### 2.5.6.1 Constructor Functions for Ellipses and Elliptical Arcs in CLIM

`make-ellipse [Function]	`

Arguments: center-point radius-1-dx radius-1-dy radius-2-dx radius-2-dy ``` &key``` start-angle end-angle

`make-ellipse* [Function]	`

Arguments: center-x center-y radius-1-dx radius-1-dy radius-2-dx radius-2-dy ``` &key``` start-angle end-angle

Summary: Returns an object of class standard-ellipse . The center of the ellipse is at the point center-point (or the position ( center-x , center-y )).

Two vectors, ( radius-1-dx , radius-1-dy ) and ( radius-2-dx , radius-2-dy ) specify the bounding parallelogram of the ellipse as explained previously. All of the radii are real numbers. If the two vectors are collinear, the ellipse is not well-defined and the ellipse-not-well-defined error will be signaled. The special case of an ellipse with its axes aligned with the coordinate axes can be obtained by setting both radius-1-dy and radius-2-dx to 0.

If start-angle or end-angle are supplied, the ellipse is the "pie slice" area swept out by a line from the center of the ellipse to a point on the boundary as the boundary point moves from the angle start-angle to end-angle . Angles are measured counter-clockwise with respect to the positive x axis. If end-angle is supplied, the default for start-angle is 0; if start-angle is supplied, the default for end-angle is 2π; if neither is supplied, then the region is a full ellipse and the angles are meaningless.

This function captures its mutable inputs; the consequences of modifying those objects are unspecified.

`make-elliptical-arc [Function]	`

Arguments: center-point radius-1-dx radius-1-dy radius-2-dx radius-2-dy ``` &key``` start-angle end-angle

`make-elliptical-arc* [Function]	`

Arguments: center-x center-y radius-1-dx radius-1-dy radius-2-dx radius-2-dy ``` &key``` start-angle end-angle

Summary: Returns an object of class standard-elliptical-arc . The center of the ellipse is at the point center-point (or the position ( center-x , center-y )).

Two vectors, ( radius-1-dx , radius-1-dy ) and ( radius-2-dx , radius-2-dy ), specify the bounding parallelogram of the ellipse as explained previously. All of the radii are real numbers. If the two vectors are collinear, the ellipse is not well-defined and the ellipse-not-well-defined error will be signaled. The special case of an elliptical arc with its axes aligned with the coordinate axes can be obtained by setting both radius-1-dy and radius-2-dx to 0.

If start-angle and start-angle are supplied, the arc is swept from start-angle to end-angle . Angles are measured counter-clockwise with respect to the positive x axis. If end-angle is supplied, the default for start-angle is 0; if start-angle is supplied, the default for end-angle is 2π; if neither is supplied, then the region is a closed elliptical path and the angles are meaningless.

This function captures its mutable inputs; the consequences of modifying those objects are unspecified.

Common Lisp Interface Manager 2.0 User's Guide - 22 Dec 2009