2010 Khronos Group
glCopyBufferSubData 3G
glCopyBufferSubData copy part of the data store of a buffer object to the data store of another buffer object

## C Specification

void `glCopyBufferSubData` GLenum readtarget GLenum writetarget GLintptr readoffset GLintptr writeoffset GLsizeiptr size

## Parameters

readtarget

  Specifies the target from whose data store data should be read.

writetarget

  Specifies the target to whose data store data should be written.

readoffset

  Specifies the offset, in basic machine units, within the data store of readtarget from which data should be read.

writeoffset

  Specifies the offset, in basic machine units, within the data store of writetarget to which data should be written.

size

  Specifies the size, in basic machine units, of the data to be copied from readtarget to writetarget.

## Description

`glCopyBufferSubData` copies part of the data store attached to readtarget to the data store attached to writetarget. The number of basic machine units indicated by size is copied from the source, at offset readoffset to the destination at writeoffset, also in basic machine units.

readtarget and writetarget must be `GL_ARRAY_BUFFER`, `GL_COPY_READ_BUFFER`, `GL_COPY_WRITE_BUFFER`, `GL_ELEMENT_ARRAY_BUFFER`, `GL_PIXEL_PACK_BUFFER`, `GL_PIXEL_UNPACK_BUFFER`, `GL_TEXTURE_BUFFER`, `GL_TRANSFORM_FEEDBACK_BUFFER` or `GL_UNIFORM_BUFFER`. Any of these targets may be used, although the targets `GL_COPY_READ_BUFFER` and `GL_COPY_WRITE_BUFFER` are provided specifically to allow copies between buffers without disturbing other GL state.

readoffset, writeoffset and size must all be greater than or equal to zero. Furthermore, readoffset + size must not exceeed the size of the buffer object bound to readtarget, and readoffset + size must not exceeed the size of the buffer bound to writetarget. If the same buffer object is bound to both readtarget and writetarget, then the ranges specified by readoffset, writeoffset and size must not overlap.

## Notes

`glCopyBufferSubData` is available only if the GL version is 3.1 or greater.

## Errors

`GL_INVALID_VALUE` is generated if any of readoffset, writeoffset or size is negative, if readoffset + size exceeds the size of the buffer object bound to readtarget or if writeoffset + size exceeds the size of the buffer object bound to writetarget.

`GL_INVALID_VALUE` is generated if the same buffer object is bound to both readtarget and writetarget and the ranges [readoffset, readoffset + size) and [writeoffset, writeoffset + size) overlap.

`GL_INVALID_OPERATION` is generated if zero is bound to readtarget or writetarget.

`GL_INVALID_OPERATION` is generated if the buffer object bound to either readtarget or writetarget is mapped.

## See Also

glGenBuffers, glBindBuffer, glBufferData, glBufferSubData, glGetBufferSubData

## Copyright

Copyright 2010 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/.