Open CASCADE Technology 7.8.2.dev
Geom2d_Transformation Class Reference

The class Transformation allows to create Translation, Rotation, Symmetry, Scaling and complex transformations obtained by combination of the previous elementary transformations. The Transformation class can also be used to construct complex transformations by combining these elementary transformations. However, these transformations can never change the type of an object. For example, the projection transformation can change a circle into an ellipse, and therefore change the real type of the object. Such a transformation is forbidden in this environment and cannot be a Geom2d_Transformation. The transformation can be represented as follow : More...

#include <Geom2d_Transformation.hxx>

Inheritance diagram for Geom2d_Transformation:

Public Member Functions

 Geom2d_Transformation ()
 Creates an identity transformation.
 
 Geom2d_Transformation (const gp_Trsf2d &T)
 Creates a persistent copy of T.
 
void SetMirror (const gp_Pnt2d &P)
 Makes the transformation into a symmetrical transformation with respect to a point P. P is the center of the symmetry.
 
void SetMirror (const gp_Ax2d &A)
 Makes the transformation into a symmetrical transformation with respect to an axis A. A is the center of the axial symmetry.
 
void SetRotation (const gp_Pnt2d &P, const Standard_Real Ang)
 Assigns to this transformation the geometric properties of a rotation at angle Ang (in radians) about point P.
 
void SetScale (const gp_Pnt2d &P, const Standard_Real S)
 Makes the transformation into a scale. P is the center of the scale and S is the scaling value.
 
void SetTransformation (const gp_Ax2d &FromSystem1, const gp_Ax2d &ToSystem2)
 Makes a transformation allowing passage from the coordinate system "FromSystem1" to the coordinate system "ToSystem2".
 
void SetTransformation (const gp_Ax2d &ToSystem)
 Makes the transformation allowing passage from the basic coordinate system {P(0.,0.,0.), VX (1.,0.,0.), VY (0.,1.,0.)} to the local coordinate system defined with the Ax2d ToSystem.
 
void SetTranslation (const gp_Vec2d &V)
 Makes the transformation into a translation. V is the vector of the translation.
 
void SetTranslation (const gp_Pnt2d &P1, const gp_Pnt2d &P2)
 Makes the transformation into a translation from the point P1 to the point P2.
 
void SetTrsf2d (const gp_Trsf2d &T)
 Makes the transformation into a transformation T from package gp.
 
Standard_Boolean IsNegative () const
 Checks whether this transformation is an indirect transformation: returns true if the determinant of the matrix of the vectorial part of the transformation is less than 0.
 
gp_TrsfForm Form () const
 Returns the nature of this transformation as a value of the gp_TrsfForm enumeration. Returns the nature of the transformation. It can be Identity, Rotation, Translation, PntMirror, Ax1Mirror, Scale, CompoundTrsf.
 
Standard_Real ScaleFactor () const
 Returns the scale value of the transformation.
 
gp_Trsf2d Trsf2d () const
 Converts this transformation into a gp_Trsf2d transformation. Returns a non persistent copy of <me>. -C++: return const&.
 
Standard_Real Value (const Standard_Integer Row, const Standard_Integer Col) const
 Returns the coefficients of the global matrix of transformation. It is a 2 rows X 3 columns matrix.
 
void Invert ()
 Computes the inverse of this transformation. and assigns the result to this transformatio.
 
Handle< Geom2d_TransformationInverted () const
 Computes the inverse of this transformation and creates a new one. Raises ConstructionError if the transformation is singular. This means that the ScaleFactor is lower or equal to Resolution from package gp.
 
Handle< Geom2d_TransformationMultiplied (const Handle< Geom2d_Transformation > &Other) const
 Computes the transformation composed with Other and <me>. <me> * Other. Returns a new transformation.
 
Handle< Geom2d_Transformationoperator* (const Handle< Geom2d_Transformation > &Other) const
 
void Multiply (const Handle< Geom2d_Transformation > &Other)
 Computes the transformation composed with Other and <me> . <me> = <me> * Other.
 
void operator*= (const Handle< Geom2d_Transformation > &Other)
 
void Power (const Standard_Integer N)
 Raised if N < 0 and if the transformation is not inversible.
 
Handle< Geom2d_TransformationPowered (const Standard_Integer N) const
 Raised if N < 0 and if the transformation is not inversible.
 
void PreMultiply (const Handle< Geom2d_Transformation > &Other)
 Computes the matrix of the transformation composed with <me> and Other. <me> = Other * <me>
 
void Transforms (Standard_Real &X, Standard_Real &Y) const
 Applies the transformation <me> to the triplet {X, Y}.
 
Handle< Geom2d_TransformationCopy () const
 Creates a new object, which is a copy of this transformation.
 
- Public Member Functions inherited from Standard_Transient
 Standard_Transient ()
 Empty constructor.
 
 Standard_Transient (const Standard_Transient &)
 Copy constructor – does nothing.
 
Standard_Transientoperator= (const Standard_Transient &)
 Assignment operator, needed to avoid copying reference counter.
 
virtual ~Standard_Transient ()
 Destructor must be virtual.
 
virtual const opencascade::handle< Standard_Type > & DynamicType () const
 Returns a type descriptor about this object.
 
Standard_Boolean IsInstance (const opencascade::handle< Standard_Type > &theType) const
 Returns a true value if this is an instance of Type.
 
Standard_Boolean IsInstance (const Standard_CString theTypeName) const
 Returns a true value if this is an instance of TypeName.
 
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.
 
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.
 
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.
 
Standard_Integer GetRefCount () const noexcept
 Get the reference counter of this object.
 
void IncrementRefCounter () noexcept
 Increments the reference counter of this object.
 
Standard_Integer DecrementRefCounter () noexcept
 Decrements the reference counter of this object; returns the decremented value.
 
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

The class Transformation allows to create Translation, Rotation, Symmetry, Scaling and complex transformations obtained by combination of the previous elementary transformations. The Transformation class can also be used to construct complex transformations by combining these elementary transformations. However, these transformations can never change the type of an object. For example, the projection transformation can change a circle into an ellipse, and therefore change the real type of the object. Such a transformation is forbidden in this environment and cannot be a Geom2d_Transformation. The transformation can be represented as follow :

V1 V2 T | a11 a12 a14 | | x | | x'| | a21 a22 a24 | | y | | y'| | 0 0 1 | | 1 | | 1 |

where {V1, V2} defines the vectorial part of the transformation and T defines the translation part of the transformation.

  • Geom2d_Transformation transformations provide the same kind of "geometric" services as gp_Trsf2d ones but have more complex data structures. The geometric objects provided by the Geom2d package use gp_Trsf2d transformations in the syntaxes Transform and Transformed.
  • Geom2d_Transformation transformations are used in a context where they can be shared by several objects contained inside a common data structure.

Constructor & Destructor Documentation

◆ Geom2d_Transformation() [1/2]

Geom2d_Transformation::Geom2d_Transformation ( )

Creates an identity transformation.

◆ Geom2d_Transformation() [2/2]

Geom2d_Transformation::Geom2d_Transformation ( const gp_Trsf2d & T)

Creates a persistent copy of T.

Member Function Documentation

◆ Copy()

Handle< Geom2d_Transformation > Geom2d_Transformation::Copy ( ) const

Creates a new object, which is a copy of this transformation.

◆ Form()

gp_TrsfForm Geom2d_Transformation::Form ( ) const

Returns the nature of this transformation as a value of the gp_TrsfForm enumeration. Returns the nature of the transformation. It can be Identity, Rotation, Translation, PntMirror, Ax1Mirror, Scale, CompoundTrsf.

◆ Invert()

void Geom2d_Transformation::Invert ( )

Computes the inverse of this transformation. and assigns the result to this transformatio.

Raised if the transformation is singular. This means that the ScaleFactor is lower or equal to Resolution from package gp.

◆ Inverted()

Handle< Geom2d_Transformation > Geom2d_Transformation::Inverted ( ) const

Computes the inverse of this transformation and creates a new one. Raises ConstructionError if the transformation is singular. This means that the ScaleFactor is lower or equal to Resolution from package gp.

◆ IsNegative()

Standard_Boolean Geom2d_Transformation::IsNegative ( ) const

Checks whether this transformation is an indirect transformation: returns true if the determinant of the matrix of the vectorial part of the transformation is less than 0.

◆ Multiplied()

Handle< Geom2d_Transformation > Geom2d_Transformation::Multiplied ( const Handle< Geom2d_Transformation > & Other) const

Computes the transformation composed with Other and <me>. <me> * Other. Returns a new transformation.

◆ Multiply()

void Geom2d_Transformation::Multiply ( const Handle< Geom2d_Transformation > & Other)

Computes the transformation composed with Other and <me> . <me> = <me> * Other.

Computes the following composition of transformations if N > 0 <me> * <me> * .......* <me>. if N = 0 Identity if N < 0 <me>.Invert() * .........* <me>.Invert()

◆ operator*()

Handle< Geom2d_Transformation > Geom2d_Transformation::operator* ( const Handle< Geom2d_Transformation > & Other) const
inline

◆ operator*=()

void Geom2d_Transformation::operator*= ( const Handle< Geom2d_Transformation > & Other)
inline

◆ Power()

void Geom2d_Transformation::Power ( const Standard_Integer N)

Raised if N < 0 and if the transformation is not inversible.

◆ Powered()

Handle< Geom2d_Transformation > Geom2d_Transformation::Powered ( const Standard_Integer N) const

Raised if N < 0 and if the transformation is not inversible.

◆ PreMultiply()

void Geom2d_Transformation::PreMultiply ( const Handle< Geom2d_Transformation > & Other)

Computes the matrix of the transformation composed with <me> and Other. <me> = Other * <me>

◆ ScaleFactor()

Standard_Real Geom2d_Transformation::ScaleFactor ( ) const

Returns the scale value of the transformation.

◆ SetMirror() [1/2]

void Geom2d_Transformation::SetMirror ( const gp_Ax2d & A)

Makes the transformation into a symmetrical transformation with respect to an axis A. A is the center of the axial symmetry.

◆ SetMirror() [2/2]

void Geom2d_Transformation::SetMirror ( const gp_Pnt2d & P)

Makes the transformation into a symmetrical transformation with respect to a point P. P is the center of the symmetry.

◆ SetRotation()

void Geom2d_Transformation::SetRotation ( const gp_Pnt2d & P,
const Standard_Real Ang )

Assigns to this transformation the geometric properties of a rotation at angle Ang (in radians) about point P.

◆ SetScale()

void Geom2d_Transformation::SetScale ( const gp_Pnt2d & P,
const Standard_Real S )

Makes the transformation into a scale. P is the center of the scale and S is the scaling value.

◆ SetTransformation() [1/2]

void Geom2d_Transformation::SetTransformation ( const gp_Ax2d & FromSystem1,
const gp_Ax2d & ToSystem2 )

Makes a transformation allowing passage from the coordinate system "FromSystem1" to the coordinate system "ToSystem2".

◆ SetTransformation() [2/2]

void Geom2d_Transformation::SetTransformation ( const gp_Ax2d & ToSystem)

Makes the transformation allowing passage from the basic coordinate system {P(0.,0.,0.), VX (1.,0.,0.), VY (0.,1.,0.)} to the local coordinate system defined with the Ax2d ToSystem.

◆ SetTranslation() [1/2]

void Geom2d_Transformation::SetTranslation ( const gp_Pnt2d & P1,
const gp_Pnt2d & P2 )

Makes the transformation into a translation from the point P1 to the point P2.

◆ SetTranslation() [2/2]

void Geom2d_Transformation::SetTranslation ( const gp_Vec2d & V)

Makes the transformation into a translation. V is the vector of the translation.

◆ SetTrsf2d()

void Geom2d_Transformation::SetTrsf2d ( const gp_Trsf2d & T)

Makes the transformation into a transformation T from package gp.

◆ Transforms()

void Geom2d_Transformation::Transforms ( Standard_Real & X,
Standard_Real & Y ) const

Applies the transformation <me> to the triplet {X, Y}.

◆ Trsf2d()

gp_Trsf2d Geom2d_Transformation::Trsf2d ( ) const

Converts this transformation into a gp_Trsf2d transformation. Returns a non persistent copy of <me>. -C++: return const&.

◆ Value()

Standard_Real Geom2d_Transformation::Value ( const Standard_Integer Row,
const Standard_Integer Col ) const

Returns the coefficients of the global matrix of transformation. It is a 2 rows X 3 columns matrix.

Raised if Row < 1 or Row > 2 or Col < 1 or Col > 2

Computes the reverse transformation.


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