/NetGore/Core/Extensions/Vector2Extensions.cs

using System;

using System.Linq;

using SFML.Graphics;



namespace NetGore

{

    /// <summary>

    /// Extension methods for the <see cref="Vector2"/>.

    /// </summary>

    public static class Vector2Extensions

    {

        /// <summary>

        /// Gets the absolute value of the components of the <see cref="Vector2"/>.

        /// </summary>

        /// <param name="source"><see cref="Vector2"/> to get the absolute value of.</param>

        /// <returns>A <see cref="Vector2"/> containing the absolute value of the <paramref name="source"/>

        /// <see cref="Vector2"/>.</returns>

        public static Vector2 Abs(this Vector2 source)

        {

            return new Vector2(Math.Abs(source.X), Math.Abs(source.Y));

        }



        /// <summary>

        /// Gets a <see cref="Vector2"/> with the X and Y components rounded up.

        /// </summary>

        /// <param name="source"><see cref="Vector2"/> to round.</param>

        /// <returns>A <see cref="Vector2"/> containing the ceiling-down value of the <paramref name="source"/>

        /// <see cref="Vector2"/>.</returns>

        public static Vector2 Ceiling(this Vector2 source)

        {

            return new Vector2((float)Math.Ceiling(source.X), (float)Math.Ceiling(source.Y));

        }



        /// <summary>

        /// Gets a <see cref="Vector2"/> with the X and Y components rounded down.

        /// </summary>

        /// <param name="source"><see cref="Vector2"/> to round.</param>

        /// <returns>A <see cref="Vector2"/> containing the rounded-down value of the <paramref name="source"/>

        /// <see cref="Vector2"/>.</returns>

        public static Vector2 Floor(this Vector2 source)

        {

            return new Vector2((float)Math.Floor(source.X), (float)Math.Floor(source.Y));

        }



        /// <summary>

        /// Checks if both of a <see cref="Vector2"/>'s coordinates are greater than or equal to the

        /// corresponding coordinates in another <see cref="Vector2"/>.

        /// </summary>

        /// <param name="source"><see cref="Vector2"/> to check.</param>

        /// <param name="other"><see cref="Vector2"/> containing the coordinates to check if are greater than or equal to the 

        /// <paramref name="source"/>'s coordinates.</param>

        /// <returns>True if both of the coordinates in the <paramref name="source"/> are greater than or equal to the

        /// corresponding coordinates in the <paramref name="other"/> <see cref="Vector2"/>. False if either or both

        /// coordinates are less than their equivalent in the <paramref name="other"/> <see cref="Vector2"/>.</returns>

        public static bool IsGreaterOrEqual(this Vector2 source, Vector2 other)

        {

            return source.X >= other.X && source.Y >= other.Y;

        }



        /// <summary>

        /// Checks if both of a <see cref="Vector2"/>'s coordinates are greater than the corresponding coordinates in another

        /// <see cref="Vector2"/>.

        /// </summary>

        /// <param name="source"><see cref="Vector2"/> to check.</param>

        /// <param name="other"><see cref="Vector2"/> containing the coordinates to check if are greater than the 

        /// <paramref name="source"/>'s coordinates.</param>

        /// <returns>True if both of the coordinates in the <paramref name="source"/> are greater than the

        /// corresponding coordinates in the <paramref name="other"/> <see cref="Vector2"/>. False if either or both

        /// coordinates are less than or equal to their equivalent in the <paramref name="other"/>

        /// <see cref="Vector2"/>.</returns>

        public static bool IsGreaterThan(this Vector2 source, Vector2 other)

        {

            return source.X > other.X && source.Y > other.Y;

        }



        /// <summary>

        /// Checks if both of a <see cref="Vector2"/>'s coordinates are less than or equal to the

        /// corresponding coordinates in another Vector2.

        /// </summary>

        /// <param name="source"><see cref="Vector2"/> to check.</param>

        /// <param name="other"><see cref="Vector2"/> containing the coordinates to check if are less than or equal to the 

        /// <paramref name="source"/>'s coordinates.</param>

        /// <returns>True if both of the coordinates in the <paramref name="source"/> are less than or equal to the

        /// corresponding coordinates in the <paramref name="other"/> <see cref="Vector2"/>. False if either or both

        /// coordinates are greater than their equivalent in the <paramref name="other"/> <see cref="Vector2"/>.</returns>

        public static bool IsLessOrEqual(this Vector2 source, Vector2 other)

        {

            return source.X <= other.X && source.Y <= other.Y;

        }



        /// <summary>

        /// Checks if both of a <see cref="Vector2"/>'s coordinates are less than the corresponding coordinates

        /// in another <see cref="Vector2"/>.

        /// </summary>

        /// <param name="source"><see cref="Vector2"/> to check.</param>

        /// <param name="other"><see cref="Vector2"/> containing the coordinates to check if are less than the 

        /// <paramref name="source"/>'s coordinates.</param>

        /// <returns>True if both of the coordinates in the <paramref name="source"/> are less than the

        /// corresponding coordinates in the <paramref name="other"/> <see cref="Vector2"/>. False if either or both

        /// coordinates are greater than or equal to their equivalent in the <paramref name="other"/>

        /// <see cref="Vector2"/>.</returns>

        public static bool IsLessThan(this Vector2 source, Vector2 other)

        {

            return source.X < other.X && source.Y < other.Y;

        }



        /// <summary>

        /// Gets a <see cref="Vector2"/> composed of the max value of the given components for the respective property.

        /// </summary>

        /// <param name="a">The first argument.</param>

        /// <param name="b">The second argument.</param>

        /// <returns>A <see cref="Vector2"/> composed of the max value of the given components for the respective

        /// property.</returns>

        public static Vector2 Max(this Vector2 a, Vector2 b)

        {

            return new Vector2(Math.Max(a.X, b.X), Math.Max(a.Y, b.Y));

        }



        /// <summary>

        /// Gets a <see cref="Vector2"/> composed of the min value of the given components for the respective property.

        /// </summary>

        /// <param name="a">The first argument.</param>

        /// <param name="b">The second argument.</param>

        /// <returns>A <see cref="Vector2"/> composed of the max value of the given components for the respective

        /// property.</returns>

        public static Vector2 Min(this Vector2 a, Vector2 b)

        {

            return new Vector2(Math.Min(a.X, b.X), Math.Min(a.Y, b.Y));

        }



        /// <summary>

        /// Calculates the <see cref="Vector2"/> position to use to make the <paramref name="source"/> travel towards

        /// the <paramref name="target"/>.

        /// </summary>

        /// <param name="source">The <see cref="Vector2"/> that will be moving.</param>

        /// <param name="target">The <see cref="Vector2"/> containing the position to move towards.</param>

        /// <param name="distance">The total number of units to move. When moving objects based on elapsed time, this will typically

        /// contain the number of pixels to move per millisecond (speed * elapsedTime).</param>

        /// <returns>The new <see cref="Vector2"/> position to give the <paramref name="source"/>.</returns>

        public static Vector2 MoveTowards(this Vector2 source, Vector2 target, float distance)

        {

            // Get the difference between the source and target

            var diff = source - target;



            // Find the angle to travel

            var angle = Math.Atan2(diff.Y, diff.X);



            // Get the offset vector

            var cos = Math.Cos(angle);

            var sin = Math.Sin(angle);

            var offset = new Vector2((float)(cos * distance), (float)(sin * distance));



            return source - offset;

        }



        /// <summary>

        /// Calculates the <see cref="Vector2"/> position to use to make the <paramref name="source"/> travel towards

        /// the <paramref name="target"/>.

        /// </summary>

        /// <param name="source">The <see cref="Vector2"/> that will be moving.</param>

        /// <param name="target">The <see cref="Vector2"/> containing the position to move towards.</param>

        /// <param name="distance">The total number of units to move. When moving objects based on elapsed time, this will typically

        /// contain the number of pixels to move per millisecond (speed * elapsedTime).</param>

        /// <param name="doNotPass">If true, the <paramref name="source"/> will stop at the <paramref name="target"/> when it has

        /// been reached instead of going past it.</param>

        /// <returns>

        /// The new <see cref="Vector2"/> position to give the <paramref name="source"/>.

        /// </returns>

        public static Vector2 MoveTowards(this Vector2 source, Vector2 target, float distance, bool doNotPass = true)

        {

            // Get the difference between the source and target

            var diff = source - target;



            // Find the angle to travel

            var angle = Math.Atan2(diff.Y, diff.X);



            // Get the offset vector

            var cos = Math.Cos(angle);

            var sin = Math.Sin(angle);

            var offset = new Vector2((float)(cos * distance), (float)(sin * distance));



            // Apply the offset to get the new position

            var newPos = source - offset;



            // Make sure we do not overshoot

            if (doNotPass)

            {

                if (offset.X > float.Epsilon)

                {

                    if (newPos.X > target.X)

                        newPos.X = target.X;

                }

                else if (offset.X < -float.Epsilon)

                {

                    if (newPos.X < target.X)

                        newPos.X = target.X;

                }



                if (offset.Y > float.Epsilon)

                {

                    if (newPos.Y > target.Y)

                        newPos.Y = target.Y;

                }

                else if (offset.Y < -float.Epsilon)

                {

                    if (newPos.Y < target.Y)

                        newPos.Y = target.Y;

                }

            }



            return newPos;

        }



        /// <summary>

        /// Gets the distance between this <see cref="Vector2"/> and another <see cref="Vector2"/> by getting the

        /// sum of the differences for the components of the <see cref="Vector2"/>s. This is a much quicker but less accurate

        /// version of Distance().

        /// </summary>

        /// <param name="source">Source <see cref="Vector2"/>.</param>

        /// <param name="target">Target <see cref="Vector2"/>.</param>

        /// <returns>The distance between this <see cref="Vector2"/> and another <see cref="Vector2"/> by getting the

        /// sum of the differences for the components of the <see cref="Vector2"/>s.</returns>

        public static float QuickDistance(this Vector2 source, Vector2 target)

        {

            var diff = source - target;

            return Abs(diff).Sum();

        }



        /// <summary>

        /// Gets the proper distance between two vectors. Slower than QuickDistance, but more accurate.

        /// </summary>

        /// <param name="source">Source <see cref="Vector2"/>.</param>

        /// <param name="target">Target <see cref="Vector2"/>.</param>

        /// <returns>The distance between the two vectors.</returns>

        public static float Distance(this Vector2 source, Vector2 target)

        {

            return Vector2.Distance(source, target);

        }



        /// <summary>

        /// Gets a <see cref="Vector2"/> with the X and Y components rounded.

        /// </summary>

        /// <param name="source"><see cref="Vector2"/> to round.</param>

        /// <returns>A <see cref="Vector2"/> containing the rounded value of the <paramref name="source"/>

        /// <see cref="Vector2"/>.</returns>

        public static Vector2 Round(this Vector2 source)

        {

            return new Vector2((float)Math.Round(source.X), (float)Math.Round(source.Y));

        }



        /// <summary>

        /// Gets the sum of the x and y components of the <see cref="Vector2"/>.

        /// </summary>

        /// <param name="source"><see cref="Vector2"/> to get the sum of the components of.</param>

        /// <returns>Sum of the x and y components of the <see cref="Vector2"/>.</returns>

        public static float Sum(this Vector2 source)

        {

            return source.X + source.Y;

        }



        /// <summary>

        /// Gets a <see cref="Rectangle"/> that describes the area around a <see cref="Vector2"/>.

        /// </summary>

        /// <param name="source">The source <see cref="Vector2"/>.</param>

        /// <param name="size">The size of the <see cref="Rectangle"/>.</param>

        /// <param name="center">If true, the <paramref name="source"/> will be at the center of the returned

        /// <see cref="Rectangle"/>. If false, the <paramref name="source"/> will be the top-left corner (min)

        /// of the <see cref="Rectangle"/>.</param>

        /// <returns>The <see cref="Rectangle"/>.</returns>

        public static Rectangle ToRectangle(this Vector2 source, Vector2 size, bool center)

        {

            return ToRectangle(source, size.X, size.Y, center);

        }



        /// <summary>

        /// Gets a <see cref="Rectangle"/> that describes the area around a <see cref="Vector2"/>.

        /// </summary>

        /// <param name="source">The source <see cref="Vector2"/>.</param>

        /// <param name="width">The width of the <see cref="Rectangle"/>.</param>

        /// <param name="height">The height of the <see cref="Rectangle"/>.</param>

        /// <param name="center">If true, the <paramref name="source"/> will be at the center of the returned

        /// <see cref="Rectangle"/>. If false, the <paramref name="source"/> will be the top-left corner (min)

        /// of the <see cref="Rectangle"/>.</param>

        /// <returns>The <see cref="Rectangle"/>.</returns>

        public static Rectangle ToRectangle(this Vector2 source, float width, float height, bool center)

        {

            Vector2 min;



            if (center)

                min = source - new Vector2(width / 2f, height / 2f);

            else

                min = source;



            return new Rectangle(Math.Round(min.X), Math.Round(min.Y), Math.Round(width), Math.Round(height));

        }

    }

}