/*
* The author of this software is Steven Fortune.  Copyright (c) 1994 by AT&T
* Bell Laboratories.
* Permission to use, copy, modify, and distribute this software for any
* purpose without fee is hereby granted, provided that this entire notice
* is included in all copies of any software which is or includes a copy
* or modification of this software and in all copies of the supporting
* documentation for such software.
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR AT&T MAKE ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
*/

/*
* This code was originally written by Stephan Fortune in C code.  I, Shane O'Sullivan,
* have since modified it, encapsulating it in a C++ class and, fixing memory leaks and
* adding accessors to the Voronoi Edges.
* Permission to use, copy, modify, and distribute this software for any
* purpose without fee is hereby granted, provided that this entire notice
* is included in all copies of any software which is or includes a copy
* or modification of this software and in all copies of the supporting
* documentation for such software.
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR AT&T MAKE ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
*/

#ifndef VORONOI_DIAGRAM_GENERATOR
#define VORONOI_DIAGRAM_GENERATOR

#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <algorithm>

#ifndef NULL
#define NULL 0
#endif
#define DELETED -2

#define le 0
#define re 1

struct Freenode
{
  struct Freenode* nextfree;
};

struct FreeNodeArrayList
{
  struct Freenode* memory;
  struct FreeNodeArrayList* next;
};

struct Freelist
{
  struct Freenode* head;
  int nodesize;
};

struct Point
{
  float x, y;
  Point() : x(0.0), y(0.0)
  {
  }
  Point(float x, float y) : x(x), y(y)
  {
  }
};

// structure used both for sites and for vertices
struct Site
{
  struct Point coord;
  int sitenbr;
  int refcnt;
};

struct Edge
{
  float a, b, c;
  struct Site* ep[2];
  struct Site* reg[2];
  int edgenbr;
  int sites[2];
};

struct GraphEdge
{
  float x1, y1, x2, y2;
  int sites[2];
  struct GraphEdge* next;
};

struct Halfedge
{
  struct Halfedge *ELleft, *ELright;
  struct Edge* ELedge;
  int ELrefcnt;
  char ELpm;
  struct Site* vertex;
  float ystar;
  struct Halfedge* PQnext;
};

class VoronoiDiagramGenerator
{
public:
  VoronoiDiagramGenerator();
  ~VoronoiDiagramGenerator();

  bool generateVoronoi(float* xValues, float* yValues, int numPoints, float minX, float maxX, float minY, float maxY,
                       float minDist = 0);

  void resetIterator()
  {
    iteratorEdges = allEdges;
  }

  bool getNext(float& x1, float& y1, float& x2, float& y2, int* s)
  {
    if (iteratorEdges == 0)
      return false;

    x1 = iteratorEdges->x1;
    x2 = iteratorEdges->x2;
    y1 = iteratorEdges->y1;
    y2 = iteratorEdges->y2;
    std::copy(iteratorEdges->sites, iteratorEdges->sites + 2, s);

    iteratorEdges = iteratorEdges->next;

    return true;
  }

private:
  void cleanup();
  void cleanupEdges();
  char* getfree(struct Freelist* fl);
  struct Halfedge* PQfind();
  int PQempty();

  struct Halfedge** ELhash;
  struct Halfedge *HEcreate(), *ELleft(), *ELright(), *ELleftbnd();
  struct Halfedge* HEcreate(struct Edge* e, int pm);

  struct Point PQ_min();
  struct Halfedge* PQextractmin();
  void freeinit(struct Freelist* fl, int size);
  void makefree(struct Freenode* curr, struct Freelist* fl);
  void geominit();
  void plotinit();
  bool voronoi(int triangulate);
  void ref(struct Site* v);
  void deref(struct Site* v);
  void endpoint(struct Edge* e, int lr, struct Site* s);

  void ELdelete(struct Halfedge* he);
  struct Halfedge* ELleftbnd(struct Point* p);
  struct Halfedge* ELright(struct Halfedge* he);
  void makevertex(struct Site* v);
  void out_triple(struct Site* s1, struct Site* s2, struct Site* s3);

  void PQinsert(struct Halfedge* he, struct Site* v, float offset);
  void PQdelete(struct Halfedge* he);
  bool ELinitialize();
  void ELinsert(struct Halfedge* lb, struct Halfedge* newHe);
  struct Halfedge* ELgethash(int b);
  struct Halfedge* ELleft(struct Halfedge* he);
  struct Site* leftreg(struct Halfedge* he);
  void out_site(struct Site* s);
  bool PQinitialize();
  int PQbucket(struct Halfedge* he);
  void clip_line(struct Edge* e);
  char* myalloc(unsigned n);
  int right_of(struct Halfedge* el, struct Point* p);

  struct Site* rightreg(struct Halfedge* he);
  struct Edge* bisect(struct Site* s1, struct Site* s2);
  float dist(struct Site* s, struct Site* t);
  struct Site* intersect(struct Halfedge* el1, struct Halfedge* el2, struct Point* p = 0);

  void out_bisector(struct Edge* e);
  void out_ep(struct Edge* e);
  void out_vertex(struct Site* v);
  struct Site* nextone();

  void pushGraphEdge(float x1, float y1, float x2, float y2, int s[2]);

  void openpl();
  void line(float x1, float y1, float x2, float y2, int s[2]);
  void circle(float x, float y, float radius);
  void range(float minX, float minY, float maxX, float maxY);

  struct Freelist hfl;
  struct Halfedge *ELleftend, *ELrightend;
  int ELhashsize;

  int triangulate, sorted, plot, debug;
  float xmin, xmax, ymin, ymax, deltax, deltay;

  struct Site* sites;
  int nsites;
  int siteidx;
  int sqrt_nsites;
  int nvertices;
  struct Freelist sfl;
  struct Site* bottomsite;

  int nedges;
  struct Freelist efl;
  int PQhashsize;
  struct Halfedge* PQhash;
  int PQcount;
  int PQmin;

  int ntry, totalsearch;
  float pxmin, pxmax, pymin, pymax, cradius;
  int total_alloc;

  float borderMinX, borderMaxX, borderMinY, borderMaxY;

  FreeNodeArrayList* allMemoryList;
  FreeNodeArrayList* currentMemoryBlock;

  GraphEdge* allEdges;
  GraphEdge* iteratorEdges;

  float minDistanceBetweenSites;
};

int scomp(const void* p1, const void* p2);

#endif