Common Lisp Interface Manager 2.0 User's Guide > Chapter 2 Drawing Graphics > 2.5 General Geometric Objects in CLIM > 2.5.6 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