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Vertices(3U) InterViews Reference Manual Vertices(3U)


Vertices - abstract base class for graphics defined by a set of coordinate pairs


#include <Unidraw/Graphic/verts.h>


Vertices is an abstract base class for graphics such as polygons and splines whose geometry is specified by a set of coordinate pairs. The Vertices class supports vertex-related operations common to all such graphical objects and also supports extent caching.


The destructor deallocates the list of coordinate pairs stored in the graphic.
Return pointers to the arrays of Coords stored internally that define the graphic's vertices. GetOriginal's return value reflects the size of the arrays.
Compare this to the given Vertices instance and return whether they (do not) store identical sets of vertices.


The constructors are protected to disallow instantiation of the abstract class. Subclasses can pass a set of vertices to copy into internal storage and an optional graphic from which to obtain an initial set of graphics state. Vertices itself stores no additional graphics state over that in the Graphic base class.

Helper functions that return extent information based on the bounding box that the vertices define. s_getExtent returns an extent that accounts for the width of a brush, as would be necessary if the vertices defined a stroked path, while f_getExtent assumes that the vertices define the graphic's extremities, as would be the case if the vertices defined a filled path. These operations cache the extent they compute initially.



2 February 1991 Unidraw