clip2d.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 __IGEOM_CLIP2D_H__
00020 #define __IGEOM_CLIP2D_H__
00021 
00022 #include "csutil/scf.h"
00023 #include "csgeom/vector2.h"
00024 #include "csgeom/box.h"
00025 
00027 #define MAX_OUTPUT_VERTICES     64
00028 
00029 /*
00030  * Clipper return codes.
00031  * <p>The clipper routines return one of the values below so that we can
00032  * distinguish between the cases when input polygon is completely outside
00033  * the clipping polygon (thus it is not visible), completely inside the
00034  * clipping polygon (thus it has not changed) and partially outside,
00035  * partially inside (thus it was clipped).
00036  */
00037 
00039 #define CS_CLIP_OUTSIDE         0
00040 
00041 #define CS_CLIP_INSIDE          1
00042 
00043 #define CS_CLIP_CLIPPED         2
00044 
00050 struct csVertexStatus
00051 {
00053   unsigned char Type;
00055   unsigned char Vertex;
00057   float Pos;
00058 };
00059 
00060 /*
00061  * The following are possible values for csVertexStatus.Type field.
00062  * The csVertexStatus is used by iClipper2D:Clip() routine which is
00063  * able to output a status structure corresponding to each output vertex.
00064  * This information is usually used to clip other information associated
00065  * with polygon vertices (i.e. z, u, v and such).
00066  */
00068 #define CS_VERTEX_ORIGINAL      0
00069 
00070 #define CS_VERTEX_ONEDGE        1
00071 
00072 #define CS_VERTEX_INSIDE        2
00073 
00074 SCF_VERSION (iClipper2D, 0, 0, 2);
00075 
00079 struct iClipper2D : public iBase
00080 {
00086   virtual uint8 Clip (csVector2 *InPolygon, int InCount,
00087     csVector2 *OutPolygon, int &OutCount) = 0;
00088 
00097   virtual uint8 Clip (csVector2 *InPolygon, int InCount,
00098     csVector2 *OutPolygon, int &OutCount, csBox2 &BoundingBox) = 0;
00099 
00108   virtual uint8 Clip (csVector2 *InPolygon, int InCount,
00109     csVector2 *OutPolygon, int &OutCount, csVertexStatus *OutStatus) = 0;
00110 
00112   virtual uint8 ClipInPlace (csVector2 *InPolygon, int &InOutCount, csBox2 &BoundingBox) = 0;
00113 
00123   virtual int ClassifyBox (const csBox2 &box) = 0;
00124 
00126   virtual bool IsInside (const csVector2& v) = 0;
00127 
00129   virtual int GetVertexCount () = 0;
00130 
00132   virtual csVector2 *GetClipPoly () = 0;
00133 };
00134 
00135 #endif
00136