ojluni/src/main/java/java/awt/geom/PathIterator.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 1997, 2000, 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;

 /**
  * The <code>PathIterator</code> interface provides the mechanism
  * for objects that implement the {@link java.awt.Shape Shape}
  * interface to return the geometry of their boundary by allowing
  * a caller to retrieve the path of that boundary a segment at a
  * time.  This interface allows these objects to retrieve the path of
  * their boundary a segment at a time by using 1st through 3rd order
  * B&eacute;zier curves, which are lines and quadratic or cubic
  * B&eacute;zier splines.
  * <p>
  * Multiple subpaths can be expressed by using a "MOVETO" segment to
  * create a discontinuity in the geometry to move from the end of
  * one subpath to the beginning of the next.
  * <p>
  * Each subpath can be closed manually by ending the last segment in
  * the subpath on the same coordinate as the beginning "MOVETO" segment
  * for that subpath or by using a "CLOSE" segment to append a line
  * segment from the last point back to the first.
  * Be aware that manually closing an outline as opposed to using a
  * "CLOSE" segment to close the path might result in different line
  * style decorations being used at the end points of the subpath.
  * For example, the {@link java.awt.BasicStroke BasicStroke} object
  * uses a line "JOIN" decoration to connect the first and last points
  * if a "CLOSE" segment is encountered, whereas simply ending the path
  * on the same coordinate as the beginning coordinate results in line
  * "CAP" decorations being used at the ends.
  *
  * @see java.awt.Shape
  * @see java.awt.BasicStroke
  *
  * @author Jim Graham
  */
 public interface PathIterator {
     /**
      * The winding rule constant for specifying an even-odd rule
      * for determining the interior of a path.
      * The even-odd rule specifies that a point lies inside the
      * path if a ray drawn in any direction from that point to
      * infinity is crossed by path segments an odd number of times.
      */
     public static final int WIND_EVEN_ODD       = 0;

     /**
      * The winding rule constant for specifying a non-zero rule
      * for determining the interior of a path.
      * The non-zero rule specifies that a point lies inside the
      * path if a ray drawn in any direction from that point to
      * infinity is crossed by path segments a different number
      * of times in the counter-clockwise direction than the
      * clockwise direction.
      */
     public static final int WIND_NON_ZERO       = 1;

     /**
      * The segment type constant for a point that specifies the
      * starting location for a new subpath.
      */
     public static final int SEG_MOVETO          = 0;

     /**
      * The segment type constant for a point that specifies the
      * end point of a line to be drawn from the most recently
      * specified point.
      */
     public static final int SEG_LINETO          = 1;

     /**
      * The segment type constant for the pair of points that specify
      * a quadratic parametric curve to be drawn from the most recently
      * specified point.
      * The curve is interpolated by solving the parametric control
      * equation in the range <code>(t=[0..1])</code> using
      * the most recently specified (current) point (CP),
      * the first control point (P1),
      * and the final interpolated control point (P2).
      * The parametric control equation for this curve is:
      * <pre>
      *          P(t) = B(2,0)*CP + B(2,1)*P1 + B(2,2)*P2
      *          0 &lt;= t &lt;= 1
      *
      *        B(n,m) = mth coefficient of nth degree Bernstein polynomial
      *               = C(n,m) * t^(m) * (1 - t)^(n-m)
      *        C(n,m) = Combinations of n things, taken m at a time
      *               = n! / (m! * (n-m)!)
      * </pre>
      */
     public static final int SEG_QUADTO          = 2;

     /**
      * The segment type constant for the set of 3 points that specify
      * a cubic parametric curve to be drawn from the most recently
      * specified point.
      * The curve is interpolated by solving the parametric control
      * equation in the range <code>(t=[0..1])</code> using
      * the most recently specified (current) point (CP),
      * the first control point (P1),
      * the second control point (P2),
      * and the final interpolated control point (P3).
      * The parametric control equation for this curve is:
      * <pre>
      *          P(t) = B(3,0)*CP + B(3,1)*P1 + B(3,2)*P2 + B(3,3)*P3
      *          0 &lt;= t &lt;= 1
      *
      *        B(n,m) = mth coefficient of nth degree Bernstein polynomial
      *               = C(n,m) * t^(m) * (1 - t)^(n-m)
      *        C(n,m) = Combinations of n things, taken m at a time
      *               = n! / (m! * (n-m)!)
      * </pre>
      * This form of curve is commonly known as a B&eacute;zier curve.
      */
     public static final int SEG_CUBICTO         = 3;

     /**
      * The segment type constant that specifies that
      * the preceding subpath should be closed by appending a line segment
      * back to the point corresponding to the most recent SEG_MOVETO.
      */
     public static final int SEG_CLOSE           = 4;

     /**
      * Returns the winding rule for determining the interior of the
      * path.
      * @return the winding rule.
      * @see #WIND_EVEN_ODD
      * @see #WIND_NON_ZERO
      */
     public int getWindingRule();

     /**
      * Tests if the iteration is complete.
      * @return <code>true</code> if all the segments have
      * been read; <code>false</code> otherwise.
      */
     public boolean isDone();

     /**
      * Moves the iterator to the next segment of the path forwards
      * along the primary direction of traversal as long as there are
      * more points in that direction.
      */
     public void next();

     /**
      * Returns the coordinates and type of the current path segment in
      * the iteration.
      * The return value is the path-segment type:
      * SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
      * A float array of length 6 must be passed in and can be used to
      * store the coordinates of the point(s).
      * Each point is stored as a pair of float x,y coordinates.
      * SEG_MOVETO and SEG_LINETO types returns one point,
      * SEG_QUADTO returns two points,
      * SEG_CUBICTO returns 3 points
      * and SEG_CLOSE does not return any points.
      * @param coords an array that holds the data returned from
      * this method
      * @return the path-segment type of the current path segment.
      * @see #SEG_MOVETO
      * @see #SEG_LINETO
      * @see #SEG_QUADTO
      * @see #SEG_CUBICTO
      * @see #SEG_CLOSE
      */
     public int currentSegment(float[] coords);

     /**
      * Returns the coordinates and type of the current path segment in
      * the iteration.
      * The return value is the path-segment type:
      * SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
      * A double array of length 6 must be passed in and can be used to
      * store the coordinates of the point(s).
      * Each point is stored as a pair of double x,y coordinates.
      * SEG_MOVETO and SEG_LINETO types returns one point,
      * SEG_QUADTO returns two points,
      * SEG_CUBICTO returns 3 points
      * and SEG_CLOSE does not return any points.
      * @param coords an array that holds the data returned from
      * this method
      * @return the path-segment type of the current path segment.
      * @see #SEG_MOVETO
      * @see #SEG_LINETO
      * @see #SEG_QUADTO
      * @see #SEG_CUBICTO
      * @see #SEG_CLOSE
      */
     public int currentSegment(double[] coords);
 }
	/*
	* Copyright (c) 1997, 2000, 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;

	/**
	* The <code>PathIterator</code> interface provides the mechanism
	* for objects that implement the {@link java.awt.Shape Shape}
	* interface to return the geometry of their boundary by allowing
	* a caller to retrieve the path of that boundary a segment at a
	* time. This interface allows these objects to retrieve the path of
	* their boundary a segment at a time by using 1st through 3rd order
	* Bézier curves, which are lines and quadratic or cubic
	* Bézier splines.
	* <p>
	* Multiple subpaths can be expressed by using a "MOVETO" segment to
	* create a discontinuity in the geometry to move from the end of
	* one subpath to the beginning of the next.
	* <p>
	* Each subpath can be closed manually by ending the last segment in
	* the subpath on the same coordinate as the beginning "MOVETO" segment
	* for that subpath or by using a "CLOSE" segment to append a line
	* segment from the last point back to the first.
	* Be aware that manually closing an outline as opposed to using a
	* "CLOSE" segment to close the path might result in different line
	* style decorations being used at the end points of the subpath.
	* For example, the {@link java.awt.BasicStroke BasicStroke} object
	* uses a line "JOIN" decoration to connect the first and last points
	* if a "CLOSE" segment is encountered, whereas simply ending the path
	* on the same coordinate as the beginning coordinate results in line
	* "CAP" decorations being used at the ends.
	*
	* @see java.awt.Shape
	* @see java.awt.BasicStroke
	*
	* @author Jim Graham
	*/
	public interface PathIterator {
	/**
	* The winding rule constant for specifying an even-odd rule
	* for determining the interior of a path.
	* The even-odd rule specifies that a point lies inside the
	* path if a ray drawn in any direction from that point to
	* infinity is crossed by path segments an odd number of times.
	*/
	public static final int WIND_EVEN_ODD = 0;

	/**
	* The winding rule constant for specifying a non-zero rule
	* for determining the interior of a path.
	* The non-zero rule specifies that a point lies inside the
	* path if a ray drawn in any direction from that point to
	* infinity is crossed by path segments a different number
	* of times in the counter-clockwise direction than the
	* clockwise direction.
	*/
	public static final int WIND_NON_ZERO = 1;

	/**
	* The segment type constant for a point that specifies the
	* starting location for a new subpath.
	*/
	public static final int SEG_MOVETO = 0;

	/**
	* The segment type constant for a point that specifies the
	* end point of a line to be drawn from the most recently
	* specified point.
	*/
	public static final int SEG_LINETO = 1;

	/**
	* The segment type constant for the pair of points that specify
	* a quadratic parametric curve to be drawn from the most recently
	* specified point.
	* The curve is interpolated by solving the parametric control
	* equation in the range <code>(t=[0..1])</code> using
	* the most recently specified (current) point (CP),
	* the first control point (P1),
	* and the final interpolated control point (P2).
	* The parametric control equation for this curve is:
	* <pre>
	* P(t) = B(2,0)CP + B(2,1)P1 + B(2,2)*P2
	* 0 <= t <= 1
	*
	* B(n,m) = mth coefficient of nth degree Bernstein polynomial
	* = C(n,m) * t^(m) * (1 - t)^(n-m)
	* C(n,m) = Combinations of n things, taken m at a time
	* = n! / (m! * (n-m)!)
	* </pre>
	*/
	public static final int SEG_QUADTO = 2;

	/**
	* The segment type constant for the set of 3 points that specify
	* a cubic parametric curve to be drawn from the most recently
	* specified point.
	* The curve is interpolated by solving the parametric control
	* equation in the range <code>(t=[0..1])</code> using
	* the most recently specified (current) point (CP),
	* the first control point (P1),
	* the second control point (P2),
	* and the final interpolated control point (P3).
	* The parametric control equation for this curve is:
	* <pre>
	* P(t) = B(3,0)CP + B(3,1)P1 + B(3,2)P2 + B(3,3)P3
	* 0 <= t <= 1
	*
	* B(n,m) = mth coefficient of nth degree Bernstein polynomial
	* = C(n,m) * t^(m) * (1 - t)^(n-m)
	* C(n,m) = Combinations of n things, taken m at a time
	* = n! / (m! * (n-m)!)
	* </pre>
	* This form of curve is commonly known as a Bézier curve.
	*/
	public static final int SEG_CUBICTO = 3;

	/**
	* The segment type constant that specifies that
	* the preceding subpath should be closed by appending a line segment
	* back to the point corresponding to the most recent SEG_MOVETO.
	*/
	public static final int SEG_CLOSE = 4;

	/**
	* Returns the winding rule for determining the interior of the
	* path.
	* @return the winding rule.
	* @see #WIND_EVEN_ODD
	* @see #WIND_NON_ZERO
	*/
	public int getWindingRule();

	/**
	* Tests if the iteration is complete.
	* @return <code>true</code> if all the segments have
	* been read; <code>false</code> otherwise.
	*/
	public boolean isDone();

	/**
	* Moves the iterator to the next segment of the path forwards
	* along the primary direction of traversal as long as there are
	* more points in that direction.
	*/
	public void next();

	/**
	* Returns the coordinates and type of the current path segment in
	* the iteration.
	* The return value is the path-segment type:
	* SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
	* A float array of length 6 must be passed in and can be used to
	* store the coordinates of the point(s).
	* Each point is stored as a pair of float x,y coordinates.
	* SEG_MOVETO and SEG_LINETO types returns one point,
	* SEG_QUADTO returns two points,
	* SEG_CUBICTO returns 3 points
	* and SEG_CLOSE does not return any points.
	* @param coords an array that holds the data returned from
	* this method
	* @return the path-segment type of the current path segment.
	* @see #SEG_MOVETO
	* @see #SEG_LINETO
	* @see #SEG_QUADTO
	* @see #SEG_CUBICTO
	* @see #SEG_CLOSE
	*/
	public int currentSegment(float[] coords);

	/**
	* Returns the coordinates and type of the current path segment in
	* the iteration.
	* The return value is the path-segment type:
	* SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
	* A double array of length 6 must be passed in and can be used to
	* store the coordinates of the point(s).
	* Each point is stored as a pair of double x,y coordinates.
	* SEG_MOVETO and SEG_LINETO types returns one point,
	* SEG_QUADTO returns two points,
	* SEG_CUBICTO returns 3 points
	* and SEG_CLOSE does not return any points.
	* @param coords an array that holds the data returned from
	* this method
	* @return the path-segment type of the current path segment.
	* @see #SEG_MOVETO
	* @see #SEG_LINETO
	* @see #SEG_QUADTO
	* @see #SEG_CUBICTO
	* @see #SEG_CLOSE
	*/
	public int currentSegment(double[] coords);
	}