| /* |
| * 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(); |
| } |