// --------------------------------------------------------------------------------------------------------------------

 // <copyright file="ScreenPoint.cs" company="OxyPlot">

 //   The MIT License (MIT)

 //

 //   Copyright (c) 2012 Oystein Bjorke

 //

 //   Permission is hereby granted, free of charge, to any person obtaining a

 //   copy of this software and associated documentation files (the

 //   "Software"), to deal in the Software without restriction, including

 //   without limitation the rights to use, copy, modify, merge, publish,

 //   distribute, sublicense, and/or sell copies of the Software, and to

 //   permit persons to whom the Software is furnished to do so, subject to

 //   the following conditions:

 //

 //   The above copyright notice and this permission notice shall be included

 //   in all copies or substantial portions of the Software.

 //

 //   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

 //   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 //   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.

 //   IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY

 //   CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,

 //   TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

 //   SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 // </copyright>

 // <summary>

 //   Describes a point defined in the screen coordinate system.

 // </summary>

 // --------------------------------------------------------------------------------------------------------------------

 namespace OxyPlot

 {

     using System;

     /// <summary>

     /// Represents a point defined in the screen coordinate system.

     /// </summary>

     /// <remarks>

     /// The rendering methods transforms <see cref="DataPoint"/>s to <see cref="ScreenPoint"/>s.

     /// </remarks>

     public struct ScreenPoint

     {

         /// <summary>

         /// The undefined point.

         /// </summary>

         public static readonly ScreenPoint Undefined = new ScreenPoint(double.NaN, double.NaN);

         /// <summary>

         /// The x-coordinate.

         /// </summary>

         internal double x;

         /// <summary>

         /// The y-coordinate.

         /// </summary>

         internal double y;

         /// <summary>

         /// Initializes a new instance of the <see cref="ScreenPoint"/> struct.

         /// </summary>

         /// <param name="x">

         /// The x-coordinate.

         /// </param>

         /// <param name="y">

         /// The y-coordinate.

         /// </param>

         public ScreenPoint(double x, double y)

         {

             this.x = x;

             this.y = y;

         }

         /// <summary>

         /// Gets or sets the x-coordinate.

         /// </summary>

         /// <value> The x-coordinate. </value>

         public double X

         {

             get

             {

                 return this.x;

             }

             set

             {

                 this.x = value;

             }

         }

         /// <summary>

         /// Gets or sets the y-coordinate.

         /// </summary>

         /// <value> The y-coordinate. </value>

         public double Y

         {

             get

             {

                 return this.y;

             }

             set

             {

                 this.y = value;

             }

         }

         /// <summary>

         /// Determines whether the specified point is undefined.

         /// </summary>

         /// <param name="point">

         /// The point.

         /// </param>

         /// <returns>

         /// <c>true</c> if the specified point is undefined; otherwise, <c>false</c> .

         /// </returns>

         public static bool IsUndefined(ScreenPoint point)

         {

             return double.IsNaN(point.X) && double.IsNaN(point.Y);

         }

         /// <summary>

         /// Gets the distance to the specified point.

         /// </summary>

         /// <param name="point">

         /// The point.

         /// </param>

         /// <returns>

         /// The distance.

         /// </returns>

         public double DistanceTo(ScreenPoint point)

         {

             double dx = point.x - this.x;

             double dy = point.y - this.y;

             return Math.Sqrt((dx * dx) + (dy * dy));

         }

         /// <summary>

         /// Gets the squared distance to the specified point.

         /// </summary>

         /// <param name="point">

         /// The point.

         /// </param>

         /// <returns>

         /// The squared distance.

         /// </returns>

         public double DistanceToSquared(ScreenPoint point)

         {

             double dx = point.x - this.x;

             double dy = point.y - this.y;

             return (dx * dx) + (dy * dy);

         }

         /// <summary>

         /// Returns a <see cref="System.String"/> that represents this instance.

         /// </summary>

         /// <returns>

         /// A <see cref="System.String"/> that represents this instance.

         /// </returns>

         public override string ToString()

         {

             return this.x + " " + this.y;

         }

         /// <summary>

         /// Translates a <see cref="ScreenPoint"/> by a <see cref="ScreenVector"/>.

         /// </summary>

         /// <param name="p1"> The point. </param>

         /// <param name="p2"> The vector. </param>

         /// <returns> The translated point. </returns>

         public static ScreenPoint operator +(ScreenPoint p1, ScreenVector p2)

         {

             return new ScreenPoint(p1.x + p2.x, p1.y + p2.y);

         }

         /// <summary>

         /// Subtracts a <see cref="ScreenPoint"/> from a <see cref="ScreenPoint"/>

         /// and returns the result as a <see cref="ScreenVector"/>.

         /// </summary>

         /// <param name="p1"> The point on which to perform the subtraction. </param>

         /// <param name="p2"> The point to subtract from p1. </param>

         /// <returns> A <see cref="ScreenVector"/> structure that represents the difference between p1 and p2. </returns>

         public static ScreenVector operator -(ScreenPoint p1, ScreenPoint p2)

         {

             return new ScreenVector(p1.x - p2.x, p1.y - p2.y);

         }

         /// <summary>

         /// Subtracts a <see cref="ScreenVector"/> from a <see cref="ScreenPoint"/> 

         /// and returns the result as a <see cref="ScreenPoint"/>.

         /// </summary>

         /// <param name="point"> The point on which to perform the subtraction. </param>

         /// <param name="vector"> The vector to subtract from p1. </param>

         /// <returns> A <see cref="ScreenPoint"/> that represents point translated by the negative vector. </returns>

         public static ScreenPoint operator -(ScreenPoint point, ScreenVector vector)

         {

             return new ScreenPoint(point.x - vector.x, point.y - vector.y);

         }

     }

 }