polyedge.h Source File

00001 /*
00002     Copyright (C) 2000 by Jorrit Tyberghein
00003 
00004     This library is free software; you can redistribute it and/or
00005     modify it under the terms of the GNU Library General Public
00006     License as published by the Free Software Foundation; either
00007     version 2 of the License, or (at your option) any later version.
00008 
00009     This library is distributed in the hope that it will be useful,
00010     but WITHOUT ANY WARRANTY; without even the implied warranty of
00011     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012     Library General Public License for more details.
00013 
00014     You should have received a copy of the GNU Library General Public
00015     License along with this library; if not, write to the Free
00016     Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00017 */
00018 
00019 #ifndef __CS_POLYEDGE_H__
00020 #define __CS_POLYEDGE_H__
00021 
00022 #include "csgeom/math2d.h"
00023 #include "csgeom/segment.h"
00024 
00029 class csPoly2DEdges
00030 {
00031 protected:
00033   csSegment2* edges;
00035   int num_edges;
00037   int max_edges;
00038 
00039 public:
00043   csPoly2DEdges (int start_size = 10);
00044 
00046   csPoly2DEdges (csPoly2DEdges& copy);
00047 
00049   virtual ~csPoly2DEdges ();
00050 
00054   void MakeEmpty ();
00055 
00059   int GetEdgeCount () { return num_edges; }
00060 
00064   csSegment2* GetEdges () { return edges; }
00065 
00069   csSegment2* GetEdge (int i)
00070   {
00071     if (i<0 || i>=num_edges) return NULL;
00072     return &edges[i];
00073   }
00074 
00078   csSegment2& operator[] (int i)
00079   {
00080     CS_ASSERT (i >= 0 && i < num_edges);
00081     return edges[i];
00082   }
00083 
00087   csSegment2* GetFirst ()
00088   { if (num_edges<=0) return NULL;  else return edges; }
00089 
00093   csSegment2* GetLast ()
00094   { if (num_edges<=0) return NULL;  else return &edges[num_edges-1]; }
00095 
00099   bool In (const csVector2& v);
00100 
00104   static bool In (csSegment2* poly, int num_edge, const csVector2& v);
00105 
00109   void MakeRoom (int new_max);
00110 
00114   void SetEdgeCount (int n) { MakeRoom (n); num_edges = n; }
00115 
00120   int AddEdge (const csSegment2& e) { return AddEdge (e.Start (), e.End ()); }
00121 
00126   int AddEdge (const csVector2& v1, const csVector2& v2);
00127 
00138   void Intersect (const csPlane2& plane,
00139         csPoly2DEdges& left, csPoly2DEdges& right, bool& onplane) const;
00140 };
00141 
00148 class csPoly2DEdgesPool
00149 {
00150 private:
00151   struct PoolObj
00152   {
00153     PoolObj* next;
00154     csPoly2DEdges* pol2d;
00155   };
00157   PoolObj* alloced;
00159   PoolObj* freed;
00160 
00161 public:
00163   csPoly2DEdgesPool () : alloced (NULL), freed (NULL) { }
00164 
00166   ~csPoly2DEdgesPool ()
00167   {
00168     while (alloced)
00169     {
00170       PoolObj* n = alloced->next;
00171       //delete alloced->pol2d; @@@ This free is not valid!
00172       // We should use a ref count on the pool itself so that we
00173       // now when all objects in the pool are freed and the
00174       // 'alloced' list will be empty.
00175       delete alloced;
00176       alloced = n;
00177     }
00178     while (freed)
00179     {
00180       PoolObj* n = freed->next;
00181       delete freed->pol2d;
00182       delete freed;
00183       freed = n;
00184     }
00185   }
00186 
00188   csPoly2DEdges* Alloc ()
00189   {
00190     PoolObj* pnew;
00191     if (freed)
00192     {
00193       pnew = freed;
00194       freed = freed->next;
00195     }
00196     else
00197     {
00198       pnew = new PoolObj ();
00199       pnew->pol2d = new csPoly2DEdges ();
00200     }
00201     pnew->next = alloced;
00202     alloced = pnew;
00203     return pnew->pol2d;
00204   }
00205 
00211   void Free (csPoly2DEdges* pol)
00212   {
00213     if (alloced)
00214     {
00215       PoolObj* po = alloced;
00216       alloced = alloced->next;
00217       po->pol2d = pol;
00218       po->next = freed;
00219       freed = po;
00220     }
00221     else
00222     {
00223       // Cannot happen!
00224       CS_ASSERT (false);
00225     }
00226   }
00227 };
00228 
00229 #endif // __CS_POLYEDGE_H__