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25 //
26 // Michael Kelsey 31 January 2019
27 //
28 // Class Description:
29 //
30 // Abstract base class to implement drawing vector field geometries
31 // (e.g., electric, magnetic or gravity). Implementation extracted
32 // from G4MagneticFieldModel, with field-value access left pure
33 // virtual for implementation by base classes.
34
35 #ifndef G4VFIELDMODEL_HH
36 #define G4VFIELDMODEL_HH
37
38 #include "G4VModel.hh"
39 #include "G4Point3D.hh"
40 #include "G4PhysicalVolumesSearchScene.hh"
41
42 #include <vector>
43
44 class G4Field;
45
46 class G4VFieldModel: public G4VModel {
47
48 public: // With description
49
50 enum Representation {fullArrow, lightArrow};
51
52 G4VFieldModel
53 (const G4String& typeOfField, const G4String& symbol="",
54 const G4VisExtent& extentForField = G4VisExtent(),
55 const std::vector<G4PhysicalVolumesSearchScene::Findings>& pvFindings
56 = std::vector<G4PhysicalVolumesSearchScene::Findings>(),
57 G4int nDataPointsPerHalfScene = 10,
58 Representation representation = Representation::fullArrow,
59 G4int arrow3DLineSegmentsPerCircle = 6);
60 // typeOfField is "Electric" or "Magnetic" etc.
61 // symbol is "E" or "B" etc.
62
63 virtual ~G4VFieldModel();
64
65 virtual void DescribeYourselfTo(G4VGraphicsScene& sceneHandler);
66 // The main task of a model is to describe itself to the graphics scene.
67 // Note: It is in this function that the extent for drawing the filed must
68 // be calcualted. If fExtentForField is null, pick up the extent from
69 // the sceneHandler.
70
71 protected:
72
73 // Subclasses MUST implement this for their particular kind of field
74 virtual void GetFieldAtLocation(const G4Field* field,
75 const G4Point3D& position, G4double time,
76 G4Point3D& result) const = 0;
77 // The appropriate output from GetFieldValue should be filled into result.
78 // If (field==0), the function should do nothing; returning without error.
79
80 private:
81
82 // Private copy contructor and assignment to forbid use...
83 G4VFieldModel(const G4VFieldModel&);
84 G4VFieldModel& operator=(const G4VFieldModel&);
85
86 G4VisExtent fExtentForField;
87 // If null, get extent from scene handler in DescribeYourselfTo.
88
89 std::vector<G4PhysicalVolumesSearchScene::Findings> fPVFindings;
90 // If empty, use fExtentForField alone for sampling and drawing.
91 // If non-empty, use fExtentForField alone for sampling, but only
92 // draw if sampling point is in the specified physical volume(s).
93
94 G4int fNDataPointsPerMaxHalfExtent;
95 // No. of data points sampled per maximum half extent.
96 // Note that total number of sampling points can be as high as
97 // (2*n+1)^3, which can get very big. However, fields are usually
98 // confined to only parts of the scene, so this may not be a problem.
99 // Sampling can be further limited with fExtentForField and/or fPVFindings.
100
101 Representation fRepresentation; // Big arrows or just lines
102 G4int fArrow3DLineSegmentsPerCircle;
103 G4String fTypeOfField; // "Electric" or "Magnetic" etc.
104 G4String fArrowPrefix; // For attaching text label to arrows
105 };
106
107 #endif
108