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      1 /*
      2  * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
      3  * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
      4  *
      5  * Permission is hereby granted, free of charge, to any person obtaining a
      6  * copy of this software and associated documentation files (the "Software"),
      7  * to deal in the Software without restriction, including without limitation
      8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
      9  * and/or sell copies of the Software, and to permit persons to whom the
     10  * Software is furnished to do so, subject to the following conditions:
     11  *
     12  * The above copyright notice including the dates of first publication and
     13  * either this permission notice or a reference to
     14  * http://oss.sgi.com/projects/FreeB/
     15  * shall be included in all copies or substantial portions of the Software.
     16  *
     17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
     20  * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
     21  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
     22  * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     23  * SOFTWARE.
     24  *
     25  * Except as contained in this notice, the name of Silicon Graphics, Inc.
     26  * shall not be used in advertising or otherwise to promote the sale, use or
     27  * other dealings in this Software without prior written authorization from
     28  * Silicon Graphics, Inc.
     29  */
     30 /*
     31 */
     32 
     33 #ifndef _DIRECTEDLINE_H
     34 #define _DIRECTEDLINE_H
     35 
     36 #include "definitions.h"
     37 #include "sampledLine.h"
     38 
     39 enum {INCREASING, DECREASING};
     40 
     41 class directedLine {
     42   short direction; /*INCREASING or DECREASING*/
     43   sampledLine* sline;
     44   directedLine* next; /*double linked list*/
     45   directedLine* prev; /*double linked list*/
     46 
     47   /*in case we need a list of polygons each
     48    *consisting of a double linked list
     49    */
     50   directedLine* nextPolygon;
     51 
     52   /*optimization make cutoff polygon faster*/
     53 /*  directedLine* prevPolygon;*/
     54 
     55   Int rootBit; /*1 if this is a root of the polygon, set by setRootBit*/
     56                /*and reset by resetRootBit()*/
     57 
     58   directedLine* rootLink; /*fast root-finding*/
     59 
     60 
     61 
     62 public:
     63   directedLine(short dir, sampledLine* sl);
     64   directedLine();
     65   ~directedLine();
     66 
     67   void init(short dir, sampledLine* sl);
     68 
     69   Real* head(); /*points[0] if INCREASING, points[n-1] otherwise*/
     70   Real* tail(); /*points[n-1] if INCREASING, points[0] otherwise*/
     71   Real* getVertex(Int i); /*points[i] if INCREASING, points[n-1-i] otherwise*/
     72   Int get_npoints() {return sline->get_npoints();}
     73   directedLine* getPrev() {return prev;}
     74   directedLine* getNext() {return next;}
     75   directedLine* getNextPolygon()  {return nextPolygon;}
     76   sampledLine*  getSampledLine()  {return sline;}
     77 
     78   short getDirection(){return direction;}
     79   void putDirection(short dir) {direction = dir;}
     80   void putPrev(directedLine *p) {prev = p;}
     81   void putNext(directedLine *p) {next = p;}
     82 
     83   /*insert a new line between prev and this*/
     84   void insert(directedLine* nl);
     85 
     86   /*delete all the polygons following the link: nextPolygon.
     87    *notice that sampledLine is not deleted. The caller is
     88    *responsible for that
     89    */
     90   void  deletePolygonList();
     91   void  deleteSinglePolygon();
     92 
     93   void  deleteSinglePolygonWithSline(); //also delete sanmpled line
     94   void  deletePolygonListWithSline(); //also delete sanmpled line
     95 
     96   void deleteSingleLine(directedLine* dline);
     97   directedLine* deleteDegenerateLines();
     98   directedLine* deleteDegenerateLinesAllPolygons();
     99   directedLine* cutIntersectionAllPoly(int& cutOccur);
    100 
    101   /*check to see if the list forms a closed polygon
    102    *return 1 if yes
    103    */
    104   short isPolygon();
    105 
    106   Int compInY(directedLine* nl);
    107   Int compInX(directedLine* nl);
    108 
    109   /*return an array of pointers.
    110    *the
    111    */
    112   directedLine** sortAllPolygons();
    113 
    114   Int numEdges();
    115   Int numEdgesAllPolygons();
    116   Int numPolygons();
    117 
    118   /*check if the head of this edge is connected to
    119    *the tail of the prev
    120    */
    121   short isConnected();
    122 
    123   Real polyArea();
    124 
    125   void printSingle();
    126   void printList();
    127   void printAllPolygons();
    128   void writeAllPolygons(char* filename);
    129 
    130 
    131   /*insert a polygon: using nextPolygon*/
    132   directedLine* insertPolygon(directedLine* newpolygon);
    133   directedLine* cutoffPolygon(directedLine *p);
    134 
    135   Int toArraySinglePolygon(directedLine** array, Int index);
    136   directedLine** toArrayAllPolygons(Int& total_num_edges);
    137 
    138   void connectDiagonal(directedLine* v1, directedLine* v2,
    139 			   directedLine** ret_p1,
    140 			   directedLine** ret_p2,
    141 			   sampledLine** generatedLine, directedLine* list);
    142 
    143   /*generate two slines
    144    */
    145   void connectDiagonal_2slines(directedLine* v1, directedLine* v2,
    146 			   directedLine** ret_p1,
    147 			   directedLine** ret_p2,
    148 			   directedLine* list);
    149 
    150   Int samePolygon(directedLine* v1, directedLine* v2);
    151   void setRootBit() {rootBit = 1;}
    152   void resetRootBit() {rootBit = 0;}
    153   directedLine* findRoot();
    154 
    155   void rootLinkSet(directedLine* r) {rootLink = r;}
    156   directedLine* rootLinkFindRoot();
    157 
    158   //the chain from begin to end is deleted (the space is deallocated)
    159   //and a new edge(which connectes the head of begin and the tail of end)
    160   // is inserted. The new polygon is returned.
    161   //notice that "this" is arbitrary
    162   directedLine* deleteChain(directedLine* begin, directedLine* end);
    163 };
    164 
    165 directedLine*  readAllPolygons(char* filename);
    166 
    167 extern Int compV2InY(Real A[2], Real B[2]);
    168 extern Int compV2InX(Real A[2], Real B[2]);
    169 
    170 #endif
    171 
    172