A vertex buffer object for instanced rendering. More...

#include <vertex_buffer_inst.hpp>

Inheritance diagram for staplegl::vertex_buffer_inst:

Collaboration diagram for staplegl::vertex_buffer_inst:

[legend]

Public Member Functions
	vertex_buffer_inst (std::span< const float > instance_data, vertex_buffer_layout &&layout) noexcept

	vertex_buffer_inst (std::span< const float > instance_data) noexcept

	~vertex_buffer_inst () noexcept=default

	vertex_buffer_inst (const vertex_buffer_inst &)=delete

auto	operator= (const vertex_buffer_inst &) -> vertex_buffer_inst &=delete

	vertex_buffer_inst (vertex_buffer_inst &&) noexcept=default

auto	operator= (vertex_buffer_inst &&) noexcept -> vertex_buffer_inst &=default

void	add_instance (std::span< const float > instance_data) noexcept
	Add an instance to the buffer.

auto	delete_instance (std::int32_t index) noexcept -> int32_t
	Delete an instance from the buffer, does not preserve the order of the instances.

void	update_instance (std::int32_t index, std::span< const float > instance_data) noexcept
	Update the data of an instance in the buffer.

constexpr auto	instance_count () const noexcept -> std::int32_t

constexpr auto	instance_size () const noexcept -> std::size_t

constexpr auto	capacity () const noexcept -> std::size_t

Public Member Functions inherited from staplegl::vertex_buffer
	vertex_buffer (std::span< const float > vertices) noexcept
	Construct a new vertex buffer object.

	vertex_buffer (std::span< const float > vertices, driver_draw_hint hint) noexcept

	vertex_buffer (std::span< const float > vertices, vertex_buffer_layout &&layout) noexcept

	vertex_buffer (std::span< const float > vertices, vertex_buffer_layout &&layout, driver_draw_hint hint) noexcept

	~vertex_buffer ()

	vertex_buffer (const vertex_buffer &)=delete

auto	operator= (const vertex_buffer &) -> vertex_buffer &=delete

	vertex_buffer (vertex_buffer &&other) noexcept

auto	operator= (vertex_buffer &&other) noexcept -> vertex_buffer &

void	bind () const
	Bind the vertex buffer object.

void	set_layout (const vertex_buffer_layout &layout)
	Set the layout object.

constexpr auto	layout () const -> const vertex_buffer_layout &

void	set_data (std::span< const float > vertices) const noexcept
	Give new data to the vertex buffer object, overwriting the old one.

void	set_data (std::span< const float > vertices, driver_draw_hint hint) const noexcept
	Give new data to the vertex buffer object, overwriting the old one. Also re-specify the hint.

constexpr auto	id () const noexcept -> std::uint32_t
	Get the id of the vertex buffer object.

constexpr auto	size () const noexcept -> std::size_t
	Get the number of vertices in the vertex buffer object.

constexpr auto	draw_hint () const noexcept -> driver_draw_hint
	Return the driver draw hint of the vertex buffer object.

constexpr auto	size_bytes () const noexcept -> std::size_t
	Get the size of the vertex buffer object in bytes.

template<plain_old_data T>
void	apply (const std::function< void(std::span< T > vertices)> &func, driver_access_specifier access_specifier=staplegl::READ_WRITE) noexcept
	Applies a function to the vertices of the vertex buffer object.

Private Member Functions
constexpr auto	calc_capacity (std::size_t capacity) const noexcept -> std::size_t
	Compute the new capacity of the buffer, given the current capacity.

void	resize_buffer (std::size_t old_capacity, std::size_t new_capacity) noexcept
	Resize the buffer to the given capacity.

Private Attributes
std::size_t	m_capacity {}
	The capacity of the buffer, in bytes.

std::int32_t	m_count {}
	The number of instances in the buffer.

Additional Inherited Members
Static Public Member Functions inherited from staplegl::vertex_buffer
static void	unbind ()
	Unbind the vertex buffer object.

Protected Attributes inherited from staplegl::vertex_buffer
std::uint32_t	m_id {}

staplegl::driver_draw_hint	m_hint {}

vertex_buffer_layout	m_layout

std::size_t	m_size {}

Detailed Description

A vertex buffer object for instanced rendering.

This class is a specialization of the vertex_buffer class, and it is meant to help with instanced rendering, allowing the user of staplegl to build a more performant renderer.

When using this class, the user should initialize the buffer with an empty span of data and a layout that describes how a single instance of the object is laid out in memory.

Alternatively, the user can also supply a span with the initial data, to avoid calling add_instance() multiple times.

Adding and deleting instances automatically resizes the buffer in a way similar to std::vector, so that the user does not have to worry about the size of the buffer.

When deleting an instance, the user should be aware that the last instance in the buffer will be moved to the position of the deleted instance, so the order of the instances is not preserved, to help the user keep track of the indices of the instances, we return the index of the deleted instance (which is the index of the last instance in the buffer before the deletion).

See also: vertex_buffer.hpp

Attention: None of the base class methods are virtual, so this class is not meant to be used polymorphically.

Examples: batches.cpp.

Definition at line 56 of file vertex_buffer_inst.hpp.

Constructor & Destructor Documentation

◆ vertex_buffer_inst() [1/4]

staplegl::vertex_buffer_inst::vertex_buffer_inst	(	std::span< const float >	instance_data,
		vertex_buffer_layout &&	layout
	)

inlinenoexcept

Definition at line 136 of file vertex_buffer_inst.hpp.

◆ vertex_buffer_inst() [2/4]

staplegl::vertex_buffer_inst::vertex_buffer_inst ( std::span< const float > instance_data )

inlinenoexcept

Definition at line 141 of file vertex_buffer_inst.hpp.

◆ ~vertex_buffer_inst()

staplegl::vertex_buffer_inst::~vertex_buffer_inst ( )

defaultnoexcept

◆ vertex_buffer_inst() [3/4]

staplegl::vertex_buffer_inst::vertex_buffer_inst ( const vertex_buffer_inst & )

delete

◆ vertex_buffer_inst() [4/4]

staplegl::vertex_buffer_inst::vertex_buffer_inst ( vertex_buffer_inst && )

defaultnoexcept

Member Function Documentation

◆ add_instance()

void staplegl::vertex_buffer_inst::add_instance ( std::span< const float > instance_data )

inlinenoexcept

Add an instance to the buffer.

Parameters

instance_data the data of the instance to be added.

Definition at line 199 of file vertex_buffer_inst.hpp.

◆ calc_capacity()

constexpr auto staplegl::vertex_buffer_inst::calc_capacity ( std::size_t capacity ) const -> std::size_t

inlineconstexprprivatenoexcept

Compute the new capacity of the buffer, given the current capacity.

Parameters

capacity the current capacity of the buffer.

Returns: std::size_t the new capacity of the buffer.

Definition at line 78 of file vertex_buffer_inst.hpp.

◆ capacity()

constexpr auto staplegl::vertex_buffer_inst::capacity ( ) const -> std::size_t

inlineconstexprnoexcept

Definition at line 189 of file vertex_buffer_inst.hpp.

◆ delete_instance()

auto staplegl::vertex_buffer_inst::delete_instance ( std::int32_t index ) -> int32_t

inlinenoexcept

Delete an instance from the buffer, does not preserve the order of the instances.

Warning: The order of the instances is not preserved, by deleting an instance, the last instance will be moved to the position of the deleted instance.

Note: For out-of-bounds indices, the function will do nothing and return the index of the last instance in the buffer (as it has not been moved).

Parameters

index the index of the instance to be deleted.

Returns: int32_t the new index of the last instance in the buffer (so that the user can keep track of the indices).

Definition at line 225 of file vertex_buffer_inst.hpp.

◆ instance_count()

constexpr auto staplegl::vertex_buffer_inst::instance_count ( ) const -> std::int32_t

inlineconstexprnoexcept

Definition at line 187 of file vertex_buffer_inst.hpp.

◆ instance_size()

constexpr auto staplegl::vertex_buffer_inst::instance_size ( ) const -> std::size_t

inlineconstexprnoexcept

Definition at line 188 of file vertex_buffer_inst.hpp.

◆ operator=() [1/2]

auto staplegl::vertex_buffer_inst::operator= ( const vertex_buffer_inst & ) -> vertex_buffer_inst &=delete

delete

◆ operator=() [2/2]

auto staplegl::vertex_buffer_inst::operator= ( vertex_buffer_inst && ) -> vertex_buffer_inst &=default

defaultnoexcept

◆ resize_buffer()

void staplegl::vertex_buffer_inst::resize_buffer	(	std::size_t	old_capacity,
		std::size_t	new_capacity
	)

inlineprivatenoexcept

Resize the buffer to the given capacity.

Note: The old buffer is regrown and a temporary buffer is created to copy the data from the old buffer to the new one. One could argue that this is not the most efficient way, as the data could be copied directly from the old buffer to the new one, however, our main concern is ID stability, so that the buffers do not have to be re-bound after resizing.

Parameters

old_capacity	the old capacity of the buffer.
new_capacity	the new capacity of the buffer.

Definition at line 103 of file vertex_buffer_inst.hpp.

◆ update_instance()

void staplegl::vertex_buffer_inst::update_instance	(	std::int32_t	index,
		std::span< const float >	instance_data
	)

inlinenoexcept

Update the data of an instance in the buffer.

Note: The entire contents of instance_data will not be written at the index, only the first layout.stride() bytes, preventing buffer overflows. Debug builds will also assert that the size of instance_data is equal to layout.stride().

See also: vertex_buffer_layout.hpp

Parameters

index	the index of the instance to be updated.
instance_data	the new data of the instance.

Definition at line 211 of file vertex_buffer_inst.hpp.

Member Data Documentation

◆ m_capacity

std::size_t staplegl::vertex_buffer_inst::m_capacity {}

private

The capacity of the buffer, in bytes.

Definition at line 63 of file vertex_buffer_inst.hpp.

◆ m_count

std::int32_t staplegl::vertex_buffer_inst::m_count {}

private

The number of instances in the buffer.

Definition at line 69 of file vertex_buffer_inst.hpp.

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

include/modules/vertex_buffer_inst.hpp

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ vertex_buffer_inst() [1/4]

◆ vertex_buffer_inst() [2/4]

◆ ~vertex_buffer_inst()

◆ vertex_buffer_inst() [3/4]

◆ vertex_buffer_inst() [4/4]

Member Function Documentation

◆ add_instance()

◆ calc_capacity()

◆ capacity()

◆ delete_instance()

◆ instance_count()

◆ instance_size()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ resize_buffer()

◆ update_instance()

Member Data Documentation

◆ m_capacity

◆ m_count