The xvgraphics library contains the low level primitives used by the xvisual library for drawing lines, plots, and annotations. It also contains the code which coverts world coordinates to device coordinates. This is a private library; it has no public routines.
$DESIGN/objects/library/xvgraphics/src
$DESIGN/include/xvgraphics/xvgraphics.h
#include <design.h>