| /* LookupTable.java -- Java class for a pixel translation table. |
| Copyright (C) 2004, 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.awt.image; |
| |
| /** |
| * LookupTable represents translation arrays for pixel values. It wraps one |
| * or more data arrays for each layer (or component) in an image, such as |
| * Alpha, R, G, and B. When doing translation, the offset is subtracted from |
| * the pixel values to allow a subset of an array to be used. |
| * |
| * @see ByteLookupTable |
| * @see ShortLookupTable |
| * |
| * @author Jerry Quinn (jlquinn@optonline.net) |
| * @version 1.0 |
| */ |
| public abstract class LookupTable |
| { |
| // Not protected since that's part of the public API. |
| int offset; |
| int numComponents; |
| |
| /** |
| * Creates a new <code>LookupTable</code> instance. |
| * |
| * If numComponents is 1, the same translation table is used for all pixel |
| * components. |
| * |
| * @param offset Offset to be subtracted. |
| * @param numComponents Number of image components. |
| * @exception IllegalArgumentException if offset < 0 or numComponents < 1. |
| */ |
| protected LookupTable(int offset, int numComponents) |
| throws IllegalArgumentException |
| { |
| if (offset < 0 || numComponents < 1) |
| throw new IllegalArgumentException(); |
| this.offset = offset; |
| this.numComponents = numComponents; |
| } |
| |
| /** Return the number of components. */ |
| public int getNumComponents() |
| { |
| return numComponents; |
| } |
| |
| /** Return the offset. */ |
| public int getOffset() |
| { |
| return offset; |
| } |
| |
| |
| /** |
| * Return translated values for a pixel. |
| * |
| * For each value in the pixel src, use the value minus offset as an index |
| * in the component array and copy the value there to the output for the |
| * component. If dest is null, the output is a new array, otherwise the |
| * translated values are written to dest. Dest can be the same array as |
| * src. |
| * |
| * For example, if the pixel src is [2, 4, 3], and offset is 1, the output |
| * is [comp1[1], comp2[3], comp3[2]], where comp1, comp2, and comp3 are the |
| * translation arrays. |
| * |
| * @param src Component values of a pixel. |
| * @param dest Destination array for values, or null. |
| * @return Translated values for the pixel. |
| */ |
| public abstract int[] lookupPixel(int[] src, int[] dest); |
| } |