Missing || this.Y == PointPairBase.Missing; }
		}

		/// <summary>
		/// Readonly value that determines if either the X or the Y
		/// coordinate in this PointPair is an invalid (not plotable) value.
		/// It is considered invalid if it is missing (equal to System.Double.Max),
		/// Infinity, or NaN.
		/// </summary>
		/// <returns>true if either value is invalid</returns>
		public bool IsInvalid
		{
			get
			{
				return this.X == PointPairBase.Missing ||
						this.Y == PointPairBase.Missing ||
						Double.IsInfinity( this.X ) ||
						Double.IsInfinity( this.Y ) ||
						Double.IsNaN( this.X ) ||
						Double.IsNaN( this.Y );
			}
		}

		/// <summary>
		/// static method to determine if the specified point value is invalid.
		/// </summary>
		/// <remarks>The value is considered invalid if it is <see cref="PointPairBase.Missing"/>,
		/// <see cref="Double.PositiveInfinity"/>, <see cref="Double.NegativeInfinity"/>
		/// or <see cref="Double.NaN"/>.</remarks>
		/// <param name="value">The value to be checked for validity.</param>
		/// <returns>true if the value is invalid, false otherwise</returns>
		public static bool IsValueInvalid( double value )
		{
			return ( value == PointPairBase.Missing ||
					Double.IsInfinity( value ) ||
					Double.IsNaN( value ) );
		}

	#endregion

	#region Operator Overloads

		/// <summary>
		/// Implicit conversion from PointPair to PointF.  Note that this conversion
		/// can result in data loss, since the data are being cast from a type
		/// double (64 bit) to a float (32 bit).
		/// </summary>
		/// <param name="pair">The PointPair struct on which to operate</param>
		/// <returns>A PointF struct equivalent to the PointPair</returns>
		public static implicit operator PointF( PointPairBase pair )
		{
			return new PointF( (float)pair.X, (float)pair.Y );
		}

	#endregion

	#region Methods

		/// <summary>
		/// Compare two <see cref="PointPairBase"/> objects for equality.  To be equal, X and Y
		/// must be exactly the same between the two objects.
		/// </summary>
		/// <param name="obj">The <see cref="PointPairBase"/> object to be compared with.</param>
		/// <returns>true if the <see cref="PointPairBase"/> objects are equal, false otherwise</returns>
		public override bool Equals( object obj )
		{
			PointPairBase rhs = obj as PointPairBase;
			return this.X == rhs.X && this.Y == rhs.Y;
		}

		/// <summary>
		/// Return the HashCode from the base class.
		/// </summary>
		/// <returns></returns>
		public override int GetHashCode()
		{
			return base.GetHashCode();
		}

		/// <summary>
		/// Format this PointPair value using the default format.  Example:  "( 12.345, -16.876 )".
		/// The two double values are formatted with the "g" format type.
		/// </summary>
		/// <returns>A string representation of the PointPair</returns>
		public override string ToString()
		{
			return this.ToString( PointPairBase.DefaultFormat );
		}

		/// <summary>
		/// Format this PointPair value using a general format string.
		/// Example:  a format string of "e2" would give "( 1.23e+001, -1.69e+001 )".
		/// </summary>
		/// <param name="format">A format string that will be used to format each of
		/// the two double type values (see <see cref="System.Double.ToString()"/>).</param>
		/// <returns>A string representation of the PointPair</returns>
		public string ToString( string format )
		{
			return "( " + this.X.ToString( format ) +
					", " + this.Y.ToString( format ) +
					" )";
		}

		/// <summary>
		/// Format this PointPair value using different general format strings for the X and Y values.
		/// Example:  a format string of "e2" would give "( 1.23e+001, -1.69e+001 )".
		/// The Z value is not displayed (see <see cref="PointPair.ToString( string, string, string )"/>).
		/// </summary>
		/// <param name="formatX">A format string that will be used to format the X
		/// double type value (see <see cref="System.Double.ToString()"/>).</param>
		/// <param name="formatY">A format string that will be used to format the Y
		/// double type value (see <see cref="System.Double.ToString()"/>).</param>
		/// <returns>A string representation of the PointPair</returns>
		public string ToString( string formatX, string formatY )
		{
			return "( " + this.X.ToString( formatX ) +
					", " + this.Y.ToString( formatY ) +
					" )";
		}

	#endregion

	}
}