#region --- License ---
/* Copyright (c) 2006, 2007 Stefanos Apostolopoulos
* See license.txt for license info
*
* Contributions by Andy Gill.
*/
#endregion
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
namespace OpenTK.Math
{
///
/// Represents a three-dimensional vector.
///
[Serializable]
[StructLayout(LayoutKind.Sequential)]
public struct Vector3 : IEquatable
{
#region Fields
///
/// The X component of the Vector3.
///
public float X;
///
/// The Y component of the Vector3.
///
public float Y;
///
/// The Z component of the Vector3.
///
public float Z;
public static readonly Vector3 UnitX = new Vector3(1, 0, 0);
public static readonly Vector3 UnitY = new Vector3(0, 1, 0);
public static readonly Vector3 UnitZ = new Vector3(0, 0, 1);
public static readonly Vector3 Zero = new Vector3(0, 0, 0);
public static readonly int SizeInBytes = Marshal.SizeOf(new Vector3());
#endregion
#region Constructors
///
/// Constructs a new Vector3.
///
/// The x component of the Vector3.
/// The y component of the Vector3.
/// The z component of the Vector3.
public Vector3(float x, float y, float z)
{
X = x;
Y = y;
Z = z;
}
///
/// Constructs a new Vector3 from the given Vector2.
///
/// The Vector2 to copy components from.
public Vector3(Vector2 v)
{
X = v.X;
Y = v.Y;
Z = 0.0f;
}
///
/// Constructs a new Vector3 from the given Vector3.
///
/// The Vector3 to copy components from.
public Vector3(Vector3 v)
{
X = v.X;
Y = v.Y;
Z = v.Z;
}
///
/// Constructs a new Vector3 from the given Vector4.
///
/// The Vector4 to copy components from.
public Vector3(Vector4 v)
{
X = v.X;
Y = v.Y;
Z = v.Z;
}
#endregion
#region Functions
#region This property
public float this[int index]
{
get
{
switch (index)
{
case 0: return X;
case 1: return Y;
case 2: return Z;
default: throw new ArgumentOutOfRangeException("index", index, "Should be 0, 1 or 2.");
}
/*
unsafe
{
fixed (float* ptr = &this.X)
return *(ptr + index);
}
*/
}
}
#endregion
#region public float Length
///
/// Gets the length (magnitude) of the vector.
///
///
///
public float Length
{
get
{
return (float)System.Math.Sqrt(X * X + Y * Y + Z * Z);
}
}
#endregion
#region public float LengthFast
///
/// Gets an approximation of the vector length (magnitude).
///
///
/// This property uses an approximation of the square root function to calculate vector magnitude, with
/// an upper error bound of 0.001.
///
///
///
///
public float LengthFast
{
get
{
return 1.0f / OpenTK.Math.Functions.InverseSqrtFast(X * X + Y * Y + Z * Z);
}
}
#endregion
#region public float LengthSquared
///
/// Gets the square of the vector length (magnitude).
///
///
/// This property avoids the costly square root operation required by the Length property. This makes it more suitable
/// for comparisons.
///
///
///
public float LengthSquared
{
get
{
return X * X + Y * Y + Z * Z;
}
}
#endregion
#region public void Normalize()
///
/// Scales the Vector3 to unit length.
///
public void Normalize()
{
float scale = 1.0f / this.Length;
X *= scale;
Y *= scale;
Z *= scale;
}
#endregion
#region public void NormalizeFast()
///
/// Scales the Vector3 to approximately unit length.
///
public void NormalizeFast()
{
float scale = Functions.InverseSqrtFast(X * X + Y * Y + Z * Z);
X *= scale;
Y *= scale;
Z *= scale;
}
#endregion
#region public void Scale(float sx, float sy, float sz)
///
/// Scales the current Vector3 by the given amounts.
///
/// The scale of the X component.
/// The scale of the Y component.
/// The scale of the Z component.
public void Scale(float sx, float sy, float sz)
{
this.X = X * sx;
this.Y = Y * sy;
this.Z = Z * sz;
}
#endregion
#endregion
#region Operator overloads
public static Vector3 operator +(Vector3 left, Vector3 right)
{
left.X += right.X;
left.Y += right.Y;
left.Z += right.Z;
return left;
}
public static Vector3 operator -(Vector3 left, Vector3 right)
{
left.X -= right.X;
left.Y -= right.Y;
left.Z -= right.Z;
return left;
}
public static Vector3 operator -(Vector3 vec)
{
vec.X = -vec.X;
vec.Y = -vec.Y;
vec.Z = -vec.Z;
return vec;
}
public static Vector3 operator *(Vector3 vec, float f)
{
vec.X *= f;
vec.Y *= f;
vec.Z *= f;
return vec;
}
public static Vector3 operator *(float f, Vector3 vec)
{
vec.X *= f;
vec.Y *= f;
vec.Z *= f;
return vec;
}
public static Vector3 operator /(Vector3 vec, float f)
{
float mult = 1.0f / f;
vec.X *= mult;
vec.Y *= mult;
vec.Z *= mult;
return vec;
}
public static bool operator ==(Vector3 left, Vector3 right)
{
return left.Equals(right);
}
public static bool operator !=(Vector3 left, Vector3 right)
{
return !left.Equals(right);
}
#endregion
#region Static functions
#region Add
///
/// Add two Vectors
///
/// First operand
/// Second operand
/// Result of addition
public static Vector3 Add(Vector3 a, Vector3 b)
{
a.X += b.X;
a.Y += b.Y;
a.Z += b.Z;
return a;
}
///
/// Add two Vectors
///
/// First operand
/// Second operand
/// Result of addition
public static void Add(ref Vector3 a, ref Vector3 b, out Vector3 result)
{
result.X = a.X + b.X;
result.Y = a.Y + b.Y;
result.Z = a.Z + b.Z;
}
#endregion
#region Sub
///
/// Subtract one Vector from another
///
/// First operand
/// Second operand
/// Result of subtraction
public static Vector3 Sub(Vector3 a, Vector3 b)
{
a.X -= b.X;
a.Y -= b.Y;
a.Z -= b.Z;
return a;
}
///
/// Subtract one Vector from another
///
/// First operand
/// Second operand
/// Result of subtraction
public static void Sub(ref Vector3 a, ref Vector3 b, out Vector3 result)
{
result.X = a.X - b.X;
result.Y = a.Y - b.Y;
result.Z = a.Z - b.Z;
}
#endregion
#region Mult
///
/// Multiply a vector and a scalar
///
/// Vector operand
/// Scalar operand
/// Result of the multiplication
public static Vector3 Mult(Vector3 a, float f)
{
a.X *= f;
a.Y *= f;
a.Z *= f;
return a;
}
///
/// Multiply a vector and a scalar
///
/// Vector operand
/// Scalar operand
/// Result of the multiplication
public static void Mult(ref Vector3 a, float f, out Vector3 result)
{
result.X = a.X * f;
result.Y = a.Y * f;
result.Z = a.Z * f;
}
#endregion
#region Div
///
/// Divide a vector by a scalar
///
/// Vector operand
/// Scalar operand
/// Result of the division
public static Vector3 Div(Vector3 a, float f)
{
float mult = 1.0f / f;
a.X *= mult;
a.Y *= mult;
a.Z *= mult;
return a;
}
///
/// Divide a vector by a scalar
///
/// Vector operand
/// Scalar operand
/// Result of the division
public static void Div(ref Vector3 a, float f, out Vector3 result)
{
float mult = 1.0f / f;
result.X = a.X * mult;
result.Y = a.Y * mult;
result.Z = a.Z * mult;
}
#endregion
#region ComponentMin
///
/// Calculate the component-wise minimum of two vectors
///
/// First operand
/// Second operand
/// The component-wise minimum
public static Vector3 ComponentMin(Vector3 a, Vector3 b)
{
a.X = a.X < b.X ? a.X : b.X;
a.Y = a.Y < b.Y ? a.Y : b.Y;
a.Z = a.Z < b.Z ? a.Z : b.Z;
return a;
}
///
/// Calculate the component-wise minimum of two vectors
///
/// First operand
/// Second operand
/// The component-wise minimum
public static void ComponentMin(ref Vector3 a, ref Vector3 b, out Vector3 result)
{
result.X = a.X < b.X ? a.X : b.X;
result.Y = a.Y < b.Y ? a.Y : b.Y;
result.Z = a.Z < b.Z ? a.Z : b.Z;
}
#endregion
#region ComponentMax
///
/// Calculate the component-wise maximum of two vectors
///
/// First operand
/// Second operand
/// The component-wise maximum
public static Vector3 ComponentMax(Vector3 a, Vector3 b)
{
a.X = a.X > b.X ? a.X : b.X;
a.Y = a.Y > b.Y ? a.Y : b.Y;
a.Z = a.Z > b.Z ? a.Z : b.Z;
return a;
}
///
/// Calculate the component-wise maximum of two vectors
///
/// First operand
/// Second operand
/// The component-wise maximum
public static void ComponentMax(ref Vector3 a, ref Vector3 b, out Vector3 result)
{
result.X = a.X > b.X ? a.X : b.X;
result.Y = a.Y > b.Y ? a.Y : b.Y;
result.Z = a.Z > b.Z ? a.Z : b.Z;
}
#endregion
#region Min
///
/// Returns the Vector3 with the minimum magnitude
///
/// Left operand
/// Right operand
/// The minimum Vector3
public static Vector3 Min(Vector3 left, Vector3 right)
{
return left.LengthSquared < right.LengthSquared ? left : right;
}
#endregion
#region Max
///
/// Returns the Vector3 with the minimum magnitude
///
/// Left operand
/// Right operand
/// The minimum Vector3
public static Vector3 Max(Vector3 left, Vector3 right)
{
return left.LengthSquared >= right.LengthSquared ? left : right;
}
#endregion
#region Clamp
///
/// Clamp a vector to the given minimum and maximum vectors
///
/// Input vector
/// Minimum vector
/// Maximum vector
/// The clamped vector
public static Vector3 Clamp(Vector3 vec, Vector3 min, Vector3 max)
{
vec.X = vec.X < min.X ? min.X : vec.X > max.X ? max.X : vec.X;
vec.Y = vec.Y < min.Y ? min.Y : vec.Y > max.Y ? max.Y : vec.Y;
vec.Z = vec.Z < min.Z ? min.Z : vec.Z > max.Z ? max.Z : vec.Z;
return vec;
}
///
/// Clamp a vector to the given minimum and maximum vectors
///
/// Input vector
/// Minimum vector
/// Maximum vector
/// The clamped vector
public static void Clamp(ref Vector3 vec, ref Vector3 min, ref Vector3 max, out Vector3 result)
{
result.X = vec.X < min.X ? min.X : vec.X > max.X ? max.X : vec.X;
result.Y = vec.Y < min.Y ? min.Y : vec.Y > max.Y ? max.Y : vec.Y;
result.Z = vec.Z < min.Z ? min.Z : vec.Z > max.Z ? max.Z : vec.Z;
}
#endregion
#region Normalize
///
/// Scale a vector to unit length
///
/// The input vector
/// The normalized vector
public static Vector3 Normalize(Vector3 vec)
{
float scale = 1.0f / vec.Length;
vec.X *= scale;
vec.Y *= scale;
vec.Z *= scale;
return vec;
}
///
/// Scale a vector to unit length
///
/// The input vector
/// The normalized vector
public static void Normalize(ref Vector3 vec, out Vector3 result)
{
float scale = 1.0f / vec.Length;
result.X = vec.X * scale;
result.Y = vec.Y * scale;
result.Z = vec.Z * scale;
}
#endregion
#region NormalizeFast
///
/// Scale a vector to approximately unit length
///
/// The input vector
/// The normalized vector
public static Vector3 NormalizeFast(Vector3 vec)
{
float scale = Functions.InverseSqrtFast(vec.X * vec.X + vec.Y * vec.Y + vec.Z * vec.Z);
vec.X *= scale;
vec.Y *= scale;
vec.Z *= scale;
return vec;
}
///
/// Scale a vector to approximately unit length
///
/// The input vector
/// The normalized vector
public static void NormalizeFast(ref Vector3 vec, out Vector3 result)
{
float scale = Functions.InverseSqrtFast(vec.X * vec.X + vec.Y * vec.Y + vec.Z * vec.Z);
result.X = vec.X * scale;
result.Y = vec.Y * scale;
result.Z = vec.Z * scale;
}
#endregion
#region Dot
///
/// Caclulate the dot (scalar) product of two vectors
///
/// First operand
/// Second operand
/// The dot product of the two inputs
public static float Dot(Vector3 left, Vector3 right)
{
return left.X * right.X + left.Y * right.Y + left.Z * right.Z;
}
#endregion
#region Cross
///
/// Caclulate the cross (vector) product of two vectors
///
/// First operand
/// Second operand
/// The cross product of the two inputs
public static Vector3 Cross(Vector3 left, Vector3 right)
{
float
x = left.Y * right.Z - left.Z * right.Y,
y = left.Z * right.X - left.X * right.Z,
z = left.X * right.Y - left.Y * right.X;
left.X = x;
left.Y = y;
left.Z = z;
return left;
}
///
/// Caclulate the cross (vector) product of two vectors
///
/// First operand
/// Second operand
/// The cross product of the two inputs
/// The cross product of the two inputs
public static void Cross(ref Vector3 left, ref Vector3 right, out Vector3 result)
{
result.X = left.Y * right.Z - left.Z * right.Y;
result.Y = left.Z * right.X - left.X * right.Z;
result.Z = left.X * right.Y - left.Y * right.X;
}
#endregion
#region Lerp
///
/// Returns a new Vector that is the linear blend of the 2 given Vectors
///
/// First input vector
/// Second input vector
/// The blend factor
/// a when blend=0, b when blend=1, and a linear combination otherwise
public static Vector3 Lerp(Vector3 a, Vector3 b, float blend)
{
a.X = blend * (b.X - a.X) + a.X;
a.Y = blend * (b.Y - a.Y) + a.Y;
a.Z = blend * (b.Z - a.Z) + a.Z;
return a;
}
#endregion
#region Barycentric
///
/// Interpolate 3 Vectors using Barycentric coordinates
///
/// First input Vector
/// Second input Vector
/// Third input Vector
/// First Barycentric Coordinate
/// Second Barycentric Coordinate
/// 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
public static Vector3 BaryCentric(Vector3 a, Vector3 b, Vector3 c, float u, float v)
{
return a + u * (b - a) + v * (c - a);
}
#endregion
#region Transform
///
/// Transform a direction vector by the given Matrix
/// Assumes the matrix has a bottom row of (0,0,0,1), that is the translation part is ignored.
///
/// The vector to transform
/// The desired transformation
/// The transformed vector
public static Vector3 TransformVector(Vector3 vec, Matrix4 mat)
{
Vector3 v;
v.X = Vector3.Dot(vec, new Vector3(mat.Column0));
v.Y = Vector3.Dot(vec, new Vector3(mat.Column1));
v.Z = Vector3.Dot(vec, new Vector3(mat.Column2));
return v;
}
///
/// Transform a Normal by the given Matrix
///
///
/// This calculates the inverse of the given matrix, use TransformNormalInverse if you
/// already have the inverse to avoid this extra calculation
///
/// The normal to transform
/// The desired transformation
/// The transformed normal
public static Vector3 TransformNormal(Vector3 norm, Matrix4 mat)
{
mat.Invert();
return TransformNormalInverse(norm, mat);
}
///
/// Transform a Normal by the (transpose of the) given Matrix
///
///
/// This version doesn't calculate the inverse matrix.
/// Use this version if you already have the inverse of the desired transform to hand
///
/// The normal to transform
/// The inverse of the desired transformation
/// The transformed normal
public static Vector3 TransformNormalInverse(Vector3 norm, Matrix4 invMat)
{
Vector3 n;
n.X = Vector3.Dot(norm, new Vector3(invMat.Row0));
n.Y = Vector3.Dot(norm, new Vector3(invMat.Row1));
n.Z = Vector3.Dot(norm, new Vector3(invMat.Row2));
return n;
}
///
/// Transform a Position by the given Matrix
///
/// The position to transform
/// The desired transformation
/// The transformed position
public static Vector3 TransformPosition(Vector3 pos, Matrix4 mat)
{
Vector3 p;
p.X = Vector3.Dot(pos, new Vector3(mat.Column0)) + mat.Row3.X;
p.Y = Vector3.Dot(pos, new Vector3(mat.Column1)) + mat.Row3.Y;
p.Z = Vector3.Dot(pos, new Vector3(mat.Column2)) + mat.Row3.Z;
return p;
}
///
/// Transform a Vector by the given Matrix
///
/// The vector to transform
/// The desired transformation
/// The transformed vector
public static Vector4 Transform(Vector3 vec, Matrix4 mat)
{
Vector4 v4 = new Vector4(vec.X, vec.Y, vec.Z, 1.0f);
Vector4 result;
result.X = Vector4.Dot(v4, mat.Column0);
result.Y = Vector4.Dot(v4, mat.Column1);
result.Z = Vector4.Dot(v4, mat.Column2);
result.W = Vector4.Dot(v4, mat.Column3);
return result;
}
///
/// Transform a Vector3 by the given Matrix, and project the resulting Vector4 back to a Vector3
///
/// The vector to transform
/// The desired transformation
/// The transformed vector
public static Vector3 TransformPerspective(Vector3 vec, Matrix4 mat)
{
Vector4 h = Transform(vec, mat);
return new Vector3(h.X / h.W, h.Y / h.W, h.Z / h.W);
}
#endregion
#region CalculateAngle
///
/// Calculates the angle (in radians) between two vectors.
///
/// The first vector.
/// The second vector.
/// Angle (in radians) between the vectors.
/// Note that the returned angle is never bigger than the constant Pi.
public static float CalculateAngle(Vector3 first, Vector3 second)
{
return (float)System.Math.Acos((Vector3.Dot(first, second)) / (first.Length * second.Length));
}
#endregion
#endregion
#region public override string ToString()
///
/// Returns a System.String that represents the current Vector3.
///
///
public override string ToString()
{
return String.Format("({0}, {1}, {2})", X, Y, Z);
}
#endregion
#region public override int GetHashCode()
///
/// Returns the hashcode for this instance.
///
/// A System.Int32 containing the unique hashcode for this instance.
public override int GetHashCode()
{
return X.GetHashCode() ^ Y.GetHashCode() ^ Z.GetHashCode();
}
#endregion
#region public override bool Equals(object obj)
///
/// Indicates whether this instance and a specified object are equal.
///
/// The object to compare to.
/// True if the instances are equal; false otherwise.
public override bool Equals(object obj)
{
if (!(obj is Vector3))
return false;
return this.Equals((Vector3)obj);
}
#endregion
#region IEquatable Members
/// Indicates whether the current vector is equal to another vector.
/// A vector to compare with this vector.
/// true if the current vector is equal to the vector parameter; otherwise, false.
public bool Equals(Vector3 other)
{
return
X == other.X &&
Y == other.Y &&
Z == other.Z;
}
#endregion
}
}