VTK
dox/Filtering/vtkPolygon.h
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00001 /*=========================================================================
00002 
00003   Program:   Visualization Toolkit
00004   Module:    vtkPolygon.h
00005 
00006   Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
00007   All rights reserved.
00008   See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
00009 
00010      This software is distributed WITHOUT ANY WARRANTY; without even
00011      the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
00012      PURPOSE.  See the above copyright notice for more information.
00013 
00014 =========================================================================*/
00030 #ifndef __vtkPolygon_h
00031 #define __vtkPolygon_h
00032 
00033 #include "vtkCell.h"
00034 
00035 class vtkDoubleArray;
00036 class vtkIdTypeArray;
00037 class vtkLine;
00038 class vtkPoints;
00039 class vtkQuad;
00040 class vtkTriangle;
00041 class vtkIncrementalPointLocator;
00042 
00043 class VTK_FILTERING_EXPORT vtkPolygon : public vtkCell
00044 {
00045 public:
00046   static vtkPolygon *New();
00047   vtkTypeMacro(vtkPolygon,vtkCell);
00048   void PrintSelf(ostream& os, vtkIndent indent);
00049 
00051 
00052   int GetCellType() {return VTK_POLYGON;};
00053   int GetCellDimension() {return 2;};
00054   int GetNumberOfEdges() {return this->GetNumberOfPoints();};
00055   int GetNumberOfFaces() {return 0;};
00056   vtkCell *GetEdge(int edgeId);
00057   vtkCell *GetFace(int) {return 0;};
00058   int CellBoundary(int subId, double pcoords[3], vtkIdList *pts);
00059   void Contour(double value, vtkDataArray *cellScalars,
00060                vtkIncrementalPointLocator *locator,vtkCellArray *verts,
00061                vtkCellArray *lines, vtkCellArray *polys,
00062                vtkPointData *inPd, vtkPointData *outPd,
00063                vtkCellData *inCd, vtkIdType cellId, vtkCellData *outCd);
00064   void Clip(double value, vtkDataArray *cellScalars,
00065             vtkIncrementalPointLocator *locator, vtkCellArray *tris,
00066             vtkPointData *inPd, vtkPointData *outPd,
00067             vtkCellData *inCd, vtkIdType cellId, vtkCellData *outCd,
00068             int insideOut);
00069   int EvaluatePosition(double x[3], double* closestPoint,
00070                        int& subId, double pcoords[3],
00071                        double& dist2, double *weights);
00072   void EvaluateLocation(int& subId, double pcoords[3], double x[3],
00073                         double *weights);
00074   int IntersectWithLine(double p1[3], double p2[3], double tol, double& t,
00075                         double x[3], double pcoords[3], int& subId);
00076   int Triangulate(int index, vtkIdList *ptIds, vtkPoints *pts);
00077   void Derivatives(int subId, double pcoords[3], double *values,
00078                    int dim, double *derivs);
00079   int IsPrimaryCell() {return 0;}
00081 
00086   double ComputeArea();
00087 
00089 
00091   virtual void InterpolateFunctions(double pcoords[3], double *sf);
00092   virtual void InterpolateDerivs(double pcoords[3], double *derivs);
00094 
00096 
00097   static void ComputeNormal(vtkPoints *p, int numPts, vtkIdType *pts,
00098                             double n[3]);
00099   static void ComputeNormal(vtkPoints *p, double n[3]);
00100   static void ComputeNormal(vtkIdTypeArray *ids, vtkPoints *pts, double n[3]);
00102 
00106   static void ComputeNormal(int numPts, double *pts, double n[3]);
00107 
00109 
00110   static void ComputeCentroid(vtkIdTypeArray *ids, vtkPoints *pts, 
00111                               double centroid[3]);
00113 
00117   VTK_LEGACY(void ComputeWeights(double x[3], double *weights));
00118 
00120 
00125   static double ComputeArea(vtkPoints *p, vtkIdType numPts, vtkIdType *pts,
00126                             double normal[3]);
00128 
00130 
00135   int ParameterizePolygon(double p0[3], double p10[3], double &l10,
00136                           double p20[3], double &l20, double n[3]);
00138 
00140 
00144   static int PointInPolygon(double x[3], int numPts, double *pts,
00145                             double bounds[6], double n[3]);
00147 
00152   int Triangulate(vtkIdList *outTris);
00153 
00156   int NonDegenerateTriangulate(vtkIdList *outTris);
00157 
00159 
00162   static double DistanceToPolygon(double x[3], int numPts, double *pts,
00163                                   double bounds[6], double closest[3]);
00165 
00167 
00173   static int IntersectPolygonWithPolygon(int npts, double *pts, double bounds[6],
00174                                          int npts2, double *pts2,
00175                                          double bounds2[3], double tol,
00176                                          double x[3]);
00178 
00179 
00180   // Intersect two convex 2D polygons to produce a line segment as output.
00181   // The return status of the methods indicated no intersection (returns 0);
00182   // a single point of intersection (returns 1); or a line segment (i.e., two
00183   // points of intersection, returns 2). The points of intersection are
00184   // returned in the arrays p0 and p1.  If less than two points of
00185   // intersection are generated then p1 and/or p0 may be
00186   // indeterminiate. Finally, if the two convex polygons are parallel, then 
00187   // "0" is returned (i.e., no intersection) even if the triangles lie on one
00188   // another.  
00189   static int IntersectConvex2DCells(vtkCell *cell1, vtkCell *cell2,
00190                                     double tol, double p0[3], double p1[3]);
00191 
00192 protected:
00193   vtkPolygon();
00194   ~vtkPolygon();
00195 
00196   // variables used by instances of this class
00197   double   Tolerance; // Intersection tolerance
00198   int      SuccessfulTriangulation; // Stops recursive tri. if necessary
00199   double   Normal[3]; //polygon normal
00200   vtkIdList *Tris;
00201   vtkTriangle *Triangle;
00202   vtkQuad *Quad;
00203   vtkDoubleArray *TriScalars;
00204   vtkLine *Line;
00205 
00206   // Helper methods for triangulation------------------------------
00211   int EarCutTriangulation();
00212 
00213 private:
00214   vtkPolygon(const vtkPolygon&);  // Not implemented.
00215   void operator=(const vtkPolygon&);  // Not implemented.
00216 };
00217 
00218 #endif
00219