Commodore 128D - Page 256

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xrad X radius (scaled)
yrad Y radius (default is xr) j^J
sa Starting arc angle (default 0 degrees)
ea Ending arc angle (default 360 degrees) *j
angle - Rotation in clockwise degrees (default
is 0 degrees) ~- ■
inc Degrees between segments (default is
2 degrees)
u
With the CIRCLE statement, the user can dravy a circle, ellipse, arc,
triangle, octagon or other polygon. The pixel cursor (PC) is left at the
circumference of the circle at the ending arc angle. Any rotation is
relative to the center. Setting the y radius equal to the x radius does
not draw a perfect circle, since the x and y coordinates are scaled
differently (x = 0 -320 and y = 0 -200). Arcs are drawn from the
starting angle clockwise to the ending angle. The increment controls
the smoothness of the shape; using lower values results in more
nearly circular shapes. Specifying the inc greater than 2 creates a
rough-edged, boxed-in shape.
The x and y values can place the pixel cursor at absolute coordi-
nates such as (100,100) or at coordinates relative to the previous
position (+ / - x and + / - y) of the pixel cursor such as (+ 20, - 10).
The coordinate of one axis (x or y) can be relative and the other can
be absolute. Here are the possible combinations of ways to specify
the x and y coordinates:
x,y .absolute x, absolute y
± x,y relative x, absolute y
x, ± y absolute x, relative y
± x, ± y relative x, relative y
Also see the LOCATE command for information on the pixel cursor.
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ea v_j
248 BASIC 7.0 ENCYCLOPEDIA—Basic Commands and Statements