.TH ellipses 3U "2 February 1991" "Unidraw" "InterViews Reference Manual"
.SH NAME
Ellipse, S_Ellipse, F_Ellipse, SF_Ellipse, S_Circle, F_Circle,
SF_Circle \- abstract base class and predefined subclasses for
elliptical structured graphics
.SH SYNOPSIS
.B #include <Unidraw/Graphic/ellipses.h>
.SH DESCRIPTION
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.
.SH ELLIPSE PUBLIC OPERATIONS
.TP
.B "void GetOriginal(Coord& x, Coord& y, int& rx, int& ry)"
Return the ellipse's geometry.  (\fIx, y\fP) defines the ellipse's
center, while \fIrx\fP and \fIry\fP define its horizontal and vertical
radii, respectively.
.SH ELLIPSE PROTECTED OPERATIONS
.TP
.B "Ellipse(Coord x, Coord y, int rx, int ry, Graphic* = nil)"
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.
.TP
.B "void s_getExtent("
.ns
.TP
.B "    float&, float&, float&, float&, float&, Graphic*"
.ns
.TP
.B ")"
.ns
.TP
.B "void f_getExtent("
.ns
.TP
.B "    float&, float&, float&, float&, float&, Graphic*"
.ns
.TP
.B ")"
.ns
.TP
.B "boolean s_contains(PointObj&, Graphic*)"
.ns
.TP
.B "boolean f_contains(PointObj&, Graphic*)"
.ns
.TP
.B "boolean s_intersects(BoxObj&, Graphic*)"
.ns
.TP
.B "boolean f_intersects(BoxObj&, Graphic*)"
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.
.SH SUBCLASS PUBLIC OPERATIONS
.TP
.B "S_Ellipse(Coord x, Coord y, int rx, int ry, Graphic* = nil)"
.ns
.TP
.B "F_Ellipse(Coord x, Coord y, int rx, int ry, Graphic* = nil)"
.ns
.TP
.B "SF_Ellipse(Coord x, Coord y, int rx, int ry, Graphic* = nil)"
.ns
.TP
.B "S_Circle(Coord x, Coord y, int radius, Graphic* = nil)"
.ns
.TP
.B "F_Circle(Coord x, Coord y, int radius, Graphic* = nil)"
.ns
.TP
.B "SF_Circle(Coord x, Coord y, int radius, Graphic* = nil)"
Constructors for the various predefined Ellipse subclasses.
.SH SEE ALSO
Graphic(3U), geomobjs(3U), pspaint(3U)