589 lines
15 KiB
C#
589 lines
15 KiB
C#
#region --- License ---
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/* Copyright (c) 2006, 2007 Stefanos Apostolopoulos
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* See license.txt for license info
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*
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* Contributions by Andy Gill.
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*/
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#endregion
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using System;
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using System.Collections.Generic;
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using System.Text;
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using System.Runtime.InteropServices;
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namespace OpenTK.Math
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{
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/// <summary>
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/// Represents a 2D vector.
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/// </summary>
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/// <remarks>
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/// The Vector2 structure is suitable for interoperation with unmanaged code requiring two consecutive floats.
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/// </remarks>
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[StructLayout(LayoutKind.Sequential)]
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public struct Vector2
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{
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#region Fields
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/// <summary>
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/// The X component of the Vector2.
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/// </summary>
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public float X;
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/// <summary>
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/// The Y component of the Vector2.
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/// </summary>
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public float Y;
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public static Vector2 UnitX = new Vector2(1, 0);
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public static Vector2 UnitY = new Vector2(0, 1);
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public static Vector2 Zero = new Vector2(0, 0);
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#endregion
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#region Constructors
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/// <summary>
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/// Constructs a new Vector2.
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/// </summary>
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/// <param name="x">The x coordinate of the net Vector2.</param>
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/// <param name="y">The y coordinate of the net Vector2.</param>
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public Vector2(float x, float y)
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{
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X = x;
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Y = y;
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}
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/// <summary>
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/// Constructs a new Vector2 from the given Vector2.
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/// </summary>
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/// <param name="v">The Vector2 to copy components from.</param>
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public Vector2(Vector2 v)
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{
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X = v.X;
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Y = v.Y;
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}
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/// <summary>
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/// Constructs a new Vector2 from the given Vector3.
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/// </summary>
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/// <param name="v">The Vector3 to copy components from. Z is discarded.</param>
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public Vector2(Vector3 v)
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{
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X = v.X;
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Y = v.Y;
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}
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/// <summary>
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/// Constructs a new Vector2 from the given Vector4.
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/// </summary>
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/// <param name="v">The Vector4 to copy components from. Z and W are discarded.</param>
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public Vector2(Vector4 v)
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{
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X = v.X;
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Y = v.Y;
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}
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#endregion
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#region Functions
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#region public float Length
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/// <summary>
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/// Gets the length (magnitude) of the vector.
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/// </summary>
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/// <see cref="FastLength"/>
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/// <seealso cref="LengthSquared"/>
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public float Length
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{
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get
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{
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return (float)System.Math.Sqrt(X * X + Y * Y);
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}
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}
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#endregion
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#region public float LengthFast
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/// <summary>
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/// Gets an approximation of the vector length (magnitude).
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/// </summary>
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/// <remarks>
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/// This property uses an approximation of the square root function to calculate vector magnitude, with
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/// an upper error bound of 0.001.
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/// </remarks>
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/// <see cref="Length"/>
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/// <seealso cref="LengthSquared"/>
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/// <seealso cref="OpenTK.Math.FastSqrt"/>
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public float LengthFast
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{
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get
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{
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return 1.0f / OpenTK.Math.Functions.InverseSqrtFast(X * X + Y * Y);
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}
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}
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#endregion
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#region public float LengthSquared
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/// <summary>
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/// Gets the square of the vector length (magnitude).
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/// </summary>
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/// <remarks>
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/// This property avoids the costly square root operation required by the Length property. This makes it more suitable
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/// for comparisons.
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/// </remarks>
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/// <see cref="Length"/>
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/// <seealso cref="FastLength"/>
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public float LengthSquared
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{
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get
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{
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return X * X + Y * Y;
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}
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}
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#endregion
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#region public void Normalize()
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/// <summary>
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/// Scales the Vector2 to unit length.
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/// </summary>
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public void Normalize()
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{
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float scale = 1.0f / this.Length;
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X *= scale;
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Y *= scale;
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}
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#endregion
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#region public void NormalizeFast()
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/// <summary>
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/// Scales the Vector2 to approximately unit length.
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/// </summary>
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public void NormalizeFast()
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{
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float scale = Functions.InverseSqrtFast(X * X + Y * Y);
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X *= scale;
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Y *= scale;
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}
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#endregion
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#region public void Scale(float sx, float sy)
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/// <summary>
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/// Scales the current Vector2 by the given amounts.
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/// </summary>
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/// <param name="sx">The scale of the X component.</param>
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/// <param name="sy">The scale of the Y component.</param>
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public void Scale(float sx, float sy)
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{
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this.X = X * sx;
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this.Y = Y * sy;
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}
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#endregion
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#endregion
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#region Operator overloads
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public static Vector2 operator +(Vector2 left, Vector2 right)
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{
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left.X += right.X;
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left.Y += right.Y;
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return left;
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}
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public static Vector2 operator -(Vector2 left, Vector2 right)
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{
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left.X -= right.X;
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left.Y -= right.Y;
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return left;
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}
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public static Vector2 operator -(Vector2 vec)
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{
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vec.X = -vec.X;
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vec.Y = -vec.Y;
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return vec;
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}
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public static Vector2 operator *(Vector2 vec, float f)
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{
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vec.X *= f;
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vec.Y *= f;
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return vec;
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}
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public static Vector2 operator *(float f, Vector2 vec)
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{
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vec.X *= f;
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vec.Y *= f;
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return vec;
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}
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public static Vector2 operator /(Vector2 vec, float f)
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{
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float mult = 1.0f / f;
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vec.X *= mult;
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vec.Y *= mult;
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return vec;
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}
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[CLSCompliant(false)]
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unsafe public static explicit operator float*(Vector2 v)
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{
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return &v.X;
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}
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public static explicit operator IntPtr(Vector2 v)
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{
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unsafe
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{
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return (IntPtr)(&v.X);
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}
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}
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#endregion
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#region Static functions
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#region Add
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/// <summary>
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/// Add two Vectors
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/// </summary>
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/// <param name="a">First operand</param>
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/// <param name="b">Second operand</param>
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/// <returns>Result of addition</returns>
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public static Vector2 Add(Vector2 a, Vector2 b)
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{
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a.X += b.X;
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a.Y += b.Y;
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return a;
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}
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/// <summary>
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/// Add two Vectors
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/// </summary>
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/// <param name="a">First operand</param>
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/// <param name="b">Second operand</param>
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/// <param name="result">Result of addition</param>
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public static void Add(ref Vector2 a, ref Vector2 b, out Vector2 result)
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{
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result.X = a.X + b.X;
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result.Y = a.Y + b.Y;
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}
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#endregion
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#region Sub
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/// <summary>
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/// Subtract one Vector from another
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/// </summary>
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/// <param name="a">First operand</param>
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/// <param name="b">Second operand</param>
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/// <returns>Result of subtraction</returns>
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public static Vector2 Sub(Vector2 a, Vector2 b)
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{
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a.X -= b.X;
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a.Y -= b.Y;
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return a;
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}
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/// <summary>
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/// Subtract one Vector from another
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/// </summary>
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/// <param name="a">First operand</param>
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/// <param name="b">Second operand</param>
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/// <param name="result">Result of subtraction</param>
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public static void Sub(ref Vector2 a, ref Vector2 b, out Vector2 result)
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{
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result.X = a.X - b.X;
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result.Y = a.Y - b.Y;
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}
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#endregion
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#region Mult
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/// <summary>
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/// Multiply a vector and a scalar
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/// </summary>
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/// <param name="a">Vector operand</param>
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/// <param name="f">Scalar operand</param>
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/// <returns>Result of the multiplication</returns>
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public static Vector2 Mult(Vector2 a, float f)
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{
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a.X *= f;
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a.Y *= f;
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return a;
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}
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/// <summary>
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/// Multiply a vector and a scalar
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/// </summary>
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/// <param name="a">Vector operand</param>
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/// <param name="f">Scalar operand</param>
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/// <param name="result">Result of the multiplication</param>
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public static void Mult(ref Vector2 a, float f, out Vector2 result)
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{
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result.X = a.X * f;
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result.Y = a.Y * f;
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}
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#endregion
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#region Div
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/// <summary>
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/// Divide a vector by a scalar
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/// </summary>
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/// <param name="a">Vector operand</param>
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/// <param name="f">Scalar operand</param>
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/// <returns>Result of the division</returns>
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public static Vector2 Div(Vector2 a, float f)
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{
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float mult = 1.0f / f;
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a.X *= mult;
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a.Y *= mult;
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return a;
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}
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/// <summary>
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/// Divide a vector by a scalar
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/// </summary>
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/// <param name="a">Vector operand</param>
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/// <param name="f">Scalar operand</param>
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/// <param name="result">Result of the division</param>
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public static void Div(ref Vector2 a, float f, out Vector2 result)
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{
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float mult = 1.0f / f;
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result.X = a.X * mult;
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result.Y = a.Y * mult;
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}
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#endregion
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#region Min
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/// <summary>
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/// Calculate the component-wise minimum of two vectors
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/// </summary>
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/// <param name="a">First operand</param>
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/// <param name="b">Second operand</param>
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/// <returns>The component-wise minimum</returns>
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public static Vector2 Min(Vector2 a, Vector2 b)
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{
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a.X = a.X < b.X ? a.X : b.X;
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a.Y = a.Y < b.Y ? a.Y : b.Y;
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return a;
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}
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/// <summary>
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/// Calculate the component-wise minimum of two vectors
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/// </summary>
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/// <param name="a">First operand</param>
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/// <param name="b">Second operand</param>
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/// <param name="result">The component-wise minimum</param>
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public static void Min(ref Vector2 a, ref Vector2 b, out Vector2 result)
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{
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result.X = a.X < b.X ? a.X : b.X;
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result.Y = a.Y < b.Y ? a.Y : b.Y;
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}
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#endregion
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#region Max
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/// <summary>
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/// Calculate the component-wise maximum of two vectors
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/// </summary>
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/// <param name="a">First operand</param>
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/// <param name="b">Second operand</param>
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/// <returns>The component-wise maximum</returns>
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public static Vector2 Max(Vector2 a, Vector2 b)
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{
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a.X = a.X > b.X ? a.X : b.X;
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a.Y = a.Y > b.Y ? a.Y : b.Y;
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return a;
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}
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/// <summary>
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/// Calculate the component-wise maximum of two vectors
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/// </summary>
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/// <param name="a">First operand</param>
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/// <param name="b">Second operand</param>
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/// <param name="result">The component-wise maximum</param>
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public static void Max(ref Vector2 a, ref Vector2 b, out Vector2 result)
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{
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result.X = a.X > b.X ? a.X : b.X;
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result.Y = a.Y > b.Y ? a.Y : b.Y;
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}
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#endregion
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#region Clamp
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/// <summary>
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/// Clamp a vector to the given minimum and maximum vectors
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/// </summary>
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/// <param name="vec">Input vector</param>
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/// <param name="min">Minimum vector</param>
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/// <param name="max">Maximum vector</param>
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/// <returns>The clamped vector</returns>
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public static Vector2 Clamp(Vector2 vec, Vector2 min, Vector2 max)
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{
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vec.X = vec.X < min.X ? min.X : vec.X > max.X ? max.X : vec.X;
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vec.Y = vec.Y < min.Y ? min.Y : vec.Y > max.Y ? max.Y : vec.Y;
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return vec;
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}
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/// <summary>
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/// Clamp a vector to the given minimum and maximum vectors
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/// </summary>
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/// <param name="vec">Input vector</param>
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/// <param name="min">Minimum vector</param>
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/// <param name="max">Maximum vector</param>
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/// <param name="result">The clamped vector</param>
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public static void Clamp(ref Vector2 vec, ref Vector2 min, ref Vector2 max, out Vector2 result)
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{
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result.X = vec.X < min.X ? min.X : vec.X > max.X ? max.X : vec.X;
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result.Y = vec.Y < min.Y ? min.Y : vec.Y > max.Y ? max.Y : vec.Y;
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}
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#endregion
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#region Normalize
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/// <summary>
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/// Scale a vector to unit length
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/// </summary>
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/// <param name="vec">The input vector</param>
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/// <returns>The normalized vector</returns>
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public static Vector2 Normalize(Vector2 vec)
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{
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float scale = 1.0f / vec.Length;
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vec.X *= scale;
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vec.Y *= scale;
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return vec;
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}
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/// <summary>
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/// Scale a vector to unit length
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/// </summary>
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/// <param name="vec">The input vector</param>
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/// <param name="result">The normalized vector</param>
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public static void Normalize(ref Vector2 vec, out Vector2 result)
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{
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float scale = 1.0f / vec.Length;
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result.X = vec.X * scale;
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result.Y = vec.Y * scale;
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}
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#endregion
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#region NormalizeFast
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/// <summary>
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/// Scale a vector to approximately unit length
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/// </summary>
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/// <param name="vec">The input vector</param>
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/// <returns>The normalized vector</returns>
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public static Vector2 NormalizeFast(Vector2 vec)
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{
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float scale = Functions.InverseSqrtFast(vec.X * vec.X + vec.Y * vec.Y);
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vec.X *= scale;
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vec.Y *= scale;
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return vec;
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}
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/// <summary>
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/// Scale a vector to approximately unit length
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/// </summary>
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/// <param name="vec">The input vector</param>
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/// <param name="result">The normalized vector</param>
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public static void NormalizeFast(ref Vector2 vec, out Vector2 result)
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{
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float scale = Functions.InverseSqrtFast(vec.X * vec.X + vec.Y * vec.Y);
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result.X = vec.X * scale;
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result.Y = vec.Y * scale;
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}
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#endregion
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#region Dot
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/// <summary>
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/// Caclulate the dot (scalar) product of two vectors
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/// </summary>
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/// <param name="left">First operand</param>
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/// <param name="right">Second operand</param>
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/// <returns>The dot product of the two inputs</returns>
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public static float Dot(Vector2 left, Vector2 right)
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{
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return left.X * right.X + left.Y * right.Y;
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}
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#endregion
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#region Lerp
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/// <summary>
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/// Returns a new Vector that is the linear blend of the 2 given Vectors
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/// </summary>
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/// <param name="a">First input vector</param>
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/// <param name="b">Second input vector</param>
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/// <param name="blend">The blend factor</param>
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/// <returns>a when blend=0, b when blend=1, and a linear combination otherwise</returns>
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public static Vector2 Lerp(Vector2 a, Vector2 b, float blend)
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{
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a.X = blend * (b.X - a.X) + a.X;
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a.Y = blend * (b.Y - a.Y) + a.Y;
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return a;
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}
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#endregion
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#region Barycentric
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/// <summary>
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/// Interpolate 3 Vectors using Barycentric coordinates
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/// </summary>
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/// <param name="a">First input Vector</param>
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/// <param name="b">Second input Vector</param>
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/// <param name="c">Third input Vector</param>
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/// <param name="u">First Barycentric Coordinate</param>
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/// <param name="v">Second Barycentric Coordinate</param>
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/// <returns>a when u=v=0, b when u=1,v=0, c when u=0,v=1, and a linear combination of a,b,c otherwise</returns>
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public static Vector2 BaryCentric(Vector2 a, Vector2 b, Vector2 c, float u, float v)
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{
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return a + u * (b - a) + v * (c - a);
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}
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#endregion
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#endregion
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#region public override string ToString()
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/// <summary>
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/// Returns a System.String that represents the current Vector2.
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/// </summary>
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/// <returns></returns>
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|
public override string ToString()
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|
{
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|
return String.Format("({0}, {1})", X, Y);
|
|
}
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|
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|
#endregion
|
|
}
|
|
}
|