HP PCL/PJL reference (PCL 5 Printer Language) - Technical Reference Manual Part II

20-16 The Vector Group EN
AT, Absolute Arc Three Point
This command draws an arc segment, using absolute coordinates,
from a starting point, through an intermediate point, to an end point.
Use AT when you know these three points of an arc.
AT Xinter,Yinter, Xend,Yend[,chord angle;]
The AT command uses the current pen location and two specified
points to calculate a circle and draw the appropriate arc segment of
its circumference. The arc starts at the current pen location, using the
current pen, line type, line attributes and pen up/down status. You
specify the intermediate and end points. After drawing the arc, the
pen location remains at the end of the arc.
z X
Inter
,Y
Inter
— Specify the absolute location of an intermediate
point of the arc. The arc is drawn in a positive or negative angle
of rotation, as necessary, so that it passes through the inter-
mediate point before the end point.
z X
End
,Y
End
— Specify the absolute location of the end point of
the arc.
z Chord Angle — Specifies the chord angle used to draw the
arc. The default is a chord angle of 5°. (The Arc Absolute (AA)
command description [earlier in this chapter] contains more
information on chords and chord angles.)
Intermediate and end point coordinates are interpreted in current
units: as user-units when scaling is on; as plotter units when scaling
is off. If current scaling is not isotropic, the arc drawn is elliptical rather
than circular. Note the following about locating the intermediate and
end points:
z If the intermediate point and end point are the same as the
current pen location, the command draws a dot.
z If the intermediate point is the same as either the current pen
location or the end point, a line is drawn between the current
pen location and the end point.
Parameter Format Functional Range Default
X
inter
, Y
inter
current units -2
30
to 2
30
- 1 no default
X
end
, Y
end
current units -2
30
to 2
30
- 1 no default
chord angle clamped real 0.5° to 180° 5°