/// <summary>
/// AngleBetween - the angle between 2 vectors
/// </summary>
/// <returns>
/// Returns the the angle in degrees between vector1 and vector2
/// </returns>
/// <param name="vector1"> The first Vector </param>
/// <param name="vector2"> The second Vector </param>
public static double AngleBetween(Vector vector1, Vector vector2)
{
double sin = vector1._x * vector2._y - vector2._x * vector1._y;
double cos = vector1._x * vector2._x + vector1._y * vector2._y;
return Math.Atan2(sin, cos) * (180 / Math.PI);
}
public static bool IsCCW(Point pt1, Point pt2, Point pt3)
{
Vector V21 = new Vector(pt2, pt1);
Vector v23 = new Vector(pt2, pt3);
return CrossProduct(V21, v23) > 0; // sin(angle pt2 pt1 pt3) < 0, 180<angle pt2 pt1 pt3 <360
}
public static bool IsClockwise(Point pt1, Point pt2, Point pt3)
{
Vector V21 = new Vector(pt2, pt1);
Vector v23 = new Vector(pt2, pt3);
return CrossProduct(V21, v23) < 0; // sin(angle pt1 pt2 pt3) > 0, 0<angle pt1 pt2 pt3 <180
}
/// <summary>
/// Equals - compares this Vector with the passed in object. In this equality
/// Double.NaN is equal to itself, unlike in numeric equality.
/// Note that double values can acquire error when operated upon, such that
/// an exact comparison between two values which
/// are logically equal may fail.
/// </summary>
/// <returns>
/// bool - true if "value" is equal to "this".
/// </returns>
/// <param name='value'>The Vector to compare to "this"</param>
public bool Equals(Vector value)
{
return Vector.Equals(this, value);
}
/// <summary>
/// Compares two Vector instances for object equality. In this equality
/// Double.NaN is equal to itself, unlike in numeric equality.
/// Note that double values can acquire error when operated upon, such that
/// an exact comparison between two values which
/// are logically equal may fail.
/// </summary>
/// <returns>
/// bool - true if the two Vector instances are exactly equal, false otherwise
/// </returns>
/// <param name='vector1'>The first Vector to compare</param>
/// <param name='vector2'>The second Vector to compare</param>
public static bool Equals(Vector vector1, Vector vector2)
{
return vector1.X.Equals(vector2.X) &&
vector1.Y.Equals(vector2.Y);
}
/// <summary>
/// Subtract: Point - Vector
/// </summary>
/// <returns>
/// Point - The result of the subtraction
/// </returns>
/// <param name="point"> The Point from which the Vector is subtracted </param>
/// <param name="vector"> The Vector which is subtracted from the Point </param>
public static Point Subtract(Point point, Vector vector)
{
return new Point(point._x - vector._x, point._y - vector._y);
}
/// <summary>
/// Offset - return the result of offsetting rect by the offset provided
/// If this is Empty, this method is illegal.
/// </summary>
public static Rect Offset(Rect rect, Vector offsetVector)
{
rect.Offset(offsetVector.X, offsetVector.Y);
return rect;
}
/// <summary>
/// Multiply: double * Vector
/// </summary>
public static Vector Multiply(double scalar, Vector vector)
{
return new Vector(vector._x * scalar,
vector._y * scalar);
}
/// <summary>
/// Multiply: Vector / double
/// </summary>
public static Vector Divide(Vector vector, double scalar)
{
return vector * (1.0 / scalar);
}
/// <summary>
/// Subtract: Vector - Vector
/// </summary>
public static Vector Subtract(Vector vector1, Vector vector2)
{
return new Vector(vector1._x - vector2._x,
vector1._y - vector2._y);
}
/// <summary>
/// Add: Vector + Point
/// </summary>
public static Point Add(Vector vector, Point point)
{
return new Point(point._x + vector._x, point._y + vector._y);
}
/// <summary>
/// Add: Vector + Vector
/// </summary>
public static Vector Add(Vector vector1, Vector vector2)
{
return new Vector(vector1._x + vector2._x,
vector1._y + vector2._y);
}
/// <summary>
/// Transform - Transforms each Vector in the array by this matrix.
/// </summary>
/// <param name="vectors"> The Vector array to transform </param>
public void Transform(Vector[] vectors)
{
if (vectors != null)
{
for (int i = 0; i < vectors.Length; i++)
{
MultiplyVector(ref vectors[i]._x, ref vectors[i]._y);
}
}
}
/// <summary>
/// Transform - returns the result of transforming the Vector by this matrix.
/// </summary>
/// <returns>
/// The transformed vector
/// </returns>
/// <param name="vector"> The Vector to transform </param>
public Vector Transform(Vector vector)
{
Vector newVector = vector;
MultiplyVector(ref newVector._x, ref newVector._y);
return newVector;
}
public static double DistancePointLine(Point pt, Point lnA, Point lnB)
{
Vector v1 = new Vector(lnA, lnB);
Vector v2 = new Vector(lnA, pt);
v1.Normalize();
return Math.Abs(CrossProduct(v2, v1));
}
/// <summary>
/// Multiply: Vector * Matrix
/// </summary>
public static Vector Multiply(Vector vector, Matrix matrix)
{
return matrix.Transform(vector);
}
/// <summary>
/// CrossProduct - Returns the cross product: vector1.X*vector2.Y - vector1.Y*vector2.X
/// </summary>
/// <returns>
/// Returns the cross product: vector1.X*vector2.Y - vector1.Y*vector2.X
/// </returns>
/// <param name="vector1"> The first Vector </param>
/// <param name="vector2"> The second Vector </param>
public static double CrossProduct(Vector vector1, Vector vector2)
{
return vector1._x * vector2._y - vector1._y * vector2._x;
}
/// <summary>
/// Multiply - Returns the dot product: vector1.X*vector2.X + vector1.Y*vector2.Y
/// </summary>
/// <returns>
/// Returns the dot product: vector1.X*vector2.X + vector1.Y*vector2.Y
/// </returns>
/// <param name="vector1"> The first Vector </param>
/// <param name="vector2"> The second Vector </param>
public static double Multiply(Vector vector1, Vector vector2)
{
return vector1._x * vector2._x + vector1._y * vector2._y;
}
/// <summary>
/// Offset - translate the Location by the offset provided.
/// If this is Empty, this method is illegal.
/// </summary>
public void Offset(Vector offsetVector)
{
if (IsEmpty)
{
throw new System.InvalidOperationException("Rect_CannotCallMethod");
}
_x += offsetVector._x;
_y += offsetVector._y;
}
/// <summary>
/// Determinant - Returns the determinant det(vector1, vector2)
/// </summary>
/// <returns>
/// Returns the determinant: vector1.X*vector2.Y - vector1.Y*vector2.X
/// </returns>
/// <param name="vector1"> The first Vector </param>
/// <param name="vector2"> The second Vector </param>
public static double Determinant(Vector vector1, Vector vector2)
{
return vector1._x * vector2._y - vector1._y * vector2._x;
}
/// <summary>
/// Constructor which sets the initial values to bound the point provided and the point
/// which results from point + vector.
/// </summary>
public Rect(Point point,
Vector vector)
: this(point, point + vector)
{
}
/// <summary>
/// Compares two Vector instances for fuzzy equality. This function
/// helps compensate for the fact that double values can
/// acquire error when operated upon
/// </summary>
/// <param name='vector1'>The first Vector to compare</param>
/// <param name='vector2'>The second Vector to compare</param>
/// <returns>Whether or not the two Vector instances are equal</returns>
public static bool AreClose(Vector vector1, Vector vector2)
{
return DoubleUtil.AreClose(vector1.X, vector2.X) &&
DoubleUtil.AreClose(vector1.Y, vector2.Y);
}
