Version 2.0 15 Jan-90
CALL AR the ARC commands
There are 5 commands that draw arcs. The arcs are drawn with the pen in the current port.
Left edge of the enclosing rectangle for the arc in LOCAL coordinates.
Top edge of the enclosing rectangle for the arc in LOCAL coordinates.
Width of the enclosing rectangle for the arc in pixels.
Height of the enclosing rectangle for the arc in pixels.
Starting angle in degrees
Ending angle in degrees
Pattern used to fill arc (0-15)
Figure 2.1 Arc construction
Arcs are constructed inside of an imaginary rectangle (enclosing rectangle) specified by X,Y,W and H. The starting angle (SA) and the ending angle (AA) are specified in degrees (0 to 360). 0 degrees is at the 12 o-clock position and the angle mcreases clockwise around the center of the enclosing rectangle, refer to Figure 3.1. Arcs made in 320 mode will follow a circular path if the width and height are the same, however arcs created in 640 mode will have to have the width twice the height for the same effect.
Paint, Erase, Invert, and Fill will create filled arcs as shown by the (pie wedged) example in Figure 3.1. Frame will produce just the curved portion of the arc.
Specifying 0 for the starting angle and 360 for the ending angle will produce an Oval or Circle depending on the shape of the enclosing rectangle.