000

End of shape definition

Draw is activated at the start of each shape. When Draw mode is turned on (code 1),
the vectors cause lines to be drawn. When Draw mode is turned off (code 2), the vectors
move to a new location without drawing.

002

Deactivate Draw mode (pen up)

004

Multiply vector lengths by next byte

006

Pop current location from stack

008

X-Y displacement given by next two bytes

Normal vector specification bytes draw only in the 16 predefined directions, and the
longest length is 15. These restrictions help make shape definitions efficient but
are sometimes limiting. Code 8 specifies the X-Y displacement given by the next two bytes. Code 8 must be followed by two specification
bytes in the format:

8,X-displacement,Y-displacement

The X-Y displacements can range from -128 to +127. A leading + is optional, and you can use
parentheses to improve readability. The following example results in a vector that
draws (or moves) 10 units to the left and three units up.

8,(-10,3)

Following the two displacement specification bytes, the shape returns to Normal Vector
mode.

You can use code 9 to draw a sequence of nonstandard vectors. Code 9 specifies any
number of X-Y displacement pairs. The code sequence is terminated by a (0,0) pair. The following
example draws three nonstandard vectors and returns to Normal Vector mode.

9,(3,1),(3,2),(2,-3),(0,0)

You must terminate the sequence of X-Y displacement pairs with a (0,0) pair in order for the program to recognize any Normal
Vectors or special codes that follow.

00A

Octant arc defined by next two bytes

This is called an octant arc because it spans one or more 45-degree octants, starting and ending on an octant boundary. Octants are numbered counterclockwise
from the 3 o’clock position, as shown in the following illustration.

The arc specification is

10,radius,(-)0SC

The radius can be any value from 1 through 255. The second specification byte indicates
the direction of the arc (counterclockwise if positive, and clockwise if negative),
its starting octant ( s , a value from 0 through 7), and the number of octants it spans ( c , a value from 0 through 7, in which 0 equals eight octants, or a full circle). You
can use parentheses to improve readability. For example, consider the following fragment
of a shape definition:

...012,10,(1,-032),01E,...

This code draws a one-unit vector up and to the right, a clockwise arc from octant
3 (with a radius of one unit for two octants), and then a one-unit vector down and
to the right, as shown in the following illustration.

00C

Arc defined by X-Y displacement and bulge

They are similar to codes 8 and 9 in that you can use them to specify X-Y displacements. However, codes 00C and 00D draw arcs by applying a bulge factor to the displacement vector. Code 00C draws one arc segment, while code 00D draws
multiple arc segments (polyarcs) until it is terminated by a (0,0) displacement.

Code 00C must be followed by three bytes describing the arc:

0C,X-displacement,Y-displacement,Bulge

Both the X and Y displacement and the bulge, which specifies the curvature of the arc, can range from
-127 to +127. If the line segment specified by the displacement has length D, and the perpendicular distance from the midpoint of that segment has height H, the magnitude of the bulge is ((2* H / D) * 127). The sign is negative if the arc from the current location to the new location
is clockwise.

A semicircle has bulge 127 (or -127) and is the greatest arc that can be represented
as a single-arc segment using these codes (use two consecutive arc segments for larger
arcs). A bulge specification of 0 is valid and represents a straight-line segment.
However, using code 8 for a straight-line segment saves a byte in the shape description.

The polyarc code (00D, or 13) is followed by 0 or by more arc segment triples, and
is terminated by a (0,0) displacement. Note that no bulge is specified after the final
displacement. For example, the letter S might be defined by the following sequence:

13,(0,5,127),(0,5,-127),(0,0)

Zero bulge segments are useful within polyarcs to represent straight segments; they
are more efficient than terminating the polyarc, inserting one straight segment, and
then starting another polyarc.

The number -128 cannot be used in arc segment and polyarc definitions.

00E

Process next command only if vertical text

When this special code is encountered in a character definition, the next code is
either processed or skipped, depending on orientation. If the orientation is vertical,
the next code is processed; if it is horizontal, the next code is skipped.

In horizontal text, the start point for each character is the left end of the baseline.
In vertical text, the start point is assumed to be the top center of the character.
At the end of each character, a pen-up segment is normally drawn to position to the
next character’s start point. For horizontal text, it is to the right; for vertical
text, it is downward. The special 00E (14) code is used primarily to adjust for differences
in start points and endpoints, permitting the same character shape definition to be
used both horizontally and vertically. For instance, the following definition of an
uppercase D could be used in either horizontal or vertical text.

*68,22,ucd 
2,14,8,(-2, 6),1,030,012,044,016,038,2,010,1,06C,2,050,
14,8,(-4,-3),0