GLBUFFERSTORAGE
Section: [FIXME: manual] (3G)
Updated: 01/26/2021
Page Index
NAME
glBufferStorage, glNamedBufferStorage - creates and initializes a buffer object's immutable data store
C SPECIFICATION
-
void glBufferStorage(GLenum target, GLsizeiptr size, const GLvoid * data, GLbitfield flags);
-
void glNamedBufferStorage(GLuint buffer, GLsizeiptr size, const void *data, GLbitfield flags);
PARAMETERS
target
-
- Specifies the target to which the buffer object is bound for
glBufferStorage, 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
glNamedBufferStorage
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.
flags
-
Specifies the intended usage of the buffer's data store. Must be a bitwise combination of the following flags.
GL_DYNAMIC_STORAGE_BIT,
GL_MAP_READ_BIT
GL_MAP_WRITE_BIT,
GL_MAP_PERSISTENT_BIT,
GL_MAP_COHERENT_BIT, and
GL_CLIENT_STORAGE_BIT.
DESCRIPTION
glBufferStorage
and
glNamedBufferStorage
create a new immutable data store. For
glBufferStorage, the buffer object currently bound to
target
will be initialized. For
glNamedBufferStorage,
buffer
is the name of the buffer object that will be configured. The size of the data store is specified by
size. If an initial data is available, its address may be supplied in
data. Otherwise, to create an uninitialized data store,
data
should be
NULL.
The
flags
parameters specifies the intended usage of the buffer's data store. It must be a bitwise combination of a subset of the following flags:
GL_DYNAMIC_STORAGE_BIT
-
The contents of the data store may be updated after creation through calls to
glBufferSubData(). If this bit is not set, the buffer content may not be directly updated by the client. The data argument may be used to specify the initial content of the buffer's data store regardless of the presence of the
GL_DYNAMIC_STORAGE_BIT. Regardless of the presence of this bit, buffers may always be updated with server-side calls such as
glCopyBufferSubData()
and
glClearBufferSubData().
GL_MAP_READ_BIT
-
The data store may be mapped by the client for read access and a pointer in the client's address space obtained that may be read from.
GL_MAP_WRITE_BIT
-
The data store may be mapped by the client for write access and a pointer in the client's address space obtained that may be written through.
GL_MAP_PERSISTENT_BIT
-
The client may request that the server read from or write to the buffer while it is mapped. The client's pointer to the data store remains valid so long as the data store is mapped, even during execution of drawing or dispatch commands.
GL_MAP_COHERENT_BIT
-
Shared access to buffers that are simultaneously mapped for client access and are used by the server will be coherent, so long as that mapping is performed using
glMapBufferRange(). That is, data written to the store by either the client or server will be immediately visible to the other with no further action taken by the application. In particular,
-
•
If
GL_MAP_COHERENT_BIT
is not set and the client performs a write followed by a call to the
glMemoryBarrier()
command with the
GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT
set, then in subsequent commands the server will see the writes.
-
•
If
GL_MAP_COHERENT_BIT
is set and the client performs a write, then in subsequent commands the server will see the writes.
-
•
If
GL_MAP_COHERENT_BIT
is not set and the server performs a write, the application must call
glMemoryBarrier()
with the
GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT
set and then call
glFenceSync()
with
GL_SYNC_GPU_COMMANDS_COMPLETE
(or
glFinish). Then the CPU will see the writes after the sync is complete.
-
•
If
GL_MAP_COHERENT_BIT
is set and the server does a write, the app must call
glFenceSync
with
GL_SYNC_GPU_COMMANDS_COMPLETE
(or
glFinish()). Then the CPU will see the writes after the sync is complete.
GL_CLIENT_STORAGE_BIT
-
When all other criteria for the buffer storage allocation are met, this bit may be used by an implementation to determine whether to use storage that is local to the server or to the client to serve as the backing store for the buffer.
The allowed combinations of flags are subject to certain restrictions. They are as follows:
-
•
If
flags
contains
GL_MAP_PERSISTENT_BIT, it must also contain at least one of
GL_MAP_READ_BIT
or
GL_MAP_WRITE_BIT.
-
•
If
flags
contains
GL_MAP_COHERENT_BIT, it must also contain
GL_MAP_PERSISTENT_BIT.
NOTES
glBufferStorage
is available only if the GL version is 4.4 or greater.
glNamedBufferStorage
is available only if the GL version is 4.5 or greater.
If
data
is
NULL, a data store of the specified size is still created, but its contents remain uninitialized and thus undefined.
ERRORS
GL_INVALID_ENUM
is generated by
glBufferStorage
if
target
is not one of the accepted buffer targets.
GL_INVALID_OPERATION
is generated by
glNamedBufferStorage
if buffer is not the name of an existing buffer object.
GL_INVALID_VALUE
is generated if
size
is less than or equal to zero.
GL_INVALID_OPERATION
is generated by
glBufferStorage
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 properties requested in
flags.
GL_INVALID_VALUE
is generated if
flags
has any bits set other than those defined above.
GL_INVALID_VALUE
error is generated if
flags
contains
GL_MAP_PERSISTENT_BIT
but does not contain at least one of
GL_MAP_READ_BIT
or
GL_MAP_WRITE_BIT.
GL_INVALID_VALUE
is generated if
flags
contains
GL_MAP_COHERENT_BIT, but does not also contain
GL_MAP_PERSISTENT_BIT.
GL_INVALID_OPERATION
is generated by
glBufferStorage
if the
GL_BUFFER_IMMUTABLE_STORAGE
flag of the buffer bound to
target
is
GL_TRUE.
ASSOCIATED GETS
glGetBufferSubData()
glGetBufferParameter()
with argument
GL_BUFFER_SIZE
or
GL_BUFFER_USAGE
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
|
|
glBufferStorage
|
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|
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|
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✔
|
✔
|
|
glNamedBufferStorage
|
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|
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✔
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SEE ALSO
glBindBuffer(),
glBufferSubData(),
glMapBuffer(),
glUnmapBuffer()
COPYRIGHT
Copyright
©
2014 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999.
m[blue]http://opencontent.org/openpub/m[].
COPYRIGHT
Copyright © 2014 Khronos Group