zmol::buffer_object Class Reference

#include <buffer_object.hpp>

Inherits zmol::noncopyable_::noncopyable.

List of all members.

Public Member Functions
	buffer_object (GLenum const p_target, GLenum const p_usage)
	~buffer_object ()
GLuint	get_name () const
GLenum	get_target () const
GLenum	get_usage () const
void	bind ()
void	unbind ()
void	upload_data (void const *p_data, unsigned long const p_num_bytes)
void	resize (unsigned long const p_num_bytes)
unsigned long	get_size () const

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Detailed Description

Buffer object wrapper class.

The class creates a buffer object in the constructor, and destroys it in the destructor. This makes proper use of the C++ RAII idiom, and ensures exception safety (-> no resource leak).

The OpenGL terminology is somewhat counter-intuitive. Informally, these entities are known as "vertex buffer objects", but are used for vertices and indices. The OpenGL target for the former is GL_ARRAY_BUFFER, the latter is GL_ELEMENT_ARRAY_BUFFER. For sake of clarity, buffers for vertices are simply called "vertex buffer objects", and buffers for indices "index buffer objects".

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Constructor & Destructor Documentation

zmol::buffer_object::buffer_object ( GLenum const  p_target, GLenum const  p_usage  )

explicit

Constructor. Creates the buffer object with glGenBuffers().

Parameters:

p_target	See the OpenGL glBindBuffer() documentation for an explanation of this value
p_usage	See the OpenGL glBindBuffer() documentation for an explanation of this value

zmol::buffer_object::~buffer_object

(

)

Destructor. Destroys the buffer object with glDeleteBuffers().

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Member Function Documentation

void zmol::buffer_object::bind

(

)

Binds the buffer object to the OpenGL context.

GLuint zmol::buffer_object::get_name ( ) const

inline

Returns the OpenGL name of the buffer object.

unsigned long zmol::buffer_object::get_size ( ) const

inline

Returns the size of the buffer object, in bytes

GLenum zmol::buffer_object::get_target ( ) const

inline

Returns the target of the buffer object.

GLenum zmol::buffer_object::get_usage ( ) const

inline

Returns the usage of the buffer object.

void zmol::buffer_object::resize

(

unsigned long const

p_num_bytes

)

Creates or resizes the buffer object with the given number of bytes. Existing contents will be erased by this call. This is mainly useful if the buffer_object_mapping class is used.

Parameters:

p_num_bytes

New size for the buffer object, in bytes

void zmol::buffer_object::unbind

(

)

Unbinds the buffer object to the OpenGL context.

void zmol::buffer_object::upload_data	(	void const *	p_data,
		unsigned long const	p_num_bytes
	)

Uploads a block of data into the buffer object. Previous contents will be erased by this call.

Parameters:

p_data	Pointer to the data block to be uploaded
p_num_bytes	Size of the data block to be uploaded, in bytes