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*/
get_npoints()72   Int get_npoints() {return sline->get_npoints();}
getPrev()73   directedLine* getPrev() {return prev;}
getNext()74   directedLine* getNext() {return next;}
getNextPolygon()75   directedLine* getNextPolygon()  {return nextPolygon;}
getSampledLine()76   sampledLine*  getSampledLine()  {return sline;}
77 
getDirection()78   short getDirection(){return direction;}
putDirection(short dir)79   void putDirection(short dir) {direction = dir;}
putPrev(directedLine * p)80   void putPrev(directedLine *p) {prev = p;}
putNext(directedLine * 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);
setRootBit()151   void setRootBit() {rootBit = 1;}
resetRootBit()152   void resetRootBit() {rootBit = 0;}
153   directedLine* findRoot();
154 
rootLinkSet(directedLine * r)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