// Copyright (c) Xenko contributors (https://xenko.com) and Silicon Studio Corp. (https://www.siliconstudio.co.jp)
// Distributed under the MIT license. See the LICENSE.md file in the project root for more information.
//
// Copyright (c) 2010-2011 SharpDX - Alexandre Mutel
//
// 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
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Runtime.Serialization;

namespace math
{
    /// <summary>
    /// Represents a two dimensional mathematical vector with half-precision floats.
    /// </summary>
    [DataContract]
    [StructLayout( LayoutKind.Sequential, Pack = 2 )]
    public struct Half2 : IEquatable<Half2>
    {
        /// <summary>
        /// Gets or sets the X component of the vector.
        /// </summary>
        /// <value>The X component of the vector.</value>
        public Half X;

        /// <summary>
        /// Gets or sets the Y component of the vector.
        /// </summary>
        /// <value>The Y component of the vector.</value>
        public Half Y;

        /// <summary>
        /// Initializes a new instance of the <see cref="Half2"/> structure.
        /// </summary>
        /// <param name="x">The X component.</param>
        /// <param name="y">The Y component.</param>
        public Half2( Half x, Half y )
        {
            this.X = x;
            this.Y = y;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="Half2"/> structure.
        /// </summary>
        /// <param name="value">The value to set for both the X and Y components.</param>
        public Half2( Half value )
        {
            this.X = value;
            this.Y = value;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="Half2"/> structure.
        /// </summary>
        /// <param name="x">The X component.</param>
        /// <param name="y">The Y component.</param>
        public Half2( float x, float y )
        {
            this.X = (Half)x;
            this.Y = (Half)y;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="Half2"/> structure.
        /// </summary>
        /// <param name="value">The value to set for both the X and Y components.</param>
        public Half2( float value )
        {
            this.X = (Half)value;
            this.Y = (Half)value;
        }

        /// <summary>
        /// Tests for equality between two objects.
        /// </summary>
        /// <param name="left">The first value to compare.</param>
        /// <param name="right">The second value to compare.</param>
        /// <returns>
        /// <c>true</c> if <paramref name="left" /> has the same value as <paramref name="right" />; otherwise, <c>false</c>.</returns>
        public static bool operator ==( Half2 left, Half2 right )
        {
            return Equals( ref left, ref right );
        }

        /// <summary>
        /// Tests for inequality between two objects.
        /// </summary>
        /// <param name="left">The first value to compare.</param>
        /// <param name="right">The second value to compare.</param>
        /// <returns>
        /// <c>true</c> if <paramref name="left" /> has a different value than <paramref name="right" />; otherwise, <c>false</c>.</returns>
        [return: MarshalAs( UnmanagedType.U1 )]
        public static bool operator !=( Half2 left, Half2 right )
        {
            return !Equals( ref left, ref right );
        }

        /// <summary>
        /// Returns the hash code for this instance.
        /// </summary>
        /// <returns>A 32-bit signed integer hash code.</returns>
        public override int GetHashCode()
        {
            return ( this.Y.GetHashCode() + this.X.GetHashCode() );
        }

        /// <summary>
        /// Determines whether the specified object instances are considered equal.
        /// </summary>
        /// <param name="value1">The first value.</param>
        /// <param name="value2">The second value.</param>
        /// <returns>
        /// <c>true</c> if <paramref name="value1" /> is the same instance as <paramref name="value2" /> or
        /// if both are <c>null</c> references or if <c>value1.Equals(value2)</c> returns <c>true</c>; otherwise, <c>false</c>.</returns>
        public static bool Equals( ref Half2 value1, ref Half2 value2 )
        {
            return ( ( value1.X == value2.X ) && ( value1.Y == value2.Y ) );
        }

        /// <summary>
        /// Returns a value that indicates whether the current instance is equal to the specified object.
        /// </summary>
        /// <param name="other">Object to make the comparison with.</param>
        /// <returns>
        /// <c>true</c> if the current instance is equal to the specified object; <c>false</c> otherwise.</returns>
        public bool Equals( Half2 other )
        {
            return ( ( this.X == other.X ) && ( this.Y == other.Y ) );
        }

        /// <summary>
        /// Returns a value that indicates whether the current instance is equal to a specified object.
        /// </summary>
        /// <param name="obj">Object to make the comparison with.</param>
        /// <returns>
        /// <c>true</c> if the current instance is equal to the specified object; <c>false</c> otherwise.</returns>
        public override bool Equals( object obj )
        {
            if( obj == null )
            {
                return false;
            }
            if( obj.GetType() != GetType() )
            {
                return false;
            }
            return this.Equals( (Half2)obj );
        }

        /// <summary>
        /// Performs an explicit conversion from <see cref="Vec2"/> to <see cref="Half2"/>.
        /// </summary>
        /// <param name="value">The value.</param>
        /// <returns>The result of the conversion.</returns>
        public static explicit operator Half2( Vec2 value )
        {
            return new Half2( (Half)value.X, (Half)value.Y );
        }

        /// <summary>
        /// Performs an explicit conversion from <see cref="Half2"/> to <see cref="Vec2"/>.
        /// </summary>
        /// <param name="value">The value.</param>
        /// <returns>The result of the conversion.</returns>
        public static explicit operator Vec2( Half2 value )
        {
            return new Vec2( value.X, value.Y );
        }
    }
}