Line segment

A line is the shortest straight path that goes through two points. A line extends infinitely in both directions. Like its 2D counterpart, the 3D line we are going to implement will actually be a Line Segment. We define this line segment using a Start point and an End point:

Getting ready

We are going to define a Line structure that holds start and end points. This structure represents a line segment. We will also implement two helper functions, Length and LengthSq. These functions will help us find the length and squared length of the line segment.

How to do it…

Follow these steps to implement a 3D line segment:

1. Add the declaration of Line to Geometry3D.h:

   typedef struct Line {
      Point start;
      Point end;
   
      inline Line() {}
      inline Line(const Point& s, const Point& e) :
          start(s), end(e) { }
   } Line;

2. Declare the helper functions Length and LengthSq in Geometry3D.h:

   float Length(const Line& line);
   float LengthSq(const Line& line);

3. Create a new file, Geometry3D...