Opentk/Source/OpenTK/Math/Box2d.cs

#region --- License ---
/*
Copyright (c) 2006 - 2008 The Open Toolkit library.

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.
*/
#endregion

using System;
using System.Runtime.InteropServices;
namespace OpenTK
{
    /// <summary>
    /// Defines a 2d box (rectangle).
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    public struct Box2d
    {
        /// <summary>
        /// The left boundary of the structure.
        /// </summary>
        public double Left;

        /// <summary>
        /// The right boundary of the structure.
        /// </summary>
        public double Right;

        /// <summary>
        /// The top boundary of the structure.
        /// </summary>
        public double Top;

        /// <summary>
        /// The bottom boundary of the structure.
        /// </summary>
        public double Bottom;

        /// <summary>
        /// Constructs a new Box2d with the specified dimensions.
        /// </summary>
        /// <param name="topLeft">An OpenTK.Vector2d describing the top-left corner of the Box2d.</param>
        /// <param name="bottomRight">An OpenTK.Vector2d describing the bottom-right corner of the Box2d.</param>
        public Box2d(Vector2d topLeft, Vector2d bottomRight)
        {
            Left = topLeft.X;
            Top = topLeft.Y;
            Right = bottomRight.X;
            Bottom = bottomRight.Y;
        }

        /// <summary>
        /// Constructs a new Box2d with the specified dimensions.
        /// </summary>
        /// <param name="left">The position of the left boundary.</param>
        /// <param name="top">The position of the top boundary.</param>
        /// <param name="right">The position of the right boundary.</param>
        /// <param name="bottom">The position of the bottom boundary.</param>
        public Box2d(double left, double top, double right, double bottom)
        {
            Left = left;
            Top = top;
            Right = right;
            Bottom = bottom;
        }

        /// <summary>
        /// Creates a new Box2d with the specified dimensions.
        /// </summary>
        /// <param name="top">The position of the top boundary.</param>
        /// <param name="left">The position of the left boundary.</param>
        /// <param name="right">The position of the right boundary.</param>
        /// <param name="bottom">The position of the bottom boundary.</param>
        /// <returns>A new OpenTK.Box2d with the specfied dimensions.</returns>
        public static Box2d FromTLRB(double top, double left, double right, double bottom)
        {
            return new Box2d(left, top, right, bottom);
        }

        /// <summary>
        /// Creates a new Box2d with the specified dimensions.
        /// </summary>
        /// <param name="top">The position of the top boundary.</param>
        /// <param name="left">The position of the left boundary.</param>
        /// <param name="width">The width of the box.</param>
        /// <param name="height">The height of the box.</param>
        /// <returns>A new OpenTK.Box2d with the specfied dimensions.</returns>
        public static Box2d FromDimensions(double left, double top, double width, double height)
        {
            return new Box2d(left, top, left + width, top + height);
        }

        /// <summary>
        /// Creates a new Box2d with the specified dimensions.
        /// </summary>
        /// <param name="position">The position of the top left corner.</param>
        /// <param name="size">The size of the box.</param>
        /// <returns>A new OpenTK.Box2d with the specfied dimensions.</returns>
        public static Box2d FromDimensions(Vector2d position, Vector2d size)
        {
            return FromDimensions(position.X, position.Y, size.X, size.Y);
        }

        /// <summary>
        /// Gets a double describing the width of the Box2d structure.
        /// </summary>
        public double Width { get { return (double)System.Math.Abs(Right - Left); } }

        /// <summary>
        /// Gets a double describing the height of the Box2d structure.
        /// </summary>
        public double Height { get { return (double)System.Math.Abs(Bottom - Top); } }

        /// <summary>
        /// Returns whether the box contains the specified point on the closed region described by this Box2.
        /// </summary>
        /// <param name="point">The point to query.</param>
        /// <returns>Whether this box contains the point.</returns>
        public bool Contains(Vector2d point)
        {
            return Contains(point, true);
        }

        /// <summary>
        /// Returns whether the box contains the specified point.
        /// </summary>
        /// <param name="point">The point to query.</param>
        /// <param name="closedRegion">Whether to include the box boundary in the test region.</param>
        /// <returns>Whether this box contains the point.</returns>
        public bool Contains(Vector2d point, bool closedRegion)
        {
            bool xOK = (closedRegion == Left <= Right) ?
                (point.X >= Left != point.X > Right) :
                (point.X > Left != point.X >= Right);

            bool yOK = (closedRegion == Top <= Bottom) ?
                (point.Y >= Top != point.Y > Bottom) :
                (point.Y > Top != point.Y >= Bottom);

            return xOK && yOK;
        }

        /// <summary>
        /// Returns a Box2d translated by the given amount.
        /// </summary>
        public Box2d Translated(Vector2d point)
        {
            return new Box2d(Left + point.X, Top + point.Y, Right + point.X, Bottom + point.Y);
        }

        /// <summary>
        /// Translates this Box2d by the given amount.
        /// </summary>
        public void Translate(Vector2d point)
        {
            Left += point.X;
            Right += point.X;
            Top += point.Y;
            Bottom += point.Y;
        }

        /// <summary>
        /// Equality comparator.
        /// </summary>
        public static bool operator ==(Box2d left, Box2d right)
        {
            return left.Bottom == right.Bottom && left.Top == right.Top &&
                left.Left == right.Left && left.Right == right.Right;
        }

        /// <summary>
        /// Inequality comparator.
        /// </summary>
        public static bool operator !=(Box2d left, Box2d right)
        {
            return !(left == right);
        }

        /// <summary>
        /// Functional equality comparator.
        /// </summary>
        public bool Equals(Box2d other)
        {
            return this == other;
        }

        /// <summary>
        /// Implements Object.Equals.
        /// </summary>
        public override bool Equals(object obj)
        {
            return obj is Box2d && Equals((Box2d) obj);
        }

        /// <summary>
        /// Gets the hash code for this Box2d.
        /// </summary>
        /// <returns></returns>
        public override int GetHashCode()
        {
            return Left.GetHashCode() ^ Right.GetHashCode() ^ Top.GetHashCode() ^ Bottom.GetHashCode();
        }

        private static string listSeparator = System.Globalization.CultureInfo.CurrentCulture.TextInfo.ListSeparator;
        /// <summary>
        /// Returns a <see cref="System.String"/> describing the current instance.
        /// </summary>
        /// <returns></returns>
        public override string ToString()
        {
            return String.Format("({0}{4} {1}) - ({2}{4} {3})", Left, Top, Right, Bottom, listSeparator);
        }
    }
}