returns a subset of a buffer object's data store
glGetBufferSubData( GLenum ( target ) , GLintptr ( offset ) , GLsizeiptr ( size ) , GLvoid * ( data ) )-> void
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 .
The GL_ATOMIC_COUNTER_BUFER target is available only if the GL version is 4.2 or greater.
The GL_DISPATCH_INDIRECT_BUFFER target is available only if the GL version is 4.3 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.
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/ .