include/Geant4/G4ClippablePolygon.hh

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0025 //
0026 // G4ClippablePolygon
0027 //
0028 // Class description:
0029 //
0030 // Declaration of a utility class of a polygon that can be
0031 // clipped by a voxel.
0032
0033 // Author: David C. Williams (davidw@scipp.ucsc.edu)
0034 // --------------------------------------------------------------------
0035 #ifndef G4CLIPPABLEPOLYGON_HH
0036 #define G4CLIPPABLEPOLYGON_HH
0037
0038 #include <vector>
0039
0040 #include "G4Types.hh"
0041 #include "geomdefs.hh"
0042 #include "G4ThreeVector.hh"
0043
0044 class G4AffineTransform;
0045 class G4VoxelLimits;
0046
0047 class G4ClippablePolygon
0048 {
0049   using G4ThreeVectorList = std::vector<G4ThreeVector>;
0050
0051   public:
0052
0053     G4ClippablePolygon();
0054     virtual ~G4ClippablePolygon();
0055       // Constructor & virtual destructor.
0056
0057     virtual void AddVertexInOrder( const G4ThreeVector vertex );
0058     virtual void ClearAllVertices();
0059
0060     inline void SetNormal( const G4ThreeVector& newNormal );
0061     inline const G4ThreeVector GetNormal() const;
0062
0063     virtual G4bool Clip( const G4VoxelLimits& voxelLimit );
0064
0065     virtual G4bool PartialClip( const G4VoxelLimits& voxelLimit,
0066                                 const EAxis IgnoreMe );
0067       // Clip, while ignoring the indicated axis.
0068
0069     virtual void ClipAlongOneAxis( const G4VoxelLimits& voxelLimit,
0070                                    const EAxis axis );
0071       // Clip along just one axis, as specified in voxelLimit.
0072
0073     virtual G4bool GetExtent( const EAxis axis,
0074                                     G4double& min, G4double& max ) const;
0075
0076     virtual const G4ThreeVector* GetMinPoint( const EAxis axis ) const;
0077       // Returns pointer to minimum point along the specified axis.
0078       // Take care! Do not use pointer after destroying parent polygon.
0079
0080     virtual const G4ThreeVector* GetMaxPoint( const EAxis axis ) const;
0081       // Returns pointer to maximum point along the specified axis.
0082       // Take care! Do not use pointer after destroying parent polygon.
0083
0084     inline std::size_t GetNumVertices() const;
0085     inline G4bool Empty() const;
0086
0087     virtual G4bool InFrontOf(const G4ClippablePolygon& other, EAxis axis) const;
0088       // Decide if the polygon is in "front" of another when
0089       // viewed along the specified axis. For our purposes here,
0090       // it is sufficient to use the minimum extent of the
0091       // polygon along the axis to determine this.
0092
0093     virtual G4bool BehindOf(const G4ClippablePolygon& other, EAxis axis) const;
0094       // Decide if this polygon is behind another.
0095       // Remarks in method "InFrontOf" are valid here too.
0096
0097     virtual G4bool GetPlanerExtent( const G4ThreeVector& pointOnPlane,
0098                                     const G4ThreeVector& planeNormal,
0099                                           G4double& min, G4double& max ) const;
0100       // Get min/max distance in or out of a plane.
0101
0102     protected:
0103
0104     void ClipToSimpleLimits( G4ThreeVectorList& pPolygon,
0105                              G4ThreeVectorList& outputPolygon,
0106                        const G4VoxelLimits& pVoxelLimit  );
0107       // pVoxelLimits must be only limited along one axis, and either
0108       // the maximum along the axis must be +kInfinity, or the minimum
0109       // -kInfinity
0110
0111     protected:
0112
0113     G4ThreeVectorList vertices;
0114     G4ThreeVector normal;
0115     G4double kCarTolerance;
0116 };
0117
0118 #include "G4ClippablePolygon.icc"
0119
0120 #endif