2005
Sams Publishing
glBufferData
3G
glBufferData
create and initialize a buffer object's data store
C Specification
void glBufferData
GLenum target
GLsizeiptr size
const GLvoid * data
GLenum usage
Parameters
target
Specifies the target buffer object.
The symbolic constant must be GL_ARRAY_BUFFER or
GL_ELEMENT_ARRAY_BUFFER.
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_STATIC_DRAW, or
GL_DYNAMIC_DRAW.
Description
glBufferData creates a new data store for the buffer object currently bound to
target. 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.
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 must be:
DRAW
The data store contents are modified by the application, 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 consistent with the requirements of the client
platform, with an additional base-level requirement that an offset within a buffer to
a datum comprising N be a
multiple of N.
Errors
GL_INVALID_ENUM is generated if target is not
GL_ARRAY_BUFFER or GL_ELEMENT_ARRAY_BUFFER.
GL_INVALID_ENUM is generated if usage is not
GL_STREAM_DRAW,
GL_STATIC_DRAW, or
GL_DYNAMIC_DRAW.
GL_INVALID_VALUE is generated if size is negative.
GL_INVALID_OPERATION is generated if the reserved buffer object name 0 is bound to target.
GL_OUT_OF_MEMORY is generated if the GL is unable to create a data store with the specified size.
Associated Gets
glGetBufferParameteriv with argument GL_BUFFER_SIZE or GL_BUFFER_USAGE
See Also
glBindBuffer,
glBufferSubData
Copyright
Copyright 2005 Addison-Wesley.
This material may be distributed subject to the terms and conditions set forth in
the Open Publication License, v 1.0, 8 June 1999.
http://opencontent.org/openpub/.