draw-line in dc<%>
Draws a line from one point to another. The line covers both the start
and end points. The current pen is used for drawing the line. For a
pen whose scaled width is larger than 1, the line is drawn
centered over the start and end points.
( -> void
send a-dc draw-line x1 y1 x2 y2)
x1 : real number
y1 : real number
x2 : real number
y2 : real number
Restrictions on the magnitude of
drawing coordinates are described with dc<%>.