library: libGeom #include "TGeoShape.h"

# TGeoShape

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

## class TGeoShape : public TNamed

| Inheritance Chart:

`TObject`

<-

`TNamed`

<-

`TGeoShape`

<-

`TGeoBBox`

<-

`TGeoArb8`

<-

`TGeoTrap`

<-

`TGeoGtra` |

`TGeoCompositeShape` |

`TGeoCone`

<-

`TGeoConeSeg` |

`TGeoPara` |

`TGeoPcon`

<-

`TGeoPgon` |

[more...]

This is an abstract class, constructors will not be documented.
Look at the header to check for available constructors.

        public:

                      virtual ~TGeoShape()
              static Double_t Big()
               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
               virtual Bool_t CouldBeCrossed(Double_t* point, Double_t* dir) const
                virtual Int_t DistancetoPrimitive(Int_t px, Int_t py)
             virtual Double_t DistToIn(Double_t* point, Double_t* dir, Int_t iact = 1, Double_t step = TGeoShape::Big(), Double_t* safe = 0) const
             virtual Double_t DistToOut(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 Int_t GetByteCount() const
                virtual Int_t GetFittingBox(const TGeoBBox* parambox, TGeoMatrix* mat, Double_t& dx, Double_t& dy, Double_t& dz) const
                        Int_t GetId() const
           virtual TGeoShape* GetMakeRuntimeShape(TGeoShape* mother, TGeoMatrix* mat) const
          virtual const char* GetName() const
                virtual Int_t GetNmeshVertices() const
                 virtual void InspectShape() const
                         void InvertShapeBit(UInt_t f)
              virtual TClass* IsA() const
                static Bool_t IsCloseToPhi(Double_t epsil, Double_t* point, Double_t c1, Double_t s1, Double_t c2, Double_t s2)
               virtual Bool_t IsComposite() const
                static Bool_t IsCrossingSemiplane(Double_t* point, Double_t* dir, Double_t cphi, Double_t sphi, Double_t& snext, Double_t& rxy)
               virtual Bool_t IsCylType() const
                static Bool_t IsInPhiRange(Double_t* point, Double_t phi1, Double_t phi2)
                       Bool_t IsRunTimeShape() const
                       Bool_t IsValid() const
               virtual Bool_t IsValidBox() const
                virtual void* Make3DBuffer(const TGeoVolume* vol) const
                  static void NormalPhi(Double_t* point, Double_t* dir, Double_t* norm, Double_t c1, Double_t s1, Double_t c2, Double_t s2)
                   TGeoShape& operator=(const TGeoShape&)
                 virtual void Paint(Option_t* option)
                 virtual void PaintNext(TGeoHMatrix* glmat, Option_t* option)
                         void ResetShapeBit(UInt_t f)
             virtual Double_t Safety(Double_t* point, Bool_t in = kTRUE) const
              static Double_t SafetyPhi(Double_t* point, Bool_t in, Double_t phi1, Double_t phi2)
                 virtual void SetDimensions(Double_t* param)
                         void SetId(Int_t id)
                 virtual void SetPoints(Double_t* buff) const
                 virtual void SetPoints(Float_t* buff) const
                         void SetRuntime(Bool_t flag = kTRUE)
                         void SetShapeBit(UInt_t f, Bool_t set)
                         void SetShapeBit(UInt_t f)
                        Int_t ShapeDistancetoPrimitive(Int_t numpoints, Int_t px, Int_t py) const
                 virtual void ShowMembers(TMemberInspector& insp, char* parent)
                 virtual void Sizeof3D() const
                 virtual void Streamer(TBuffer& b)
                         void StreamerNVirtual(TBuffer& b)
                       Bool_t TestShapeBit(UInt_t f) const
                        Int_t TestShapeBits(UInt_t f) const

### Data Members

        protected:

           Int_t fShapeId    shape id
          UInt_t fShapeBits  shape bits

        public:

          static const TGeoShape::EShapeType kGeoNoShape
          static const TGeoShape::EShapeType kGeoBad
          static const TGeoShape::EShapeType kGeoRSeg
          static const TGeoShape::EShapeType kGeoPhiSeg
          static const TGeoShape::EShapeType kGeoThetaSeg
          static const TGeoShape::EShapeType kGeoVisX
          static const TGeoShape::EShapeType kGeoVisY
          static const TGeoShape::EShapeType kGeoVisZ
          static const TGeoShape::EShapeType kGeoRunTimeShape
          static const TGeoShape::EShapeType kGeoInvalidShape
          static const TGeoShape::EShapeType kGeoTorus
          static const TGeoShape::EShapeType kGeoBox
          static const TGeoShape::EShapeType kGeoPara
          static const TGeoShape::EShapeType kGeoSph
          static const TGeoShape::EShapeType kGeoTube
          static const TGeoShape::EShapeType kGeoTubeSeg
          static const TGeoShape::EShapeType kGeoCone
          static const TGeoShape::EShapeType kGeoConeSeg
          static const TGeoShape::EShapeType kGeoPcon
          static const TGeoShape::EShapeType kGeoPgon
          static const TGeoShape::EShapeType kGeoArb8
          static const TGeoShape::EShapeType kGeoEltu
          static const TGeoShape::EShapeType kGeoTrap
          static const TGeoShape::EShapeType kGeoCtub
          static const TGeoShape::EShapeType kGeoTrd1
          static const TGeoShape::EShapeType kGeoTrd2
          static const TGeoShape::EShapeType kGeoComb
          static const TGeoShape::EShapeType kGeoClosedShape
          static const TGeoShape::EShapeType kGeoXtru

## Class Description

     TGeoShape - Base abstract class for all shapes.
    ____________________________________________________________________________

       Shapes are geometrical objects that provide the basic modelling
     functionality. They provide the definition of the LOCAL frame of coordinates,
     with respect to which they are defined. Any implementation of a shape deriving
     from the base TGeoShape class has to provide methods for :
      - finding out if a point defined in their local frame is or not contained
     inside;
      - computing the distance from a local point to getting outside/entering the
     shape, given a known direction;
      - computing the maximum distance in any direction from a local point that
     does NOT result in a boundary crossing of the shape (safe distance);
      - computing the cosines of the normal vector to the crossed shape surface,
     given a starting local point and an ongoing direction.
       All the features above are globally managed by the modeller in order to
     provide navigation functionality. In addition to those, shapes have also to
     implement additional specific abstract methods :
      - computation of the minimal box bounding the shape, given that this box have
     to be aligned with the local coordinates;
      - algorithms for dividing the shape along a given axis and producing resulting
     divisions volumes.

       The modeler currently provides a set of 16 basic shapes, which we will call
     primitives. It also provides a special class allowing the creation of shapes
     made as a result of boolean operations between primitives. These are called
     composite shapes and the composition operation can be recursive (composition
     of composites). This allows the creation of a quite large number of different
     shape topologies and combinations.

       Shapes are named objects and register themselves to the manager class at
     creation time. This is responsible for their final deletion. Shapes
     can be created without name if their retreival by name is no needed. Generally
     shapes are objects that are usefull only at geometry creation stage. The pointer
     to a shape is in fact needed only when referring to a given volume and it is
     always accessible at that level. A shape may be referenced by several volumes,
     therefore its deletion is not possible once volumes were defined based on it.

     Creating shapes
    ================
       Shape objects embeed only the minimum set of parameters that are fully
     describing a valid physical shape. For instance, a tube is represented by
     its half length, the minimum radius and the maximum radius. Shapes are used
     togeather with media in order to create volumes, which in their turn
     are the main components of the geometrical tree. A specific shape can be created
     stand-alone :

       TGeoBBox *box = new TGeoBBox("s_box", halfX, halfY, halfZ); // named
       TGeoTube *tub = new TGeoTube(rmin, rmax, halfZ);            // no name
       ...  (see each specific shape constructors)

       Sometimes it is much easier to create a volume having a given shape in one
     step, since shapes are not direcly linked in the geometrical tree but volumes
     are :

       TGeoVolume *vol_box = gGeoManager->MakeBox("BOX_VOL", "mat1", halfX, halfY, halfZ);
       TGeoVolume *vol_tub = gGeoManager->MakeTube("TUB_VOL", "mat2", rmin, rmax, halfZ);
       ...  (see MakeXXX() utilities in TGeoManager class)

     Shape queries
    ===============
     Note that global queries related to a geometry are handled by the manager class.
     However, shape-related queries might be sometimes usefull.

     A) Bool_t TGeoShape::Contains(Double_t *point[3])
       - this method returns true if POINT is actually inside the shape. The point
     has to be defined in the local shape reference. For instance, for a box having
     DX, DY and DZ half-lengths a point will be considered inside if :
       | -DX <= point[0] <= DX
       | -DY <= point[1] <= DY
       | -DZ <= point[2] <= DZ

     B) Double_t TGeoShape::DistToOut(Double_t *point[3], Double_t *dir[3],
                                      Int_t iact, Double_t step, Double_t *safe)
       - computes the distance to exiting a shape from a given point INSIDE, along
     a given direction. The direction is given by its director cosines with respect
     to the local shape coordinate system. This method provides additional
     information according the value of IACT input parameter :
       IACT = 0     => compute only safe distance and fill it at the location
                       given by SAFE
       IACT = 1     => a proposed STEP is supplied. The safe distance is computed
                       first. If this is bigger than STEP than the proposed step
                       is approved and returned by the method since it does not
                       cross the shape boundaries. Otherwise, the distance to
                       exiting the shape is computed and returned.
       IACT = 2     => compute both safe distance and distance to exiting, ignoring
                       the proposed step.
       IACT > 2     => compute only the distance to exiting, ignoring anything else.

     C) Double_t TGeoShape::DistToOut(Double_t *point[3], Double_t *dir[3],
                                      Int_t iact, Double_t step, Double_t *safe)
       - computes the distance to entering a shape from a given point OUTSIDE. Acts
     in the same way as B).

     D) Double_t Safety(Double_t *point[3], Bool_t inside)

       - compute maximum shift of a point in any direction that does not change its
     INSIDE/OUTSIDE state (does not cross shape boundaries). The state of the point
     have to be properly supplied.

     E) Double_t *Normal(Double_t *point[3], Double_t *dir[3], Bool_t inside)

       - returns director cosines of normal to the crossed shape surface from a
     given point towards a direction. One has to specify if the point is inside
     or outside shape. According to this, the normal will be outwards or inwards
     shape respectively. Normal components are statically stored by shape class,
     so it has to be copied after retreival in a different array.

     Dividing shapes
    =================
       Shapes can generally be divided along a given axis. Supported axis are
     X, Y, Z, Rxy, Phi, Rxyz. A given shape cannot be divided however on any axis.
     The general rule is that that divisions are possible on whatever axis that
     produces still known shapes as slices. The division of shapes should not be
     performed by TGeoShape::Divide() calls, but rather by TGeoVolume::Divide().
     The algorithm for dividing a specific shape is known by the shape object, but
     is always invoked in a generic way from the volume level. Details on how to
     do that can be found in TGeoVolume class. One can see how all division options
     are interpreted and which is their result inside specific shape classes.
    _____________________________________________________________________________

/* */

~TGeoShape()

     Destructor

const char* GetName() const

Int_t ShapeDistancetoPrimitive(Int_t numpoints, Int_t px, Int_t py) const

Bool_t IsCloseToPhi(Double_t epsil, Double_t *point, Double_t c1, Double_t s1, Double_t c2, Double_t s2)

     True if point is closer than epsil to one of the phi planes defined by c1,s1 or c2,s2

Bool_t IsInPhiRange(Double_t *point, Double_t phi1, Double_t phi2)

     Static method to check if a point is in the phi range (phi1, phi2) [degrees]

Bool_t IsCrossingSemiplane(Double_t *point, Double_t *dir, Double_t cphi, Double_t sphi, Double_t &snext, Double_t &rxy)

     Compute distance from POINT to semiplane defined by PHI angle along DIR. Computes
     also radius at crossing point. This might be negative in case the crossing is
     on the other side of the semiplane.

void NormalPhi(Double_t *point, Double_t *dir, Double_t *norm, Double_t c1, Double_t s1, Double_t c2, Double_t s2)

     Static method to compute normal to phi planes.

Double_t SafetyPhi(Double_t *point, Bool_t in, Double_t phi1, Double_t phi2)

     Static method to compute safety w.r.t a phi corner defined by cosines/sines
     of the angles phi1, phi2.

void SetShapeBit(UInt_t f, Bool_t set)

### Inline Functions

               Double_t Big()
                   void ComputeBBox()
                   void ComputeNormal(Double_t* point, Double_t* dir, Double_t* norm)
                 Bool_t Contains(Double_t* point) const
                 Bool_t CouldBeCrossed(Double_t* point, Double_t* dir) const
                  Int_t DistancetoPrimitive(Int_t px, Int_t py)
               Double_t DistToOut(Double_t* point, Double_t* dir, Int_t iact = 1, Double_t step = TGeoShape::Big(), Double_t* safe = 0) const
               Double_t DistToIn(Double_t* point, Double_t* dir, Int_t iact = 1, Double_t step = TGeoShape::Big(), Double_t* safe = 0) const
            TGeoVolume* Divide(TGeoVolume* voldiv, const char* divname, Int_t iaxis, Int_t ndiv, Double_t start, Double_t step)
            const char* GetAxisName(Int_t iaxis) const
               Double_t GetAxisRange(Int_t iaxis, Double_t& xlo, Double_t& xhi) const
                   void GetBoundingCylinder(Double_t* param) const
                  Int_t GetByteCount() const
                  Int_t GetFittingBox(const TGeoBBox* parambox, TGeoMatrix* mat, Double_t& dx, Double_t& dy, Double_t& dz) const
                  Int_t GetId() const
             TGeoShape* GetMakeRuntimeShape(TGeoShape* mother, TGeoMatrix* mat) const
                  Int_t GetNmeshVertices() const
                 Bool_t IsComposite() const
                 Bool_t IsCylType() const
                 Bool_t IsRunTimeShape() const
                 Bool_t IsValid() const
                 Bool_t IsValidBox() const
                   void InspectShape() const
                  void* Make3DBuffer(const TGeoVolume* vol) const
                   void Paint(Option_t* option)
                   void PaintNext(TGeoHMatrix* glmat, Option_t* option)
               Double_t Safety(Double_t* point, Bool_t in = kTRUE) const
                   void SetDimensions(Double_t* param)
                   void SetId(Int_t id)
                   void SetPoints(Double_t* buff) const
                   void SetPoints(Float_t* buff) const
                   void SetRuntime(Bool_t flag = kTRUE)
                   void Sizeof3D() const
                   void SetShapeBit(UInt_t f)
                   void ResetShapeBit(UInt_t f)
                 Bool_t TestShapeBit(UInt_t f) const
                  Int_t TestShapeBits(UInt_t f) const
                   void InvertShapeBit(UInt_t f)
                TClass* Class()
                TClass* IsA() const
                   void ShowMembers(TMemberInspector& insp, char* parent)
                   void Streamer(TBuffer& b)
                   void StreamerNVirtual(TBuffer& b)
             TGeoShape& operator=(const TGeoShape&)

Author: Andrei Gheata 31/01/02
Last update: root/geom:$Name: $:$Id: TGeoShape.cxx,v 1.17 2003/12/11 10:34:33 brun Exp $
Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *