src/main/java/org/apache/xmlgraphics/image/rendered/CachableRed.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.
 */

/* $Id$ */

package org.apache.xmlgraphics.image.rendered;

import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.image.RenderedImage;

/**
 * This provides a number of extra methods that enable a system to
 * better analyse the dependencies between nodes in a render graph.
 *
 * @version $Id$
 *
 * Originally authored by Thomas DeWeese.
*/
public interface CachableRed extends RenderedImage {

    /**
     * Returns the bounds of the current image.
     * This should be 'in sync' with getMinX, getMinY, getWidth, getHeight
     */
    Rectangle getBounds();

    /**
     * Returns the region of input data is is required to generate
     * outputRgn.
     * @param srcIndex  The source to do the dependency calculation for.
     * @param outputRgn The region of output you are interested in
     * generating dependencies for.  The is given in the output pixel
     * coordiate system for this node.
     * @return The region of input required.  This is in the output pixel
     * coordinate system for the source indicated by srcIndex.
     */
    Shape getDependencyRegion(int srcIndex, Rectangle outputRgn);

    /**
     * This calculates the region of output that is affected by a change
     * in a region of input.
     * @param srcIndex The input that inputRgn reflects changes in.
     * @param inputRgn the region of input that has changed, used to
     *  calculate the returned shape.  This is given in the pixel
     *  coordinate system of the source indicated by srcIndex.
     * @return The region of output that would be invalid given
     *  a change to inputRgn of the source selected by srcIndex.
     *  this is in the output pixel coordinate system of this node.
     */
    Shape getDirtyRegion(int srcIndex, Rectangle inputRgn);
}