directedLine.h

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/*
 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
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/*
*/
 
#ifndef _DIRECTEDLINE_H
#define _DIRECTEDLINE_H
 
//#include "definitions.h"
#include "sampledLine.h"
 
enum {INCREASING, DECREASING};
 
class directedLine {
  short direction; /*INCREASING or DECREASING*/
  sampledLine* sline;
  directedLine* next; /*double linked list*/
  directedLine* prev; /*double linked list*/
 
  /*in case we need a list of polygons each 
   *consisting of a double linked list
   */
  directedLine* nextPolygon; 
 
  /*optimization make cutoff polygon faster*/
/*  directedLine* prevPolygon;*/
 
  Int rootBit; /*1 if this is a root of the polygon, set by setRootBit*/
               /*and reset by resetRootBit()*/
 
  directedLine* rootLink; /*fast root-finding*/
 
 
 
public:
  directedLine(short dir, sampledLine* sl);
  directedLine();
  ~directedLine();
 
  void init(short dir, sampledLine* sl);
  
  Real* head(); /*points[0] if INCREASING, points[n-1] otherwise*/
  Real* tail(); /*points[n-1] if INCREASING, points[0] otherwise*/
  Real* getVertex(Int i); /*points[i] if INCREASING, points[n-1-i] otherwise*/
  Int get_npoints() {return sline->get_npoints();}
  directedLine* getPrev() {return prev;}
  directedLine* getNext() {return next;}
  directedLine* getNextPolygon()  {return nextPolygon;}
  sampledLine*  getSampledLine()  {return sline;}
 
  short getDirection(){return direction;}
  void putDirection(short dir) {direction = dir;}
  void putPrev(directedLine *p) {prev = p;}
  void putNext(directedLine *p) {next = p;}
 
  /*insert a new line between prev and this*/
  void insert(directedLine* nl);
 
  /*delete all the polygons following the link: nextPolygon.
   *notice that sampledLine is not deleted. The caller is
   *responsible for that
   */
  void  deletePolygonList();
  void  deleteSinglePolygon();
 
  void  deleteSinglePolygonWithSline(); //also delete sanmpled line
  void  deletePolygonListWithSline(); //also delete sanmpled line
 
  void deleteSingleLine(directedLine* dline);
  directedLine* deleteDegenerateLines();
  directedLine* deleteDegenerateLinesAllPolygons();
  directedLine* cutIntersectionAllPoly(int& cutOccur);
 
  /*check to see if the list forms a closed polygon
   *return 1 if yes
   */
  short isPolygon(); 
  
  Int compInY(directedLine* nl);
  Int compInX(directedLine* nl);
 
  /*return an array of pointers.
   *the 
   */
  directedLine** sortAllPolygons();
 
  Int numEdges();
  Int numEdgesAllPolygons();
  Int numPolygons();
 
  /*check if the head of this edge is connected to 
   *the tail of the prev
   */
  short isConnected();
 
  Real polyArea();
 
  void printSingle();
  void printList();
  void printAllPolygons();
  void writeAllPolygons(char* filename);
  
 
  /*insert a polygon: using nextPolygon*/
  directedLine* insertPolygon(directedLine* newpolygon);
  directedLine* cutoffPolygon(directedLine *p);
 
  Int toArraySinglePolygon(directedLine** array, Int index);
  directedLine** toArrayAllPolygons(Int& total_num_edges);
 
  void connectDiagonal(directedLine* v1, directedLine* v2, 
               directedLine** ret_p1, 
               directedLine** ret_p2,
               sampledLine** generatedLine, directedLine* list);
 
  /*generate two slines
   */
  void connectDiagonal_2slines(directedLine* v1, directedLine* v2, 
               directedLine** ret_p1, 
               directedLine** ret_p2,
               directedLine* list);
 
  Int samePolygon(directedLine* v1, directedLine* v2);
  void setRootBit() {rootBit = 1;}
  void resetRootBit() {rootBit = 0;}
  directedLine* findRoot();
 
  void rootLinkSet(directedLine* r) {rootLink = r;}
  directedLine* rootLinkFindRoot();
 
  //the chain from begin to end is deleted (the space is deallocated)
  //and a new edge(which connectes the head of begin and the tail of end)
  // is inserted. The new polygon is returned.
  //notice that "this" is arbitrary
  directedLine* deleteChain(directedLine* begin, directedLine* end);
};
 
directedLine*  readAllPolygons(char* filename);
 
extern Int compV2InY(Real A[2], Real B[2]);
extern Int compV2InX(Real A[2], Real B[2]);
 
#endif