/* * Copyright (c) 2007, 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; /** * The API for an object that generates alpha coverage tiles for a given * path. * The {@link RenderingEngine} will be consulted as a factory to return * one of these objects for a given Shape and a given set of rendering * attributes. * This object will iterate through the bounds of the rendering primitive * and return tiles of a constant size as specified by the getTileWidth() * and getTileHeight() parameters. * The iteration order of the tiles will be as specified by the pseudo-code: * <pre> *     int bbox[] = {left, top, right, bottom}; *     AATileGenerator aatg = renderengine.getAATileGenerator(..., bbox); *     int tw = aatg.getTileWidth(); *     int th = aatg.getTileHeight(); *     byte tile[] = new byte[tw * th]; *     for (y = top; y < bottom; y += th) { *         for (x = left; x < right; x += tw) { *             int a = aatg.getTypicalAlpha(); *             int w = Math.min(tw, right-x); *             int h = Math.min(th, bottom-y); *             if (a == 0x00) { *                 // can skip this tile... *                 aatg.nextTile(); *             } else if (a == 0xff) { *                 // can treat this tile like a fillRect *                 aatg.nextTile(); *                 doFill(x, y, w, h); *             } else { *                 aatg.getAlpha(tile, 0, tw); *                 handleAlpha(tile, x, y, w, h); *             } *         } *     } *     aatg.dispose(); * </pre> * The bounding box for the iteration will be returned by the * {@code RenderingEngine} via an argument to the getAATileGenerator() method. */public interface AATileGenerator {    /**     * Gets the width of the tiles that the generator batches output into.     * @return the width of the standard alpha tile     */    public int getTileWidth();     /**     * Gets the height of the tiles that the generator batches output into.     * @return the height of the standard alpha tile     */    public int getTileHeight();     /**     * Gets the typical alpha value that will characterize the current     * tile.     * The answer may be 0x00 to indicate that the current tile has     * no coverage in any of its pixels, or it may be 0xff to indicate     * that the current tile is completely covered by the path, or any     * other value to indicate non-trivial coverage cases.     * @return 0x00 for no coverage, 0xff for total coverage, or any other     *         value for partial coverage of the tile     */    public int getTypicalAlpha();     /**     * Skips the current tile and moves on to the next tile.     * Either this method, or the getAlpha() method should be called     * once per tile, but not both.     */    public void nextTile();     /**     * Gets the alpha coverage values for the current tile.     * Either this method, or the nextTile() method should be called     * once per tile, but not both.     */    public void getAlpha(byte tile[], int offset, int rowstride);     /**     * Disposes this tile generator.     * No further calls will be made on this instance.     */    public void dispose();}