2D points

A point is the simplest two-dimensional primitive we can implement. It is infinitely small; it has x and y coordinates. A good way to think of a 2D point is like an alternate representation of a 2D vector. A vector points to somewhere in space; a point is where the vector points to:

Getting ready

Since this is the first geometry object we are creating, we also need to create a new header file, Geometry2D.h. All future 2D geometry and intersection tests will be added to this file. Because a point has the same definition as a 2D vector, we're not going to create a new structure; instead we will redefine the vec2 struct as Point2D.

How to do it…

Follow these steps to create a new header file in which we will define 2D geometry:

1. Create a new C++ header file; call this file Geometry2D.h.

2. Add standard header guards to the file, and include vectors.h.

   #ifndef _H_2D_GEOMTRY_
   #define _H_2D_GEOMETRY_
   
   #include "vectors.h"
   
   #endif

3. Because a point is practically the same thing as a 2D vector, we are...