sources/org/apache/batik/ext/awt/geom/ExtendedPathIterator.java

/*

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */
package org.apache.batik.ext.awt.geom;

import java.awt.geom.PathIterator;

/**
 * The <code>ExtendedPathIterator</code> class represents a geometric
 * path constructed from straight lines, quadratic and cubic (Bezier)
 * curves and elliptical arcs.  This interface is identical to that of
 * PathIterator except it can return SEG_ARCTO from currentSegment,
 * also the array of values passed to currentSegment must be of length
 * 7 or an error will be thrown.
 * 
 * This does not extend PathIterator as it would break the interface
 * contract for that class.
 *
 * @author <a href="mailto:deweese@apache.org">Thomas DeWeese</a>
 * @version $Id$
 */
public interface ExtendedPathIterator {

    /**
     * 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.
     */
    int SEG_CLOSE   = PathIterator.SEG_CLOSE;

    /** 
     * The segment type constant for a point that specifies the end
     * point of a line to be drawn from the most recently specified
     * point.  */
    int SEG_MOVETO  = PathIterator.SEG_MOVETO;

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

    /**
     * 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 (t=[0..1]) using the
     * most recently specified (current) point (CP), the first control
     * point (P1), and the final interpolated control point (P2). 
     */
    int SEG_QUADTO  = PathIterator.SEG_QUADTO;

    /**
     * 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 (t=[0..1]) 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).
     */
    int SEG_CUBICTO = PathIterator.SEG_CUBICTO;

    /** The segment type constant for an elliptical arc.  This consists of
     *  Seven values [rx, ry, angle, largeArcFlag, sweepFlag, x, y].
     *  rx, ry are the radious of the ellipse.
     *  angle is angle of the x axis of the ellipse.
     *  largeArcFlag is zero if the smaller of the two arcs are to be used.
     *  sweepFlag is zero if the 'left' branch is taken one otherwise.
     *  x and y are the destination for the ellipse.  */
    int SEG_ARCTO = 4321;

    /** 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.  
     */ 
    int WIND_EVEN_ODD = PathIterator.WIND_EVEN_ODD; 

    /**
     * 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.
     */
    int WIND_NON_ZERO = PathIterator.WIND_NON_ZERO;

    int currentSegment();
    int currentSegment(double[] coords);
    int currentSegment(float[] coords);
    int getWindingRule(); 
    boolean isDone();
    void next();
}