org.epseelon.mobimap.geom
Class Rectangle2D

java.lang.Object
  org.epseelon.mobimap.geom.RectangularShape
      org.epseelon.mobimap.geom.Rectangle2D

All Implemented Interfaces:

Shape

Direct Known Subclasses:

Rectangle, Rectangle2D.Double, Rectangle2D.Float

public abstract class Rectangle2D
extends RectangularShape

This class describes a rectangle by a point (x,y) and dimension (w x h). The actual storage is left up to subclasses.

It is valid for a rectangle to have negative width or height; but it is considered to have no area or internal points. Therefore, the behavior in methods like contains or intersects is undefined unless the rectangle has positive width and height.

Since:

1.2

Author:

Tom Tromey (tromey@cygnus.com), Eric Blake (ebb9@email.byu.edu)

Nested Class Summary

static class	Rectangle2D.Double This class defines a rectangle in double precision.
static class	Rectangle2D.Float This class defines a rectangle in float precision.

Field Summary

static int	OUT_BOTTOM The point lies below of the rectangle (p.y > r.maxY).
static int	OUT_LEFT The point lies left of the rectangle (p.x < r.x).
static int	OUT_RIGHT The point lies right of the rectangle (p.x > r.maxX).
static int	OUT_TOP The point lies above the rectangle (p.y < r.y).

Constructor Summary

protected

Rectangle2D() Default constructor.

Method Summary

void	add(double newx, double newy) Modifies this rectangle so that it represents the smallest rectangle that contains both the existing rectangle and the specified point.
void	add(Point2D p) Modifies this rectangle so that it represents the smallest rectangle that contains both the existing rectangle and the specified point.
void	add(Rectangle2D r) Modifies this rectangle so that it represents the smallest rectangle that contains both the existing rectangle and the specified rectangle.
boolean	contains(double x, double y) Test if the given point is contained in the rectangle.
boolean	contains(double x, double y, double w, double h) Tests if this rectangle contains the given one.
abstract Rectangle2D	createIntersection(Rectangle2D r) Return a new rectangle which is the intersection of this and the given one.
abstract Rectangle2D	createUnion(Rectangle2D r) Return a new rectangle which is the union of this and the given one.
boolean	equals(java.lang.Object obj) Tests this rectangle for equality against the specified object.
int	hashCode() Return the hashcode for this rectangle.
static void	intersect(Rectangle2D src1, Rectangle2D src2, Rectangle2D dest) Intersects a pair of rectangles, and places the result in the destination; this can be used to avoid object creation.
boolean	intersects(double x, double y, double w, double h) Tests if the given rectangle intersects this one.
boolean	intersectsLine(double x1, double y1, double x2, double y2) Tests if the specified line intersects the interior of this rectangle.
boolean	intersectsLine(Line2D l) Tests if the specified line intersects the interior of this rectangle.
abstract int	outcode(double x, double y) Determine where the point lies with respect to this rectangle.
int	outcode(Point2D p) Determine where the point lies with respect to this rectangle.
void	setFrame(double x, double y, double w, double h) Set the bounding box of this rectangle.
abstract void	setRect(double x, double y, double w, double h) Set the bounding box of this rectangle.
void	setRect(Rectangle2D r) Set the bounding box of this rectangle from the given one.
static void	union(Rectangle2D src1, Rectangle2D src2, Rectangle2D dest) Joins a pair of rectangles, and places the result in the destination; this can be used to avoid object creation.

Methods inherited from class org.epseelon.mobimap.geom.RectangularShape

contains, contains, getBounds, getCenterX, getCenterY, getFrame, getHeight, getMaxX, getMaxY, getMinX, getMinY, getWidth, getX, getY, intersects, isEmpty, setFrame, setFrame, setFrameFromCenter, setFrameFromCenter, setFrameFromDiagonal, setFrameFromDiagonal

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.epseelon.mobimap.geom.Shape

getBounds2D

Field Detail

OUT_LEFT

public static final int OUT_LEFT

The point lies left of the rectangle (p.x < r.x).

See Also:

outcode(double, double), Constant Field Values

OUT_TOP

public static final int OUT_TOP

The point lies above the rectangle (p.y < r.y).

See Also:

outcode(double, double), Constant Field Values

OUT_RIGHT

public static final int OUT_RIGHT

The point lies right of the rectangle (p.x > r.maxX).

See Also:

outcode(double, double), Constant Field Values

OUT_BOTTOM

public static final int OUT_BOTTOM

The point lies below of the rectangle (p.y > r.maxY).

See Also:

outcode(double, double), Constant Field Values

Constructor Detail

Rectangle2D

protected Rectangle2D()

Default constructor.

Method Detail

setRect

public abstract void setRect(double x,
                             double y,
                             double w,
                             double h)

Set the bounding box of this rectangle.

Parameters:

x - the new X coordinate

y - the new Y coordinate

w - the new width

h - the new height

setRect

public void setRect(Rectangle2D r)

Set the bounding box of this rectangle from the given one.

Parameters:

r - rectangle to copy

Throws:

java.lang.NullPointerException - if r is null

intersectsLine

public boolean intersectsLine(double x1,
                              double y1,
                              double x2,
                              double y2)

Tests if the specified line intersects the interior of this rectangle.

Parameters:

x1 - the first x coordinate of line segment

y1 - the first y coordinate of line segment

x2 - the second x coordinate of line segment

y2 - the second y coordinate of line segment

Returns:

true if the line intersects the rectangle

intersectsLine

public boolean intersectsLine(Line2D l)

Tests if the specified line intersects the interior of this rectangle.

Parameters:

l - the line segment

Returns:

true if the line intersects the rectangle

Throws:

java.lang.NullPointerException - if l is null

outcode

public abstract int outcode(double x,
                            double y)

Determine where the point lies with respect to this rectangle. The result will be the binary OR of the appropriate bit masks.

Parameters:

x - the x coordinate to check

y - the y coordinate to check

Returns:

the binary OR of the result

See Also:

OUT_LEFT, OUT_TOP, OUT_RIGHT, OUT_BOTTOM

outcode

public int outcode(Point2D p)

Determine where the point lies with respect to this rectangle. The result will be the binary OR of the appropriate bit masks.

Parameters:

p - the point to check

Returns:

the binary OR of the result

Throws:

java.lang.NullPointerException - if p is null

See Also:

OUT_LEFT, OUT_TOP, OUT_RIGHT, OUT_BOTTOM

setFrame

public void setFrame(double x,
                     double y,
                     double w,
                     double h)

Set the bounding box of this rectangle.

Specified by:

setFrame in class RectangularShape

Parameters:

x - the new X coordinate

y - the new Y coordinate

w - the new width

h - the new height

See Also:

RectangularShape.getFrame()

contains

public boolean contains(double x,
                        double y)

Test if the given point is contained in the rectangle.

Parameters:

x - the x coordinate of the point

y - the y coordinate of the point

Returns:

true if (x,y) is in the rectangle

intersects

public boolean intersects(double x,
                          double y,
                          double w,
                          double h)

Tests if the given rectangle intersects this one. In other words, test if the two rectangles share at least one internal point.

Parameters:

x - the x coordinate of the other rectangle

y - the y coordinate of the other rectangle

w - the width of the other rectangle

h - the height of the other rectangle

Returns:

true if the rectangles intersect

contains

public boolean contains(double x,
                        double y,
                        double w,
                        double h)

Tests if this rectangle contains the given one. In other words, test if this rectangle contains all points in the given one.

Parameters:

x - the x coordinate of the other rectangle

y - the y coordinate of the other rectangle

w - the width of the other rectangle

h - the height of the other rectangle

Returns:

true if this rectangle contains the other

createIntersection

public abstract Rectangle2D createIntersection(Rectangle2D r)

Return a new rectangle which is the intersection of this and the given one. The result will be empty if there is no intersection.

Parameters:

r - the rectangle to be intersected

Returns:

the intersection

Throws:

java.lang.NullPointerException - if r is null

intersect

public static void intersect(Rectangle2D src1,
                             Rectangle2D src2,
                             Rectangle2D dest)

Intersects a pair of rectangles, and places the result in the destination; this can be used to avoid object creation. This method even works when the destination is also a source, although you stand to lose the original data.

Parameters:

src1 - the first source

src2 - the second source

dest - the destination for the intersection

Throws:

java.lang.NullPointerException - if any rectangle is null

createUnion

public abstract Rectangle2D createUnion(Rectangle2D r)

Return a new rectangle which is the union of this and the given one.

Parameters:

r - the rectangle to be merged

Returns:

the union

Throws:

java.lang.NullPointerException - if r is null

union

public static void union(Rectangle2D src1,
                         Rectangle2D src2,
                         Rectangle2D dest)

Joins a pair of rectangles, and places the result in the destination; this can be used to avoid object creation. This method even works when the destination is also a source, although you stand to lose the original data.

Parameters:

src1 - the first source

src2 - the second source

dest - the destination for the union

Throws:

java.lang.NullPointerException - if any rectangle is null

add

public void add(double newx,
                double newy)

Modifies this rectangle so that it represents the smallest rectangle that contains both the existing rectangle and the specified point. However, if the point falls on one of the two borders which are not inside the rectangle, a subsequent call to contains may return false.

Parameters:

newx - the X coordinate of the point to add to this rectangle

newy - the Y coordinate of the point to add to this rectangle

add

public void add(Point2D p)

Modifies this rectangle so that it represents the smallest rectangle that contains both the existing rectangle and the specified point. However, if the point falls on one of the two borders which are not inside the rectangle, a subsequent call to contains may return false.

Parameters:

p - the point to add to this rectangle

Throws:

java.lang.NullPointerException - if p is null

add

public void add(Rectangle2D r)

Modifies this rectangle so that it represents the smallest rectangle that contains both the existing rectangle and the specified rectangle.

Parameters:

r - the rectangle to add to this rectangle

Throws:

java.lang.NullPointerException - if r is null

See Also:

union(Rectangle2D, Rectangle2D, Rectangle2D)

hashCode

public int hashCode()

Return the hashcode for this rectangle. The formula is not documented, but appears to be the same as:

 long l = Double.doubleToLongBits(getX())
   + 37 * Double.doubleToLongBits(getY())
   + 43 * Double.doubleToLongBits(getWidth())
   + 47 * Double.doubleToLongBits(getHeight());
 return (int) ((l >> 32) ^ l);
 

Overrides:

hashCode in class java.lang.Object

Returns:

the hashcode

equals

public boolean equals(java.lang.Object obj)

Tests this rectangle for equality against the specified object. This will be true if an only if the specified object is an instance of Rectangle2D with the same coordinates and dimensions.

Overrides:

equals in class java.lang.Object

Parameters:

obj - the object to test against for equality

Returns:

true if the specified object is equal to this one