BPolygon¶
A BPolygon
object represents a polygon—a closed, many-sided
figure that describes an area within a two-dimensional coordinate system.
It differs from a BRect
object in that it can have any number
of sides and the sides don’t have to be aligned with the coordinate axes.
A BPolygon
is defined as a series of connected points. Each
point is a potential vertex in the polygon. An outline of the polygon could
be constructed by tracing a straight line from the first point to the
second, from the second point to the third, and so on through the whole
series, then by connecting the first and last points if they’re not
identical.
The BView
functions that draw a
polygon—StrokePolygon()
and
FillPolygon()
—take BPolygon
objects as
arguments. StrokePolygon()
offers the option of leaving
the polygon open—of not stroking the line that connects the first and last
points in the list. The polygon therefore won’t look like a polygon, but
like an chain of lines fastened at their endpoints.