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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 // Delaunay.h
     18 // $Id: Delaunay.h,v 1.9 2011/06/17 13:35:48 mbansal Exp $
     19 
     20 #ifndef DELAUNAY_H
     21 #define DELAUNAY_H
     22 #include <stdio.h>
     23 #include <math.h>
     24 #include "CSite.h"
     25 #include "EdgePointerUtil.h"
     26 
     27 #ifndef TRUE
     28 #define TRUE 1==1
     29 #define FALSE 0==1
     30 #endif
     31 
     32 //******************************************************************************
     33 // Reference for Quad-edge data structure:
     34 //
     35 // Leonidas Guibas and Jorge Stolfi, "Primitives for the manipulation of general
     36 //     subdivisions and the computations of Voronoi diagrams",
     37 //     ACM Transactions on Graphics 4, 74-123 (1985).
     38 //
     39 //******************************************************************************
     40 
     41 //
     42 // Common data structures
     43 //
     44 
     45 typedef short SitePointer;
     46 typedef short TrianglePointer;
     47 
     48 class CDelaunay
     49 {
     50 private:
     51   CSite *sa;
     52   EdgePointer oneBndryEdge;
     53   EdgePointer *next;
     54   SitePointer *org;
     55   struct EDGE_INFO *ei;
     56   SitePointer *sp;
     57   SEdgeVector *ev;
     58 
     59   SitePointer sp1;
     60   EdgePointer nextEdge;
     61   EdgePointer availEdge;
     62 
     63 private:
     64   void build(int lo, int hi, EdgePointer *le, EdgePointer *re, int rows);
     65   void buildTriangulation(int size);
     66 
     67   EdgePointer allocEdge();
     68   void freeEdge(EdgePointer e);
     69 
     70   EdgePointer makeEdge(SitePointer origin, SitePointer destination);
     71   void deleteEdge(EdgePointer e);
     72 
     73   void splice(EdgePointer, EdgePointer);
     74   EdgePointer consolidateEdges();
     75   void deleteAllEdges();
     76 
     77   void spsortx(SitePointer *, int, int);
     78   void spsorty(SitePointer *, int, int);
     79 
     80   int cmpev(int i, int j);
     81   int xcmpsp(int i, int j);
     82   int ycmpsp(int i, int j);
     83 
     84   void swapsp(int i, int j);
     85   void swapev(int i, int j);
     86 
     87   void copysp(int i, int j);
     88   void copyev(int i, int j);
     89 
     90   void rcssort(int lowelt, int highelt, int temp,
     91                  int (CDelaunay::*comparison)(int,int),
     92                  void (CDelaunay::*swap)(int,int),
     93                  void (CDelaunay::*copy)(int,int));
     94 
     95   void doMerge(EdgePointer *ldo, EdgePointer ldi, EdgePointer rdi, EdgePointer *rdo);
     96   EdgePointer connectLeft(EdgePointer a, EdgePointer b);
     97   EdgePointer connectRight(EdgePointer a, EdgePointer b);
     98   int ccw(SitePointer a, SitePointer b, SitePointer c);
     99   int incircle(SitePointer a, SitePointer b, SitePointer c, SitePointer d);
    100   int constructList(EdgePointer e, int width, int height);
    101 
    102 public:
    103   CDelaunay();
    104   ~CDelaunay();
    105 
    106   CSite *allocMemory(int nsite);
    107   void freeMemory();
    108   int triangulate(SEdgeVector **edge, int nsite, int width, int height);
    109   void linkNeighbors(SEdgeVector *edge, int nedge, int nsite);
    110 };
    111 
    112 #define onext(a) next[a]
    113 #define oprev(a) rot(onext(rot(a)))
    114 #define lnext(a) rot(onext(rotinv(a)))
    115 #define lprev(a) sym(onext(a))
    116 #define rnext(a) rotinv(onext(rot(a)))
    117 #define rprev(a) onext(sym(a))
    118 #define dnext(a) sym(onext(sym(a)))
    119 #define dprev(a) rotinv(onext(rotinv(a)))
    120 
    121 #define orig(a) org[a]
    122 #define dest(a) orig(sym(a))
    123 #define left(a) orig(rotinv(a))
    124 #define right(a) orig(rot(a))
    125 
    126 #endif
    127