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docs.GL

glBufferData

Name

glBufferData, glNamedBufferData — creates and initializes a buffer object's data store

C Specification

void glBufferData( GLenum target,
GLsizeiptr size,
const GLvoid * data,
GLenum usage);
void glNamedBufferData( GLuint buffer,
GLsizeiptr size,
const void *data,
GLenum usage);

Parameters

target

Specifies the target to which the buffer object is bound for glBufferData, which must be one of the buffer binding targets in the following table:

Buffer Binding Target Purpose
GL_ARRAY_BUFFER Vertex attributes
GL_ATOMIC_COUNTER_BUFFER Atomic counter storage
GL_COPY_READ_BUFFER Buffer copy source
GL_COPY_WRITE_BUFFER Buffer copy destination
GL_DISPATCH_INDIRECT_BUFFER Indirect compute dispatch commands
GL_DRAW_INDIRECT_BUFFER Indirect command arguments
GL_ELEMENT_ARRAY_BUFFER Vertex array indices
GL_PIXEL_PACK_BUFFER Pixel read target
GL_PIXEL_UNPACK_BUFFER Texture data source
GL_QUERY_BUFFER Query result buffer
GL_SHADER_STORAGE_BUFFER Read-write storage for shaders
GL_TEXTURE_BUFFER Texture data buffer
GL_TRANSFORM_FEEDBACK_BUFFER Transform feedback buffer
GL_UNIFORM_BUFFER Uniform block storage
buffer

Specifies the name of the buffer object for glNamedBufferData function.

size

Specifies the size in bytes of the buffer object's new data store.

data

Specifies a pointer to data that will be copied into the data store for initialization, or NULL if no data is to be copied.

usage

Specifies the expected usage pattern of the data store. The symbolic constant must be GL_STREAM_DRAW, GL_STREAM_READ, GL_STREAM_COPY, GL_STATIC_DRAW, GL_STATIC_READ, GL_STATIC_COPY, GL_DYNAMIC_DRAW, GL_DYNAMIC_READ, or GL_DYNAMIC_COPY.

Description

glBufferData and glNamedBufferData create a new data store for a buffer object. In case of glBufferData, the buffer object currently bound to target is used. For glNamedBufferData, a buffer object associated with ID specified by the caller in buffer will be used instead.

While creating the new storage, any pre-existing data store is deleted. The new data store is created with the specified size in bytes and usage. If data is not NULL, the data store is initialized with data from this pointer. In its initial state, the new data store is not mapped, it has a NULL mapped pointer, and its mapped access is GL_READ_WRITE.

usage is a hint to the GL implementation as to how a buffer object's data store will be accessed. This enables the GL implementation to make more intelligent decisions that may significantly impact buffer object performance. It does not, however, constrain the actual usage of the data store. usage can be broken down into two parts: first, the frequency of access (modification and usage), and second, the nature of that access. The frequency of access may be one of these:

STREAM

The data store contents will be modified once and used at most a few times.

STATIC

The data store contents will be modified once and used many times.

DYNAMIC

The data store contents will be modified repeatedly and used many times.

The nature of access may be one of these:

DRAW

The data store contents are modified by the application, and used as the source for GL drawing and image specification commands.

READ

The data store contents are modified by reading data from the GL, and used to return that data when queried by the application.

COPY

The data store contents are modified by reading data from the GL, and used as the source for GL drawing and image specification commands.

Notes

If data is NULL, a data store of the specified size is still created, but its contents remain uninitialized and thus undefined.

Clients must align data elements consistently with the requirements of the client platform, with an additional base-level requirement that an offset within a buffer to a datum comprising N bytes be a multiple of N.

The GL_ATOMIC_COUNTER_BUFFER target is available only if the GL version is 4.2 or greater.

The GL_DISPATCH_INDIRECT_BUFFER and GL_SHADER_STORAGE_BUFFER targets are available only if the GL version is 4.3 or greater.

The GL_QUERY_BUFFER target is available only if the GL version is 4.4 or greater.

Errors

GL_INVALID_ENUM is generated by glBufferData if target is not one of the accepted buffer targets.

GL_INVALID_ENUM is generated if usage is not GL_STREAM_DRAW, GL_STREAM_READ, GL_STREAM_COPY, GL_STATIC_DRAW, GL_STATIC_READ, GL_STATIC_COPY, GL_DYNAMIC_DRAW, GL_DYNAMIC_READ, or GL_DYNAMIC_COPY.

GL_INVALID_VALUE is generated if size is negative.

GL_INVALID_OPERATION is generated by glBufferData if the reserved buffer object name 0 is bound to target.

GL_INVALID_OPERATION is generated by glNamedBufferData if buffer is not the name of an existing buffer object.

GL_INVALID_OPERATION is generated if the GL_BUFFER_IMMUTABLE_STORAGE flag of the buffer object is GL_TRUE.

GL_OUT_OF_MEMORY is generated if the GL is unable to create a data store with the specified size.

Associated Gets

glGetBufferSubData

glGetBufferParameter with argument GL_BUFFER_SIZE or GL_BUFFER_USAGE

Examples

Load a vertex buffer into OpenGL for later rendering.
// data_size_in_bytes is the size in bytes of your vertex data.
// data_vertices is your actual vertex data, probably a huge array of floats

GLuint vertex_buffer; // Save this for later rendering
glGenBuffers(1, &vertex_buffer);
glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
glBufferData(GL_ARRAY_BUFFER, data_size_in_bytes, 0, GL_STATIC_DRAW);
glBufferSubData(GL_ARRAY_BUFFER, 0, data_size_in_bytes, data_vertices);

GLint size = 0;
glGetBufferParameteriv(GL_ARRAY_BUFFER, GL_BUFFER_SIZE, &size);
if(data_size_in_bytes != size)
{
    glDeleteBuffers(1, &vertex_buffer);
    // Log the error
    return;
}

// Success
Load an index buffer into OpenGL for later rendering.
// data_size_in_bytes is the size in bytes of your vertex data.
// data_indices is an array of integer offsets into your vertex data.

GLuint index_buffer; // Save this for later rendering
glGenBuffers(1, &index_buffer);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, index_buffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, data_size_in_bytes, 0, GL_STATIC_DRAW);
glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, data_size_in_bytes, data_indices);

GLint size = 0;
glGetBufferParameteriv(GL_ELEMENT_ARRAY_BUFFER, GL_BUFFER_SIZE, &size);
if(data_size_in_bytes != size)
{
    glDeleteBuffers(1, &index_buffer);
    // Log the error
    return;
}

// Success

Version Support

OpenGL Version
Function / Feature Name 2.0 2.1 3.0 3.1 3.2 3.3 4.0 4.1 4.2 4.3 4.4 4.5
glBufferData ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔
glNamedBufferData - - - - - - - - - - - ✔
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