Point

A point in 3D is very similar to a point in 2D. The 3D point adds a new Z component:

Like the 2D point, the 3D point can also be expressed by a vector. The point is where the vector points to.

Getting ready

We are going to create a new header file for 3D geometry, Geometry3D.h. All future 3D geometry will be added to this file. Because a 3D point has the same definition as a 3D vector, we're not creating a point struct. Instead we are going to re-declare the vec3 struct as a point using the typedef keyword.

How to do it…

Follow these steps to redefine a 3D vector as a 3D point:

1. Create a new C++ header file, call this file Geometry3D.h.

2. Add the basic header guards to the file and include vectors.h and matrices.h:

   #ifndef _H_GEOMETRY_3D_
   #define _H_GEOMETRY_3D_
   
   #include "vectors.h"
   #include "matrices.h"
   
   #endif

3. Because a Point has the same definition as a 3D vector, we are not going to make a new Point structure. Instead, we will re-define vec3 as Point using a typedef:

   typedef vec3 Point;

How...