bionic (3) Grid.3U.gz

NAME

       Grid - displays a grid in a viewer and constrains points to lie on it

SYNOPSIS

       #include <Unidraw/grid.h>

DESCRIPTION

       The  Grid  object  performs two functions: it displays a grid in a viewer, and it can constrain points to
       lie on the grid.  The base class draws  the  grid  as  a  simple  array  of  dots;  subclasses  can  draw
       arbitrarily complex grids.

PUBLIC OPERATIONS

       Grid(float w, float h, float xincr, float yincr)
              The  constructor  parameters  correspond to a width, a height, and independent units of graduation
              for the horizontal and vertical axes, all in pixels.  The  Grid  base  class  employs  a  special-
              purpose  graphic  to  render  itself,  one  that  draws  an array of dots based on the information
              supplied in this constructor.

       virtual Graphic* GetGraphic()
              Return the graphic used to render the grid.

       virtual void Constrain(Coord&, Coord&)
              Constrain the given coordinate pair to fall on the grid.  The pair  is  changed  to  fall  on  the
              nearest grid point by default.

       virtual void Visiblity(boolean)
              Make the grid visible (specify true) or invisible (specify false).

       virtual boolean IsVisible()
              Return whether the grid is visible or not.

       virtual void SetSpacing(float xincr, float yincr)
              Reset the grid's units of graduation.

PROTECTED OPERATIONS

       Grid(Graphic*)
              The  protected  constructor  allows  subclasses  to specify an arbitrary graphic for rendering the
              grid.  Subclasses that use this constructor must also redefine the Constrain operation.

SEE ALSO

       Graphic(3U), Viewer(3U)