# Geom2d_TrimmedCurve Class Reference

Defines a portion of a curve limited by two values of parameters inside the parametric domain of the curve. The trimmed curve is defined by: More...

`#include <Geom2d_TrimmedCurve.hxx>`

Inheritance diagram for Geom2d_TrimmedCurve: [legend]

## Public Member Functions

Geom2d_TrimmedCurve (const Handle< Geom2d_Curve > &C, const Standard_Real U1, const Standard_Real U2, const Standard_Boolean Sense=Standard_True, const Standard_Boolean theAdjustPeriodic=Standard_True)
Creates a trimmed curve from the basis curve C limited between U1 and U2. More...

void Reverse () override
Changes the direction of parametrization of <me>. The first and the last parametric values are modified. The "StartPoint" of the initial curve becomes the "EndPoint" of the reversed curve and the "EndPoint" of the initial curve becomes the "StartPoint" of the reversed curve. Example - If the trimmed curve is defined by: More...

Standard_Real ReversedParameter (const Standard_Real U) const override
Returns the parameter on the reversed curve for the point of parameter U on <me>. More...

void SetTrim (const Standard_Real U1, const Standard_Real U2, const Standard_Boolean Sense=Standard_True, const Standard_Boolean theAdjustPeriodic=Standard_True)
Changes this trimmed curve, by redefining the parameter values U1 and U2, which limit its basis curve. Note: If the basis curve is periodic, the trimmed curve has the same orientation as the basis curve if Sense is true (default value) or the opposite orientation if Sense is false. Warning If the basis curve is periodic and theAdjustPeriodic is True, the bounds of the trimmed curve may be different from U1 and U2 if the parametric origin of the basis curve is within the arc of the trimmed curve. In this case, the modified parameter will be equal to U1 or U2 plus or minus the period. If theAdjustPeriodic is False, parameters U1 and U2 will stay unchanged. Exceptions Standard_ConstructionError if: More...

Handle< Geom2d_CurveBasisCurve () const
Returns the basis curve. Warning This function does not return a constant reference. Consequently, any modification of the returned value directly modifies the trimmed curve. More...

GeomAbs_Shape Continuity () const override
Returns the global continuity of the basis curve of this trimmed curve. C0 : only geometric continuity, C1 : continuity of the first derivative all along the Curve, C2 : continuity of the second derivative all along the Curve, C3 : continuity of the third derivative all along the Curve, CN : the order of continuity is infinite. More...

Standard_Boolean IsCN (const Standard_Integer N) const override
— Purpose Returns True if the order of continuity of the trimmed curve is N. A trimmed curve is at least "C0" continuous. Warnings : The continuity of the trimmed curve can be greater than the continuity of the basis curve because you consider only a part of the basis curve. Raised if N < 0. More...

gp_Pnt2d EndPoint () const override
Returns the end point of <me>. This point is the evaluation of the curve for the "LastParameter". More...

Standard_Real FirstParameter () const override
Returns the value of the first parameter of <me>. The first parameter is the parameter of the "StartPoint" of the trimmed curve. More...

Standard_Boolean IsClosed () const override
Returns True if the distance between the StartPoint and the EndPoint is lower or equal to Resolution from package gp. More...

Standard_Boolean IsPeriodic () const override
Always returns FALSE (independently of the type of basis curve). More...

virtual Standard_Real Period () const override
Returns the period of the basis curve of this trimmed curve. Exceptions Standard_NoSuchObject if the basis curve is not periodic. More...

Standard_Real LastParameter () const override
Returns the value of the last parameter of <me>. The last parameter is the parameter of the "EndPoint" of the trimmed curve. More...

gp_Pnt2d StartPoint () const override
Returns the start point of <me>. This point is the evaluation of the curve from the "FirstParameter". value and derivatives Warnings : The returned derivatives have the same orientation as the derivatives of the basis curve. More...

void D0 (const Standard_Real U, gp_Pnt2d &P) const override
If the basis curve is an OffsetCurve sometimes it is not possible to do the evaluation of the curve at the parameter U (see class OffsetCurve). More...

void D1 (const Standard_Real U, gp_Pnt2d &P, gp_Vec2d &V1) const override
Raised if the continuity of the curve is not C1. More...

void D2 (const Standard_Real U, gp_Pnt2d &P, gp_Vec2d &V1, gp_Vec2d &V2) const override
Raised if the continuity of the curve is not C2. More...

void D3 (const Standard_Real U, gp_Pnt2d &P, gp_Vec2d &V1, gp_Vec2d &V2, gp_Vec2d &V3) const override
Raised if the continuity of the curve is not C3. More...

gp_Vec2d DN (const Standard_Real U, const Standard_Integer N) const override
For the point of parameter U of this trimmed curve, computes the vector corresponding to the Nth derivative. Warning The returned derivative vector has the same orientation as the derivative vector of the basis curve, even if the trimmed curve does not have the same orientation as the basis curve. Exceptions Standard_RangeError if N is less than 1. geometric transformations. More...

void Transform (const gp_Trsf2d &T) override
Applies the transformation T to this trimmed curve. Warning The basis curve is also modified. More...

virtual Standard_Real TransformedParameter (const Standard_Real U, const gp_Trsf2d &T) const override
Returns the parameter on the transformed curve for the transform of the point of parameter U on <me>. More...

virtual Standard_Real ParametricTransformation (const gp_Trsf2d &T) const override
Returns a coefficient to compute the parameter on the transformed curve for the transform of the point on <me>. More...

Handle< Geom2d_GeometryCopy () const override
Creates a new object, which is a copy of this trimmed curve. More...

virtual void DumpJson (Standard_OStream &theOStream, Standard_Integer theDepth=-1) const override
Dumps the content of me into the stream. More... Public Member Functions inherited from Geom2d_Curve
Handle< Geom2d_CurveReversed () const
Creates a reversed duplicate Changes the orientation of this curve. The first and last parameters are not changed, but the parametric direction of the curve is reversed. If the curve is bounded: More...

gp_Pnt2d Value (const Standard_Real U) const
Computes the point of parameter U on <me>. If the curve is periodic then the returned point is P(U) with U = Ustart + (U - Uend) where Ustart and Uend are the parametric bounds of the curve. More... Public Member Functions inherited from Geom2d_Geometry
void Mirror (const gp_Pnt2d &P)
Performs the symmetrical transformation of a Geometry with respect to the point P which is the center of the symmetry and assigns the result to this geometric object. More...

void Mirror (const gp_Ax2d &A)
Performs the symmetrical transformation of a Geometry with respect to an axis placement which is the axis of the symmetry. More...

void Rotate (const gp_Pnt2d &P, const Standard_Real Ang)
Rotates a Geometry. P is the center of the rotation. Ang is the angular value of the rotation in radians. More...

void Scale (const gp_Pnt2d &P, const Standard_Real S)
Scales a Geometry. S is the scaling value. More...

void Translate (const gp_Vec2d &V)
Translates a Geometry. V is the vector of the translation. More...

void Translate (const gp_Pnt2d &P1, const gp_Pnt2d &P2)
Translates a Geometry from the point P1 to the point P2. More...

Handle< Geom2d_GeometryMirrored (const gp_Pnt2d &P) const

Handle< Geom2d_GeometryMirrored (const gp_Ax2d &A) const

Handle< Geom2d_GeometryRotated (const gp_Pnt2d &P, const Standard_Real Ang) const

Handle< Geom2d_GeometryScaled (const gp_Pnt2d &P, const Standard_Real S) const

Handle< Geom2d_GeometryTransformed (const gp_Trsf2d &T) const

Handle< Geom2d_GeometryTranslated (const gp_Vec2d &V) const

Handle< Geom2d_GeometryTranslated (const gp_Pnt2d &P1, const gp_Pnt2d &P2) const Public Member Functions inherited from Standard_Transient
Standard_Transient ()
Empty constructor. More...

Standard_Transient (const Standard_Transient &)
Copy constructor – does nothing. More...

Standard_Transientoperator= (const Standard_Transient &)
Assignment operator, needed to avoid copying reference counter. More...

virtual ~Standard_Transient ()
Destructor must be virtual. More...

virtual void Delete () const
Memory deallocator for transient classes. More...

virtual const opencascade::handle< Standard_Type > & DynamicType () const

Standard_Boolean IsInstance (const opencascade::handle< Standard_Type > &theType) const
Returns a true value if this is an instance of Type. More...

Standard_Boolean IsInstance (const Standard_CString theTypeName) const
Returns a true value if this is an instance of TypeName. More...

Standard_Boolean 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. More...

Standard_Boolean IsKind (const Standard_CString 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. More...

Standard_TransientThis () 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. More...

Standard_Integer GetRefCount () const
Get the reference counter of this object. More...

void IncrementRefCounter () const
Increments the reference counter of this object. More...

Standard_Integer DecrementRefCounter () const
Decrements the reference counter of this object; returns the decremented value. More... Public Types inherited from Standard_Transient
typedef void base_type Static Public Member Functions inherited from Standard_Transient
static const char * get_type_name ()

static const opencascade::handle< Standard_Type > & get_type_descriptor ()
Returns type descriptor of Standard_Transient class. More...

## Detailed Description

Defines a portion of a curve limited by two values of parameters inside the parametric domain of the curve. The trimmed curve is defined by:

• the basis curve, and
• the two parameter values which limit it. The trimmed curve can either have the same orientation as the basis curve or the opposite orientation.

## ◆ Geom2d_TrimmedCurve()

 Geom2d_TrimmedCurve::Geom2d_TrimmedCurve ( const Handle< Geom2d_Curve > & C, const Standard_Real U1, const Standard_Real U2, const Standard_Boolean Sense = `Standard_True`, const Standard_Boolean theAdjustPeriodic = `Standard_True` )

Creates a trimmed curve from the basis curve C limited between U1 and U2.

. U1 can be greater or lower than U2. . The returned curve is oriented from U1 to U2. . If the basis curve C is periodic there is an ambiguity because two parts are available. In this case by default the trimmed curve has the same orientation as the basis curve (Sense = True). If Sense = False then the orientation of the trimmed curve is opposite to the orientation of the basis curve C. If the curve is closed but not periodic it is not possible to keep the part of the curve including the junction point (except if the junction point is at the beginning or at the end of the trimmed curve) because you could lose the fundamental characteristics of the basis curve which are used for example to compute the derivatives of the trimmed curve. So for a closed curve the rules are the same as for a open curve. Warnings : In this package the entities are not shared. The TrimmedCurve is built with a copy of the curve C. So when C is modified the TrimmedCurve is not modified Warnings : If ` is periodic and <theAdjustPeriodic> is True, parametrics bounds of the TrimmedCurve, can be different to [<U1>;<U2>}, if <U1> or <U2> are not in the principal period. Include : For more explanation see the scheme given with this class. Raises ConstructionError the C is not periodic and U1 or U2 are out of the bounds of C. Raised if U1 = U2. `

## ◆ BasisCurve()

 Handle< Geom2d_Curve > Geom2d_TrimmedCurve::BasisCurve ( ) const

Returns the basis curve. Warning This function does not return a constant reference. Consequently, any modification of the returned value directly modifies the trimmed curve.

## ◆ Continuity()

 GeomAbs_Shape Geom2d_TrimmedCurve::Continuity ( ) const
overridevirtual

Returns the global continuity of the basis curve of this trimmed curve. C0 : only geometric continuity, C1 : continuity of the first derivative all along the Curve, C2 : continuity of the second derivative all along the Curve, C3 : continuity of the third derivative all along the Curve, CN : the order of continuity is infinite.

Implements Geom2d_Curve.

## ◆ Copy()

 Handle< Geom2d_Geometry > Geom2d_TrimmedCurve::Copy ( ) const
overridevirtual

Creates a new object, which is a copy of this trimmed curve.

Implements Geom2d_Geometry.

## ◆ D0()

 void Geom2d_TrimmedCurve::D0 ( const Standard_Real U, gp_Pnt2d & P ) const
overridevirtual

If the basis curve is an OffsetCurve sometimes it is not possible to do the evaluation of the curve at the parameter U (see class OffsetCurve).

Implements Geom2d_Curve.

## ◆ D1()

 void Geom2d_TrimmedCurve::D1 ( const Standard_Real U, gp_Pnt2d & P, gp_Vec2d & V1 ) const
overridevirtual

Raised if the continuity of the curve is not C1.

Implements Geom2d_Curve.

## ◆ D2()

 void Geom2d_TrimmedCurve::D2 ( const Standard_Real U, gp_Pnt2d & P, gp_Vec2d & V1, gp_Vec2d & V2 ) const
overridevirtual

Raised if the continuity of the curve is not C2.

Implements Geom2d_Curve.

## ◆ D3()

 void Geom2d_TrimmedCurve::D3 ( const Standard_Real U, gp_Pnt2d & P, gp_Vec2d & V1, gp_Vec2d & V2, gp_Vec2d & V3 ) const
overridevirtual

Raised if the continuity of the curve is not C3.

Implements Geom2d_Curve.

## ◆ DN()

 gp_Vec2d Geom2d_TrimmedCurve::DN ( const Standard_Real U, const Standard_Integer N ) const
overridevirtual

For the point of parameter U of this trimmed curve, computes the vector corresponding to the Nth derivative. Warning The returned derivative vector has the same orientation as the derivative vector of the basis curve, even if the trimmed curve does not have the same orientation as the basis curve. Exceptions Standard_RangeError if N is less than 1. geometric transformations.

Implements Geom2d_Curve.

## ◆ DumpJson()

 virtual void Geom2d_TrimmedCurve::DumpJson ( Standard_OStream & theOStream, Standard_Integer theDepth = `-1` ) const
overridevirtual

Dumps the content of me into the stream.

Reimplemented from Geom2d_BoundedCurve.

## ◆ EndPoint()

 gp_Pnt2d Geom2d_TrimmedCurve::EndPoint ( ) const
overridevirtual

Returns the end point of <me>. This point is the evaluation of the curve for the "LastParameter".

Implements Geom2d_BoundedCurve.

## ◆ FirstParameter()

 Standard_Real Geom2d_TrimmedCurve::FirstParameter ( ) const
overridevirtual

Returns the value of the first parameter of <me>. The first parameter is the parameter of the "StartPoint" of the trimmed curve.

Implements Geom2d_Curve.

## ◆ IsClosed()

 Standard_Boolean Geom2d_TrimmedCurve::IsClosed ( ) const
overridevirtual

Returns True if the distance between the StartPoint and the EndPoint is lower or equal to Resolution from package gp.

Implements Geom2d_Curve.

## ◆ IsCN()

 Standard_Boolean Geom2d_TrimmedCurve::IsCN ( const Standard_Integer N ) const
overridevirtual

— Purpose Returns True if the order of continuity of the trimmed curve is N. A trimmed curve is at least "C0" continuous. Warnings : The continuity of the trimmed curve can be greater than the continuity of the basis curve because you consider only a part of the basis curve. Raised if N < 0.

Implements Geom2d_Curve.

## ◆ IsPeriodic()

 Standard_Boolean Geom2d_TrimmedCurve::IsPeriodic ( ) const
overridevirtual

Always returns FALSE (independently of the type of basis curve).

Implements Geom2d_Curve.

## ◆ LastParameter()

 Standard_Real Geom2d_TrimmedCurve::LastParameter ( ) const
overridevirtual

Returns the value of the last parameter of <me>. The last parameter is the parameter of the "EndPoint" of the trimmed curve.

Implements Geom2d_Curve.

## ◆ ParametricTransformation()

 virtual Standard_Real Geom2d_TrimmedCurve::ParametricTransformation ( const gp_Trsf2d & T ) const
overridevirtual

Returns a coefficient to compute the parameter on the transformed curve for the transform of the point on <me>.

Transformed(T)->Value(U * ParametricTransformation(T))

is the same point as

Value(U).Transformed(T)

This methods calls the basis curve method.

Reimplemented from Geom2d_Curve.

## ◆ Period()

 virtual Standard_Real Geom2d_TrimmedCurve::Period ( ) const
overridevirtual

Returns the period of the basis curve of this trimmed curve. Exceptions Standard_NoSuchObject if the basis curve is not periodic.

Reimplemented from Geom2d_Curve.

## ◆ Reverse()

 void Geom2d_TrimmedCurve::Reverse ( )
overridevirtual

Changes the direction of parametrization of <me>. The first and the last parametric values are modified. The "StartPoint" of the initial curve becomes the "EndPoint" of the reversed curve and the "EndPoint" of the initial curve becomes the "StartPoint" of the reversed curve. Example - If the trimmed curve is defined by:

• a basis curve whose parameter range is [ 0.,1. ], and
• the two trim values U1 (first parameter) and U2 (last parameter), the reversed trimmed curve is defined by:
• the reversed basis curve, whose parameter range is still [ 0.,1. ], and
• the two trim values 1. - U2 (first parameter) and 1. - U1 (last parameter).

Implements Geom2d_Curve.

## ◆ ReversedParameter()

 Standard_Real Geom2d_TrimmedCurve::ReversedParameter ( const Standard_Real U ) const
overridevirtual

Returns the parameter on the reversed curve for the point of parameter U on <me>.

returns UFirst + ULast - U

Implements Geom2d_Curve.

## ◆ SetTrim()

 void Geom2d_TrimmedCurve::SetTrim ( const Standard_Real U1, const Standard_Real U2, const Standard_Boolean Sense = `Standard_True`, const Standard_Boolean theAdjustPeriodic = `Standard_True` )

Changes this trimmed curve, by redefining the parameter values U1 and U2, which limit its basis curve. Note: If the basis curve is periodic, the trimmed curve has the same orientation as the basis curve if Sense is true (default value) or the opposite orientation if Sense is false. Warning If the basis curve is periodic and theAdjustPeriodic is True, the bounds of the trimmed curve may be different from U1 and U2 if the parametric origin of the basis curve is within the arc of the trimmed curve. In this case, the modified parameter will be equal to U1 or U2 plus or minus the period. If theAdjustPeriodic is False, parameters U1 and U2 will stay unchanged. Exceptions Standard_ConstructionError if:

• the basis curve is not periodic, and either U1 or U2 are outside the bounds of the basis curve, or
• U1 is equal to U2.

## ◆ StartPoint()

 gp_Pnt2d Geom2d_TrimmedCurve::StartPoint ( ) const
overridevirtual

Returns the start point of <me>. This point is the evaluation of the curve from the "FirstParameter". value and derivatives Warnings : The returned derivatives have the same orientation as the derivatives of the basis curve.

Implements Geom2d_BoundedCurve.

## ◆ Transform()

 void Geom2d_TrimmedCurve::Transform ( const gp_Trsf2d & T )
overridevirtual

Applies the transformation T to this trimmed curve. Warning The basis curve is also modified.

Implements Geom2d_Geometry.

## ◆ TransformedParameter()

 virtual Standard_Real Geom2d_TrimmedCurve::TransformedParameter ( const Standard_Real U, const gp_Trsf2d & T ) const
overridevirtual

Returns the parameter on the transformed curve for the transform of the point of parameter U on <me>.

me->Transformed(T)->Value(me->TransformedParameter(U,T))

is the same point as

me->Value(U).Transformed(T)

This methods calls the basis curve method.

Reimplemented from Geom2d_Curve.

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