/*

 * Copyright (c) 1998, 2012, 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 sun.java2d.pipe;

import java.awt.Rectangle;

/**

 * This class defines the API for iterating through the bands

 * of a region object.

 */

public class RegionIterator {

    Region region;

    int curIndex;

    int numXbands;

    RegionIterator(Region r) {

        region = r;

    }

    /**

     * Returns a new RegionIterator object representing the same

     * iteration state as this object to allow multiple iteration

     * branches from the current position.

     */

    public RegionIterator createCopy() {

        RegionIterator r = new RegionIterator(region);

        r.curIndex = this.curIndex;

        r.numXbands = this.numXbands;

        return r;

    }

    /**

     * Copies the iteration state from this RegionIterator object

     * into another RegionIterator object to allow multiple iteration

     * branches from the current position.

     */

    public void copyStateFrom(RegionIterator ri) {

        if (this.region != ri.region) {

            throw new InternalError("region mismatch");

        }

        this.curIndex = ri.curIndex;

        this.numXbands = ri.numXbands;

    }

    /**

     * Moves the iteration state to the beginning of the next

     * Y range in the region returning true if one is found

     * and recording the low and high Y coordinates of the

     * range in the array at locations 1 and 3 respectively.

     */

    public boolean nextYRange(int range[]) {

        curIndex += numXbands * 2;

        numXbands = 0;

        if (curIndex >= region.endIndex) {

            return false;

        }

        range[1] = region.bands[curIndex++];

        range[3] = region.bands[curIndex++];

        numXbands = region.bands[curIndex++];

        return true;

    }

    /**

     * Moves the iteration state to the beginning of the next

     * X band in the current Y range returning true if one is

     * found and recording the low and high X coordinates of

     * the range in the array at locations 0 and 2 respectively.

     */

    public boolean nextXBand(int range[]) {

        if (numXbands <= 0) {

            return false;

        }

        numXbands--;

        range[0] = region.bands[curIndex++];

        range[2] = region.bands[curIndex++];

        return true;

    }

}