vedge.h

#ifndef VEDGE_H
#define VEDGE_H

#include "vpoint.h"
#include <iostream>

/*
 *   A class that stores an edge in Voronoi diagram
 *
 *   start     : pointer to start point
 *   end       : pointer to end point
 *   left      : pointer to Voronoi place on the left side of edge
 *   right     : pointer to Voronoi place on the right side of edge
 *
 *   neighbour : some edges consist of two parts, so we add the pointer to
 *                another part to connect them at the end of an algorithm
 *
 *   direction : directional vector, from "start", points to "end",
 *               normal of |left, right|
 *   f, g      : directional coeffitients satisfying equation y = f*x + g
 *               (edge lies on this line)
 */

class VEdge
{
public:

    VPoint *start;
    VPoint *end;
    VPoint *direction;
    VPoint *left;
    VPoint *right;

    double f;
    double g;

    VEdge *neighbour;

    /*
     *   Constructor of the class
     *
     *   s : pointer to start
     *   a : pointer to left place
     *   b : pointer to right place
     */

    VEdge(VPoint *s, VPoint *a, VPoint *b)
    {
        start = s;
        left = a;
        right = b;
        neighbour = 0;
        end = 0;

        f = (b->x - a->x) / (a->y - b->y);
        g = s->y - f * s->x;
        direction = new VPoint(b->y - a->y, -(b->x - a->x));
    }

    /*
     *   Destructor of the class
     *     - direction belongs only to the current edge,
     *       other pointers can be shared by other edges
     */

    ~VEdge()
    {
        delete direction;
    }
};

#endif // VEDGE_H