| library: libCore #include "TBuffer3D.h" |
| Inheritance Chart: | |||||||||
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private:
TBuffer3D(const TBuffer3D&)
void Init()
const TBuffer3D& operator=(const TBuffer3D&) const
public:
TBuffer3D(Int_t type, UInt_t reqPnts = 0, UInt_t reqPntsCapacity = 0, UInt_t reqSegs = 0, UInt_t reqSegsCapacity = 0, UInt_t reqPols = 0, UInt_t reqPolsCapacity = 0)
virtual ~TBuffer3D()
static TClass* Class()
void ClearSectionsValid()
static UInt_t DecCSLevel()
static UInt_t GetCSLevel()
UInt_t GetSections(UInt_t mask) const
static void IncCSLevel()
virtual TClass* IsA() const
UInt_t NbPnts() const
UInt_t NbPols() const
UInt_t NbSegs() const
Bool_t SectionsValid(UInt_t mask) const
void SetAABoundingBox(const Double_t* origin, const Double_t* halfLengths)
void SetLocalMasterIdentity()
Bool_t SetRawSizes(UInt_t reqPnts, UInt_t reqPntsCapacity, UInt_t reqSegs, UInt_t reqSegsCapacity, UInt_t reqPols, UInt_t reqPolsCapacity)
void SetSectionsValid(UInt_t mask)
virtual void ShowMembers(TMemberInspector& insp, char* parent)
virtual void Streamer(TBuffer& b)
void StreamerNVirtual(TBuffer& b)
Int_t Type() const
private:
const Int_t fType Primitive type - predefined ones in TBuffer3DTypes.h
UInt_t fNbPnts Number of points describing the shape
UInt_t fNbSegs Number of segments describing the shape
UInt_t fNbPols Number of polygons describing the shape
UInt_t fPntsCapacity Current capacity of fPnts space
UInt_t fSegsCapacity Current capacity of fSegs space
UInt_t fPolsCapacity Current capacity of fSegs space
UInt_t fSections Section validity flags
static UInt_t fgCSLevel
public:
static const TBuffer3D::EBoolOpCode kCSUnion
static const TBuffer3D::EBoolOpCode kCSIntersection
static const TBuffer3D::EBoolOpCode kCSDifference
static const TBuffer3D::EBoolOpCode kCSNoOp
static const TBuffer3D::ESection kNone
static const TBuffer3D::ESection kCore
static const TBuffer3D::ESection kBoundingBox
static const TBuffer3D::ESection kShapeSpecific
static const TBuffer3D::ESection kRawSizes
static const TBuffer3D::ESection kRaw
static const TBuffer3D::ESection kAll
TObject* fID ID/object generating buffer - see TVirtualViewer3D for setting
Int_t fColor Color index
Short_t fTransparency Percentage transparency [0,100]
Bool_t fLocalFrame True = Local, False = Master reference frame
Bool_t fReflection Matrix is reflection - TODO: REMOVE when OGL viewer rewokred to local frame
Double_t fLocalMaster[16] Local->Master Matrix - identity if master frame
Double_t fBBVertex[8][3] 8 verticies defining bounding box.
Double_t* fPnts x0, y0, z0, x1, y1, z1, ..... ..... ....
Int_t* fSegs c0, p0, q0, c1, p1, q1, ..... ..... ....
Int_t* fPols c0, n0, s0, s1, ... sn, c1, n1, s0, ... sn
TBuffer3D
Generic 3D primitive description class - see TBuffer3DTypes for
producer classes
The viewers behind the TVirtualViewer3D interface differ greatly in their capabilities e.g.
To cope with these situations the object buffer is filled out in negotiation with the viewer. TBuffer3D classes are conceptually divided into enumerated sections Core, BoundingBox, Raw etc (see TBuffer3D.h for more details).
The SectionsValid() / SetSectionsValid / ClearSectionsValid() methods of TBuffer3D are used to test/set/clear these section valid flags.
The sections found in TBuffer3D (Core/BoundingBox/Raw Sizes/Raw) are sufficient to describe any tessellated shape in a generic fashion. An additional ShapeSpecific section in derived shape specific classes allows a more abstract shape description ("a sphere of inner radius x, outer radius y"). This enables a viewer which knows how to draw (tessellate) the shape itself to do so, which can bring considerable performance and quality benefits, while providing a generic fallback suitable for all viewers.
The rules for client negotiation with the viewer are:
If the viewer requires more sections to be completed (Raw/RawSizes) AddObject() will return flags indicating which ones, otherwise it returns kNone. You must fill the buffer and mark these sections valid, and pass the buffer again. A typical code snippet would be:
TBuffer3DSphere sphereBuffer;
Fill out kCore...
Fill out kBoundingBox...
Fill out kShapeSpecific for TBuffer3DSphere
Try first add to viewer
Int_t reqSections = viewer->AddObject(buffer);
if (reqSections != TBuffer3D::kNone) {
if (reqSections & TBuffer3D::kRawSizes) {
Fill out kRawSizes...
}
if (reqSections & TBuffer3D::kRaw) {
Fill out kRaw...
}
Add second time to viewer - ignore return cannot do more
viewer->AddObject(buffer);
}
}
ShapeSpecific: If the viewer can directly display the buffer without
filling of the kRaw/kRawSizes section it will not need to request client side
tessellation.
Currently we provide the following various shape specific classes, which the
OpenGL viewer can take advantage of (see TBuffer3D.h and TBuffer3DTypes.h)
*OpenGL only supports solid spheres at present - cut/hollow ones will be requested tessellated.
Anyone is free to add new TBuffer3D classes, but it should be clear that the viewers require updating to be able to take advantage of them. The number of native shapes in OpenGL will be expanded over time.
BoundingBox: You are not obliged to complete this, as any viewer requiring one internally (OpenGL) will build one for you if you do not provide. However to do this the viewer will force you to provide the raw tessellation, and the resulting box will be axis aligned with the overall scene, which is non-ideal for rotated shapes.
As we need to support orientated (rotated) bounding boxes, TBuffer3D requires the 6 vertices of the box. We also provide a convenience function, SetAABoundingBox(), for simpler case of setting an axis aligned bounding box.
If fLocalFrame is kFALSE, fLocalMaster should contain an
identity matrix. This is set by default, and can be reset using SetLocalMasterIdentity() function.
Logical & Physical Objects
There are two cases of object addition:
The second case is very typical in geometry packages, GEANT4, where we have very large number repeated placements of relatively few logical (unique) shapes. Some viewers (OpenGL only at present) are able to take advantage of this by identifying unique logical shapes from the fID logical ID member of TBuffer3D. If repeated addition of the same fID is found, the shape is cached already - and the costly tessellation does not need to be sent again. The viewer can also perform internal GL specific caching with considerable performance gains in these cases.
For this to work correctly the logical object in must be described in TBuffer3D in the local reference frame, complete with the local/master translation. The viewer indicates this through the interface method
PreferLocalFrame()If this returns kTRUE you can make repeated calls to AddObject(), with TBuffer3D containing the same fID, and different fLocalMaster placements.
For viewers supporting logical/physical objects, the TBuffer3D content refers to the properties of logical object, with the fLocalMaster transform and the fColor and fTransparency attributes, which can be varied for each physical object.
As a minimum requirement all clients must be capable of filling the raw tessellation of the object buffer, in the master reference frame. Conversely viewers must always be capable of displaying the object described by this buffer.
Scene Rebuilds
It should be understood that AddObject is not an explicit command to the viewer - it may for various reasons decide to ignore it:
In all these cases AddObject() returns kNone, as it does for successful addition, simply indicating it does not require you to provide further information about this object. You should not try to make any assumptions about what the viewer did with it.
This enables the viewer to be connected to a client which sends potentially millions of objects, and only accept those that are of interest at a certain time, caching the relatively small number of CPU/memory costly logical shapes, and retaining/discarding the physical placements as required. The viewer may decide to force the client to rebuild (republish) the scene (via a TPad repaint at present), and thus collect these objects if the internal viewer state changes. It does this presently by forcing a repaint on the attached TPad object - hence the reason for putting all publishing to the viewer in the attached pad objects Paint() method. We will likely remove this requirement in the future, indicating the rebuild request via a normal ROOT signal, which the client can detect.
virtual Int_t AddObject(UInt_t physicalID, const TBuffer3D & buffer, Bool_t * addChildren = 0)If you use the first (simple) case a viewer using logical/physical pairs will generate IDs for each physical object internally. In the second you can specify a unique identifier from the client, which allows the viewer to be more efficient. It can now cache both logical and physical objects, and only discard physical objects no longer of interest as part of scene rebuilds.
Child Objects
In many geometries there is a rigid containment hierarchy, and so if the viewer is not interested in a certain object due to limits/size then it will also not be interest in any of the contained branch of descendents. Both AddObject() methods have an addChildren parameter. The viewer will complete this (if passed) indicating if children (contained within the one just sent) are worth adding.
Recyling TBuffer3D
Once add AddObject() has been called, the contents are copied to the viewer internally. You are free to destroy this object, or recycle it for the next object if suitable.
TBuffer3D(Int_t type, UInt_t reqPnts, UInt_t reqPntsCapacity, UInt_t reqSegs, UInt_t reqSegsCapacity, UInt_t reqPols, UInt_t reqPolsCapacity) : fType(type) // Initialise buffer
Destructor Construct from supplied shape type and raw sizes
~TBuffer3D() // Initialise buffer
Destructor
void Init()
Initialise buffer
void ClearSectionsValid()
Clear any sections marked valid
void SetLocalMasterIdentity()
Set kRaw tesselation section of buffer with supplied sizes Set fLocalMaster in section kCore to identity
void SetAABoundingBox(const Double_t origin[3], const Double_t halfLengths[3])
Set fBBVertex in kBoundingBox section to a axis aligned (local) BB using supplied origin and box half lengths 7-------6 /| /| 3-------2 | | 4-----|-5 |/ | 0-------1
Bool_t SetRawSizes(UInt_t reqPnts, UInt_t reqPntsCapacity, UInt_t reqSegs, UInt_t reqSegsCapacity, UInt_t reqPols, UInt_t reqPolsCapacity)
Set kRaw tesselation section of buffer with supplied sizes
UInt_t GetCSLevel()
void IncCSLevel()
UInt_t DecCSLevel()
Inline Functions
const TBuffer3D& operator=(const TBuffer3D&) const TBuffer3D TBuffer3D(Int_t type, UInt_t reqPnts = 0, UInt_t reqPntsCapacity = 0, UInt_t reqSegs = 0, UInt_t reqSegsCapacity = 0, UInt_t reqPols = 0, UInt_t reqPolsCapacity = 0) void SetSectionsValid(UInt_t mask) Bool_t SectionsValid(UInt_t mask) const UInt_t GetSections(UInt_t mask) const UInt_t NbPnts() const UInt_t NbSegs() const UInt_t NbPols() const Int_t Type() const TClass* Class() TClass* IsA() const void ShowMembers(TMemberInspector& insp, char* parent) void Streamer(TBuffer& b) void StreamerNVirtual(TBuffer& b)
Author: Olivier Couet 05/05/04
Last update: root/base:$Name: $:$Id: TBuffer3D.cxx,v 1.00
Copyright (C) 1995-2004, Rene Brun and Fons Rademakers. *
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