math.geom2d.curve
Class GeneralPath2D

java.lang.Object
  math.geom2d.curve.GeneralPath2D

All Implemented Interfaces:

java.awt.Shape, java.lang.Cloneable

public final class GeneralPath2D
extends java.lang.Object
implements java.awt.Shape, java.lang.Cloneable

The GeneralPath class represents a geometric path constructed from straight lines, and quadratic and cubic (Bezier) curves. It can contain multiple subpaths.

The winding rule specifies how the interior of a path is determined. There are two types of winding rules: EVEN_ODD and NON_ZERO.

An EVEN_ODD winding rule means that enclosed regions of the path alternate between interior and exterior areas as traversed from the outside of the path towards a point inside the region.

A NON_ZERO winding rule means that if a ray is drawn in any direction from a given point to infinity and the places where the path intersects the ray are examined, the point is inside of the path if and only if the number of times that the path crosses the ray from left to right does not equal the number of times that the path crosses the ray from right to left.

Version:

1.54, 02/02/00

Author:

Jim Graham

Field Summary

static int	WIND_EVEN_ODD An even-odd winding rule for determining the interior of a path.
static int	WIND_NON_ZERO A non-zero winding rule for determining the interior of a path.

Constructor Summary

GeneralPath2D()
Constructs a new GeneralPath object.

GeneralPath2D(int rule)
Constructs a new GeneralPath object with the specified winding rule to control operations that require the interior of the path to be defined.

GeneralPath2D(int rule, int initialCapacity)
Constructs a new GeneralPath object with the specified winding rule and the specified initial capacity to store path coordinates.

GeneralPath2D(java.awt.Shape s)
Constructs a new GeneralPath object from an arbitrary Shape object.

Method Summary

void	append(java.awt.geom.PathIterator pi, boolean connect) Appends the geometry of the specified PathIterator object to the path, possibly connecting the new geometry to the existing path segments with a line segment.
void	append(java.awt.Shape s, boolean connect) Appends the geometry of the specified Shape object to the path, possibly connecting the new geometry to the existing path segments with a line segment.
java.lang.Object	clone() Creates a new object of the same class as this object.
void	closePath() Closes the current subpath by drawing a straight line back to the coordinates of the last moveTo.
boolean	contains(double x, double y) Tests if the specified coordinates are inside the boundary of this Shape.
boolean	contains(double x, double y, double w, double h) Tests if the specified rectangular area is inside the boundary of this Shape.
boolean	contains(java.awt.geom.Point2D p) Tests if the specified Point2D is inside the boundary of this Shape.
boolean	contains(Point2D p) Tests if the specified Point2D is inside the boundary of this Shape.
boolean	contains(java.awt.geom.Rectangle2D r) Tests if the specified Rectangle2D is inside the boundary of this Shape.
java.awt.Shape	createTransformedShape(java.awt.geom.AffineTransform at) Returns a new transformed Shape.
void	curveTo(double x1, double y1, double x2, double y2, double x3, double y3) Adds a curved segment, defined by three new points, to the path by drawing a Bezier curve that intersects both the current coordinates and the coordinates (x3, y3), using the specified points (x1, y1) and (x2, y2) as Bezier control points.
void	curveTo(Point2D p1, Point2D p2, Point2D p3) Adds a curved segment, defined by three new points, to the path by drawing a Bezier curve that intersects both the current coordinates and the coordinates (x3, y3), using the specified points (x1, y1) and (x2, y2) as Bezier control points.
boolean	equals(java.lang.Object obj)
java.awt.Rectangle	getBounds() Return the bounding box of the path.
java.awt.geom.Rectangle2D	getBounds2D() Returns the bounding box of the path.
Point2D	getCurrentPoint() Returns the coordinates most recently added to the end of the path as a Point2D object.
java.awt.geom.PathIterator	getPathIterator(java.awt.geom.AffineTransform at) Returns a PathIterator object that iterates along the boundary of this Shape and provides access to the geometry of the outline of this Shape.
java.awt.geom.PathIterator	getPathIterator(java.awt.geom.AffineTransform at, double flatness) Returns a PathIterator object that iterates along the boundary of the flattened Shape and provides access to the geometry of the outline of the Shape.
int	getWindingRule() Returns the fill style winding rule.
boolean	intersects(double x, double y, double w, double h) Tests if the interior of this Shape intersects the interior of a specified set of rectangular coordinates.
boolean	intersects(java.awt.geom.Rectangle2D r) Tests if the interior of this Shape intersects the interior of a specified Rectangle2D.
void	lineTo(double x, double y) Adds a point to the path by drawing a straight line from the current coordinates to the new specified coordinates.
void	lineTo(Point2D p) Adds a point to the path by drawing a straight line from the current coordinates to the new specified coordinates.
void	moveTo(double x, double y) Adds a point to the path by moving to the specified coordinates.
void	moveTo(Point2D p) Adds a point to the path by moving to the specified coordinates.
void	quadTo(double x1, double y1, double x2, double y2) Adds a curved segment, defined by two new points, to the path by drawing a Quadratic curve that intersects both the current coordinates and the coordinates (x2, y2), using the specified point (x1, y1) as a quadratic parametric control point.
void	quadTo(Point2D p1, Point2D p2) Adds a curved segment, defined by two new points, to the path by drawing a Quadratic curve that intersects both the current coordinates and the coordinates (x2, y2), using the specified point (x1, y1) as a quadratic parametric control point.
void	reset() Resets the path to empty.
void	setWindingRule(int rule) Sets the winding rule for this path to the specified value.
void	transform(java.awt.geom.AffineTransform at) Transforms the geometry of this path using the specified AffineTransform.

Methods inherited from class java.lang.Object

getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

WIND_EVEN_ODD

public static final int WIND_EVEN_ODD

An even-odd winding rule for determining the interior of a path.

See Also:

Constant Field Values

WIND_NON_ZERO

public static final int WIND_NON_ZERO

A non-zero winding rule for determining the interior of a path.

See Also:

Constant Field Values

Constructor Detail

GeneralPath2D

public GeneralPath2D()

Constructs a new GeneralPath object. If an operation performed on this path requires the interior of the path to be defined then the default NON_ZERO winding rule is used.

See Also:

WIND_NON_ZERO

GeneralPath2D

public GeneralPath2D(int rule)

Constructs a new GeneralPath object with the specified winding rule to control operations that require the interior of the path to be defined.

Parameters:

rule - the winding rule

See Also:

WIND_EVEN_ODD, WIND_NON_ZERO

GeneralPath2D

public GeneralPath2D(int rule,
                     int initialCapacity)

Constructs a new GeneralPath object with the specified winding rule and the specified initial capacity to store path coordinates. This number is an initial guess as to how many path segments are in the path, but the storage is expanded as needed to store whatever path segments are added to this path.

Parameters:

rule - the winding rule

initialCapacity - the estimate for the number of path segments in the path

See Also:

WIND_EVEN_ODD, WIND_NON_ZERO

GeneralPath2D

public GeneralPath2D(java.awt.Shape s)

Constructs a new GeneralPath object from an arbitrary Shape object. All of the initial geometry and the winding rule for this path are taken from the specified Shape object.

Parameters:

s - the specified Shape object

Method Detail

moveTo

public void moveTo(double x,
                   double y)

Adds a point to the path by moving to the specified coordinates.

Parameters:

x - the x-coordinate of the destination

y - the y-coordinate of the destination

moveTo

public void moveTo(Point2D p)

Adds a point to the path by moving to the specified coordinates.

Parameters:

p - the specified point

lineTo

public void lineTo(double x,
                   double y)

Adds a point to the path by drawing a straight line from the current coordinates to the new specified coordinates.

Parameters:

x - the x-coordinate of the destination

y - the y-coordinate of the destination

lineTo

public void lineTo(Point2D p)

Adds a point to the path by drawing a straight line from the current coordinates to the new specified coordinates.

Parameters:

p - the coordinate of the destionation point

quadTo

public void quadTo(double x1,
                   double y1,
                   double x2,
                   double y2)

Adds a curved segment, defined by two new points, to the path by drawing a Quadratic curve that intersects both the current coordinates and the coordinates (x2, y2), using the specified point (x1, y1) as a quadratic parametric control point.

Parameters:

x1 - the x-coordinate of the control point

y1 - the y-coordinate of the control point

x2 - the x-coordinate of the end point

y2 - the y-coordinate of the end point

quadTo

public void quadTo(Point2D p1,
                   Point2D p2)

Adds a curved segment, defined by two new points, to the path by drawing a Quadratic curve that intersects both the current coordinates and the coordinates (x2, y2), using the specified point (x1, y1) as a quadratic parametric control point.

Parameters:

p1 - the control point

p2 - the end point

curveTo

public void curveTo(double x1,
                    double y1,
                    double x2,
                    double y2,
                    double x3,
                    double y3)

Adds a curved segment, defined by three new points, to the path by drawing a Bezier curve that intersects both the current coordinates and the coordinates (x3, y3), using the specified points (x1, y1) and (x2, y2) as Bezier control points.

Parameters:

x1 - the x-coordinate of the first control point

y1 - the y-coordinate of the first control point

x2 - the x-coordinate of the second control point

y2 - the y-coordinate of the second control point

x3 - the x-coordinate of the end point

y3 - the y-coordinate of the end point

curveTo

public void curveTo(Point2D p1,
                    Point2D p2,
                    Point2D p3)

Adds a curved segment, defined by three new points, to the path by drawing a Bezier curve that intersects both the current coordinates and the coordinates (x3, y3), using the specified points (x1, y1) and (x2, y2) as Bezier control points.

Parameters:

p1 - the coordinates of the first control point

p2 - the coordinates of the second control point

p3 - the coordinates of the final endpoint

closePath

public void closePath()

Closes the current subpath by drawing a straight line back to the coordinates of the last moveTo. If the path is already closed then this method has no effect.

append

public void append(java.awt.Shape s,
                   boolean connect)

Appends the geometry of the specified Shape object to the path, possibly connecting the new geometry to the existing path segments with a line segment. If the connect parameter is true and the path is not empty then any initial moveTo in the geometry of the appended Shape is turned into a lineTo segment. If the destination coordinates of such a connecting lineTo segment match the ending coordinates of a currently open subpath then the segment is omitted as superfluous. The winding rule of the specified Shape is ignored and the appended geometry is governed by the winding rule specified for this path.

Parameters:

s - the Shape whose geometry is appended to this path

connect - a boolean to control whether or not to turn an initial moveTo segment into a lineTo segment to connect the new geometry to the existing path

append

public void append(java.awt.geom.PathIterator pi,
                   boolean connect)

Appends the geometry of the specified PathIterator object to the path, possibly connecting the new geometry to the existing path segments with a line segment. If the connect parameter is true and the path is not empty then any initial moveTo in the geometry of the appended Shape is turned into a lineTo segment. If the destination coordinates of such a connecting lineTo segment match the ending coordinates of a currently open subpath then the segment is omitted as superfluous. The winding rule of the specified Shape is ignored and the appended geometry is governed by the winding rule specified for this path.

Parameters:

pi - the PathIterator whose geometry is appended to this path

connect - a boolean to control whether or not to turn an initial moveTo segment into a lineTo segment to connect the new geometry to the existing path

getWindingRule

public int getWindingRule()

Returns the fill style winding rule.

Returns:

an integer representing the current winding rule.

See Also:

WIND_EVEN_ODD, WIND_NON_ZERO

setWindingRule

public void setWindingRule(int rule)

Sets the winding rule for this path to the specified value.

Parameters:

rule - an integer representing the specified winding rule

Throws:

IllegalArgumentException - if rule is not either WIND_EVEN_ODD or WIND_NON_ZERO

See Also:

WIND_EVEN_ODD, WIND_NON_ZERO

getCurrentPoint

public Point2D getCurrentPoint()

Returns the coordinates most recently added to the end of the path as a Point2D object.

Returns:

a Point2D object containing the ending coordinates of the path or null if there are no points in the path.

reset

public void reset()

Resets the path to empty. The append position is set back to the beginning of the path and all coordinates and point types are forgotten.

transform

public void transform(java.awt.geom.AffineTransform at)

Transforms the geometry of this path using the specified AffineTransform. The geometry is transformed in place, which permanently changes the boundary defined by this object.

Parameters:

at - the AffineTransform used to transform the area

createTransformedShape

public java.awt.Shape createTransformedShape(java.awt.geom.AffineTransform at)

Returns a new transformed Shape.

Parameters:

at - the AffineTransform used to transform a new Shape.

Returns:

a new Shape, transformed with the specified AffineTransform.

getBounds

public java.awt.Rectangle getBounds()

Return the bounding box of the path.

Specified by:

getBounds in interface java.awt.Shape

Returns:

a Rectangle object that bounds the current path.

getBounds2D

public java.awt.geom.Rectangle2D getBounds2D()

Returns the bounding box of the path.

Specified by:

getBounds2D in interface java.awt.Shape

Returns:

a Rectangle2D object that bounds the current path.

contains

public boolean contains(double x,
                        double y)

Tests if the specified coordinates are inside the boundary of this Shape.

Specified by:

contains in interface java.awt.Shape

Parameters:

x - the x-coordinate of the point

y - the y-coordinate of the point

Returns:

true if the specified coordinates are inside this Shape; false otherwise

contains

public boolean contains(java.awt.geom.Point2D p)

Tests if the specified Point2D is inside the boundary of this Shape.

Specified by:

contains in interface java.awt.Shape

Parameters:

p - the specified Point2D

Returns:

true if this Shape contains the specified Point2D, false otherwise.

contains

public boolean contains(Point2D p)

Tests if the specified Point2D is inside the boundary of this Shape.

Parameters:

p - the specified Point2D

Returns:

true if this Shape contains the specified Point2D, false otherwise.

contains

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

Tests if the specified rectangular area is inside the boundary of this Shape.

Specified by:

contains in interface java.awt.Shape

Parameters:

x - the x coordinate of the rectangle

y - the y coordinate of the rectangle

w - the width of the specified rectangular area

h - the height of the specified rectangular area

Returns:

true if this Shape contains the specified rectangluar area; false otherwise.

contains

public boolean contains(java.awt.geom.Rectangle2D r)

Tests if the specified Rectangle2D is inside the boundary of this Shape.

Specified by:

contains in interface java.awt.Shape

Parameters:

r - a specified Rectangle2D

Returns:

true if this Shape bounds the specified Rectangle2D; false otherwise.

intersects

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

Tests if the interior of this Shape intersects the interior of a specified set of rectangular coordinates.

Specified by:

intersects in interface java.awt.Shape

Parameters:

x - the position of the left corner

y - the position of the bottom corner

w - the width of the specified rectangular coordinates

h - the height of the specified rectangular coordinates

Returns:

true if this Shape and the interior of the specified set of rectangular coordinates intersect each other; false otherwise.

intersects

public boolean intersects(java.awt.geom.Rectangle2D r)

Tests if the interior of this Shape intersects the interior of a specified Rectangle2D.

Specified by:

intersects in interface java.awt.Shape

Parameters:

r - the specified Rectangle2D

Returns:

true if this Shape and the interior of the specified Rectangle2D intersect each other; false otherwise.

getPathIterator

public java.awt.geom.PathIterator getPathIterator(java.awt.geom.AffineTransform at)

Returns a PathIterator object that iterates along the boundary of this Shape and provides access to the geometry of the outline of this Shape. The iterator for this class is not multi-threaded safe, which means that this GeneralPath class does not guarantee that modifications to the geometry of this GeneralPath object do not affect any iterations of that geometry that are already in process.

Specified by:

getPathIterator in interface java.awt.Shape

Parameters:

at - an AffineTransform

Returns:

a new PathIterator that iterates along the boundary of this Shape and provides access to the geometry of this Shape's outline

getPathIterator

public java.awt.geom.PathIterator getPathIterator(java.awt.geom.AffineTransform at,
                                                  double flatness)

Returns a PathIterator object that iterates along the boundary of the flattened Shape and provides access to the geometry of the outline of the Shape. The iterator for this class is not multi-threaded safe, which means that this GeneralPath class does not guarantee that modifications to the geometry of this GeneralPath object do not affect any iterations of that geometry that are already in process.

Specified by:

getPathIterator in interface java.awt.Shape

Parameters:

at - an AffineTransform

flatness - the maximum distance that the line segments used to approximate the curved segments are allowed to deviate from any point on the original curve

Returns:

a new PathIterator that iterates along the flattened Shape boundary.

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

clone

public java.lang.Object clone()

Creates a new object of the same class as this object.

Overrides:

clone in class java.lang.Object

Returns:

a clone of this instance.

Throws:

java.lang.OutOfMemoryError - if there is not enough memory.

Since:

1.2

See Also:

Cloneable