Buffer Object - is a general storage object for arbitrary data (see sub-classes). More...

#include <OpenGl_Buffer.hxx>

Inheritance diagram for OpenGl_Buffer:

[legend]

Public Member Functions
	OpenGl_Buffer ()
	Create uninitialized buffer.

virtual	~OpenGl_Buffer ()
	Destroy object.

virtual unsigned int	GetTarget () const =0
	Return buffer target.

virtual bool	IsVirtual () const
	Return TRUE if this is a virtual (for backward compatibility) VBO object.

bool	IsValid () const

unsigned int	GetComponentsNb () const

Standard_Integer	GetElemsNb () const

void	SetElemsNb (Standard_Integer theNbElems)
	Overrides the number of vertex attributes / number of vertexes. It is up to user specifying this number correct (e.g. below initial value)!

unsigned int	GetDataType () const

Standard_Byte *	GetDataOffset () const

virtual bool	Create (const Handle< OpenGl_Context > &theGlCtx)
	Creates buffer object name (id) if not yet generated. Data should be initialized by another method.

virtual void	Release (OpenGl_Context *theGlCtx) override
	Destroy object - will release GPU memory if any.

virtual void	Bind (const Handle< OpenGl_Context > &theGlCtx) const
	Bind this buffer object.

virtual void	Unbind (const Handle< OpenGl_Context > &theGlCtx) const
	Unbind this buffer object.

bool	Init (const Handle< OpenGl_Context > &theGlCtx, const unsigned int theComponentsNb, const Standard_Integer theElemsNb, const float *theData)
	Notice that buffer object will be unbound after this call.

bool	Init (const Handle< OpenGl_Context > &theGlCtx, const unsigned int theComponentsNb, const Standard_Integer theElemsNb, const unsigned int *theData)
	Notice that buffer object will be unbound after this call.

bool	Init (const Handle< OpenGl_Context > &theGlCtx, const unsigned int theComponentsNb, const Standard_Integer theElemsNb, const unsigned short *theData)
	Notice that buffer object will be unbound after this call.

bool	Init (const Handle< OpenGl_Context > &theGlCtx, const unsigned int theComponentsNb, const Standard_Integer theElemsNb, const Standard_Byte *theData)
	Notice that buffer object will be unbound after this call.

bool	SubData (const Handle< OpenGl_Context > &theGlCtx, const Standard_Integer theElemFrom, const Standard_Integer theElemsNb, const float *theData)
	Notice that buffer object will be unbound after this call. Function replaces portion of data within this buffer object using glBufferSubData(). The buffer object should be initialized before call.

bool	GetSubData (const Handle< OpenGl_Context > &theGlCtx, const Standard_Integer theElemFrom, const Standard_Integer theElemsNb, float *theData)
	Read back buffer sub-range. Notice that buffer object will be unbound after this call. Function reads portion of data from this buffer object using glGetBufferSubData().

bool	SubData (const Handle< OpenGl_Context > &theGlCtx, const Standard_Integer theElemFrom, const Standard_Integer theElemsNb, const unsigned int *theData)
	Notice that buffer object will be unbound after this call. Function replaces portion of data within this buffer object using glBufferSubData(). The buffer object should be initialized before call.

bool	GetSubData (const Handle< OpenGl_Context > &theGlCtx, const Standard_Integer theElemFrom, const Standard_Integer theElemsNb, unsigned int *theData)
	Read back buffer sub-range. Notice that buffer object will be unbound after this call. Function reads portion of data from this buffer object using glGetBufferSubData().

bool	SubData (const Handle< OpenGl_Context > &theGlCtx, const Standard_Integer theElemFrom, const Standard_Integer theElemsNb, const unsigned short *theData)
	Notice that buffer object will be unbound after this call. Function replaces portion of data within this buffer object using glBufferSubData(). The buffer object should be initialized before call.

bool	GetSubData (const Handle< OpenGl_Context > &theGlCtx, const Standard_Integer theElemFrom, const Standard_Integer theElemsNb, unsigned short *theData)
	Read back buffer sub-range. Notice that buffer object will be unbound after this call. Function reads portion of data from this buffer object using glGetBufferSubData().

bool	SubData (const Handle< OpenGl_Context > &theGlCtx, const Standard_Integer theElemFrom, const Standard_Integer theElemsNb, const Standard_Byte *theData)
	Notice that buffer object will be unbound after this call. Function replaces portion of data within this buffer object using glBufferSubData(). The buffer object should be initialized before call.

bool	GetSubData (const Handle< OpenGl_Context > &theGlCtx, const Standard_Integer theElemFrom, const Standard_Integer theElemsNb, Standard_Byte *theData)
	Read back buffer sub-range. Notice that buffer object will be unbound after this call. Function reads portion of data from this buffer object using glGetBufferSubData().

Public Member Functions inherited from OpenGl_Resource
	OpenGl_Resource ()
	Empty constructor.

virtual	~OpenGl_Resource ()
	Destructor. Inheritors should call Clean (NULL) within it.

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 ()
	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_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.

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.

Static Public Member Functions
static TCollection_AsciiString	FormatTarget (unsigned int theTarget)
	Format VBO target enumeration value.

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.

Static Public Attributes
static const unsigned int	NO_BUFFER = 0
	Helpful constants.

advanced methods
Standard_Byte *	myOffset
	offset to data

unsigned int	myBufferId
	VBO name (index)

unsigned int	myComponentsNb
	Number of components per generic vertex attribute, must be 1, 2, 3, or 4.

Standard_Integer	myElemsNb
	Number of vertex attributes / number of vertices.

unsigned int	myDataType
	Data type (GL_FLOAT, GL_UNSIGNED_INT, GL_UNSIGNED_BYTE etc.)

static size_t	sizeOfGlType (unsigned int theType)

virtual Standard_Size	EstimatedDataSize () const override
	Returns estimated GPU memory usage for holding data without considering overheads and allocation alignment rules.

virtual bool	init (const Handle< OpenGl_Context > &theGlCtx, const unsigned int theComponentsNb, const Standard_Integer theElemsNb, const void *theData, const unsigned int theDataType, const Standard_Integer theStride)
	Initialize buffer with new data.

bool	init (const Handle< OpenGl_Context > &theGlCtx, const unsigned int theComponentsNb, const Standard_Integer theElemsNb, const void *theData, const unsigned int theDataType)
	Initialize buffer with new data.

virtual bool	subData (const Handle< OpenGl_Context > &theGlCtx, const Standard_Integer theElemFrom, const Standard_Integer theElemsNb, const void *theData, const unsigned int theDataType)
	Update part of the buffer with new data.

virtual bool	getSubData (const Handle< OpenGl_Context > &theGlCtx, const Standard_Integer theElemFrom, const Standard_Integer theElemsNb, void *theData, const unsigned int theDataType)
	Read back buffer sub-range.

virtual void	DumpJson (Standard_OStream &theOStream, Standard_Integer theDepth=-1) const override
	Dumps the content of me into the stream.

void	BindBufferBase (const Handle< OpenGl_Context > &theGlCtx, unsigned int theIndex)
	Binds a buffer object to an indexed buffer target. Wrapper for glBindBufferBase().

void	UnbindBufferBase (const Handle< OpenGl_Context > &theGlCtx, unsigned int theIndex)
	Unbinds a buffer object from an indexed buffer target. Wrapper for glBindBufferBase().

void	BindBufferRange (const Handle< OpenGl_Context > &theGlCtx, unsigned int theIndex, const intptr_t theOffset, const size_t theSize)
	Binds a buffer object to an indexed buffer target with specified offset and size. Wrapper for glBindBufferRange().

Additional Inherited Members
Public Types inherited from Standard_Transient
typedef void	base_type
	Returns a type descriptor about this object.

Detailed Description

Buffer Object - is a general storage object for arbitrary data (see sub-classes).

Constructor & Destructor Documentation

◆ OpenGl_Buffer()

OpenGl_Buffer::OpenGl_Buffer ( )

Create uninitialized buffer.

◆ ~OpenGl_Buffer()

virtual OpenGl_Buffer::~OpenGl_Buffer ( )

virtual

Destroy object.

Member Function Documentation

◆ Bind()

virtual void OpenGl_Buffer::Bind ( const Handle< OpenGl_Context > & theGlCtx ) const

virtual

Bind this buffer object.

◆ BindBufferBase()

void OpenGl_Buffer::BindBufferBase	(	const Handle< OpenGl_Context > &	theGlCtx,
		unsigned int	theIndex )

protected

Binds a buffer object to an indexed buffer target. Wrapper for glBindBufferBase().

Parameters

theGlCtx	[in] active OpenGL context
theIndex	[in] index to bind

◆ BindBufferRange()

void OpenGl_Buffer::BindBufferRange	(	const Handle< OpenGl_Context > &	theGlCtx,
		unsigned int	theIndex,
		const intptr_t	theOffset,
		const size_t	theSize )

protected

Binds a buffer object to an indexed buffer target with specified offset and size. Wrapper for glBindBufferRange().

Parameters

theGlCtx	[in] active OpenGL context
theIndex	[in] index to bind (

See also: GL_MAX_UNIFORM_BUFFER_BINDINGS in case of uniform buffer)

Parameters

theOffset [in] offset within the buffer (

See also: GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT in case of uniform buffer)

Parameters

theSize [in] sub-section length starting from offset

◆ Create()

virtual bool OpenGl_Buffer::Create ( const Handle< OpenGl_Context > & theGlCtx )

virtual

Creates buffer object name (id) if not yet generated. Data should be initialized by another method.

Reimplemented in OpenGl_TextureBuffer.

◆ DumpJson()

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

overridevirtual

Dumps the content of me into the stream.

Reimplemented from OpenGl_Resource.

Reimplemented in OpenGl_IndexBuffer.

◆ EstimatedDataSize()

virtual Standard_Size OpenGl_Buffer::EstimatedDataSize ( ) const

inlineoverridevirtual

Returns estimated GPU memory usage for holding data without considering overheads and allocation alignment rules.

Implements OpenGl_Resource.

◆ FormatTarget()

static TCollection_AsciiString OpenGl_Buffer::FormatTarget ( unsigned int theTarget )

static

Format VBO target enumeration value.

◆ GetComponentsNb()

unsigned int OpenGl_Buffer::GetComponentsNb ( ) const

inline

Returns: the number of components per generic vertex attribute.

◆ GetDataOffset()

Standard_Byte * OpenGl_Buffer::GetDataOffset ( ) const

inline

Returns: offset to data, NULL by default

◆ GetDataType()

unsigned int OpenGl_Buffer::GetDataType ( ) const

inline

Returns: data type of each component in the array.

◆ GetElemsNb()

Standard_Integer OpenGl_Buffer::GetElemsNb ( ) const

inline

Returns: number of vertex attributes / number of vertices specified within Init()

◆ GetSubData() [1/4]

bool OpenGl_Buffer::GetSubData	(	const Handle< OpenGl_Context > &	theGlCtx,
		const Standard_Integer	theElemFrom,
		const Standard_Integer	theElemsNb,
		float *	theData )

Read back buffer sub-range. Notice that buffer object will be unbound after this call. Function reads portion of data from this buffer object using glGetBufferSubData().

Parameters

theElemFrom	[in] element id from which replace buffer data (>=0);
theElemsNb	[in] elements count (theElemFrom + theElemsNb <= GetElemsNb());
theData	[out] destination pointer to float data.

◆ GetSubData() [2/4]

bool OpenGl_Buffer::GetSubData	(	const Handle< OpenGl_Context > &	theGlCtx,
		const Standard_Integer	theElemFrom,
		const Standard_Integer	theElemsNb,
		Standard_Byte *	theData )

Read back buffer sub-range. Notice that buffer object will be unbound after this call. Function reads portion of data from this buffer object using glGetBufferSubData().

Parameters

theElemFrom	[in] element id from which replace buffer data (>=0);
theElemsNb	[in] elements count (theElemFrom + theElemsNb <= GetElemsNb());
theData	[out] destination pointer to Standard_Byte data.

◆ GetSubData() [3/4]

bool OpenGl_Buffer::GetSubData	(	const Handle< OpenGl_Context > &	theGlCtx,
		const Standard_Integer	theElemFrom,
		const Standard_Integer	theElemsNb,
		unsigned int *	theData )

Read back buffer sub-range. Notice that buffer object will be unbound after this call. Function reads portion of data from this buffer object using glGetBufferSubData().

Parameters

theElemFrom	[in] element id from which replace buffer data (>=0);
theElemsNb	[in] elements count (theElemFrom + theElemsNb <= GetElemsNb());
theData	[out] destination pointer to unsigned int data.

◆ GetSubData() [4/4]

bool OpenGl_Buffer::GetSubData	(	const Handle< OpenGl_Context > &	theGlCtx,
		const Standard_Integer	theElemFrom,
		const Standard_Integer	theElemsNb,
		unsigned short *	theData )

Read back buffer sub-range. Notice that buffer object will be unbound after this call. Function reads portion of data from this buffer object using glGetBufferSubData().

Parameters

theElemFrom	[in] element id from which replace buffer data (>=0);
theElemsNb	[in] elements count (theElemFrom + theElemsNb <= GetElemsNb());
theData	[out] destination pointer to unsigned short data.

◆ getSubData()

virtual bool OpenGl_Buffer::getSubData	(	const Handle< OpenGl_Context > &	theGlCtx,
		const Standard_Integer	theElemFrom,
		const Standard_Integer	theElemsNb,
		void *	theData,
		const unsigned int	theDataType )

virtual

Read back buffer sub-range.

◆ GetTarget()

virtual unsigned int OpenGl_Buffer::GetTarget ( ) const

pure virtual

Return buffer target.

Implemented in OpenGl_IndexBuffer, OpenGl_TextureBuffer, OpenGl_UniformBuffer, and OpenGl_VertexBuffer.

◆ Init() [1/4]

bool OpenGl_Buffer::Init	(	const Handle< OpenGl_Context > &	theGlCtx,
		const unsigned int	theComponentsNb,
		const Standard_Integer	theElemsNb,
		const float *	theData )

Notice that buffer object will be unbound after this call.

Parameters

theComponentsNb	[in] specifies the number of components per generic vertex attribute; must be 1, 2, 3, or 4;
theElemsNb	[in] elements count;
theData	[in] pointer to float data (vertices/normals etc.).

◆ Init() [2/4]

bool OpenGl_Buffer::Init	(	const Handle< OpenGl_Context > &	theGlCtx,
		const unsigned int	theComponentsNb,
		const Standard_Integer	theElemsNb,
		const Standard_Byte *	theData )

Notice that buffer object will be unbound after this call.

Parameters

theComponentsNb	[in] specifies the number of components per generic vertex attribute; must be 1, 2, 3, or 4;
theElemsNb	[in] elements count;
theData	[in] pointer to Standard_Byte data (indices/colors etc.).

◆ Init() [3/4]

bool OpenGl_Buffer::Init	(	const Handle< OpenGl_Context > &	theGlCtx,
		const unsigned int	theComponentsNb,
		const Standard_Integer	theElemsNb,
		const unsigned int *	theData )

Notice that buffer object will be unbound after this call.

Parameters

theComponentsNb	[in] specifies the number of components per generic vertex attribute; must be 1, 2, 3, or 4;
theElemsNb	[in] elements count;
theData	[in] pointer to unsigned int data (indices etc.).

◆ Init() [4/4]

bool OpenGl_Buffer::Init	(	const Handle< OpenGl_Context > &	theGlCtx,
		const unsigned int	theComponentsNb,
		const Standard_Integer	theElemsNb,
		const unsigned short *	theData )

Notice that buffer object will be unbound after this call.

Parameters

theComponentsNb	[in] specifies the number of components per generic vertex attribute; must be 1, 2, 3, or 4;
theElemsNb	[in] elements count;
theData	[in] pointer to unsigned short data (indices etc.).

◆ init() [1/2]

bool OpenGl_Buffer::init	(	const Handle< OpenGl_Context > &	theGlCtx,
		const unsigned int	theComponentsNb,
		const Standard_Integer	theElemsNb,
		const void *	theData,
		const unsigned int	theDataType )

inline

Initialize buffer with new data.

◆ init() [2/2]

virtual bool OpenGl_Buffer::init	(	const Handle< OpenGl_Context > &	theGlCtx,
		const unsigned int	theComponentsNb,
		const Standard_Integer	theElemsNb,
		const void *	theData,
		const unsigned int	theDataType,
		const Standard_Integer	theStride )

virtual

Initialize buffer with new data.

◆ IsValid()

bool OpenGl_Buffer::IsValid ( ) const

inline

Returns: true if current object was initialized

◆ IsVirtual()

virtual bool OpenGl_Buffer::IsVirtual ( ) const

inlinevirtual

Return TRUE if this is a virtual (for backward compatibility) VBO object.

◆ Release()

virtual void OpenGl_Buffer::Release ( OpenGl_Context * theGlCtx )

overridevirtual

Destroy object - will release GPU memory if any.

Implements OpenGl_Resource.

Reimplemented in OpenGl_TextureBuffer.

◆ SetElemsNb()

void OpenGl_Buffer::SetElemsNb ( Standard_Integer theNbElems )

inline

Overrides the number of vertex attributes / number of vertexes. It is up to user specifying this number correct (e.g. below initial value)!

◆ sizeOfGlType()

static size_t OpenGl_Buffer::sizeOfGlType ( unsigned int theType )

static

Returns: size of specified GL type

◆ SubData() [1/4]

bool OpenGl_Buffer::SubData	(	const Handle< OpenGl_Context > &	theGlCtx,
		const Standard_Integer	theElemFrom,
		const Standard_Integer	theElemsNb,
		const float *	theData )

Notice that buffer object will be unbound after this call. Function replaces portion of data within this buffer object using glBufferSubData(). The buffer object should be initialized before call.

Parameters

theElemFrom	[in] element id from which replace buffer data (>=0);
theElemsNb	[in] elements count (theElemFrom + theElemsNb <= GetElemsNb());
theData	[in] pointer to float data.

◆ SubData() [2/4]

bool OpenGl_Buffer::SubData	(	const Handle< OpenGl_Context > &	theGlCtx,
		const Standard_Integer	theElemFrom,
		const Standard_Integer	theElemsNb,
		const Standard_Byte *	theData )

Notice that buffer object will be unbound after this call. Function replaces portion of data within this buffer object using glBufferSubData(). The buffer object should be initialized before call.

Parameters

theElemFrom	[in] element id from which replace buffer data (>=0);
theElemsNb	[in] elements count (theElemFrom + theElemsNb <= GetElemsNb());
theData	[in] pointer to Standard_Byte data.

◆ SubData() [3/4]

bool OpenGl_Buffer::SubData	(	const Handle< OpenGl_Context > &	theGlCtx,
		const Standard_Integer	theElemFrom,
		const Standard_Integer	theElemsNb,
		const unsigned int *	theData )

Notice that buffer object will be unbound after this call. Function replaces portion of data within this buffer object using glBufferSubData(). The buffer object should be initialized before call.

Parameters

theElemFrom	[in] element id from which replace buffer data (>=0);
theElemsNb	[in] elements count (theElemFrom + theElemsNb <= GetElemsNb());
theData	[in] pointer to unsigned int data.

◆ SubData() [4/4]

bool OpenGl_Buffer::SubData	(	const Handle< OpenGl_Context > &	theGlCtx,
		const Standard_Integer	theElemFrom,
		const Standard_Integer	theElemsNb,
		const unsigned short *	theData )

Notice that buffer object will be unbound after this call. Function replaces portion of data within this buffer object using glBufferSubData(). The buffer object should be initialized before call.

Parameters

theElemFrom	[in] element id from which replace buffer data (>=0);
theElemsNb	[in] elements count (theElemFrom + theElemsNb <= GetElemsNb());
theData	[in] pointer to unsigned short data.

◆ subData()

virtual bool OpenGl_Buffer::subData	(	const Handle< OpenGl_Context > &	theGlCtx,
		const Standard_Integer	theElemFrom,
		const Standard_Integer	theElemsNb,
		const void *	theData,
		const unsigned int	theDataType )

virtual

Update part of the buffer with new data.

◆ Unbind()

virtual void OpenGl_Buffer::Unbind ( const Handle< OpenGl_Context > & theGlCtx ) const

virtual

Unbind this buffer object.

◆ UnbindBufferBase()

void OpenGl_Buffer::UnbindBufferBase	(	const Handle< OpenGl_Context > &	theGlCtx,
		unsigned int	theIndex )

protected

Unbinds a buffer object from an indexed buffer target. Wrapper for glBindBufferBase().

Parameters

theGlCtx	[in] active OpenGL context
theIndex	[in] index to bind

Field Documentation

◆ myBufferId

unsigned int OpenGl_Buffer::myBufferId

protected

VBO name (index)

◆ myComponentsNb

unsigned int OpenGl_Buffer::myComponentsNb

protected

Number of components per generic vertex attribute, must be 1, 2, 3, or 4.

◆ myDataType

unsigned int OpenGl_Buffer::myDataType

protected

Data type (GL_FLOAT, GL_UNSIGNED_INT, GL_UNSIGNED_BYTE etc.)

◆ myElemsNb

Standard_Integer OpenGl_Buffer::myElemsNb

protected

Number of vertex attributes / number of vertices.

◆ myOffset

Standard_Byte* OpenGl_Buffer::myOffset

protected

offset to data

◆ NO_BUFFER

const unsigned int OpenGl_Buffer::NO_BUFFER = 0

static

Helpful constants.

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

OpenGl_Buffer.hxx

Public Member Functions

Static Public Member Functions

Static Public Attributes

advanced methods

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ OpenGl_Buffer()

◆ ~OpenGl_Buffer()

Member Function Documentation

◆ Bind()

◆ BindBufferBase()

◆ BindBufferRange()

◆ Create()

◆ DumpJson()

◆ EstimatedDataSize()

◆ FormatTarget()

◆ GetComponentsNb()

◆ GetDataOffset()

◆ GetDataType()

◆ GetElemsNb()

◆ GetSubData() [1/4]

◆ GetSubData() [2/4]

◆ GetSubData() [3/4]

◆ GetSubData() [4/4]

◆ getSubData()

◆ GetTarget()

◆ Init() [1/4]

◆ Init() [2/4]

◆ Init() [3/4]

◆ Init() [4/4]

◆ init() [1/2]

◆ init() [2/2]

◆ IsValid()

◆ IsVirtual()

◆ Release()

◆ SetElemsNb()

◆ sizeOfGlType()

◆ SubData() [1/4]

◆ SubData() [2/4]

◆ SubData() [3/4]

◆ SubData() [4/4]

◆ subData()

◆ Unbind()

◆ UnbindBufferBase()

Field Documentation

◆ myBufferId

◆ myComponentsNb

◆ myDataType

◆ myElemsNb

◆ myOffset

◆ NO_BUFFER