Derived attribute class that stores the actual information. More...

#include <lagrange/Attribute.h>

Public Types
using	ValueType = ValueType_
	Attribute value type.

Public Member Functions
template<typename SourceValueType >
Attribute< TargetValueType >	cast_copy (const Attribute< SourceValueType > &source)

template<typename SourceValueType >
Attribute< TargetValueType > &	cast_assign (const Attribute< SourceValueType > &source)

Attribute growth
void	set_default_value (ValueType value)
	Sets the default value to use when growing the attribute. More...

ValueType	get_default_value () const
	Gets the default value to use when growing the attribute.

void	set_growth_policy (AttributeGrowthPolicy policy)
	Sets the growth policy for external buffers. More...

AttributeGrowthPolicy	get_growth_policy () const
	Gets the growth policy for external buffers. More...

void	set_shrink_policy (AttributeShrinkPolicy policy)
	Sets the shrink policy for external buffers. More...

AttributeShrinkPolicy	get_shrink_policy () const
	Gets the shrink policy for external buffers. More...

void	set_write_policy (AttributeWritePolicy policy)
	Sets the write policy for read-only external buffers. More...

AttributeWritePolicy	get_write_policy () const
	Gets the write policy for read-only external buffers. More...

void	set_copy_policy (AttributeCopyPolicy policy)
	Set copy policy for external buffers. More...

AttributeCopyPolicy	get_copy_policy () const
	Get the copy policy for external buffers. More...

void	create_internal_copy ()
	Creates an internal copy of the attribute data. More...

void	clear ()
	Clears the attribute buffer (new number of elements is 0).

void	shrink_to_fit ()
	Shrink attribute buffer to fit the current number of entries. More...

void	reserve_entries (size_t new_cap)
	Reserve enough memory for `new_cap` entries. More...

void	resize_elements (size_t num_elements)
	Resize the buffer to contain `num_elements` elements. More...

void	insert_elements (span< const ValueType > values)
	Inserts values for new elements. More...

void	insert_elements (std::initializer_list< const ValueType > values)
	Inserts values for new elements. More...

void	insert_elements (size_t count)
	Inserts new elements. More...

Attribute access
bool	empty () const
	Test whether the attribute is empty (its size is 0). More...

size_t	get_num_elements () const
	Gets the number of elements. More...

bool	is_external () const
	Checks whether an attribute buffer is external or internally managed. More...

bool	is_managed () const
	Checks whether the attribute is managing the lifetime of the underlying buffer. More...

bool	is_read_only () const
	Checks whether the attribute is external and pointing to a const buffer. More...

ValueType	get (size_t i, size_t c) const
	Gets an entry for element `i`, at channel `p`. More...

ValueType &	ref (size_t i, size_t c)
	Gets a writable reference to the entry for element `i`, at channel `p`. More...

ValueType	get (size_t i) const
	Gets an entry for a scalar element `i`. More...

ValueType &	ref (size_t i)
	Gets a writable reference to a scalar element `i`, at channel `p`. More...

lagrange::span< const ValueType >	get_all () const
	Returns a read-only view of the buffer spanning num elements x num channels. More...

lagrange::span< ValueType >	ref_all ()
	Returns a writable view of the buffer spanning num elements x num channels. More...

lagrange::span< const ValueType >	get_first (size_t num_elements) const
	Returns a read-only view of the attribute values for the first elements in the buffer. More...

lagrange::span< ValueType >	ref_first (size_t num_elements)
	Returns a writable view of the attribute values for the first elements in the buffer. More...

lagrange::span< const ValueType >	get_last (size_t num_elements) const
	Returns a read-only view of the attribute values for the last elements in the buffer. More...

lagrange::span< ValueType >	ref_last (size_t num_elements)
	Returns a writable view of the attribute values for the last elements in the buffer. More...

lagrange::span< const ValueType >	get_middle (size_t first_element, size_t num_elements) const
	Returns a read-only view of the attribute values for the middle elements in the buffer. More...

lagrange::span< ValueType >	ref_middle (size_t first_element, size_t num_elements)
	Returns a writable view of the attribute values for the middle elements in the buffer. More...

lagrange::span< const ValueType >	get_row (size_t element) const
	Returns a read-only view of the attribute values for the element in the buffer. More...

lagrange::span< ValueType >	ref_row (size_t element)
	Returns a writable view of the attribute values for the element in the buffer. More...

Public Member Functions inherited from AttributeBase
	AttributeBase (AttributeElement element, AttributeUsage usage, size_t num_channels)
	Constructs a new instance. More...

virtual	~AttributeBase ()
	Destroys the object.

	AttributeBase (AttributeBase &&other)=default
	Move constructor. More...

AttributeBase &	operator= (AttributeBase &&other)=default
	Assignment move operator. More...

	AttributeBase (const AttributeBase &other)=default
	Copy constructor. More...

AttributeBase &	operator= (const AttributeBase &other)=default
	Assignment copy operator. More...

virtual AttributeValueType	get_value_type () const =0
	Gets the attribute value type. More...

AttributeElement	get_element_type () const
	Gets the attribute element type. More...

AttributeUsage	get_usage () const
	Gets the attribute usage tag. More...

size_t	get_num_channels () const
	Gets the number of channels for the attribute. More...

void	unsafe_set_usage (AttributeUsage usage)
	Sets the attribute usage tag. More...

void	unsafe_set_element_type (AttributeElement element)
	Sets the attribute element type. More...

Static Public Attributes
static constexpr bool	IsIndexed = false
	Whether this attribute type is indexed.

Protected Attributes
std::vector< ValueType >	m_data
	Internal buffer storing the data (when the attribute is not external).

std::shared_ptr< const ValueType >	m_owner
	Optional aliased ptr to extend the lifetime of memory owner object of external buffer.

ValueType	m_default_value = ValueType(0)
	Default values used to populate buffer when the attribute grows.

lagrange::span< ValueType >	m_view
	Writable pointer to the buffer storing the attribute data. More...

lagrange::span< const ValueType >	m_const_view
	Read-only pointer to the buffer storing the attribute data. More...

AttributeGrowthPolicy	m_growth_policy = AttributeGrowthPolicy::ErrorIfExternal
	Growth policy for external buffers.

AttributeShrinkPolicy	m_shrink_policy = AttributeShrinkPolicy::ErrorIfExternal
	Shrink policy for external buffers.

AttributeWritePolicy	m_write_policy = AttributeWritePolicy::ErrorIfReadOnly
	Policy for write access to read-only external buffers.

AttributeCopyPolicy	m_copy_policy = AttributeCopyPolicy::CopyIfExternal
	Copy policy for external buffers.

bool	m_is_external = false
	Flag to determine whether an attribute is using an external or internal buffer. More...

bool	m_is_read_only = false
	Flag to determine whether an external attribute is read-only or writable. More...

size_t	m_num_elements = 0
	Number of elements associated with the attribute.

Protected Attributes inherited from AttributeBase
AttributeElement	m_element
	Element type (vertex, facet, indexed, etc.).

AttributeUsage	m_usage
	Attribute usage tag.

size_t	m_num_channels = 0
	Number of channel for each value.

Attribute construction
	Attribute (AttributeElement element, AttributeUsage usage, size_t num_channels)
	Constructs a new instance. More...

	~Attribute () override
	Destroys the object.

	Attribute (Attribute &&other) noexcept
	Move constructor. More...

Attribute &	operator= (Attribute &&other) noexcept
	Assignment move operator. More...

	Attribute (const Attribute &other)
	Copy constructor. More...

Attribute &	operator= (const Attribute &other)
	Assignment copy operator. More...

template<typename OtherValue >
Attribute &	cast_assign (const Attribute< OtherValue > &other)
	Cast assignment operator. More...

AttributeValueType	get_value_type () const override
	Gets the attribute value type. More...

void	wrap (span< ValueType > buffer, size_t num_elements)
	Wraps an external buffer into the attribute. More...

void	wrap (SharedSpan< ValueType > buffer_ptr, size_t num_elements)
	Wraps an external buffer into the attribute. More...

void	wrap_const (span< const ValueType > buffer, size_t num_elements)
	Wraps a const external buffer into the attribute. More...

void	wrap_const (SharedSpan< const ValueType > shared_buffer, size_t num_elements)
	Wraps a const external buffer into the attribute. More...

template<typename OtherValue >
static Attribute	cast_copy (const Attribute< OtherValue > &other)
	Cast copy operator. More...

Detailed Description

template<typename ValueType_>
class lagrange::Attribute< ValueType_ >

Derived attribute class that stores the actual information.

Template Parameters

ValueType_ Attribute value type.

Constructor & Destructor Documentation

◆ Attribute() [1/3]

Attribute	(	AttributeElement	element,
		AttributeUsage	usage,
		size_t	num_channels
	)

Constructs a new instance.

Parameters

[in]	element	Element type (vertex, facet, etc.).
[in]	usage	Usage tag.
[in]	num_channels	Number of channels.

◆ Attribute() [2/3]

Attribute ( Attribute< ValueType_ > && other )

noexcept

Move constructor.

Parameters

other Instance to move from.

◆ Attribute() [3/3]

Attribute ( const Attribute< ValueType_ > & other )

explicit

Copy constructor.

Parameters

[in] other Instance to copy from.

Member Function Documentation

◆ operator=() [1/2]

Attribute & operator= ( Attribute< ValueType_ > && other )

noexcept

Assignment move operator.

Parameters

other Instance to move from.

Returns: The result of the assignment.

◆ operator=() [2/2]

Attribute & operator= ( const Attribute< ValueType_ > & other )

Assignment copy operator.

Parameters

[in] other Instance to copy from.

Returns: The result of the assignment.

◆ cast_copy()

static Attribute cast_copy ( const Attribute< OtherValue > & other )

static

Cast copy operator.

Creates an attribute by copying and casting values from another attribute with a different ValueType. Will print a warning if the source and target value types are identical.

Parameters

[in] other The other attribute to copy & cast from.

Template Parameters

OtherValue Value type for the other attribute.

Returns: A new attribute object whose values have been cast to the desired type.

◆ cast_assign()

Attribute & cast_assign ( const Attribute< OtherValue > & other )

Cast assignment operator.

Replace the current attribute by copying and casting values from another attribute with a different ValueType. Will print a warning if the source and target value types are identical.

Parameters

[in] other The other attribute to copy & cast from.

Template Parameters

OtherValue Value type for the other attribute.

Returns: A reference to the assignment result.

◆ get_value_type()

AttributeValueType get_value_type ( ) const

overridevirtual

Gets the attribute value type.

Returns: An enum describing the value type.

Implements AttributeBase.

◆ wrap() [1/2]

void wrap	(	lagrange::span< ValueType >	buffer,
		size_t	num_elements
	)

Wraps an external buffer into the attribute.

The pointer must remain valid for the lifetime of the attribute. Note that only the number of element is allowed to change when wrapping an external buffer (the number of channels is fixed during the attribute construction).

Parameters

[in]	buffer	Pointer to an external buffer to be used as storage. The pointed buffer must have a capacity (determined by span::size()) that is large enough to store num elements x num channels entries. The pointed buffer can be larger than required, in which case the padding capacity can be used to grow the attribute, as determined by the AttributeGrowthPolicy.
[in]	num_elements	New number of elements associated with the attribute.

◆ wrap() [2/2]

void wrap	(	SharedSpan< ValueType >	buffer_ptr,
		size_t	num_elements
	)

Wraps an external buffer into the attribute.

The buffer ownership is shared with the attribute. Note that only the number of element is allowed to change when wrapping an external buffer (the number of channels is fixed during the attribute construction).

Parameters

[in]	shared_buffer	Pointer to an external buffer managed by a SharedSpan to be used as storage. This pointer exposes a view of the buffer managed by the owner. The buffer must have a capacity (determined by buffer_ptr.size()) that is large enough to store num elements x num channels entries. The buffer can be larger than required, in which case the padding capacity can be used to grow the attribute, as determined by the AttributeGrowthPolicy.
[in]	num_elements	New number of elements associated with the attribute.

◆ wrap_const() [1/2]

void wrap_const	(	lagrange::span< const ValueType >	buffer,
		size_t	num_elements
	)

Wraps a const external buffer into the attribute.

The pointer must remain valid for the lifetime of the attribute. Note that only the number of element is allowed to change when wrapping an external buffer (the number of channels is fixed during the attribute construction). Following this, any write operation to the attribute will throw an exception.

Parameters

[in]	buffer	Pointer to an external buffer to be used as storage. The pointed buffer must have a capacity (determined by span::size()) that is large enough to store num elements x num channels entries. The pointed buffer can be larger than required, in which case the padding capacity can be used to grow the attribute, as determined by the AttributeGrowthPolicy.
[in]	num_elements	New number of elements associated with the attribute.

◆ wrap_const() [2/2]

void wrap_const	(	SharedSpan< const ValueType >	shared_buffer,
		size_t	num_elements
	)

Wraps a const external buffer into the attribute.

The buffer ownership is shared with the attribute. Note that only the number of element is allowed to change when wrapping an external buffer (the number of channels is fixed during the attribute construction).

Parameters

[in]	shared_buffer	Pointer to an external buffer managed by a SharedSpan to be used as storage. This pointer exposes a view of the buffer managed by the owner. The buffer must have a capacity (determined by shared_buffer.size()) that is large enough to store num elements x num channels entries. The buffer can be larger than required, in which case the padding capacity can be used to grow the attribute, as determined by the AttributeGrowthPolicy.
[in]	num_elements	New number of elements associated with the attribute.

◆ set_default_value()

void set_default_value ( ValueType value )

inline

Sets the default value to use when growing the attribute.

Parameters

[in] value New default value.

◆ set_growth_policy()

void set_growth_policy ( AttributeGrowthPolicy policy )

inline

Sets the growth policy for external buffers.

Parameters

[in] policy New policy.

◆ get_growth_policy()

AttributeGrowthPolicy get_growth_policy ( ) const

inline

Gets the growth policy for external buffers.

Returns: The growth policy.

◆ set_shrink_policy()

void set_shrink_policy ( AttributeShrinkPolicy policy )

inline

Sets the shrink policy for external buffers.

Parameters

[in] policy New policy.

◆ get_shrink_policy()

AttributeShrinkPolicy get_shrink_policy ( ) const

inline

Gets the shrink policy for external buffers.

Returns: The shrink policy.

◆ set_write_policy()

void set_write_policy ( AttributeWritePolicy policy )

inline

Sets the write policy for read-only external buffers.

Parameters

[in] policy New policy.

◆ get_write_policy()

AttributeWritePolicy get_write_policy ( ) const

inline

Gets the write policy for read-only external buffers.

Returns: The attribute write policy.

◆ set_copy_policy()

void set_copy_policy ( AttributeCopyPolicy policy )

inline

Set copy policy for external buffers.

Parameters

[in] policy New policy

◆ get_copy_policy()

AttributeCopyPolicy get_copy_policy ( ) const

inline

Get the copy policy for external buffers.

Returns: The attribute copy policy.

◆ create_internal_copy()

void create_internal_copy

Creates an internal copy of the attribute data.

The attribute buffer must be external before calling this function. An internal copy of the buffer is created (including padding size). This can be used prior to attribute export to ensure lifetime of the underlying object.

◆ shrink_to_fit()

void shrink_to_fit

Shrink attribute buffer to fit the current number of entries.

If the attribute points to an external buffer, an internal copy will be created if the external buffer capacity exceeds the number of entries in the attribute.

◆ reserve_entries()

void reserve_entries ( size_t new_cap )

Reserve enough memory for new_cap entries.

The new capacity does not need to be a multiple of the number of channels (e.g. one may want to pad the last vertex coordinate with a single value).

Parameters

[in] new_cap The new buffer capacity.

◆ resize_elements()

void resize_elements ( size_t num_elements )

Resize the buffer to contain num_elements elements.

New attribute entries will be zero-initialized.

Parameters

[in] num_elements New number of elements.

◆ insert_elements() [1/3]

void insert_elements ( lagrange::span< const ValueType > values )

Inserts values for new elements.

Parameters

[in] values Values to be inserted. The span size must be a multiple of number of channels for the attribute.

◆ insert_elements() [2/3]

void insert_elements ( std::initializer_list< const ValueType > values )

Inserts values for new elements.

Parameters

[in] values Values to be inserted. The span size must be a multiple of number of channels for the attribute.

◆ insert_elements() [3/3]

void insert_elements ( size_t count )

Inserts new elements.

Use set_default_value to use a non-zero default value to initialize the new elements.

See also: set_default_value

Parameters

[in] count The number elements to insert.

◆ empty()

bool empty ( ) const

inline

Test whether the attribute is empty (its size is 0).

Returns: Whether the attribute is empty.

◆ get_num_elements()

size_t get_num_elements ( ) const

inline

Gets the number of elements.

Returns: The number of elements.

◆ is_external()

bool is_external ( ) const

inline

Checks whether an attribute buffer is external or internally managed.

External buffers must remain valid for the lifetime of the attribute object.

Returns: True if the buffer is external, False otherwise.

◆ is_managed()

bool is_managed ( ) const

inline

Checks whether the attribute is managing the lifetime of the underlying buffer.

This is true for internal attributes (the buffer is allocated by the attribute itself), or for external attributes created by wrapping a SharedSpan object.

Returns: True if the buffer is managed, False otherwise.

◆ is_read_only()

bool is_read_only ( ) const

inline

Checks whether the attribute is external and pointing to a const buffer.

If the attribute data is internally managed, this always returns false.

Returns: True if the data is read only, False otherwise.

◆ get() [1/2]

ValueType get	(	size_t	i,
		size_t	c
	)		const

Gets an entry for element i, at channel p.

Note that due to internal checks, it is more efficient to first retrieve a span() of the whole buffer, then do access operations on this span inside a for loop.

Parameters

[in]	i	Element to access.
[in]	c	Channel to access.

Returns: Value of the element attribute for the given channel.

◆ ref() [1/2]

ValueType & ref	(	size_t	i,
		size_t	c
	)

Gets a writable reference to the entry for element i, at channel p.

Note that due to internal checks, it is more efficient to first retrieve a span() of the whole buffer, then do access operations on this span inside a for loop.

Parameters

[in]	i	Element to access.
[in]	c	Channel to access.

Returns: Reference to the element attribute for the given channel.

◆ get() [2/2]

ValueType get ( size_t i ) const

Gets an entry for a scalar element i.

Note that due to internal checks, it is more efficient to first retrieve a span() of the whole buffer, then do access operations on this span inside a for loop.

Parameters

[in] i Element to access.

Returns: Value of the element attribute.

◆ ref() [2/2]

ValueType & ref ( size_t i )

Gets a writable reference to a scalar element i, at channel p.

Note that due to internal checks, it is more efficient to first retrieve a span() of the whole buffer, then do access operations on this span inside a for loop.

Parameters

[in] i Element to access.

Returns: Reference to the element attribute.

◆ get_all()

lagrange::span< const ValueType > get_all

Returns a read-only view of the buffer spanning num elements x num channels.

The actual buffer may have a larger capacity (e.g. used for padding).

Returns: A read-only view of the attribute buffer.

◆ ref_all()

lagrange::span< ValueType > ref_all

Returns a writable view of the buffer spanning num elements x num channels.

The actual buffer may have a larger capacity (e.g. used for padding).

Returns: A writable view of the attribute buffer.

◆ get_first()

lagrange::span< const ValueType > get_first ( size_t num_elements ) const

Returns a read-only view of the attribute values for the first elements in the buffer.

Parameters

[in] num_elements Number of elements to retrieve.

Returns: A read-only view of the attribute values.

◆ ref_first()

lagrange::span< ValueType > ref_first ( size_t num_elements )

Returns a writable view of the attribute values for the first elements in the buffer.

Parameters

[in] num_elements Number of elements to retrieve.

Returns: A writable view of the attribute values.

◆ get_last()

lagrange::span< const ValueType > get_last ( size_t num_elements ) const

Returns a read-only view of the attribute values for the last elements in the buffer.

Parameters

[in] num_elements Number of elements to retrieve.

Returns: A read-only view of the attribute values.

◆ ref_last()

lagrange::span< ValueType > ref_last ( size_t num_elements )

Returns a writable view of the attribute values for the last elements in the buffer.

Parameters

[in] num_elements Number of elements to retrieve.

Returns: A writable view of the attribute values.

◆ get_middle()

lagrange::span< const ValueType > get_middle	(	size_t	first_element,
		size_t	num_elements
	)		const

Returns a read-only view of the attribute values for the middle elements in the buffer.

Parameters

[in]	first_element	Index of the first element to retrieve.
[in]	num_elements	Number of elements to retrieve.

Returns: A read-only view of the attribute values.

◆ ref_middle()

lagrange::span< ValueType > ref_middle	(	size_t	first_element,
		size_t	num_elements
	)

Returns a writable view of the attribute values for the middle elements in the buffer.

Parameters

[in]	first_element	Index of the first element to retrieve.
[in]	num_elements	Number of elements to retrieve.

Returns: A writable view of the attribute values.

◆ get_row()

lagrange::span< const ValueType > get_row ( size_t element ) const

Returns a read-only view of the attribute values for the element in the buffer.

Parameters

[in] element Index of the element to retrieve.

Returns: A read-only view of the attribute values.

◆ ref_row()

lagrange::span< ValueType > ref_row ( size_t element )

Returns a writable view of the attribute values for the element in the buffer.

Parameters

[in] element Index of the first element to retrieve.

Returns: A writable view of the attribute values.

Member Data Documentation

◆ m_view

lagrange::span<ValueType> m_view

protected

Writable pointer to the buffer storing the attribute data.

For internal buffers, this will point to m_data.data(). For external buffers, it will be empty() if we are wrapping a read-only buffer, and point to the external data otherwise.

◆ m_const_view

lagrange::span<const ValueType> m_const_view

protected

Read-only pointer to the buffer storing the attribute data.

For internal buffers, this will point to m_data.data(). For external buffers, it will point to the external data.

◆ m_is_external

bool m_is_external = false

protected

Flag to determine whether an attribute is using an external or internal buffer.

We need this flag to distinguish if an empty buffer is internally managed or external.

◆ m_is_read_only

bool m_is_read_only = false

protected

Flag to determine whether an external attribute is read-only or writable.

We need this to distinguish whether a pointer to an empty buffer is read-only or "writable" (in the sense that a call to ref_all() should not produce an error).

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

lagrange/Attribute.h
Attribute.cpp

Public Types

Public Member Functions

Static Public Attributes

Protected Attributes

Attribute construction

Detailed Description

Constructor & Destructor Documentation

◆ Attribute() [1/3]

◆ Attribute() [2/3]

◆ Attribute() [3/3]

Member Function Documentation

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ cast_copy()

◆ cast_assign()

◆ get_value_type()

◆ wrap() [1/2]

◆ wrap() [2/2]

◆ wrap_const() [1/2]

◆ wrap_const() [2/2]

◆ set_default_value()

◆ set_growth_policy()

◆ get_growth_policy()

◆ set_shrink_policy()

◆ get_shrink_policy()

◆ set_write_policy()

◆ get_write_policy()

◆ set_copy_policy()

◆ get_copy_policy()

◆ create_internal_copy()

◆ shrink_to_fit()

◆ reserve_entries()

◆ resize_elements()

◆ insert_elements() [1/3]

◆ insert_elements() [2/3]

◆ insert_elements() [3/3]

◆ empty()

◆ get_num_elements()

◆ is_external()

◆ is_managed()

◆ is_read_only()

◆ get() [1/2]

◆ ref() [1/2]

◆ get() [2/2]

◆ ref() [2/2]

◆ get_all()

◆ ref_all()

◆ get_first()

◆ ref_first()

◆ get_last()

◆ ref_last()

◆ get_middle()

◆ ref_middle()

◆ get_row()

◆ ref_row()

Member Data Documentation

◆ m_view

◆ m_const_view

◆ m_is_external

◆ m_is_read_only