2010 Khronos Group glCopyBufferSubData 3G glCopyBufferSubData copy part of the data store of a buffer object to the data store of another buffer object void glCopyBufferSubData GLenum readtarget GLenum writetarget GLintptr readoffset GLintptr writeoffset GLsizeiptr size 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. 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_DRAW_INDIRECT_BUFFER, GL_DISPATCH_INDIRECT_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, GL_PIXEL_UNPACK_BUFFER, GL_QUERY_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. 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. 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. glGenBuffers, glBindBuffer, glBufferData, glBufferSubData, glGetBufferSubData Copyright 2010-2013 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/.