Back to index...

	/*
	* Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.awt.geom;

	import java.io.Serializable;

	/**
	* <CODE>Arc2D</CODE> is the abstract superclass for all objects that
	* store a 2D arc defined by a framing rectangle,
	* start angle, angular extent (length of the arc), and a closure type
	* (<CODE>OPEN</CODE>, <CODE>CHORD</CODE>, or <CODE>PIE</CODE>).
	* <p>
	* <a name="inscribes">
	* The arc is a partial section of a full ellipse which
	* inscribes the framing rectangle of its parent {@link RectangularShape}.
	* </a>
	* <a name="angles">
	* The angles are specified relative to the non-square
	* framing rectangle such that 45 degrees always falls on the line from
	* the center of the ellipse to the upper right corner of the framing
	* rectangle.
	* As a result, if the framing rectangle is noticeably longer along one
	* axis than the other, the angles to the start and end of the arc segment
	* will be skewed farther along the longer axis of the frame.
	* </a>
	* <p>
	* The actual storage representation of the coordinates is left to
	* the subclass.
	*
	* @author Jim Graham
	* @since 1.2
	*/
	public abstract class Arc2D extends RectangularShape {

	/**
	* The closure type for an open arc with no path segments
	* connecting the two ends of the arc segment.
	* @since 1.2
	*/
	public final static int OPEN = 0;

	/**
	* The closure type for an arc closed by drawing a straight
	* line segment from the start of the arc segment to the end of the
	* arc segment.
	* @since 1.2
	*/
	public final static int CHORD = 1;

	/**
	* The closure type for an arc closed by drawing straight line
	* segments from the start of the arc segment to the center
	* of the full ellipse and from that point to the end of the arc segment.
	* @since 1.2
	*/
	public final static int PIE = 2;

	/**
	* This class defines an arc specified in {@code float} precision.
	* @since 1.2
	*/
	public static class Float extends Arc2D implements Serializable {
	/**
	* The X coordinate of the upper-left corner of the framing
	* rectangle of the arc.
	* @since 1.2
	* @serial
	*/
	public float x;

	/**
	* The Y coordinate of the upper-left corner of the framing
	* rectangle of the arc.
	* @since 1.2
	* @serial
	*/
	public float y;

	/**
	* The overall width of the full ellipse of which this arc is
	* a partial section (not considering the
	* angular extents).
	* @since 1.2
	* @serial
	*/
	public float width;

	/**
	* The overall height of the full ellipse of which this arc is
	* a partial section (not considering the
	* angular extents).
	* @since 1.2
	* @serial
	*/
	public float height;

	/**
	* The starting angle of the arc in degrees.
	* @since 1.2
	* @serial
	*/
	public float start;

	/**
	* The angular extent of the arc in degrees.
	* @since 1.2
	* @serial
	*/
	public float extent;

	/**
	* Constructs a new OPEN arc, initialized to location (0, 0),
	* size (0, 0), angular extents (start = 0, extent = 0).
	* @since 1.2
	*/
	public Float() {
	super(OPEN);
	}

	/**
	* Constructs a new arc, initialized to location (0, 0),
	* size (0, 0), angular extents (start = 0, extent = 0), and
	* the specified closure type.
	*
	* @param type The closure type for the arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @since 1.2
	*/
	public Float(int type) {
	super(type);
	}

	/**
	* Constructs a new arc, initialized to the specified location,
	* size, angular extents, and closure type.
	*
	* @param x The X coordinate of the upper-left corner of
	* the arc's framing rectangle.
	* @param y The Y coordinate of the upper-left corner of
	* the arc's framing rectangle.
	* @param w The overall width of the full ellipse of which
	* this arc is a partial section.
	* @param h The overall height of the full ellipse of which this
	* arc is a partial section.
	* @param start The starting angle of the arc in degrees.
	* @param extent The angular extent of the arc in degrees.
	* @param type The closure type for the arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @since 1.2
	*/
	public Float(float x, float y, float w, float h,
	float start, float extent, int type) {
	super(type);
	this.x = x;
	this.y = y;
	this.width = w;
	this.height = h;
	this.start = start;
	this.extent = extent;
	}

	/**
	* Constructs a new arc, initialized to the specified location,
	* size, angular extents, and closure type.
	*
	* @param ellipseBounds The framing rectangle that defines the
	* outer boundary of the full ellipse of which this arc is a
	* partial section.
	* @param start The starting angle of the arc in degrees.
	* @param extent The angular extent of the arc in degrees.
	* @param type The closure type for the arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @since 1.2
	*/
	public Float(Rectangle2D ellipseBounds,
	float start, float extent, int type) {
	super(type);
	this.x = (float) ellipseBounds.getX();
	this.y = (float) ellipseBounds.getY();
	this.width = (float) ellipseBounds.getWidth();
	this.height = (float) ellipseBounds.getHeight();
	this.start = start;
	this.extent = extent;
	}

	/**
	* {@inheritDoc}
	* Note that the arc
	* <a href="Arc2D.html#inscribes">partially inscribes</a>
	* the framing rectangle of this {@code RectangularShape}.
	*
	* @since 1.2
	*/
	public double getX() {
	return (double) x;
	}

	/**
	* {@inheritDoc}
	* Note that the arc
	* <a href="Arc2D.html#inscribes">partially inscribes</a>
	* the framing rectangle of this {@code RectangularShape}.
	*
	* @since 1.2
	*/
	public double getY() {
	return (double) y;
	}

	/**
	* {@inheritDoc}
	* Note that the arc
	* <a href="Arc2D.html#inscribes">partially inscribes</a>
	* the framing rectangle of this {@code RectangularShape}.
	*
	* @since 1.2
	*/
	public double getWidth() {
	return (double) width;
	}

	/**
	* {@inheritDoc}
	* Note that the arc
	* <a href="Arc2D.html#inscribes">partially inscribes</a>
	* the framing rectangle of this {@code RectangularShape}.
	*
	* @since 1.2
	*/
	public double getHeight() {
	return (double) height;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public double getAngleStart() {
	return (double) start;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public double getAngleExtent() {
	return (double) extent;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public boolean isEmpty() {
	return (width <= 0.0 \|\| height <= 0.0);
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public void setArc(double x, double y, double w, double h,
	double angSt, double angExt, int closure) {
	this.setArcType(closure);
	this.x = (float) x;
	this.y = (float) y;
	this.width = (float) w;
	this.height = (float) h;
	this.start = (float) angSt;
	this.extent = (float) angExt;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public void setAngleStart(double angSt) {
	this.start = (float) angSt;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public void setAngleExtent(double angExt) {
	this.extent = (float) angExt;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	protected Rectangle2D makeBounds(double x, double y,
	double w, double h) {
	return new Rectangle2D.Float((float) x, (float) y,
	(float) w, (float) h);
	}

	/*
	* JDK 1.6 serialVersionUID
	*/
	private static final long serialVersionUID = 9130893014586380278L;

	/**
	* Writes the default serializable fields to the
	* <code>ObjectOutputStream</code> followed by a byte
	* indicating the arc type of this <code>Arc2D</code>
	* instance.
	*
	* @serialData
	* <ol>
	* <li>The default serializable fields.
	* <li>
	* followed by a <code>byte</code> indicating the arc type
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* </ol>
	*/
	private void writeObject(java.io.ObjectOutputStream s)
	throws java.io.IOException
	{
	s.defaultWriteObject();

	s.writeByte(getArcType());
	}

	/**
	* Reads the default serializable fields from the
	* <code>ObjectInputStream</code> followed by a byte
	* indicating the arc type of this <code>Arc2D</code>
	* instance.
	*
	* @serialData
	* <ol>
	* <li>The default serializable fields.
	* <li>
	* followed by a <code>byte</code> indicating the arc type
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* </ol>
	*/
	private void readObject(java.io.ObjectInputStream s)
	throws java.lang.ClassNotFoundException, java.io.IOException
	{
	s.defaultReadObject();

	try {
	setArcType(s.readByte());
	} catch (IllegalArgumentException iae) {
	throw new java.io.InvalidObjectException(iae.getMessage());
	}
	}
	}

	/**
	* This class defines an arc specified in {@code double} precision.
	* @since 1.2
	*/
	public static class Double extends Arc2D implements Serializable {
	/**
	* The X coordinate of the upper-left corner of the framing
	* rectangle of the arc.
	* @since 1.2
	* @serial
	*/
	public double x;

	/**
	* The Y coordinate of the upper-left corner of the framing
	* rectangle of the arc.
	* @since 1.2
	* @serial
	*/
	public double y;

	/**
	* The overall width of the full ellipse of which this arc is
	* a partial section (not considering the angular extents).
	* @since 1.2
	* @serial
	*/
	public double width;

	/**
	* The overall height of the full ellipse of which this arc is
	* a partial section (not considering the angular extents).
	* @since 1.2
	* @serial
	*/
	public double height;

	/**
	* The starting angle of the arc in degrees.
	* @since 1.2
	* @serial
	*/
	public double start;

	/**
	* The angular extent of the arc in degrees.
	* @since 1.2
	* @serial
	*/
	public double extent;

	/**
	* Constructs a new OPEN arc, initialized to location (0, 0),
	* size (0, 0), angular extents (start = 0, extent = 0).
	* @since 1.2
	*/
	public Double() {
	super(OPEN);
	}

	/**
	* Constructs a new arc, initialized to location (0, 0),
	* size (0, 0), angular extents (start = 0, extent = 0), and
	* the specified closure type.
	*
	* @param type The closure type for the arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @since 1.2
	*/
	public Double(int type) {
	super(type);
	}

	/**
	* Constructs a new arc, initialized to the specified location,
	* size, angular extents, and closure type.
	*
	* @param x The X coordinate of the upper-left corner
	* of the arc's framing rectangle.
	* @param y The Y coordinate of the upper-left corner
	* of the arc's framing rectangle.
	* @param w The overall width of the full ellipse of which this
	* arc is a partial section.
	* @param h The overall height of the full ellipse of which this
	* arc is a partial section.
	* @param start The starting angle of the arc in degrees.
	* @param extent The angular extent of the arc in degrees.
	* @param type The closure type for the arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @since 1.2
	*/
	public Double(double x, double y, double w, double h,
	double start, double extent, int type) {
	super(type);
	this.x = x;
	this.y = y;
	this.width = w;
	this.height = h;
	this.start = start;
	this.extent = extent;
	}

	/**
	* Constructs a new arc, initialized to the specified location,
	* size, angular extents, and closure type.
	*
	* @param ellipseBounds The framing rectangle that defines the
	* outer boundary of the full ellipse of which this arc is a
	* partial section.
	* @param start The starting angle of the arc in degrees.
	* @param extent The angular extent of the arc in degrees.
	* @param type The closure type for the arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @since 1.2
	*/
	public Double(Rectangle2D ellipseBounds,
	double start, double extent, int type) {
	super(type);
	this.x = ellipseBounds.getX();
	this.y = ellipseBounds.getY();
	this.width = ellipseBounds.getWidth();
	this.height = ellipseBounds.getHeight();
	this.start = start;
	this.extent = extent;
	}

	/**
	* {@inheritDoc}
	* Note that the arc
	* <a href="Arc2D.html#inscribes">partially inscribes</a>
	* the framing rectangle of this {@code RectangularShape}.
	*
	* @since 1.2
	*/
	public double getX() {
	return x;
	}

	/**
	* {@inheritDoc}
	* Note that the arc
	* <a href="Arc2D.html#inscribes">partially inscribes</a>
	* the framing rectangle of this {@code RectangularShape}.
	*
	* @since 1.2
	*/
	public double getY() {
	return y;
	}

	/**
	* {@inheritDoc}
	* Note that the arc
	* <a href="Arc2D.html#inscribes">partially inscribes</a>
	* the framing rectangle of this {@code RectangularShape}.
	*
	* @since 1.2
	*/
	public double getWidth() {
	return width;
	}

	/**
	* {@inheritDoc}
	* Note that the arc
	* <a href="Arc2D.html#inscribes">partially inscribes</a>
	* the framing rectangle of this {@code RectangularShape}.
	*
	* @since 1.2
	*/
	public double getHeight() {
	return height;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public double getAngleStart() {
	return start;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public double getAngleExtent() {
	return extent;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public boolean isEmpty() {
	return (width <= 0.0 \|\| height <= 0.0);
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public void setArc(double x, double y, double w, double h,
	double angSt, double angExt, int closure) {
	this.setArcType(closure);
	this.x = x;
	this.y = y;
	this.width = w;
	this.height = h;
	this.start = angSt;
	this.extent = angExt;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public void setAngleStart(double angSt) {
	this.start = angSt;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	public void setAngleExtent(double angExt) {
	this.extent = angExt;
	}

	/**
	* {@inheritDoc}
	* @since 1.2
	*/
	protected Rectangle2D makeBounds(double x, double y,
	double w, double h) {
	return new Rectangle2D.Double(x, y, w, h);
	}

	/*
	* JDK 1.6 serialVersionUID
	*/
	private static final long serialVersionUID = 728264085846882001L;

	/**
	* Writes the default serializable fields to the
	* <code>ObjectOutputStream</code> followed by a byte
	* indicating the arc type of this <code>Arc2D</code>
	* instance.
	*
	* @serialData
	* <ol>
	* <li>The default serializable fields.
	* <li>
	* followed by a <code>byte</code> indicating the arc type
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* </ol>
	*/
	private void writeObject(java.io.ObjectOutputStream s)
	throws java.io.IOException
	{
	s.defaultWriteObject();

	s.writeByte(getArcType());
	}

	/**
	* Reads the default serializable fields from the
	* <code>ObjectInputStream</code> followed by a byte
	* indicating the arc type of this <code>Arc2D</code>
	* instance.
	*
	* @serialData
	* <ol>
	* <li>The default serializable fields.
	* <li>
	* followed by a <code>byte</code> indicating the arc type
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* </ol>
	*/
	private void readObject(java.io.ObjectInputStream s)
	throws java.lang.ClassNotFoundException, java.io.IOException
	{
	s.defaultReadObject();

	try {
	setArcType(s.readByte());
	} catch (IllegalArgumentException iae) {
	throw new java.io.InvalidObjectException(iae.getMessage());
	}
	}
	}

	private int type;

	/**
	* This is an abstract class that cannot be instantiated directly.
	* Type-specific implementation subclasses are available for
	* instantiation and provide a number of formats for storing
	* the information necessary to satisfy the various accessor
	* methods below.
	* <p>
	* This constructor creates an object with a default closure
	* type of {@link #OPEN}. It is provided only to enable
	* serialization of subclasses.
	*
	* @see java.awt.geom.Arc2D.Float
	* @see java.awt.geom.Arc2D.Double
	*/
	protected Arc2D() {
	this(OPEN);
	}

	/**
	* This is an abstract class that cannot be instantiated directly.
	* Type-specific implementation subclasses are available for
	* instantiation and provide a number of formats for storing
	* the information necessary to satisfy the various accessor
	* methods below.
	*
	* @param type The closure type of this arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @see java.awt.geom.Arc2D.Float
	* @see java.awt.geom.Arc2D.Double
	* @since 1.2
	*/
	protected Arc2D(int type) {
	setArcType(type);
	}

	/**
	* Returns the starting angle of the arc.
	*
	* @return A double value that represents the starting angle
	* of the arc in degrees.
	* @see #setAngleStart
	* @since 1.2
	*/
	public abstract double getAngleStart();

	/**
	* Returns the angular extent of the arc.
	*
	* @return A double value that represents the angular extent
	* of the arc in degrees.
	* @see #setAngleExtent
	* @since 1.2
	*/
	public abstract double getAngleExtent();

	/**
	* Returns the arc closure type of the arc: {@link #OPEN},
	* {@link #CHORD}, or {@link #PIE}.
	* @return One of the integer constant closure types defined
	* in this class.
	* @see #setArcType
	* @since 1.2
	*/
	public int getArcType() {
	return type;
	}

	/**
	* Returns the starting point of the arc. This point is the
	* intersection of the ray from the center defined by the
	* starting angle and the elliptical boundary of the arc.
	*
	* @return A <CODE>Point2D</CODE> object representing the
	* x,y coordinates of the starting point of the arc.
	* @since 1.2
	*/
	public Point2D getStartPoint() {
	double angle = Math.toRadians(-getAngleStart());
	double x = getX() + (Math.cos(angle) * 0.5 + 0.5) * getWidth();
	double y = getY() + (Math.sin(angle) * 0.5 + 0.5) * getHeight();
	return new Point2D.Double(x, y);
	}

	/**
	* Returns the ending point of the arc. This point is the
	* intersection of the ray from the center defined by the
	* starting angle plus the angular extent of the arc and the
	* elliptical boundary of the arc.
	*
	* @return A <CODE>Point2D</CODE> object representing the
	* x,y coordinates of the ending point of the arc.
	* @since 1.2
	*/
	public Point2D getEndPoint() {
	double angle = Math.toRadians(-getAngleStart() - getAngleExtent());
	double x = getX() + (Math.cos(angle) * 0.5 + 0.5) * getWidth();
	double y = getY() + (Math.sin(angle) * 0.5 + 0.5) * getHeight();
	return new Point2D.Double(x, y);
	}

	/**
	* Sets the location, size, angular extents, and closure type of
	* this arc to the specified double values.
	*
	* @param x The X coordinate of the upper-left corner of the arc.
	* @param y The Y coordinate of the upper-left corner of the arc.
	* @param w The overall width of the full ellipse of which
	* this arc is a partial section.
	* @param h The overall height of the full ellipse of which
	* this arc is a partial section.
	* @param angSt The starting angle of the arc in degrees.
	* @param angExt The angular extent of the arc in degrees.
	* @param closure The closure type for the arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @since 1.2
	*/
	public abstract void setArc(double x, double y, double w, double h,
	double angSt, double angExt, int closure);

	/**
	* Sets the location, size, angular extents, and closure type of
	* this arc to the specified values.
	*
	* @param loc The <CODE>Point2D</CODE> representing the coordinates of
	* the upper-left corner of the arc.
	* @param size The <CODE>Dimension2D</CODE> representing the width
	* and height of the full ellipse of which this arc is
	* a partial section.
	* @param angSt The starting angle of the arc in degrees.
	* @param angExt The angular extent of the arc in degrees.
	* @param closure The closure type for the arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @since 1.2
	*/
	public void setArc(Point2D loc, Dimension2D size,
	double angSt, double angExt, int closure) {
	setArc(loc.getX(), loc.getY(), size.getWidth(), size.getHeight(),
	angSt, angExt, closure);
	}

	/**
	* Sets the location, size, angular extents, and closure type of
	* this arc to the specified values.
	*
	* @param rect The framing rectangle that defines the
	* outer boundary of the full ellipse of which this arc is a
	* partial section.
	* @param angSt The starting angle of the arc in degrees.
	* @param angExt The angular extent of the arc in degrees.
	* @param closure The closure type for the arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @since 1.2
	*/
	public void setArc(Rectangle2D rect, double angSt, double angExt,
	int closure) {
	setArc(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight(),
	angSt, angExt, closure);
	}

	/**
	* Sets this arc to be the same as the specified arc.
	*
	* @param a The <CODE>Arc2D</CODE> to use to set the arc's values.
	* @since 1.2
	*/
	public void setArc(Arc2D a) {
	setArc(a.getX(), a.getY(), a.getWidth(), a.getHeight(),
	a.getAngleStart(), a.getAngleExtent(), a.type);
	}

	/**
	* Sets the position, bounds, angular extents, and closure type of
	* this arc to the specified values. The arc is defined by a center
	* point and a radius rather than a framing rectangle for the full ellipse.
	*
	* @param x The X coordinate of the center of the arc.
	* @param y The Y coordinate of the center of the arc.
	* @param radius The radius of the arc.
	* @param angSt The starting angle of the arc in degrees.
	* @param angExt The angular extent of the arc in degrees.
	* @param closure The closure type for the arc:
	* {@link #OPEN}, {@link #CHORD}, or {@link #PIE}.
	* @since 1.2
	*/
	public void setArcByCenter(double x, double y, double radius,
	double angSt, double angExt, int closure) {
	setArc(x - radius, y - radius, radius * 2.0, radius * 2.0,
	angSt, angExt, closure);
	}

	/**
	* Sets the position, bounds, and angular extents of this arc to the
	* specified value. The starting angle of the arc is tangent to the
	* line specified by points (p1, p2), the ending angle is tangent to
	* the line specified by points (p2, p3), and the arc has the
	* specified radius.
	*
	* @param p1 The first point that defines the arc. The starting
	* angle of the arc is tangent to the line specified by points (p1, p2).
	* @param p2 The second point that defines the arc. The starting
	* angle of the arc is tangent to the line specified by points (p1, p2).
	* The ending angle of the arc is tangent to the line specified by
	* points (p2, p3).
	* @param p3 The third point that defines the arc. The ending angle
	* of the arc is tangent to the line specified by points (p2, p3).
	* @param radius The radius of the arc.
	* @since 1.2
	*/
	public void setArcByTangent(Point2D p1, Point2D p2, Point2D p3,
	double radius) {
	double ang1 = Math.atan2(p1.getY() - p2.getY(),
	p1.getX() - p2.getX());
	double ang2 = Math.atan2(p3.getY() - p2.getY(),
	p3.getX() - p2.getX());
	double diff = ang2 - ang1;
	if (diff > Math.PI) {
	ang2 -= Math.PI * 2.0;
	} else if (diff < -Math.PI) {
	ang2 += Math.PI * 2.0;
	}
	double bisect = (ang1 + ang2) / 2.0;
	double theta = Math.abs(ang2 - bisect);
	double dist = radius / Math.sin(theta);
	double x = p2.getX() + dist * Math.cos(bisect);
	double y = p2.getY() + dist * Math.sin(bisect);
	// REMIND: This needs some work...
	if (ang1 < ang2) {
	ang1 -= Math.PI / 2.0;
	ang2 += Math.PI / 2.0;
	} else {
	ang1 += Math.PI / 2.0;
	ang2 -= Math.PI / 2.0;
	}
	ang1 = Math.toDegrees(-ang1);
	ang2 = Math.toDegrees(-ang2);
	diff = ang2 - ang1;
	if (diff < 0) {
	diff += 360;
	} else {
	diff -= 360;
	}
	setArcByCenter(x, y, radius, ang1, diff, type);
	}

	/**
	* Sets the starting angle of this arc to the specified double
	* value.
	*
	* @param angSt The starting angle of the arc in degrees.
	* @see #getAngleStart
	* @since 1.2
	*/
	public abstract void setAngleStart(double angSt);

	/**
	* Sets the angular extent of this arc to the specified double
	* value.
	*
	* @param angExt The angular extent of the arc in degrees.
	* @see #getAngleExtent
	* @since 1.2
	*/
	public abstract void setAngleExtent(double angExt);

	/**
	* Sets the starting angle of this arc to the angle that the
	* specified point defines relative to the center of this arc.
	* The angular extent of the arc will remain the same.
	*
	* @param p The <CODE>Point2D</CODE> that defines the starting angle.
	* @see #getAngleStart
	* @since 1.2
	*/
	public void setAngleStart(Point2D p) {
	// Bias the dx and dy by the height and width of the oval.
	double dx = getHeight() * (p.getX() - getCenterX());
	double dy = getWidth() * (p.getY() - getCenterY());
	setAngleStart(-Math.toDegrees(Math.atan2(dy, dx)));
	}

	/**
	* Sets the starting angle and angular extent of this arc using two
	* sets of coordinates. The first set of coordinates is used to
	* determine the angle of the starting point relative to the arc's
	* center. The second set of coordinates is used to determine the
	* angle of the end point relative to the arc's center.
	* The arc will always be non-empty and extend counterclockwise
	* from the first point around to the second point.
	*
	* @param x1 The X coordinate of the arc's starting point.
	* @param y1 The Y coordinate of the arc's starting point.
	* @param x2 The X coordinate of the arc's ending point.
	* @param y2 The Y coordinate of the arc's ending point.
	* @since 1.2
	*/
	public void setAngles(double x1, double y1, double x2, double y2) {
	double x = getCenterX();
	double y = getCenterY();
	double w = getWidth();
	double h = getHeight();
	// Note: reversing the Y equations negates the angle to adjust
	// for the upside down coordinate system.
	// Also we should bias atans by the height and width of the oval.
	double ang1 = Math.atan2(w * (y - y1), h * (x1 - x));
	double ang2 = Math.atan2(w * (y - y2), h * (x2 - x));
	ang2 -= ang1;
	if (ang2 <= 0.0) {
	ang2 += Math.PI * 2.0;
	}
	setAngleStart(Math.toDegrees(ang1));
	setAngleExtent(Math.toDegrees(ang2));
	}

	/**
	* Sets the starting angle and angular extent of this arc using
	* two points. The first point is used to determine the angle of
	* the starting point relative to the arc's center.
	* The second point is used to determine the angle of the end point
	* relative to the arc's center.
	* The arc will always be non-empty and extend counterclockwise
	* from the first point around to the second point.
	*
	* @param p1 The <CODE>Point2D</CODE> that defines the arc's
	* starting point.
	* @param p2 The <CODE>Point2D</CODE> that defines the arc's
	* ending point.
	* @since 1.2
	*/
	public void setAngles(Point2D p1, Point2D p2) {
	setAngles(p1.getX(), p1.getY(), p2.getX(), p2.getY());
	}

	/**
	* Sets the closure type of this arc to the specified value:
	* <CODE>OPEN</CODE>, <CODE>CHORD</CODE>, or <CODE>PIE</CODE>.
	*
	* @param type The integer constant that represents the closure
	* type of this arc: {@link #OPEN}, {@link #CHORD}, or
	* {@link #PIE}.
	*
	* @throws IllegalArgumentException if <code>type</code> is not
	* 0, 1, or 2.+
	* @see #getArcType
	* @since 1.2
	*/
	public void setArcType(int type) {
	if (type < OPEN \|\| type > PIE) {
	throw new IllegalArgumentException("invalid type for Arc: "+type);
	}
	this.type = type;
	}

	/**
	* {@inheritDoc}
	* Note that the arc
	* <a href="Arc2D.html#inscribes">partially inscribes</a>
	* the framing rectangle of this {@code RectangularShape}.
	*
	* @since 1.2
	*/
	public void setFrame(double x, double y, double w, double h) {
	setArc(x, y, w, h, getAngleStart(), getAngleExtent(), type);
	}

	/**
	* Returns the high-precision framing rectangle of the arc. The framing
	* rectangle contains only the part of this <code>Arc2D</code> that is
	* in between the starting and ending angles and contains the pie
	* wedge, if this <code>Arc2D</code> has a <code>PIE</code> closure type.
	* <p>
	* This method differs from the
	* {@link RectangularShape#getBounds() getBounds} in that the
	* <code>getBounds</code> method only returns the bounds of the
	* enclosing ellipse of this <code>Arc2D</code> without considering
	* the starting and ending angles of this <code>Arc2D</code>.
	*
	* @return the <CODE>Rectangle2D</CODE> that represents the arc's
	* framing rectangle.
	* @since 1.2
	*/
	public Rectangle2D getBounds2D() {
	if (isEmpty()) {
	return makeBounds(getX(), getY(), getWidth(), getHeight());
	}
	double x1, y1, x2, y2;
	if (getArcType() == PIE) {
	x1 = y1 = x2 = y2 = 0.0;
	} else {
	x1 = y1 = 1.0;
	x2 = y2 = -1.0;
	}
	double angle = 0.0;
	for (int i = 0; i < 6; i++) {
	if (i < 4) {
	// 0-3 are the four quadrants
	angle += 90.0;
	if (!containsAngle(angle)) {
	continue;
	}
	} else if (i == 4) {
	// 4 is start angle
	angle = getAngleStart();
	} else {
	// 5 is end angle
	angle += getAngleExtent();
	}
	double rads = Math.toRadians(-angle);
	double xe = Math.cos(rads);
	double ye = Math.sin(rads);
	x1 = Math.min(x1, xe);
	y1 = Math.min(y1, ye);
	x2 = Math.max(x2, xe);
	y2 = Math.max(y2, ye);
	}
	double w = getWidth();
	double h = getHeight();
	x2 = (x2 - x1) * 0.5 * w;
	y2 = (y2 - y1) * 0.5 * h;
	x1 = getX() + (x1 * 0.5 + 0.5) * w;
	y1 = getY() + (y1 * 0.5 + 0.5) * h;
	return makeBounds(x1, y1, x2, y2);
	}

	/**
	* Constructs a <code>Rectangle2D</code> of the appropriate precision
	* to hold the parameters calculated to be the framing rectangle
	* of this arc.
	*
	* @param x The X coordinate of the upper-left corner of the
	* framing rectangle.
	* @param y The Y coordinate of the upper-left corner of the
	* framing rectangle.
	* @param w The width of the framing rectangle.
	* @param h The height of the framing rectangle.
	* @return a <code>Rectangle2D</code> that is the framing rectangle
	* of this arc.
	* @since 1.2
	*/
	protected abstract Rectangle2D makeBounds(double x, double y,
	double w, double h);

	/*
	* Normalizes the specified angle into the range -180 to 180.
	*/
	static double normalizeDegrees(double angle) {
	if (angle > 180.0) {
	if (angle <= (180.0 + 360.0)) {
	angle = angle - 360.0;
	} else {
	angle = Math.IEEEremainder(angle, 360.0);
	// IEEEremainder can return -180 here for some input values...
	if (angle == -180.0) {
	angle = 180.0;
	}
	}
	} else if (angle <= -180.0) {
	if (angle > (-180.0 - 360.0)) {
	angle = angle + 360.0;
	} else {
	angle = Math.IEEEremainder(angle, 360.0);
	// IEEEremainder can return -180 here for some input values...
	if (angle == -180.0) {
	angle = 180.0;
	}
	}
	}
	return angle;
	}

	/**
	* Determines whether or not the specified angle is within the
	* angular extents of the arc.
	*
	* @param angle The angle to test.
	*
	* @return <CODE>true</CODE> if the arc contains the angle,
	* <CODE>false</CODE> if the arc doesn't contain the angle.
	* @since 1.2
	*/
	public boolean containsAngle(double angle) {
	double angExt = getAngleExtent();
	boolean backwards = (angExt < 0.0);
	if (backwards) {
	angExt = -angExt;
	}
	if (angExt >= 360.0) {
	return true;
	}
	angle = normalizeDegrees(angle) - normalizeDegrees(getAngleStart());
	if (backwards) {
	angle = -angle;
	}
	if (angle < 0.0) {
	angle += 360.0;
	}


	return (angle >= 0.0) && (angle < angExt);
	}

	/**
	* Determines whether or not the specified point is inside the boundary
	* of the arc.
	*
	* @param x The X coordinate of the point to test.
	* @param y The Y coordinate of the point to test.
	*
	* @return <CODE>true</CODE> if the point lies within the bound of
	* the arc, <CODE>false</CODE> if the point lies outside of the
	* arc's bounds.
	* @since 1.2
	*/
	public boolean contains(double x, double y) {
	// Normalize the coordinates compared to the ellipse
	// having a center at 0,0 and a radius of 0.5.
	double ellw = getWidth();
	if (ellw <= 0.0) {
	return false;
	}
	double normx = (x - getX()) / ellw - 0.5;
	double ellh = getHeight();
	if (ellh <= 0.0) {
	return false;
	}
	double normy = (y - getY()) / ellh - 0.5;
	double distSq = (normx * normx + normy * normy);
	if (distSq >= 0.25) {
	return false;
	}
	double angExt = Math.abs(getAngleExtent());
	if (angExt >= 360.0) {
	return true;
	}
	boolean inarc = containsAngle(-Math.toDegrees(Math.atan2(normy,
	normx)));
	if (type == PIE) {
	return inarc;
	}
	// CHORD and OPEN behave the same way
	if (inarc) {
	if (angExt >= 180.0) {
	return true;
	}
	// point must be outside the "pie triangle"
	} else {
	if (angExt <= 180.0) {
	return false;
	}
	// point must be inside the "pie triangle"
	}
	// The point is inside the pie triangle iff it is on the same
	// side of the line connecting the ends of the arc as the center.
	double angle = Math.toRadians(-getAngleStart());
	double x1 = Math.cos(angle);
	double y1 = Math.sin(angle);
	angle += Math.toRadians(-getAngleExtent());
	double x2 = Math.cos(angle);
	double y2 = Math.sin(angle);
	boolean inside = (Line2D.relativeCCW(x1, y1, x2, y2, 2normx, 2normy) *
	Line2D.relativeCCW(x1, y1, x2, y2, 0, 0) >= 0);
	return inarc ? !inside : inside;
	}

	/**
	* Determines whether or not the interior of the arc intersects
	* the interior of the specified rectangle.
	*
	* @param x The X coordinate of the rectangle's upper-left corner.
	* @param y The Y coordinate of the rectangle's upper-left corner.
	* @param w The width of the rectangle.
	* @param h The height of the rectangle.
	*
	* @return <CODE>true</CODE> if the arc intersects the rectangle,
	* <CODE>false</CODE> if the arc doesn't intersect the rectangle.
	* @since 1.2
	*/
	public boolean intersects(double x, double y, double w, double h) {

	double aw = getWidth();
	double ah = getHeight();

	if ( w <= 0 \|\| h <= 0 \|\| aw <= 0 \|\| ah <= 0 ) {
	return false;
	}
	double ext = getAngleExtent();
	if (ext == 0) {
	return false;
	}

	double ax = getX();
	double ay = getY();
	double axw = ax + aw;
	double ayh = ay + ah;
	double xw = x + w;
	double yh = y + h;

	// check bbox
	if (x >= axw \|\| y >= ayh \|\| xw <= ax \|\| yh <= ay) {
	return false;
	}

	// extract necessary data
	double axc = getCenterX();
	double ayc = getCenterY();
	Point2D sp = getStartPoint();
	Point2D ep = getEndPoint();
	double sx = sp.getX();
	double sy = sp.getY();
	double ex = ep.getX();
	double ey = ep.getY();

	/*
	* Try to catch rectangles that intersect arc in areas
	* outside of rectagle with left top corner coordinates
	* (min(center x, start point x, end point x),
	* min(center y, start point y, end point y))
	* and rigth bottom corner coordinates
	* (max(center x, start point x, end point x),
	* max(center y, start point y, end point y)).
	* So we'll check axis segments outside of rectangle above.
	*/
	if (ayc >= y && ayc <= yh) { // 0 and 180
	if ((sx < xw && ex < xw && axc < xw &&
	axw > x && containsAngle(0)) \|\|
	(sx > x && ex > x && axc > x &&
	ax < xw && containsAngle(180))) {
	return true;
	}
	}
	if (axc >= x && axc <= xw) { // 90 and 270
	if ((sy > y && ey > y && ayc > y &&
	ay < yh && containsAngle(90)) \|\|
	(sy < yh && ey < yh && ayc < yh &&
	ayh > y && containsAngle(270))) {
	return true;
	}
	}

	/*
	* For PIE we should check intersection with pie slices;
	* also we should do the same for arcs with extent is greater
	* than 180, because we should cover case of rectangle, which
	* situated between center of arc and chord, but does not
	* intersect the chord.
	*/
	Rectangle2D rect = new Rectangle2D.Double(x, y, w, h);
	if (type == PIE \|\| Math.abs(ext) > 180) {
	// for PIE: try to find intersections with pie slices
	if (rect.intersectsLine(axc, ayc, sx, sy) \|\|
	rect.intersectsLine(axc, ayc, ex, ey)) {
	return true;
	}
	} else {
	// for CHORD and OPEN: try to find intersections with chord
	if (rect.intersectsLine(sx, sy, ex, ey)) {
	return true;
	}
	}

	// finally check the rectangle corners inside the arc
	if (contains(x, y) \|\| contains(x + w, y) \|\|
	contains(x, y + h) \|\| contains(x + w, y + h)) {
	return true;
	}

	return false;
	}

	/**
	* Determines whether or not the interior of the arc entirely contains
	* the specified rectangle.
	*
	* @param x The X coordinate of the rectangle's upper-left corner.
	* @param y The Y coordinate of the rectangle's upper-left corner.
	* @param w The width of the rectangle.
	* @param h The height of the rectangle.
	*
	* @return <CODE>true</CODE> if the arc contains the rectangle,
	* <CODE>false</CODE> if the arc doesn't contain the rectangle.
	* @since 1.2
	*/
	public boolean contains(double x, double y, double w, double h) {
	return contains(x, y, w, h, null);
	}

	/**
	* Determines whether or not the interior of the arc entirely contains
	* the specified rectangle.
	*
	* @param r The <CODE>Rectangle2D</CODE> to test.
	*
	* @return <CODE>true</CODE> if the arc contains the rectangle,
	* <CODE>false</CODE> if the arc doesn't contain the rectangle.
	* @since 1.2
	*/
	public boolean contains(Rectangle2D r) {
	return contains(r.getX(), r.getY(), r.getWidth(), r.getHeight(), r);
	}

	private boolean contains(double x, double y, double w, double h,
	Rectangle2D origrect) {
	if (!(contains(x, y) &&
	contains(x + w, y) &&
	contains(x, y + h) &&
	contains(x + w, y + h))) {
	return false;
	}
	// If the shape is convex then we have done all the testing
	// we need. Only PIE arcs can be concave and then only if
	// the angular extents are greater than 180 degrees.
	if (type != PIE \|\| Math.abs(getAngleExtent()) <= 180.0) {
	return true;
	}
	// For a PIE shape we have an additional test for the case where
	// the angular extents are greater than 180 degrees and all four
	// rectangular corners are inside the shape but one of the
	// rectangle edges spans across the "missing wedge" of the arc.
	// We can test for this case by checking if the rectangle intersects
	// either of the pie angle segments.
	if (origrect == null) {
	origrect = new Rectangle2D.Double(x, y, w, h);
	}
	double halfW = getWidth() / 2.0;
	double halfH = getHeight() / 2.0;
	double xc = getX() + halfW;
	double yc = getY() + halfH;
	double angle = Math.toRadians(-getAngleStart());
	double xe = xc + halfW * Math.cos(angle);
	double ye = yc + halfH * Math.sin(angle);
	if (origrect.intersectsLine(xc, yc, xe, ye)) {
	return false;
	}
	angle += Math.toRadians(-getAngleExtent());
	xe = xc + halfW * Math.cos(angle);
	ye = yc + halfH * Math.sin(angle);
	return !origrect.intersectsLine(xc, yc, xe, ye);
	}

	/**
	* Returns an iteration object that defines the boundary of the
	* arc.
	* This iterator is multithread safe.
	* <code>Arc2D</code> guarantees that
	* modifications to the geometry of the arc
	* do not affect any iterations of that geometry that
	* are already in process.
	*
	* @param at an optional <CODE>AffineTransform</CODE> to be applied
	* to the coordinates as they are returned in the iteration, or null
	* if the untransformed coordinates are desired.
	*
	* @return A <CODE>PathIterator</CODE> that defines the arc's boundary.
	* @since 1.2
	*/
	public PathIterator getPathIterator(AffineTransform at) {
	return new ArcIterator(this, at);
	}

	/**
	* Returns the hashcode for this <code>Arc2D</code>.
	* @return the hashcode for this <code>Arc2D</code>.
	* @since 1.6
	*/
	public int hashCode() {
	long bits = java.lang.Double.doubleToLongBits(getX());
	bits += java.lang.Double.doubleToLongBits(getY()) * 37;
	bits += java.lang.Double.doubleToLongBits(getWidth()) * 43;
	bits += java.lang.Double.doubleToLongBits(getHeight()) * 47;
	bits += java.lang.Double.doubleToLongBits(getAngleStart()) * 53;
	bits += java.lang.Double.doubleToLongBits(getAngleExtent()) * 59;
	bits += getArcType() * 61;
	return (((int) bits) ^ ((int) (bits >> 32)));
	}

	/**
	* Determines whether or not the specified <code>Object</code> is
	* equal to this <code>Arc2D</code>. The specified
	* <code>Object</code> is equal to this <code>Arc2D</code>
	* if it is an instance of <code>Arc2D</code> and if its
	* location, size, arc extents and type are the same as this
	* <code>Arc2D</code>.
	* @param obj an <code>Object</code> to be compared with this
	* <code>Arc2D</code>.
	* @return <code>true</code> if <code>obj</code> is an instance
	* of <code>Arc2D</code> and has the same values;
	* <code>false</code> otherwise.
	* @since 1.6
	*/
	public boolean equals(Object obj) {
	if (obj == this) {
	return true;
	}
	if (obj instanceof Arc2D) {
	Arc2D a2d = (Arc2D) obj;
	return ((getX() == a2d.getX()) &&
	(getY() == a2d.getY()) &&
	(getWidth() == a2d.getWidth()) &&
	(getHeight() == a2d.getHeight()) &&
	(getAngleStart() == a2d.getAngleStart()) &&
	(getAngleExtent() == a2d.getAngleExtent()) &&
	(getArcType() == a2d.getArcType()));
	}
	return false;
	}
	}

Back to index...