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1: /* ByteLookupTable.java -- Java class for a pixel translation table. 2: Copyright (C) 2004, 2005, 2006, Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package java.awt.image; 40: 41: /** 42: * ByteLookupTable represents translation arrays for pixel values. It wraps 43: * one or more data arrays for each layer (or component) in an image, such as 44: * Alpha, R, G, and B. When doing translation, the offset is subtracted from 45: * the pixel values to allow a subset of an array to be used. 46: * 47: * @author Jerry Quinn (jlquinn@optonline.net) 48: * @version 1.0 49: */ 50: public class ByteLookupTable extends LookupTable 51: { 52: // Array of translation tables. 53: private byte data[][]; 54: 55: /** 56: * Creates a new <code>ByteLookupTable</code> instance. 57: * 58: * Offset is subtracted from pixel values when looking up in the translation 59: * tables. If data.length is one, the same table is applied to all pixel 60: * components. 61: * 62: * @param offset Offset to be subtracted. 63: * @param data Array of lookup tables (<code>null</code> not permitted). 64: * @exception IllegalArgumentException if offset < 0 or data.length < 1. 65: */ 66: public ByteLookupTable(int offset, byte[][] data) 67: throws IllegalArgumentException 68: { 69: super(offset, data.length); 70: 71: // tests show that Sun's implementation creates a new array to store the 72: // references from the incoming 'data' array - not sure why, but we'll 73: // match that behaviour just in case it matters... 74: this.data = new byte[data.length][]; 75: for (int i = 0; i < data.length; i++) 76: this.data[i] = data[i]; 77: } 78: 79: /** 80: * Creates a new <code>ByteLookupTable</code> instance. 81: * 82: * Offset is subtracted from pixel values when looking up in the translation 83: * table. The same table is applied to all pixel components. 84: * 85: * @param offset Offset to be subtracted. 86: * @param data Lookup table for all components (<code>null</code> not 87: * permitted). 88: * @exception IllegalArgumentException if offset < 0. 89: */ 90: public ByteLookupTable(int offset, byte[] data) 91: throws IllegalArgumentException 92: { 93: super(offset, 1); 94: if (data == null) 95: throw new NullPointerException("Null 'data' argument."); 96: this.data = new byte[][] {data}; 97: } 98: 99: /** 100: * Return the lookup tables. 101: * 102: * @return the tables 103: */ 104: public final byte[][] getTable() 105: { 106: return data; 107: } 108: 109: /** 110: * Return translated values for a pixel. 111: * 112: * For each value in the pixel src, use the value minus offset as an index 113: * in the component array and copy the value there to the output for the 114: * component. If dest is null, the output is a new array, otherwise the 115: * translated values are written to dest. Dest can be the same array as 116: * src. 117: * 118: * For example, if the pixel src is [2, 4, 3], and offset is 1, the output 119: * is [comp1[1], comp2[3], comp3[2]], where comp1, comp2, and comp3 are the 120: * translation arrays. 121: * 122: * @param src Component values of a pixel. 123: * @param dst Destination array for values, or null. 124: * @return Translated values for the pixel. 125: */ 126: public int[] lookupPixel(int[] src, int[] dst) 127: throws ArrayIndexOutOfBoundsException 128: { 129: if (dst == null) 130: dst = new int[src.length]; 131: 132: if (data.length == 1) 133: for (int i=0; i < src.length; i++) 134: dst[i] = data[0][src[i] - offset]; 135: else 136: for (int i=0; i < src.length; i++) 137: dst[i] = data[i][src[i] - offset]; 138: 139: return dst; 140: } 141: 142: /** 143: * Return translated values for a pixel. 144: * 145: * For each value in the pixel src, use the value minus offset as an index 146: * in the component array and copy the value there to the output for the 147: * component. If dest is null, the output is a new array, otherwise the 148: * translated values are written to dest. Dest can be the same array as 149: * src. 150: * 151: * For example, if the pixel src is [2, 4, 3], and offset is 1, the output 152: * is [comp1[1], comp2[3], comp3[2]], where comp1, comp2, and comp3 are the 153: * translation arrays. 154: * 155: * @param src Component values of a pixel. 156: * @param dst Destination array for values, or null. 157: * @return Translated values for the pixel. 158: */ 159: public byte[] lookupPixel(byte[] src, byte[] dst) 160: throws ArrayIndexOutOfBoundsException 161: { 162: if (dst == null) 163: dst = new byte[src.length]; 164: 165: if (data.length == 1) 166: for (int i=0; i < src.length; i++) 167: dst[i] = data[0][((int)src[i]) - offset]; 168: else 169: for (int i=0; i < src.length; i++) 170: dst[i] = data[i][((int)src[i]) - offset]; 171: 172: return dst; 173: 174: } 175: }