org.jadice.util.base.geometry

Class Rectangles

java.lang.Object

org.jadice.util.base.geometry.Rectangles

public class Rectangles
extends Object

A few utility methods related to Rectangles, Rectangle2Ds and RectangularShapes.

Method Summary

Modifier and Type	Method and Description
static double	area(Rectangle2D r)
static Rectangle2D	dilate(Rectangle2D r, double marginX, double marginY) Return a new rectangle which covers the area of the given rectangle with an additional margin on the sides.
static Rectangle	dilate(Rectangle r, int marginX, int marginY) Return a new rectangle which covers the area of the given rectangle with an additional margin on the sides.
static double	distance(Rectangle2D r, Point2D p) Calculate the shortest distance from the point to any point within the given rectangle.
static Rectangle	enlargeToGrid(Rectangle2D r) Create a rectangle with the same area as the given input rectangle but with all of its edges snapped (rounded) to the integer grid.
static Rectangle2D.Double	ensureDoublePrecision(Rectangle2D input) Converts the given Rectangle2D to double precision, if necessary.
static Rectangle2D	intersectNullSafe(Rectangle2D a, Rectangle2D b) Computes the intersection of two rectangles, considering that one or both of them might be null.
static Rectangle2D	normalize(Rectangle2D r) Returns a rectangle which is normalized, that is, it has positive values for width and height.
static Rectangle2D	unionNullSafe(Rectangle2D a, Rectangle2D b) Computes the union area of two rectangles, considering that one or both of them might be null.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

enlargeToGrid

public static Rectangle enlargeToGrid(Rectangle2D r)

Create a rectangle with the same area as the given input rectangle but with all of its edges snapped (rounded) to the integer grid. The resulting rectangle is guaranteed to cover all of the input rectangle's area, so that enlargeToGrid(r).contains(r) == true holds. This can be depicted as the edges being stretched in an outward direction.

Parameters:

r -

Returns:

distance

public static double distance(Rectangle2D r,
                              Point2D p)

Calculate the shortest distance from the point to any point within the given rectangle. For points within the rectangle the result is always zero.

Parameters:

r - the rectangle

p - the point

Returns:

the shortest distance

dilate

public static Rectangle dilate(Rectangle r,
                               int marginX,
                               int marginY)

Return a new rectangle which covers the area of the given rectangle with an additional margin on the sides.

Parameters:

r -

marginX -

dilate

public static Rectangle2D dilate(Rectangle2D r,
                                 double marginX,
                                 double marginY)

Return a new rectangle which covers the area of the given rectangle with an additional margin on the sides.

Parameters:

r -

marginX -

area

public static double area(Rectangle2D r)

normalize

public static Rectangle2D normalize(Rectangle2D r)

Returns a rectangle which is normalized, that is, it has positive values for width and height. It will occupy the same area as the rectangle which is passed in.

Parameters:

r - the rectangle to be normalized. The given instance will not be modified.

Returns:

the normalized rectangle. Typically this is a new instance. If the rectangle passed to this function is already normalized, it may be returned as-is.

unionNullSafe

public static Rectangle2D unionNullSafe(Rectangle2D a,
                                        Rectangle2D b)

Computes the union area of two rectangles, considering that one or both of them might be null. This method automatically chooses the best subtype of Rectangle2D. For example, passing two Rectangles will return a Rectangle.

Parameters:

a - first rectangle

b - second rectangle

Returns:

union rectangle if both parameters are non-null. If only one of them is non-null, it will be returned unchanged. If both are null, null will be returned.

intersectNullSafe

public static Rectangle2D intersectNullSafe(Rectangle2D a,
                                            Rectangle2D b)

Computes the intersection of two rectangles, considering that one or both of them might be null. This method automatically chooses the best subtype of Rectangle2D. For example, passing two Rectangles will return a Rectangle.

Parameters:

a - first rectangle

b - second rectangle

Returns:

intersection rectangle if both parameters are non-null. If only one of them is non-null, it will be returned unchanged. If both are null, null will be returned.

ensureDoublePrecision

public static Rectangle2D.Double ensureDoublePrecision(Rectangle2D input)

Converts the given Rectangle2D to double precision, if necessary.

Parameters:

input - any rectangle, or null

Returns:

If input is a Rectangle2D.Double, it will be returned unchanged. If input is null, null will be returned. In all other cases, a new Rectangle2D.Double will be created using input's size and position.