VertexArrayObject Class Reference

A thin wrapper around an OpenGL Vertex Array Object (VAO). More...

#include <easy3d/renderer/vertex_array_object.h>

Public Member Functions
GLuint	id () const
void	bind ()
void	release () const
bool	create_array_buffer (GLuint &buffer, GLuint index, const void *data, std::size_t size, std::size_t dim, bool dynamic=false)
	Creates an OpenGL array buffer and upload data to the buffer. More...
bool	create_element_buffer (GLuint &buffer, const void *data, std::size_t size, bool dynamic=false)
bool	create_storage_buffer (GLuint &buffer, GLuint index, const void *data, std::size_t size)
bool	update_storage_buffer (GLuint &buffer, GLintptr offset, GLsizeiptr size, const void *data)

Static Public Member Functions
static bool	is_supported ()
static void	release_buffer (GLuint &buffer)
	Frees the GPU memory of the buffer specified by 'handle'.
static void	get_buffer_data (GLenum target, GLuint buffer, GLintptr offset, GLsizeiptr size, void *data)
static void *	map_buffer (GLenum target, GLuint buffer, GLenum access)
static void	unmap_buffer (GLenum target, GLuint buffer)

Detailed Description

A thin wrapper around an OpenGL Vertex Array Object (VAO).

A VAO is an OpenGL container object that encapsulates the state needed to specify per-vertex attribute data to the OpenGL pipeline. To put it another way, a VAO remembers the states of buffer objects (i.e., vertex buffers) and their associated state (e.g. vertex attribute divisors). This allows a very easy and efficient method of switching between OpenGL buffer states for rendering different "objects" in a scene.

Note

This implementation is more than the standard VAO. It also provides functions for creating and managing other buffer objects (i.e., shader storage buffer).

Member Function Documentation

create_array_buffer()

bool create_array_buffer	(	GLuint &	buffer,
		GLuint	index,
		const void *	data,
		std::size_t	size,
		std::size_t	dim,
		bool	dynamic = false
	)

Creates an OpenGL array buffer and upload data to the buffer.

Parameters

handle	The name of the buffer object.
index	The index of the generic vertex attribute to be enabled.
data	The pointer to the data.
size	The size of the data in bytes.
dim	The number of components per generic vertex attribute. Must be 1, 2, 3, 4.
dynamic	The expected usage pattern is GL_STATIC_DRAW or GL_DYNAMIC_DRAW.

Returns

OpenGL error code.

get_buffer_data()

void get_buffer_data ( GLenum  target, GLuint  buffer, GLintptr  offset, GLsizeiptr  size, void *  data  )

static

Returns a subset of a buffer object's data store.

Parameters

target	can be GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_SHADER_STORAGE_BUFFER, etc.
handle	the name of the buffer object.
offset	the offset into the buffer object's data store from which data will be returned, measured in bytes.
size	the size in bytes of the data store region being returned.
data	a pointer to the location where buffer object data is returned.

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

• /Users/lnan/Documents/Projects/Easy3D/easy3d/renderer/vertex_array_object.h
• /Users/lnan/Documents/Projects/Easy3D/easy3d/renderer/vertex_array_object.cpp