| Allegro CL version 10.1Unrevised from 10.0 to 10.1. 10.0 version |

**Arguments: ***
stream center semi-major-axis
semi-minor-axis
semi-major-axis-angle start-angle
length-angle
*

Draws an ellipse sector on *stream*. An
ellipse-sector is an ellipse-arc with the endpoints of the arc
connected to the center of the ellipse, like a piece of an elliptical
pie.

The ellipse is defined by the *center* (a position)
and the two half-axes, lengths from the center to the farthest point
on the edge and to the nearest point on the edge, called the
semi-major-axis and the semi-minor-axis. (Technically, the major axis
should be longer than the minor axis but the two arguments need not
have that relationship.) Because the Windows ellipse drawer can only
draw ellipses that are vertically or horizontally oriented, the
*semi-major-axis-angle* argument must be a multiple
of 90. Other values will signal an error. The argument specifies the
angle between the semi-major-axis and a line parallel to the x-axis
passing through the *center*.

Angles are measured in degrees clockwise from the 3 o'clock
position. The endpoint coordinates may be determined by calling
**ellipse-start-and-end**.

So, the ellipse created when specifying semi-major-axis 200, semi-minor-axis 10, and semi-major-axis-angle 90 is a long, thin ellipse, 400 pixels wide, with the long axis vertical, centered at center. Now, with a start-angle of 0 and a length-angle of 90, all of the ellipse in the lower right quadrant is drawn, along with the lines from the ends of the arc to the center and no part is drawn in any other quadrant.

*center* should be a position (see **make-position**).
*stream* should be a `cg-stream`

.

See also cg-drawing.htm.

Copyright (c) 1998-2017, Franz Inc. Oakland, CA., USA. All rights reserved.

This page was not revised from the 10.0 page.

Created 2017.2.15.

| Allegro CL version 10.1Unrevised from 10.0 to 10.1. 10.0 version |