The basic elements constituting a graphic are called output primitives. GRPH1 has the following output primitives.
Five of these six primitives (excluding the tone primitive) all consist of line segments.
Line segments have two attributes: the line index and line type.
A tone has the attribute of tone pattern index.
These attributes are defined as follows.
Coordinates handled by GRPH1 include curvilinear coordinates, so it is not appropriate in some cases to connect coordinates specifying line segments and boundaries of tone patterns with straight lines. Therefore, a function is available that interpolates between the coordinates by dividing the space between the coordinates into several sections. Furthermore, all primitives are subject to clipping at a certain boundary.