Class IndexBuffer

ClassList > IndexBuffer

OpenGL element buffer object wrapper. More...

• #include <IndexBuffer.h>

Inherits the following classes: Buffers

Public Functions

Type	Name
void	Bind () const Binds this IBO to GL_ELEMENT_ARRAY_BUFFER.
GLuint	Count () const Returns the number of indices.
GLuint	GetID () const Returns the OpenGL buffer object ID (inherited from Buffers ).
	IndexBuffer (const GLuint * data, GLuint size) Constructs IBO from an index array.
	IndexBuffer () = default Default constructor (empty buffer, buf_ID = 0).
	IndexBuffer (const IndexBuffer & ibo) Copy constructor. Deep-copies GPU buffer content.
	IndexBuffer (IndexBuffer && ibo) noexcept Move constructor. Transfers ownership; ibo is left empty.
void	Unbind () const Unbinds the current IBO (binds GL_ELEMENT_ARRAY_BUFFER to 0).
IndexBuffer &	operator= (const IndexBuffer & ibo) Copy assignment. Deep-copies GPU buffer content.
IndexBuffer &	operator= (IndexBuffer && ibo) noexcept Move assignment. Transfers ownership; ibo is left empty.
	~IndexBuffer () = default Destructor. Releases OpenGL IBO (via Buffers ).

Public Functions inherited from Buffers

See Buffers

Type	Name
	Buffers () = default
	Buffers (const Buffers & buf) Copy constructor. Performs a GPU-side deep copy of buf .
	Buffers (Buffers && buf) noexcept Move constructor. Transfers ownership from buf .
GLuint	GetID () const Returns the OpenGL buffer object ID.
GLuint	GetSize () const Returns the allocated buffer size in bytes.
Buffers &	operator= (const Buffers & buf) Copy assignment. Performs a GPU-side deep copy of buf .
Buffers &	operator= (Buffers && buf) noexcept Move assignment. Transfers ownership from buf .
	~Buffers () Destructor. Releases the OpenGL buffer object if valid.

Protected Attributes inherited from Buffers

See Buffers

Type	Name
GLuint	buf_ID = 0 OpenGL buffer object ID (0 = invalid/empty)
GLuint	buf_size = 0 Allocated buffer size in bytes.

Protected Functions inherited from Buffers

See Buffers

Type	Name
void	_deepCopyFrom (const Buffers & src) GPU-side deep copy from src .
void	_delBuffer () Deletes the OpenGL buffer object and resets buf_ID to 0.

Detailed Description

IndexBuffer encapsulates a single IBO/EBO bound to GL_ELEMENT_ARRAY_BUFFER for indexed rendering. It inherits RAII resource management from Buffers, including GPU-side deep copy via glCopyBufferSubData.

Usage:

GLuint indices[] = {0, 1, 2, 2, 3, 0};
IndexBuffer ibo(indices, sizeof(indices));
ibo.Bind();
glDrawElements(GL_TRIANGLES, ibo.Count(), GL_UNSIGNED_INT, 0);

// Deep copy (new GPU buffer allocated):
IndexBuffer copy = ibo;

// Transfer ownership (ibo is empty after this):
IndexBuffer moved = std::move(ibo);

Note:

Thread-safety: Not thread-safe. Must be used from the OpenGL context thread.

Note:

Ownership: Inherits Buffers ownership; releases via glDeleteBuffers in destructor.

Note:

size parameter in the main constructor is in bytes, not element count.

Public Functions Documentation

function Bind

Binds this IBO to GL_ELEMENT_ARRAY_BUFFER.

void IndexBuffer::Bind () const

---

function Count

Returns the number of indices.

GLuint IndexBuffer::Count () const

Returns:

Index count (buf_size / sizeof(GLuint)).

Note:

Pass as the count argument to glDrawElements.

---

function GetID

Returns the OpenGL buffer object ID (inherited from Buffers ).

inline GLuint IndexBuffer::GetID () const

Returns:

buf_ID.

---

function IndexBuffer [1/4]

Constructs IBO from an index array.

IndexBuffer::IndexBuffer (
    const GLuint * data,
    GLuint size
) 

Parameters:

• data Pointer to index data (GLuint array)
• size Size in bytes (= element count * sizeof(GLuint))

Note:

Uploads data to GPU using GL_STATIC_DRAW. Sets buf_size accordingly.

---

function IndexBuffer [2/4]

Default constructor (empty buffer, buf_ID = 0).

IndexBuffer::IndexBuffer () = default

---

function IndexBuffer [3/4]

Copy constructor. Deep-copies GPU buffer content.

IndexBuffer::IndexBuffer (
    const IndexBuffer & ibo
) 

Parameters:

• ibo Source index buffer.

---

function IndexBuffer [4/4]

Move constructor. Transfers ownership; ibo is left empty.

IndexBuffer::IndexBuffer (
    IndexBuffer && ibo
) noexcept

Parameters:

• ibo Source index buffer (invalidated after move).

---

function Unbind

Unbinds the current IBO (binds GL_ELEMENT_ARRAY_BUFFER to 0).

void IndexBuffer::Unbind () const

---

function operator=

Copy assignment. Deep-copies GPU buffer content.

IndexBuffer & IndexBuffer::operator= (
    const IndexBuffer & ibo
) 

Parameters:

• ibo Source index buffer.

Returns:

Reference to this.

---

function operator=

Move assignment. Transfers ownership; ibo is left empty.

IndexBuffer & IndexBuffer::operator= (
    IndexBuffer && ibo
) noexcept

Parameters:

• ibo Source index buffer (invalidated after move).

Returns:

Reference to this.

---

function ~IndexBuffer

Destructor. Releases OpenGL IBO (via Buffers ).

IndexBuffer::~IndexBuffer () = default

---

---

The documentation for this class was generated from the following file src/render/buffers/IndexBuffer.h