library: libGeom #include "TGeoTorus.h"

# TGeoTorus

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

## class TGeoTorus : public TGeoBBox

| Inheritance Chart:
`TObject`
| <- | `TNamed`
| <- | `TGeoShape`
| <- | `TGeoBBox`
| <- | `TGeoTorus` |

        public:

                                   TGeoTorus()
                                   TGeoTorus(Double_t r, Double_t rmin, Double_t rmax, Double_t phi1 = 0, Double_t dphi = 360)
                                   TGeoTorus(const char* name, Double_t r, Double_t rmin, Double_t rmax, Double_t phi1 = 0, Double_t dphi = 360)
                                   TGeoTorus(Double_t* params)
                                   TGeoTorus(const TGeoTorus&)
                           virtual ~TGeoTorus()
                    static TClass* Class()
                      virtual void ComputeBBox()
                      virtual void ComputeNormal(Double_t* point, Double_t* dir, Double_t* norm)
                    virtual Bool_t Contains(Double_t* point) const
                          Double_t Daxis(Double_t* pt, Double_t* dir, Double_t t) const
                          Double_t DDaxis(Double_t* pt, Double_t* dir, Double_t t) const
                          Double_t DDDaxis(Double_t* pt, Double_t* dir, Double_t t) const
                     virtual Int_t DistancetoPrimitive(Int_t px, Int_t py)
                  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
               virtual TGeoVolume* Divide(TGeoVolume* voldiv, const char* divname, Int_t iaxis, Int_t ndiv, Double_t start, Double_t step)
               virtual const char* GetAxisName(Int_t iaxis) const
                  virtual Double_t GetAxisRange(Int_t iaxis, Double_t& xlo, Double_t& xhi) const
                      virtual void GetBoundingCylinder(Double_t* param) const
          virtual const TBuffer3D& GetBuffer3D(Int_t reqSections, Bool_t localFrame) const
                     virtual Int_t GetByteCount() const
                          Double_t GetDphi() const
                virtual TGeoShape* GetMakeRuntimeShape(TGeoShape* mother, TGeoMatrix* mat) const
                     virtual Int_t GetNmeshVertices() const
                          Double_t GetPhi1() const
                          Double_t GetR() const
                          Double_t GetRmax() const
                          Double_t GetRmin() const
                      virtual void InspectShape() const
                   virtual TClass* IsA() const
                    virtual Bool_t IsCylType() const
                virtual TBuffer3D* MakeBuffer3D() const
                        TGeoTorus& operator=(const TGeoTorus&)
                  virtual Double_t Safety(Double_t* point, Bool_t in = kTRUE) const
                      virtual void SavePrimitive(ofstream& out, Option_t* option)
                      virtual void SetDimensions(Double_t* param)
                      virtual void SetPoints(Double_t* points) const
                      virtual void SetPoints(Float_t* points) const
                      virtual void SetSegsAndPols(TBuffer3D& buff) const
                              void SetTorusDimensions(Double_t r, Double_t rmin, Double_t rmax, Double_t phi1, Double_t dphi)
                      virtual void ShowMembers(TMemberInspector& insp, char* parent)
                      virtual void Sizeof3D() const
                             Int_t SolveCubic(Double_t a, Double_t b, Double_t c, Double_t* x) const
                             Int_t SolveQuartic(Double_t a, Double_t b, Double_t c, Double_t d, Double_t* x) const
                      virtual void Streamer(TBuffer& b)
                              void StreamerNVirtual(TBuffer& b)
                          Double_t ToBoundary(Double_t* pt, Double_t* dir, Double_t r) const

### Data Members

        protected:

          Double_t fR     axial radius
          Double_t fRmin  inner radius
          Double_t fRmax  outer radius
          Double_t fPhi1  starting phi
          Double_t fDphi  phi extent

## Class Description

     TGeoTorus - Torus segment class. A torus has 5 parameters :
                R    - axial radius
                Rmin - inner radius
                Rmax - outer radius
                Phi1 - starting phi
                Dphi - phi extent

    _____________________________________________________________________________

TGeoTorus()

     Default constructor

TGeoTorus(Double_t r, Double_t rmin, Double_t rmax, Double_t phi1, Double_t dphi) :TGeoBBox(0, 0, 0)

     Constructor without name.

TGeoTorus(const char *name, Double_t r, Double_t rmin, Double_t rmax, Double_t phi1, Double_t dphi) :TGeoBBox(name, 0, 0, 0)

     Constructor with name.

TGeoTorus(Double_t *param) :TGeoBBox(0, 0, 0)

     Constructor based on an array of parameters.
     param[0] = R
     param[1] = Rmin
     param[2] = Rmax
     param[3] = Phi1
     param[4] = Dphi

void ComputeBBox()

     Compute bounding box of the torus.

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 the torus.
     check phi range

Int_t DistancetoPrimitive(Int_t px, Int_t py)

     Compute closest distance from point px,py to each vertex.

Double_t Daxis(Double_t *pt, Double_t *dir, Double_t t) const

     Computes distance to axis of the torus from point pt + t*dir;

Double_t DDaxis(Double_t *pt, Double_t *dir, Double_t t) const

     Computes derivative w.r.t. t of the distance to axis of the torus from point pt + t*dir;

Double_t DDDaxis(Double_t *pt, Double_t *dir, Double_t t) const

     Second derivative of distance to torus axis w.r.t t.

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 torus.

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 torus.

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

    --- Divide this torus shape belonging to volume "voldiv" into ndiv volumes
     called divname, from start position with the given step.

const char* GetAxisName(Int_t iaxis) const

     Returns name of axis IAXIS.

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

     Get range of shape for a given axis.

void GetBoundingCylinder(Double_t *param) const

    --- Fill vector param[4] with the bounding cylinder parameters. The order
     is the following : Rmin, Rmax, Phi1, Phi2, dZ

TGeoShape* GetMakeRuntimeShape(TGeoShape * /*mother*/, TGeoMatrix * /*mat*/) const

void InspectShape() const

     print shape parameters

TBuffer3D* MakeBuffer3D() const

     Creates a TBuffer3D describing *this* shape.
     Coordinates are in local reference frame.

void SetSegsAndPols(TBuffer3D &buff) const

     Fill TBuffer3D structure for segments and polygons.

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.

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

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

void SetTorusDimensions(Double_t r, Double_t rmin, Double_t rmax, Double_t phi1, Double_t dphi)

void SetDimensions(Double_t *param)

void SetPoints(Double_t *points) const

     Create torus mesh points

void SetPoints(Float_t *points) const

     Create torus mesh points

Int_t GetNmeshVertices() const

     Return number of vertices of the mesh representation

void Sizeof3D() const

    /// fill size of this 3-D object
    /   TVirtualGeoPainter *painter = gGeoManager->GetGeomPainter();
    /   if (!painter) return;
    /   Int_t n = gGeoManager->GetNsegments()+1;
    /   Int_t numPoints = n*(n-1);
    /   Int_t numSegs   = (2*n-1)*(n-1);
    /   Int_t numPolys  = (n-1)*(n-1);

    /   Bool_t hasrmin = (fRmin>0)?kTRUE:kFALSE;
    /   Bool_t hasphi  = (fDphi<360)?kTRUE:kFALSE;
    /   if (hasrmin) numPoints *= 2;
    /   else if (hasphi) numPoints += 2;
    /   if (hasrmin) {
    /      numSegs   += (2*n-1)*(n-1);
    /      numPolys  += (n-1)*(n-1);
    /   }
    /   if (hasphi) {
    /      numSegs   += 2*(n-1);
    /      numPolys  += 2*(n-1);
    /   }

    /   painter->AddSize3D(numPoints, numSegs, numPolys);

Int_t SolveCubic(Double_t a, Double_t b, Double_t c, Double_t *x) const

     Find real solutions of the cubic equation : x^3 + a*x^2 + b*x + c = 0
     Input: a,b,c
     Output: x[3] real solutions
     Returns number of real solutions (1 or 3)

Int_t SolveQuartic(Double_t a, Double_t b, Double_t c, Double_t d, Double_t *x) const

     Find real solutions of the quartic equation : x^4 + a*x^3 + b*x^2 + c*x + d = 0
     Input: a,b,c,d
     Output: x[4] - real solutions
     Returns number of real solutions (0 to 4)

Double_t ToBoundary(Double_t *pt, Double_t *dir, Double_t r) const

     Returns distance to the surface or the torus (fR,r) from a point, along
     a direction. Point is close enough to the boundary so that the distance
     to the torus is decreasing while moving along the given direction.

const TBuffer3D& GetBuffer3D(Int_t reqSections, Bool_t localFrame) const

### Inline Functions

                   void ~TGeoTorus()
                  Int_t GetByteCount() const
               Double_t GetR() const
               Double_t GetRmin() const
               Double_t GetRmax() const
               Double_t GetPhi1() const
               Double_t GetDphi() const
                 Bool_t IsCylType() const
                TClass* Class()
                TClass* IsA() const
                   void ShowMembers(TMemberInspector& insp, char* parent)
                   void Streamer(TBuffer& b)
                   void StreamerNVirtual(TBuffer& b)
              TGeoTorus TGeoTorus(const TGeoTorus&)
             TGeoTorus& operator=(const TGeoTorus&)

Author: Andrei Gheata 28/07/03
Last update: root/geom:$Name: $:$Id: TGeoTorus.cxx,v 1.26 2005/06/17 20:31:52 brun Exp $
Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *