CLIM 2 User Guide

This function is equivalent to calling draw-rectangle repeatedly, but it can be more convenient
and more efficient when drawing more than one rectangle. See the function drawrectangle.
draw-rectangles*
[Function]
Arguments: medium coord-seq &key (filled t) line-style line-thickness
line-unit line-dashes line-joint-shape ink clipping-region
transformation
■ Draws a set of axis-aligned rectangles on medium. coord-seq is a sequence of 4-tuples x1,
y1, x2, and y2, with (x1,y1) at the upper left and (x2,y2) at the lower right in the standard +Y-downward
coordinate system.
This function is equivalent to calling draw-rectangle* repeatedly, but it can be more convenient
and more efficient when drawing more than one rectangle. See the function drawrectangle*.
Both draw-rectangles* and draw-rectangles call medium-draw-rectangles* to do
the actual drawing.
draw-ellipse
[Function]
Arguments: medium point-1 radius-1-dx radius-1-dy radius-2-dx
radius-2-dy &key start-angle end-angle (filled t)
line-style line-thickness line-unit line-dashes
line-cap-shape ink clipping-region transformation
IMPLEMENTATION LIMITATION: Because of limitations in X, only ellipses with axes
aligned with the X and Y axes will be drawn. If you specify an ellipse with other axes, X (and thus
CLIM) will draw an ellipse with aligned axes anyway.
■ Draws an ellipse or elliptical arc on medium. The center of the ellipse is specified by point.
This function is the same as draw-ellipse*, except that the center position is expressed as
a point instead of x and y. See the function draw-ellipse*.
■ Two vectors, radius-1-dx, radius-1-dy, and radius-2-dx, radius-2-dy specify
the bounding parallelogram of the ellipse. Those two vectors must not be collinear in order for the
ellipse to be well defined. The special case of an ellipse with its major axes aligned with the coordinate
axes can be obtained by setting both radius-1-dy and radius-2-dx to 0. For more information
about the bounding parallelogram of an ellipse, see the section 3.6.8 Ellipses and elliptical
arcs in CLIM.
start-angle and end-angle enable you to draw an arc rather than a complete ellipse.
Angles are measured with respect to the positive x axis. The elliptical arc runs positively from
start-angle to end-angle. The angles are measured from the positive x axis toward the positive
y axis. In a right-handed coordinate system this direction is counter-clockwise.
The defaults for start-angle and end-angle are nil (that is, there is no default). If you
supply start-angle, then end-angle defaults to 2π. If you supply end-angle, then
start-angle defaults to 0.
filled specifies whether the ellipse should be filled, a boolean value.
In the case of a filled arc, the figure drawn 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 start-angle to endangle.
When drawing unfilled ellipses, the current line style affects the drawing as usual, except that the
joint shape has no effect. The dashing of an elliptical arc starts at start-angle.
34 CLIM 2.2 User Guide