Full Arc - IBM 6400 Programmer's Reference Manual

Description: This order specifies a curved line that the printer draws tangential
to a specified set of connected, imaginary, straight lines. The printer uses the
current graphics position for the first point and the parameter (or parameters)
specifies additional points to use.
The printer joins the points specified by imaginary straight lines. The printer
then fits a curve to the lines, as follows:
The curve is tangent to the first line at the start point and to the last line at
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its end point.
If there are intermediate lines, the curve is tangent to these lines at their
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center points.
L1 specifies the length of the parameter (or parameters) in this order. The value
of L1 must be a multiple of four. A value of zero for L1 is invalid.
The first end point for the imaginary line specifying the fillet is the graphics
current position. Parameters P1 to Pn form two byte values that specify
additional X and Y coordinates. These coordinates are additional, sequential
end points of the imaginary lines specifying the fillet.
The printer uses the current values of color, mix, line type, and line width when
drawing the fillet.
This order updates the current graphics position to the coordinates of the last
point.

Full Arc

C7 L1 P1-P6
Description: This order specifies a full arc (circle or ellipse) with the center at
the specified point. A previous Set Arc Parameters order determines the shape
and orientation of the arc. If no previous Set Arc Parameters order was
processed, the printer draws the arc using the graphics default arc parameters.
Parameters P1 and P2 form a two byte value that specifies the X coordinate for
the center of the arc. Parameters P3 and P4 form a two byte value that specifies
the Y coordinate for the center of the arc. Parameters P5 and P6 form a two
byte, unsigned, floating point value that specifies the scale. P5 specifies the
integer portion of the scale; P6 specifies the fractional portion of the scale.
There is an implied decimal point between P5 and P6. Byte P6 represents the
fraction given by the value of P6 divided by 256 (see "Full Arc at Current
Position" on page 104).
The scale value acts as a multiplier for the arc parameters, as follows:
For a circle: The radius is P5P6 x r. A previous Set Arc Parameters order
specifies the value of r. For an ellipse: The major axis is P5P6 x a and the
minor axis is P5P6 x b.
A previous Set Arc Parameters order specifies the values for a and b. The
printer uses the current values of color, mix, line type, and line width when
drawing the arc.
This order does not update the current graphics position.
Graphics Command Set
Chapter 3. IPDS Commands Reference
103