ellipses(3U) InterViews Reference Manual ellipses(3U)

Ellipse, S_Ellipse, F_Ellipse, SF_Ellipse, S_Circle, F_Circle, SF_Circle - abstract base class and predefined subclasses for elliptical structured graphics

#include <Unidraw/Graphic/ellipses.h>

Ellipse is an abstract base class for elliptical structured graphics objects. It stores geometric information that such graphics require and provides helper functions for calculating extents and for hit detection. Predefined subclasses include S_Ellipse, F_Ellipse, and SF_Ellipse, which draw stroked, filled, and stroked-filled ellipses, respectively; and S_Circle, F_Circle, and SF_Circle, which draw stroked, filled, and stroked-filled circles, respectively. The stroked subclasses store a PSBrush, the filled subclasses store a PSPattern, and the stroked-filled subclasses store one of each.

Return the ellipse's geometry. (x, y) defines the ellipse's center, while rx and ry define its horizontal and vertical radii, respectively.

The constructor is protected to disallow instantiation of the abstract base class. An ellipse's geometry is defined in terms of its center and its horizontal and vertical radii. The constructor also takes an optional graphic from which to obtain an initial set of graphics state.
)
)
Helper functions that return extent and hit detection information based on the bounding box that the ellipse defines. s_getExtent, s_contains, and s_intersects return information that accounts for the width of a brush, as would be necessary if the ellipse is stroked, while f_getExtent, f_contains, and f_intersects assumes that the ellipse is filled. Subclasses can use the operations to help implement their getExtent, contains, and intersects operations.

Constructors for the various predefined Ellipse subclasses.

Graphic(3U), geomobjs(3U), pspaint(3U)

2 February 1991 Unidraw