glGetBufferSubData — returns a subset of a buffer object's data store
void glGetBufferSubData( | GLenum | target, |
GLintptr | offset, | |
GLsizeiptr | size, | |
GLvoid * | data) ; |
target
Specifies the target buffer object.
The symbolic constant must be GL_ARRAY_BUFFER
,
GL_ELEMENT_ARRAY_BUFFER
,
GL_PIXEL_PACK_BUFFER
, or
GL_PIXEL_UNPACK_BUFFER
.
offset
Specifies the offset into the buffer object's data store from which data will be returned, measured in bytes.
size
Specifies the size in bytes of the data store region being returned.
data
Specifies a pointer to the location where buffer object data is returned.
glGetBufferSubData
returns some or all of the data from the buffer object currently
bound to target
. Data starting at byte offset offset
and
extending for size
bytes is copied from the data store to the memory pointed to by
data
. An error is thrown if the buffer object is currently mapped, or if
offset
and size
together define a range beyond the bounds
of the buffer object's data store.
If an error is generated,
no change is made to the contents of data
.
glGetBufferSubData
is available only if the GL version is 1.5 or greater.
Targets GL_PIXEL_PACK_BUFFER
and GL_PIXEL_UNPACK_BUFFER
are available
only if the GL version is 2.1 or greater.
GL_INVALID_ENUM
is generated if target
is not
GL_ARRAY_BUFFER
, GL_ELEMENT_ARRAY_BUFFER
,
GL_PIXEL_PACK_BUFFER
, or GL_PIXEL_UNPACK_BUFFER
.
GL_INVALID_VALUE
is generated if offset
or
size
is negative, or if together they define a region of memory
that extends beyond the buffer object's allocated data store.
GL_INVALID_OPERATION
is generated if the reserved buffer object name 0 is bound to target
.
GL_INVALID_OPERATION
is generated if the buffer object being queried is mapped.
GL_INVALID_OPERATION
is generated if glGetBufferSubData
is executed between the execution of
glBegin and the corresponding execution of
glEnd.
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/.