2011

Quick Reference
Commands
LOAD
Makes shapes available for use by the SHAPE command.
SHAPE
Inserts a shape from a shape file that has been loaded using LOAD.
Codes 00C and 00D: Bulge-Specified Arcs
Special codes 00C and 00D (12 and 13) provide another mechanism for
including arc segments in shape descriptions.
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. Note, however, that using code 8 for a straight-line
segment saves a byte in the shape description.
Special Codes | 117