grid (3U)

NAME
SYNOPSIS
DESCRIPTION
PUBLIC OPERATIONS
PROTECTED OPERATIONS
SEE ALSO

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.