polyclip.h Source File

00001 /*
00002     Crystal Space polygon clipping routines
00003     Copyright (C) 1998 by Jorrit Tyberghein
00004     Contributed by Ivan Avramovic <ivan@avramovic.com> and
00005                    Andrew Zabolotny <bit@eltech.ru>
00006 
00007     This library is free software; you can redistribute it and/or
00008     modify it under the terms of the GNU Library General Public
00009     License as published by the Free Software Foundation; either
00010     version 2 of the License, or (at your option) any later version.
00011 
00012     This library is distributed in the hope that it will be useful,
00013     but WITHOUT ANY WARRANTY; without even the implied warranty of
00014     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015     Library General Public License for more details.
00016 
00017     You should have received a copy of the GNU Library General Public
00018     License along with this library; if not, write to the Free
00019     Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00020 */
00021 
00022 #ifndef __CS_POLYCLIP_H__
00023 #define __CS_POLYCLIP_H__
00024 
00025 #include "csgeom/math2d.h"
00026 #include "csgeom/polypool.h"
00027 #include "igeom/clip2d.h"
00028 
00032 class csClipper : public iClipper2D
00033 {
00034 protected:
00036   static csPoly2DPool *polypool;
00037 
00039   uint8 mrClipping;
00040 
00041 public:
00042   static csPoly2DPool *GetSharedPool ();
00043 
00044 public:
00046   csClipper ();
00047 
00049   virtual ~csClipper () { }
00050 
00052   virtual uint8 ClipInPlace (csVector2 *InPolygon, int &InOutCount, csBox2 &BoundingBox);
00053 
00055   uint8 LastClipResult () { return mrClipping; }
00056 
00057   SCF_DECLARE_IBASE;
00058 };
00059 
00064 class csBoxClipper : public csClipper
00065 {
00067   csBox2 region;
00069   csVector2 ClipBox [4];
00070 
00072   inline void InitClipBox ()
00073   {
00074     ClipBox [0].Set (region.MinX (), region.MinY ());
00075     ClipBox [1].Set (region.MinX (), region.MaxY ());
00076     ClipBox [2].Set (region.MaxX (), region.MaxY ());
00077     ClipBox [3].Set (region.MaxX (), region.MinY ());
00078   }
00079 
00080 public:
00082   csBoxClipper (const csBox2& b) : region (b)
00083   { InitClipBox (); }
00085   csBoxClipper (float x1, float y1, float x2, float y2) : region (x1,y1,x2,y2)
00086   { InitClipBox (); }
00087 
00089   virtual uint8 Clip (csVector2 *InPolygon, int InCount,
00090     csVector2 *OutPolygon, int &OutCount);
00091 
00093   virtual uint8 Clip (csVector2 *InPolygon, int InCount,
00094     csVector2 *OutPolygon, int &OutCount, csBox2 &BoundingBox);
00095 
00097   virtual uint8 Clip (csVector2 *InPolygon, int InCount,
00098     csVector2 *OutPolygon, int &OutCount, csVertexStatus *OutStatus);
00099 
00101   virtual int ClassifyBox (const csBox2 &box);
00102 
00104   virtual bool IsInside (const csVector2& v)
00105   { return region.In (v.x, v.y); }
00106 
00108   virtual int GetVertexCount ()
00109   { return 4; }
00110 
00112   virtual csVector2 *GetClipPoly ()
00113   { return ClipBox; }
00114 };
00115 
00126 class csPolygonClipper : public csClipper
00127 {
00129   csVector2 *ClipData;
00131   csVector2 *ClipPoly;
00133   csPoly2D *ClipPoly2D;
00135   int ClipPolyVertices;
00137   csBox2 ClipBox;
00138 
00140   void Prepare ();
00141 
00142 public:
00144   csPolygonClipper (csPoly2D *Clipper, bool mirror = false,
00145     bool copy = false);
00147   csPolygonClipper (csVector2 *Clipper, int Count, bool mirror = false,
00148     bool copy = false);
00150   virtual ~csPolygonClipper ();
00151 
00153   virtual uint8 Clip (csVector2 *InPolygon, int InCount,
00154     csVector2 *OutPolygon, int &OutCount);
00155 
00157   virtual uint8 Clip (csVector2 *InPolygon, int InCount,
00158     csVector2 *OutPolygon, int &OutCount, csBox2 &BoundingBox);
00159 
00161   virtual uint8 Clip (csVector2 *InPolygon, int InCount,
00162     csVector2 *OutPolygon, int &OutCount, csVertexStatus *OutStatus);
00163 
00165   virtual int ClassifyBox (const csBox2 &box);
00166 
00168   virtual bool IsInside (const csVector2& v);
00169 
00171   virtual int GetVertexCount () { return ClipPolyVertices; }
00172 
00174   virtual csVector2 *GetClipPoly ()
00175   { return ClipPoly; }
00176 };
00177 
00178 #endif // __CS_POLYCLIP_H__