glGetBufferSubData

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Returns a subset of a buffer object's data store.

C Specification[edit]

void glGetBufferSubData( GLenum target, GLintptr offset, GLsizeiptr size, void * data );
void glGetNamedBufferSubData( GLuint buffer, GLintptr offset, GLsizeiptr size, void * data );


Parameters[edit]

target - Specifies the target to which the buffer object is bound for glGetBufferSubData , which must be one of the buffer binding targets in the following table:
buffer - Specifies the name of the buffer object for glGetNamedBufferSubData .
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.


Description[edit]

 glGetBufferSubData and glGetNamedBufferSubData return some or all of the data contents of the data store of the specified buffer object. Data starting at byte offset offset and extending for size bytes is copied from the buffer object's 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.


Notes[edit]

If an error is generated, no change is made to the contents of data .

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[edit]

 GL_INVALID_ENUM is generated by glGetBufferSubData if target is not one of the generic buffer binding targets.

 GL_INVALID_OPERATION is generated by glGetBufferSubData if zero is bound to target .

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

 GL_INVALID_VALUE is generated if offset or size is negative, or if $offset + size$ is greater than the value of GL_BUFFER_SIZE for the buffer object.

 GL_INVALID_OPERATION is generated if the buffer object is mapped with glMapBufferRange or glMapBuffer , unless it was mapped with the GL_MAP_PERSISTENT_BIT bit set in the glMapBufferRange  access flags.


Version Support[edit]

 glGetBufferSubData  2.0+
 glGetNamedBufferSubData  4.5+

See Also[edit]

 glBindBuffer , glBufferData , glBufferSubData , glMapBuffer , glUnmapBuffer 


Copyright[edit]

Copyright© 2005 Addison-Wesley. Copyright© 2011-2014 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. http://opencontent.org/openpub/.