library: libGeom #include "TGeoArb8.h"

# TGeoArb8

class description - source file - inheritance tree (.pdf)

## class TGeoArb8 : public TGeoBBox

| Inheritance Chart:

`TObject`

<-

`TNamed`

<-

`TGeoShape`

<-

`TGeoBBox`

<-

`TGeoArb8`

<-

`TGeoTrap`

<-

`TGeoGtra` |

        public:

                              TGeoArb8()
                              TGeoArb8(Double_t dz, Double_t* vertices = 0)
                              TGeoArb8(const char* name, Double_t dz, Double_t* vertices = 0)
                              TGeoArb8(const TGeoArb8&)
                      virtual ~TGeoArb8()
               static TClass* Class()
                 virtual void ComputeBBox()
                 virtual void ComputeNormal(Double_t* point, Double_t* dir, Double_t* norm)
                         void ComputeTwist()
               virtual Bool_t Contains(Double_t* point) const
             virtual Double_t DistFromInside(Double_t* point, Double_t* dir, Int_t iact = 1, Double_t step = TGeoShape::Big(), Double_t* safe = 0) const
             virtual Double_t DistFromOutside(Double_t* point, Double_t* dir, Int_t iact = 1, Double_t step = TGeoShape::Big(), Double_t* safe = 0) const
                     Double_t DistToPlane(Double_t* point, Double_t* dir, Int_t ipl, Bool_t in) const
          virtual TGeoVolume* Divide(TGeoVolume* voldiv, const char* divname, Int_t iaxis, Int_t ndiv, Double_t start, Double_t step)
             virtual Double_t GetAxisRange(Int_t iaxis, Double_t& xlo, Double_t& xhi) const
                 virtual void GetBoundingCylinder(Double_t* param) const
                virtual Int_t GetByteCount() const
                     Double_t GetDz() const
                virtual Int_t GetFittingBox(const TGeoBBox* parambox, TGeoMatrix* mat, Double_t& dx, Double_t& dy, Double_t& dz) const
           virtual TGeoShape* GetMakeRuntimeShape(TGeoShape*, TGeoMatrix*) const
                virtual Int_t GetNmeshVertices() const
                  static void GetPlaneNormal(Double_t* p1, Double_t* p2, Double_t* p3, Double_t* norm)
                     Double_t GetTwist(Int_t iseg) const
                    Double_t* GetVertices()
                static Bool_t InsidePolygon(Double_t x, Double_t y, Double_t* pts)
                 virtual void InspectShape() const
              virtual TClass* IsA() const
               virtual Bool_t IsCylType() const
                static Bool_t IsSamePoint(Double_t* p1, Double_t* p2)
                       Bool_t IsTwisted() const
                    TGeoArb8& operator=(const TGeoArb8&)
             virtual Double_t Safety(Double_t* point, Bool_t in = kTRUE) const
                     Double_t SafetyToFace(Double_t* point, Int_t iseg, Bool_t in) const
                 virtual void SavePrimitive(ofstream& out, Option_t* option)
                 virtual void SetDimensions(Double_t* param)
                         void SetPlaneVertices(Double_t zpl, Double_t* vertices) const
                 virtual void SetPoints(Double_t* points) const
                 virtual void SetPoints(Float_t* points) const
                 virtual void SetVertex(Int_t vnum, Double_t x, Double_t y)
                 virtual void ShowMembers(TMemberInspector& insp, char* parent)
                 virtual void Sizeof3D() const
                 virtual void Streamer(TBuffer& b)
                         void StreamerNVirtual(TBuffer& b)

### Data Members

        protected:

           Double_t fDz        half length in Z
          Double_t* fTwist     ! [4] tangents of twist angles
           Double_t fXY[8][2]  list of vertices

        public:

          static const TGeoArb8::EGeoArb8Type kArb8Trap
          static const TGeoArb8::EGeoArb8Type kArb8Tra

## Class Description

     TGeoArb8 - a arbitrary trapezoid with less than 8 vertices standing on
       two paralel planes perpendicular to Z axis. Parameters :
                - dz - half length in Z;
                - xy[8][2] - vector of (x,y) coordinates of vertices
                   - first four points (xy[i][j], i<4, j<2) are the (x,y)
                     coordinates of the vertices sitting on the -dz plane;
                   - last four points (xy[i][j], i>=4, j<2) are the (x,y)
                     coordinates of the vertices sitting on the +dz plane;
       The order of defining the vertices of an arb8 is the following :
          - point 0 is connected with points 1,3,4
          - point 1 is connected with points 0,2,5
          - point 2 is connected with points 1,3,6
          - point 3 is connected with points 0,2,7
          - point 4 is connected with points 0,5,7
          - point 5 is connected with points 1,4,6
          - point 6 is connected with points 2,5,7
          - point 7 is connected with points 3,4,6
       Points can be identical in order to create shapes with less than
       8 vertices.

TGeoArb8()

     dummy ctor

TGeoArb8(Double_t dz, Double_t *vertices) :TGeoBBox(0,0,0)

     constructor. If the array of vertices is not null, this should be
     in the format : (x0, y0, x1, y1, ... , x7, y7)

TGeoArb8(const char *name, Double_t dz, Double_t *vertices) :TGeoBBox(name, 0,0,0)

     constructor. If the array of vertices is not null, this should be
     in the format : (x0, y0, x1, y1, ... , x7, y7)

~TGeoArb8()

     destructor

void ComputeBBox()

     compute bounding box for a Arb8

void ComputeTwist()

     compute tangents of twist angles (angles between projections on XY plane
     of corresponding -dz +dz edges). Called after last point [7] was set.

Double_t GetTwist(Int_t iseg) const

     Get twist for segment I in range [0,3]

void ComputeNormal(Double_t *point, Double_t *dir, Double_t *norm)

     Compute normal to closest surface from POINT.

Bool_t Contains(Double_t *point) const

     test if point is inside this sphere
     first check Z range

Double_t DistToPlane(Double_t *point, Double_t *dir, Int_t ipl, Bool_t in) const

     compute distance to plane ipl :
     ipl=0 : points 0,4,1,5
     ipl=1 : points 1,5,2,6
     ipl=2 : points 2,6,3,7
     ipl=3 : points 3,7,0,4

Double_t DistFromOutside(Double_t *point, Double_t *dir, Int_t /*iact*/, Double_t /*step*/, Double_t * /*safe*/) const

     compute distance from outside point to surface of the arb8

Double_t DistFromInside(Double_t *point, Double_t *dir, Int_t /*iact*/, Double_t /*step*/, Double_t * /*safe*/) const

     compute distance from inside point to surface of the arb8

TGeoVolume* Divide(TGeoVolume *voldiv, const char * /*divname*/, Int_t /*iaxis*/, Int_t /*ndiv*/, Double_t /*start*/, Double_t /*step*/)

Double_t GetAxisRange(Int_t iaxis, Double_t &xlo, Double_t &xhi) const

void GetBoundingCylinder(Double_t *param) const

    --- Fill vector param[4] with the bounding cylinder parameters. The order
     is the following : Rmin, Rmax, Phi1, Phi2
    --- first compute rmin/rmax

Int_t GetFittingBox(const TGeoBBox *parambox, TGeoMatrix *mat, Double_t &dx, Double_t &dy, Double_t &dz) const

     Fills real parameters of a positioned box inside this arb8. Returns 0 if successfull.

void GetPlaneNormal(Double_t *p1, Double_t *p2, Double_t *p3, Double_t *norm)

     Compute normal to plane defined by P1, P2 and P3

Bool_t InsidePolygon(Double_t x, Double_t y, Double_t *pts)

     Find if a point in XY plane is inside the polygon defines by PTS.

void InspectShape() const

     print shape parameters

Double_t Safety(Double_t *point, Bool_t in) const

     computes the closest distance from given point to this shape, according
     to option. The matching point on the shape is stored in spoint.

Double_t SafetyToFace(Double_t *point, Int_t iseg, Bool_t in) const

     Estimate safety to lateral plane defined by segment iseg in range [0,3]
     might be negative: plane seen only from inside

void SavePrimitive(ofstream &out, Option_t * /*option*/)

     Save a primitive as a C++ statement(s) on output stream "out".

void SetPlaneVertices(Double_t zpl, Double_t *vertices) const

     compute intersection points between plane at zpl and non-horizontal edges

void SetDimensions(Double_t *param)

     set arb8 params in one step :

void SetPoints(Double_t *points) const

     create arb8 mesh points

void SetPoints(Float_t *points) const

     create arb8 mesh points

void SetVertex(Int_t vnum, Double_t x, Double_t y)

      set values for a given vertex

void Sizeof3D() const

     fill size of this 3-D object

### Inline Functions

                  Int_t GetByteCount() const
               Double_t GetDz() const
             TGeoShape* GetMakeRuntimeShape(TGeoShape*, TGeoMatrix*) const
                  Int_t GetNmeshVertices() const
              Double_t* GetVertices()
                 Bool_t IsCylType() const
                 Bool_t IsSamePoint(Double_t* p1, Double_t* p2)
                 Bool_t IsTwisted() const
                TClass* Class()
                TClass* IsA() const
                   void ShowMembers(TMemberInspector& insp, char* parent)
                   void Streamer(TBuffer& b)
                   void StreamerNVirtual(TBuffer& b)
               TGeoArb8 TGeoArb8(const TGeoArb8&)
              TGeoArb8& operator=(const TGeoArb8&)

Author: Andrei Gheata 31/01/02
Last update: root/geom:$Name: $:$Id: TGeoArb8.cxx,v 1.43 2005/05/13 16:20:38 brun Exp $
Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *