(gdb) f 2
#2  0x085042fa in CVertexBuffer::UpdateChunkVertices (this=0xd545480, 
    chunk=0x15ea7748, data=0x1673df30)
    at ../../../source/renderer/VertexBuffer.cpp:156
156                     pglBufferSubDataARB(m_Target, chunk->m_Index * m_VertexSize, chunk->m_Count * m_VertexSize, data);
(gdb) print *this
$1 = {m_VertexSize = 32, m_MaxVertices = 16384, 
  m_FreeList = {<std::_List_base<CVertexBuffer::VBChunk*, std::allocator<CVertexBuffer::VBChunk*> >> = {
      _M_impl = {<std::allocator<std::_List_node<CVertexBuffer::VBChunk*> >> = {<__gnu_cxx::new_allocator<std::_List_node<CVertexBuffer::VBChunk*> >> = {<No data fields>}, <No data fields>}, _M_node = {_M_next = 0x15b97840, 
          _M_prev = 0x15b97840}}}, <No data fields>}, m_FreeVertices = 16301, 
  m_Handle = 51, m_SysMem = 0x0, m_Usage = 35048, m_Target = 34962}
(gdb) print *chunk
$2 = {m_Owner = 0xd545480, m_Index = 0, m_Count = 83}
(gdb)