HLRBRep_PolyAlgo Class Reference

to remove Hidden lines on Shapes with Triangulations. A framework to compute the shape as seen in a projection plane. This is done by calculating the visible and the hidden parts of the shape. HLRBRep_PolyAlgo works with three types of entity: More...

#include <HLRBRep_PolyAlgo.hxx>

Inheritance diagram for HLRBRep_PolyAlgo:

Public Member Functions
	HLRBRep_PolyAlgo ()
	Constructs an empty framework for the calculation of the visible and hidden lines of a shape in a projection. Use the functions:
	HLRBRep_PolyAlgo (const occ::handle< HLRBRep_PolyAlgo > &A)
	HLRBRep_PolyAlgo (const TopoDS_Shape &S)
int	NbShapes () const
TopoDS_Shape &	Shape (const int I)
void	Remove (const int I)
	remove the Shape of Index .
int	Index (const TopoDS_Shape &S) const
	return the index of the Shape and return 0 if the Shape is not found.
void	Load (const TopoDS_Shape &theShape)
	Loads the shape S into this framework. Warning S must have already been triangulated.
const occ::handle< HLRAlgo_PolyAlgo > &	Algo () const
const HLRAlgo_Projector &	Projector () const
	Sets the parameters of the view for this framework. These parameters are defined by an HLRAlgo_Projector object, which is returned by the Projector function on a Prs3d_Projector object.
void	Projector (const HLRAlgo_Projector &theProj)
double	TolAngular () const
void	TolAngular (const double theTol)
double	TolCoef () const
void	TolCoef (const double theTol)
void	Update ()
	Launches calculation of outlines of the shape visualized by this framework. Used after setting the point of view and defining the shape or shapes to be visualized.
void	InitHide ()
bool	MoreHide () const
void	NextHide ()
HLRAlgo_BiPoint::PointsT &	Hide (HLRAlgo_EdgeStatus &status, TopoDS_Shape &S, bool &reg1, bool &regn, bool &outl, bool &intl)
void	InitShow ()
bool	MoreShow () const
void	NextShow ()
HLRAlgo_BiPoint::PointsT &	Show (TopoDS_Shape &S, bool &reg1, bool &regn, bool &outl, bool &intl)
TopoDS_Shape	OutLinedShape (const TopoDS_Shape &S) const
	Make a shape with the internal outlines in each face.
bool	Debug () const
void	Debug (const bool theDebug)
Public Member Functions inherited from Standard_Transient
	Standard_Transient ()
	Empty constructor.
	Standard_Transient (const Standard_Transient &)
	Copy constructor – does nothing.
Standard_Transient &	operator= (const Standard_Transient &)
	Assignment operator, needed to avoid copying reference counter.
virtual	~Standard_Transient ()=default
	Destructor must be virtual.
virtual const opencascade::handle< Standard_Type > &	DynamicType () const
	Returns a type descriptor about this object.
bool	IsInstance (const opencascade::handle< Standard_Type > &theType) const
	Returns a true value if this is an instance of Type.
bool	IsInstance (const char *const theTypeName) const
	Returns a true value if this is an instance of TypeName.
bool	IsKind (const opencascade::handle< Standard_Type > &theType) const
	Returns true if this is an instance of Type or an instance of any class that inherits from Type. Note that multiple inheritance is not supported by OCCT RTTI mechanism.
bool	IsKind (const char *const theTypeName) const
	Returns true if this is an instance of TypeName or an instance of any class that inherits from TypeName. Note that multiple inheritance is not supported by OCCT RTTI mechanism.
Standard_Transient *	This () const
	Returns non-const pointer to this object (like const_cast). For protection against creating handle to objects allocated in stack or call from constructor, it will raise exception Standard_ProgramError if reference counter is zero.
int	GetRefCount () const noexcept
	Get the reference counter of this object.
void	IncrementRefCounter () noexcept
	Increments the reference counter of this object. Uses relaxed memory ordering since incrementing only requires atomicity, not synchronization with other memory operations.
int	DecrementRefCounter () noexcept
	Decrements the reference counter of this object; returns the decremented value. Uses release ordering for the decrement to ensure all writes to the object are visible before the count reaches zero. An acquire fence is added only when the count reaches zero, ensuring proper synchronization before deletion. This is more efficient than using acq_rel for every decrement.
virtual void	Delete () const
	Memory deallocator for transient classes.

Additional Inherited Members
Public Types inherited from Standard_Transient
typedef void	base_type
	Returns a type descriptor about this object.
Static Public Member Functions inherited from Standard_Transient
static constexpr const char *	get_type_name ()
	Returns a type descriptor about this object.
static const opencascade::handle< Standard_Type > &	get_type_descriptor ()
	Returns type descriptor of Standard_Transient class.

Detailed Description

to remove Hidden lines on Shapes with Triangulations. A framework to compute the shape as seen in a projection plane. This is done by calculating the visible and the hidden parts of the shape. HLRBRep_PolyAlgo works with three types of entity:

• shapes to be visualized (these shapes must have already been triangulated.)
• edges in these shapes (these edges are defined as polygonal lines on the triangulation of the shape, and are the basic entities which will be visualized or hidden), and
• triangles in these shapes which hide the edges. HLRBRep_PolyAlgo is based on the principle of comparing each edge of the shape to be visualized with each of the triangles produced by the triangulation of the shape, and calculating the visible and the hidden parts of each edge. For a given projection, HLRBRep_PolyAlgo calculates a set of lines characteristic of the object being represented. It is also used in conjunction with the HLRBRep_PolyHLRToShape extraction utilities, which reconstruct a new, simplified shape from a selection of calculation results. This new shape is made up of edges, which represent the shape visualized in the projection. HLRBRep_PolyAlgo works with a polyhedral simplification of the shape whereas HLRBRep_Algo takes the shape itself into account. When you use HLRBRep_Algo, you obtain an exact result, whereas, when you use HLRBRep_PolyAlgo, you reduce computation time but obtain polygonal segments. An HLRBRep_PolyAlgo object provides a framework for:
• defining the point of view
• identifying the shape or shapes to be visualized
• calculating the outlines
• calculating the visible and hidden lines of the shape. Warning
• Superimposed lines are not eliminated by this algorithm.
• There must be no unfinished objects inside the shape you wish to visualize.
• Points are not treated.
• Note that this is not the sort of algorithm used in generating shading, which calculates the visible and hidden parts of each face in a shape to be visualized by comparing each face in the shape with every other face in the same shape.

Constructor & Destructor Documentation

HLRBRep_PolyAlgo() [1/3]

HLRBRep_PolyAlgo::HLRBRep_PolyAlgo

(

)

Constructs an empty framework for the calculation of the visible and hidden lines of a shape in a projection. Use the functions:

• Projector to define the point of view
• Load to select the shape or shapes to be visualized
• Update to compute the visible and hidden lines of the shape. Warning The shape or shapes to be visualized must have already been triangulated.

HLRBRep_PolyAlgo() [2/3]

HLRBRep_PolyAlgo::HLRBRep_PolyAlgo

(

const occ::handle< HLRBRep_PolyAlgo > &

A

)

HLRBRep_PolyAlgo() [3/3]

HLRBRep_PolyAlgo::HLRBRep_PolyAlgo

(

const TopoDS_Shape &

S

)

Member Function Documentation

Algo()

const occ::handle< HLRAlgo_PolyAlgo > & HLRBRep_PolyAlgo::Algo ( ) const

inline

Debug() [1/2]

bool HLRBRep_PolyAlgo::Debug ( ) const

inline

Debug() [2/2]

void HLRBRep_PolyAlgo::Debug ( const bool theDebug )

inline

Hide()

HLRAlgo_BiPoint::PointsT & HLRBRep_PolyAlgo::Hide	(	HLRAlgo_EdgeStatus &	status,
		TopoDS_Shape &	S,
		bool &	reg1,
		bool &	regn,
		bool &	outl,
		bool &	intl )

Index()

int HLRBRep_PolyAlgo::Index

(

const TopoDS_Shape &

S

)

const

return the index of the Shape and return 0 if the Shape is not found.

InitHide()

void HLRBRep_PolyAlgo::InitHide ( )

inline

InitShow()

void HLRBRep_PolyAlgo::InitShow ( )

inline

Load()

void HLRBRep_PolyAlgo::Load ( const TopoDS_Shape & theShape )

inline

Loads the shape S into this framework. Warning S must have already been triangulated.

MoreHide()

bool HLRBRep_PolyAlgo::MoreHide ( ) const

inline

MoreShow()

bool HLRBRep_PolyAlgo::MoreShow ( ) const

inline

NbShapes()

int HLRBRep_PolyAlgo::NbShapes ( ) const

inline

NextHide()

void HLRBRep_PolyAlgo::NextHide ( )

inline

NextShow()

void HLRBRep_PolyAlgo::NextShow ( )

inline

OutLinedShape()

TopoDS_Shape HLRBRep_PolyAlgo::OutLinedShape

(

const TopoDS_Shape &

S

)

const

Make a shape with the internal outlines in each face.

Projector() [1/2]

const HLRAlgo_Projector & HLRBRep_PolyAlgo::Projector ( ) const

inline

Sets the parameters of the view for this framework. These parameters are defined by an HLRAlgo_Projector object, which is returned by the Projector function on a Prs3d_Projector object.

Projector() [2/2]

void HLRBRep_PolyAlgo::Projector ( const HLRAlgo_Projector & theProj )

inline

Remove()

void HLRBRep_PolyAlgo::Remove

(

const int

I

)

remove the Shape of Index .

Shape()

TopoDS_Shape & HLRBRep_PolyAlgo::Shape

(

const int

I

)

Show()

HLRAlgo_BiPoint::PointsT & HLRBRep_PolyAlgo::Show	(	TopoDS_Shape &	S,
		bool &	reg1,
		bool &	regn,
		bool &	outl,
		bool &	intl )

TolAngular() [1/2]

double HLRBRep_PolyAlgo::TolAngular ( ) const

inline

TolAngular() [2/2]

void HLRBRep_PolyAlgo::TolAngular ( const double theTol )

inline

TolCoef() [1/2]

double HLRBRep_PolyAlgo::TolCoef ( ) const

inline

TolCoef() [2/2]

void HLRBRep_PolyAlgo::TolCoef ( const double theTol )

inline

Update()

void HLRBRep_PolyAlgo::Update

(

)

Launches calculation of outlines of the shape visualized by this framework. Used after setting the point of view and defining the shape or shapes to be visualized.

---

The documentation for this class was generated from the following file:

• HLRBRep_PolyAlgo.hxx