(bind-func VBO_update_data
"update the full buffer"
(lambda (vbo:VBO*)
(glBindBuffer GL_ARRAY_BUFFER (VBO_id vbo))
(gl_print_error "Error binding VBO")
(glBufferSubData GL_ARRAY_BUFFER 0 (VBO_size vbo) (VBO_data vbo))
(gl_print_error "Error updating VBO subdata")
(glBindBuffer GL_ARRAY_BUFFER 0)))