class Point2D

Defined in: TSVector2D.h

The Point2D class encapsulates a 2D point.

Definition

class Point2D : public Vector2D

Constructor

Point2D();

Point2D(float a, float b);

Parameters

`a`	The value of the x coordinate.
`b`	The value of the y coordinate.

Description

The Point2D class is used to store a two-dimensional point having floating-point coordinates x and y. The difference between a point and a vector is that a point is assumed to have a w coordinate of 1 whenever it needs to be converted to a four-dimensional representation, whereas a vector is assumed to have a w coordinate of 0. Such a conversion occurs when a vector or point is assigned to a Vector4D object or is multiplied by a Transform4D object.

The default constructor leaves the components of the vector undefined. If the values a and b are supplied, then they are assigned to the x and y coordinates of the base vector object, respectively.

The difference between two points produces a direction vector. A two-dimensional direction vector is converted to a point by adding it to the identifier Zero2D.

Overloaded Operators

`Point2D& operator *=(float n);`	Multiplies by the scalar `n`.
`Point2D& operator /=(float n);`	Divides by the scalar `n`.

Nonmember Operations

`Point2D operator -(const Point2D& p);`	Returns the negation of the point `p`.
`Point2D operator +(const Point2D& a, const Point2D& b);`	Returns the sum of the points `a` and `b`.
`Point2D operator +(const Point2D& p, const Vector2D& v);`	Returns the sum of the point `p` and the vector `v`.
`Point2D operator -(const Point2D& p, const Vector2D& v);`	Returns the difference of the point `p` and the vector `v`.
`Vector2D operator -(const Point2D& a, const Point2D& b);`	Returns the difference of the points `a` and `b`.
`Point2D operator *(const Point2D& p, float n);`	Returns the product of the point `p` and the scalar `n`.
`Point2D operator *(float n, const Point2D& p);`	Returns the product of the point `p` and the scalar `n`.
`Point2D operator /(const Point2D& p, float n) const;`	Returns the product of the point `p` and the inverse of the scalar `n`.
`Point2D operator *(const Point2D& a, const Point2D& b);`	Returns the componentwise product of the points `a` and `b`.
`Point2D operator *(const Point2D& p, const Vector2D& v);`	Returns the componentwise product of the point `p` and the vector `v`.
`Point2D operator *(const Vector2D& v, const Point2D& p);`	Returns the componentwise product of the vector `v` and the point `p`.

Base Classes

Vector2D A Point2D object behaves much like a Vector2D object, but some properties are altered.