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GCPnts


GCPnts_QuasiUniformDeflection Class Reference

This class computes a distribution of points on a
curve. The points may respect the deflection. The algorithm
is not based on the classical prediction (with second
derivative of curve), but either on the evaluation of
the distance between the mid point and the point of
mid parameter of the two points, or the distance
between the mid point and the point at parameter 0.5
on the cubic interpolation of the two points and their
tangents.
Note: this algorithm is faster than a
GCPnts_UniformDeflection algorithm, and is
able to work with non-"C2" continuous curves.
However, it generates more points in the distribution.
.

#include <GCPnts_QuasiUniformDeflection.hxx>


Public Member Functions

void * operator new (size_t, void *anAddress)
void * operator new (size_t size)
void operator delete (void *anAddress)
Standard_EXPORT GCPnts_QuasiUniformDeflection ()
 Constructs an empty algorithm. To define the problem
to be solved, use the function Initialize.
.
Standard_EXPORT GCPnts_QuasiUniformDeflection (Adaptor3d_Curve &C, const Standard_Real Deflection, const GeomAbs_Shape Continuity=GeomAbs_C1)
 Computes a QuasiUniform Deflection distribution
of points on the Curve <c>.
.
Standard_EXPORT GCPnts_QuasiUniformDeflection (Adaptor2d_Curve2d &C, const Standard_Real Deflection, const GeomAbs_Shape Continuity=GeomAbs_C1)
 Computes a QuasiUniform Deflection distribution
of points on the Curve <c>.
.
Standard_EXPORT GCPnts_QuasiUniformDeflection (Adaptor3d_Curve &C, const Standard_Real Deflection, const Standard_Real U1, const Standard_Real U2, const GeomAbs_Shape Continuity=GeomAbs_C1)
 Computes a QuasiUniform Deflection distribution
of points on a part of the Curve <c>.
.
Standard_EXPORT GCPnts_QuasiUniformDeflection (Adaptor2d_Curve2d &C, const Standard_Real Deflection, const Standard_Real U1, const Standard_Real U2, const GeomAbs_Shape Continuity=GeomAbs_C1)
 Computes a QuasiUniform Deflection distribution
of points on a part of the Curve <c>.
This and the above algorithms compute a distribution of points:
- on the curve C, or
- on the part of curve C limited by the two
parameter values U1 and U2,
where the deflection resulting from the distributed
points is not greater than Deflection.
The first point of the distribution is either the origin of
curve C or the point of parameter U1. The last point
of the distribution is either the end point of curve C or
the point of parameter U2.
Intermediate points of the distribution are built such
that the deflection is not greater than Deflection.
Using the following evaluation of the deflection:
if Pi and Pj are two consecutive points of the
distribution, respectively of parameter ui and uj on
the curve, the deflection is the distance between:
- the mid-point of Pi and Pj (the center of the
chord joining these two points)
- and the point of mid-parameter of these two
points (the point of parameter [(ui+uj) / 2 ] on curve C).
Continuity, defaulted to GeomAbs_C1, gives the
degree of continuity of the curve C. (Note that C is an
Adaptor3d_Curve or an Adaptor2d_Curve2d
object, and does not know the degree of continuity of
the underlying curve).
Use the function IsDone to verify that the
computation was successful, the function NbPoints
to obtain the number of points of the computed
distribution, and the function Parameter to read the
parameter of each point.
Warning
- The roles of U1 and U2 are inverted if U1 > U2.
- Derivative functions on the curve are called
according to Continuity. An error may occur if
Continuity is greater than the real degree of
continuity of the curve.
Warning
C is an adapted curve, i.e. an object which is an
interface between:
- the services provided by either a 2D curve from
the package Geom2d (in the case of an
Adaptor2d_Curve2d curve) or a 3D curve from
the package Geom (in the case of an
Adaptor3d_Curve curve),
- and those required on the curve by the
computation algorithm.
.
Standard_EXPORT void Initialize (Adaptor3d_Curve &C, const Standard_Real Deflection, const GeomAbs_Shape Continuity=GeomAbs_C1)
 Initialize the algoritms with <c>, <deflection>
.
Standard_EXPORT void Initialize (Adaptor2d_Curve2d &C, const Standard_Real Deflection, const GeomAbs_Shape Continuity=GeomAbs_C1)
 Initialize the algoritms with <c>, <deflection>
.
Standard_EXPORT void Initialize (Adaptor3d_Curve &C, const Standard_Real Deflection, const Standard_Real U1, const Standard_Real U2, const GeomAbs_Shape Continuity=GeomAbs_C1)
 Initialize the algoritms with <c>, <deflection>,
<u1>,<u2>
.
Standard_EXPORT void Initialize (Adaptor2d_Curve2d &C, const Standard_Real Deflection, const Standard_Real U1, const Standard_Real U2, const GeomAbs_Shape Continuity=GeomAbs_C1)
 Initialize the algoritms with <c>, <deflection>,
-- <u1>,<u2>
This and the above algorithms initialize (or reinitialize)
this algorithm and compute a distribution of points:
- on the curve C, or
- on the part of curve C limited by the two
parameter values U1 and U2,
where the deflection resulting from the distributed
points is not greater than Deflection.
The first point of the distribution is either the origin
of curve C or the point of parameter U1. The last
point of the distribution is either the end point of
curve C or the point of parameter U2.
Intermediate points of the distribution are built in
such a way that the deflection is not greater than
Deflection. Using the following evaluation of the deflection:
if Pi and Pj are two consecutive points of the
distribution, respectively of parameter ui and uj
on the curve, the deflection is the distance between:
- the mid-point of Pi and Pj (the center of the
chord joining these two points)
- and the point of mid-parameter of these two
points (the point of parameter [(ui+uj) / 2 ] on curve C).
Continuity, defaulted to GeomAbs_C1, gives the
degree of continuity of the curve C. (Note that C is
an Adaptor3d_Curve or an
Adaptor2d_Curve2d object, and does not know
the degree of continuity of the underlying curve).
Use the function IsDone to verify that the
computation was successful, the function NbPoints
to obtain the number of points of the computed
distribution, and the function Parameter to read
the parameter of each point.
Warning
- The roles of U1 and U2 are inverted if U1 > U2.
- Derivative functions on the curve are called
according to Continuity. An error may occur if
Continuity is greater than the real degree of
continuity of the curve.
Warning
C is an adapted curve, i.e. an object which is an
interface between:
- the services provided by either a 2D curve from
the package Geom2d (in the case of an
Adaptor2d_Curve2d curve) or a 3D curve from
the package Geom (in the case of an Adaptor3d_Curve curve),
and those required on the curve by the computation algorithm.
.
Standard_Boolean IsDone () const
 Returns true if the computation was successful.
IsDone is a protection against:
- non-convergence of the algorithm
- querying the results before computation.
.
Standard_Integer NbPoints () const
 Returns the number of points of the distribution
computed by this algorithm.
Exceptions
StdFail_NotDone if this algorithm has not been
initialized, or if the computation was not successful.
.
Standard_Real Parameter (const Standard_Integer Index) const
 Returns the parameter of the point of index Index in
the distribution computed by this algorithm.
Warning
Index must be greater than or equal to 1, and less
than or equal to the number of points of the
distribution. However, pay particular attention as this
condition is not checked by this function.
Exceptions
StdFail_NotDone if this algorithm has not been
initialized, or if the computation was not successful.
.
Standard_EXPORT gp_Pnt Value (const Standard_Integer Index) const
 Returns the point of index Index in the distribution
computed by this algorithm.
Warning
Index must be greater than or equal to 1, and less
than or equal to the number of points of the
distribution. However, pay particular attention as this
condition is not checked by this function.
Exceptions
StdFail_NotDone if this algorithm has not been
initialized, or if the computation was not successful.
.
Standard_Real Deflection () const
 Returns the deflection between the curve and the
polygon resulting from the points of the distribution
computed by this algorithm.
This is the value given to the algorithm at the time
of construction (or initialization).
Exceptions
StdFail_NotDone if this algorithm has not been
initialized, or if the computation was not successful.
.

Private Attributes

Standard_Boolean myDone
Standard_Real myDeflection
TColStd_SequenceOfReal myParams
TColgp_SequenceOfPnt myPoints
GeomAbs_Shape myCont


Constructor & Destructor Documentation

Standard_EXPORT GCPnts_QuasiUniformDeflection::GCPnts_QuasiUniformDeflection  ) 
 

Standard_EXPORT GCPnts_QuasiUniformDeflection::GCPnts_QuasiUniformDeflection Adaptor3d_Curve C,
const Standard_Real  Deflection,
const GeomAbs_Shape  Continuity = GeomAbs_C1
 

Standard_EXPORT GCPnts_QuasiUniformDeflection::GCPnts_QuasiUniformDeflection Adaptor2d_Curve2d C,
const Standard_Real  Deflection,
const GeomAbs_Shape  Continuity = GeomAbs_C1
 

Standard_EXPORT GCPnts_QuasiUniformDeflection::GCPnts_QuasiUniformDeflection Adaptor3d_Curve C,
const Standard_Real  Deflection,
const Standard_Real  U1,
const Standard_Real  U2,
const GeomAbs_Shape  Continuity = GeomAbs_C1
 

Standard_EXPORT GCPnts_QuasiUniformDeflection::GCPnts_QuasiUniformDeflection Adaptor2d_Curve2d C,
const Standard_Real  Deflection,
const Standard_Real  U1,
const Standard_Real  U2,
const GeomAbs_Shape  Continuity = GeomAbs_C1
 


Member Function Documentation

Standard_Real GCPnts_QuasiUniformDeflection::Deflection  )  const [inline]
 

Standard_EXPORT void GCPnts_QuasiUniformDeflection::Initialize Adaptor2d_Curve2d C,
const Standard_Real  Deflection,
const Standard_Real  U1,
const Standard_Real  U2,
const GeomAbs_Shape  Continuity = GeomAbs_C1
 

Standard_EXPORT void GCPnts_QuasiUniformDeflection::Initialize Adaptor3d_Curve C,
const Standard_Real  Deflection,
const Standard_Real  U1,
const Standard_Real  U2,
const GeomAbs_Shape  Continuity = GeomAbs_C1
 

Standard_EXPORT void GCPnts_QuasiUniformDeflection::Initialize Adaptor2d_Curve2d C,
const Standard_Real  Deflection,
const GeomAbs_Shape  Continuity = GeomAbs_C1
 

Standard_EXPORT void GCPnts_QuasiUniformDeflection::Initialize Adaptor3d_Curve C,
const Standard_Real  Deflection,
const GeomAbs_Shape  Continuity = GeomAbs_C1
 

Standard_Boolean GCPnts_QuasiUniformDeflection::IsDone  )  const [inline]
 

Standard_Integer GCPnts_QuasiUniformDeflection::NbPoints  )  const [inline]
 

void GCPnts_QuasiUniformDeflection::operator delete void *  anAddress  )  [inline]
 

void* GCPnts_QuasiUniformDeflection::operator new size_t  size  )  [inline]
 

void* GCPnts_QuasiUniformDeflection::operator new size_t  ,
void *  anAddress
[inline]
 

Standard_Real GCPnts_QuasiUniformDeflection::Parameter const Standard_Integer  Index  )  const [inline]
 

Standard_EXPORT gp_Pnt GCPnts_QuasiUniformDeflection::Value const Standard_Integer  Index  )  const
 


Field Documentation

GeomAbs_Shape GCPnts_QuasiUniformDeflection::myCont [private]
 

Standard_Real GCPnts_QuasiUniformDeflection::myDeflection [private]
 

Standard_Boolean GCPnts_QuasiUniformDeflection::myDone [private]
 

TColStd_SequenceOfReal GCPnts_QuasiUniformDeflection::myParams [private]
 

TColgp_SequenceOfPnt GCPnts_QuasiUniformDeflection::myPoints [private]
 


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