1 /*
2 * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /* ****************************************************************
27 ******************************************************************
28 ******************************************************************
29 *** COPYRIGHT (c) Eastman Kodak Company, 1997
30 *** As an unpublished work pursuant to Title 17 of the United
31 *** States Code. All rights reserved.
32 ******************************************************************
33 ******************************************************************
34 ******************************************************************/
35
36 package java.awt.image;
37
38 import static sun.java2d.StateTrackable.State.*;
39
40 /**
41 * This class extends <CODE>DataBuffer</CODE> and stores data internally as bytes.
42 * Values stored in the byte array(s) of this <CODE>DataBuffer</CODE> are treated as
43 * unsigned values.
44 * <p>
45 * <a name="optimizations">
46 * Note that some implementations may function more efficiently
47 * if they can maintain control over how the data for an image is
48 * stored.
49 * For example, optimizations such as caching an image in video
50 * memory require that the implementation track all modifications
51 * to that data.
52 * Other implementations may operate better if they can store the
53 * data in locations other than a Java array.
54 * To maintain optimum compatibility with various optimizations
55 * it is best to avoid constructors and methods which expose the
56 * underlying storage as a Java array, as noted below in the
57 * documentation for those methods.
58 * </a>
59 */
60 public final class DataBufferByte extends DataBuffer
61 {
62 /** The default data bank. */
63 byte data[];
64
65 /** All data banks */
66 byte bankdata[][];
67
68 /**
69 * Constructs a byte-based <CODE>DataBuffer</CODE> with a single bank and the
70 * specified size.
71 *
72 * @param size The size of the <CODE>DataBuffer</CODE>.
73 */
74 public DataBufferByte(int size) {
75 super(STABLE, TYPE_BYTE, size);
76 data = new byte[size];
77 bankdata = new byte[1][];
78 bankdata[0] = data;
79 }
80
81 /**
82 * Constructs a byte based <CODE>DataBuffer</CODE> with the specified number of
83 * banks all of which are the specified size.
84 *
85 * @param size The size of the banks in the <CODE>DataBuffer</CODE>.
86 * @param numBanks The number of banks in the a<CODE>DataBuffer</CODE>.
87 */
88 public DataBufferByte(int size, int numBanks) {
89 super(STABLE, TYPE_BYTE, size, numBanks);
90 bankdata = new byte[numBanks][];
91 for (int i= 0; i < numBanks; i++) {
92 bankdata[i] = new byte[size];
93 }
94 data = bankdata[0];
95 }
96
97 /**
98 * Constructs a byte-based <CODE>DataBuffer</CODE> with a single bank using the
99 * specified array.
100 * Only the first <CODE>size</CODE> elements should be used by accessors of
101 * this <CODE>DataBuffer</CODE>. <CODE>dataArray</CODE> must be large enough to
102 * hold <CODE>size</CODE> elements.
103 * <p>
104 * Note that {@code DataBuffer} objects created by this constructor
105 * may be incompatible with <a href="#optimizations">performance
106 * optimizations</a> used by some implementations (such as caching
107 * an associated image in video memory).
108 *
109 * @param dataArray The byte array for the <CODE>DataBuffer</CODE>.
110 * @param size The size of the <CODE>DataBuffer</CODE> bank.
111 */
112 public DataBufferByte(byte dataArray[], int size) {
113 super(UNTRACKABLE, TYPE_BYTE, size);
114 data = dataArray;
115 bankdata = new byte[1][];
116 bankdata[0] = data;
117 }
118
119 /**
120 * Constructs a byte-based <CODE>DataBuffer</CODE> with a single bank using the
121 * specified array, size, and offset. <CODE>dataArray</CODE> must have at least
122 * <CODE>offset</CODE> + <CODE>size</CODE> elements. Only elements <CODE>offset</CODE>
123 * through <CODE>offset</CODE> + <CODE>size</CODE> - 1
124 * should be used by accessors of this <CODE>DataBuffer</CODE>.
125 * <p>
126 * Note that {@code DataBuffer} objects created by this constructor
127 * may be incompatible with <a href="#optimizations">performance
128 * optimizations</a> used by some implementations (such as caching
129 * an associated image in video memory).
130 *
131 * @param dataArray The byte array for the <CODE>DataBuffer</CODE>.
132 * @param size The size of the <CODE>DataBuffer</CODE> bank.
133 * @param offset The offset into the <CODE>dataArray</CODE>. <CODE>dataArray</CODE>
134 * must have at least <CODE>offset</CODE> + <CODE>size</CODE> elements.
135 */
136 public DataBufferByte(byte dataArray[], int size, int offset){
137 super(UNTRACKABLE, TYPE_BYTE, size, 1, offset);
138 data = dataArray;
139 bankdata = new byte[1][];
140 bankdata[0] = data;
141 }
142
143 /**
144 * Constructs a byte-based <CODE>DataBuffer</CODE> with the specified arrays.
145 * The number of banks is equal to <CODE>dataArray.length</CODE>.
146 * Only the first <CODE>size</CODE> elements of each array should be used by
147 * accessors of this <CODE>DataBuffer</CODE>.
148 * <p>
149 * Note that {@code DataBuffer} objects created by this constructor
150 * may be incompatible with <a href="#optimizations">performance
151 * optimizations</a> used by some implementations (such as caching
152 * an associated image in video memory).
153 *
154 * @param dataArray The byte arrays for the <CODE>DataBuffer</CODE>.
155 * @param size The size of the banks in the <CODE>DataBuffer</CODE>.
156 */
157 public DataBufferByte(byte dataArray[][], int size) {
158 super(UNTRACKABLE, TYPE_BYTE, size, dataArray.length);
159 bankdata = (byte[][]) dataArray.clone();
160 data = bankdata[0];
161 }
162
163 /**
164 * Constructs a byte-based <CODE>DataBuffer</CODE> with the specified arrays, size,
165 * and offsets.
166 * The number of banks is equal to <CODE>dataArray.length</CODE>. Each array must
167 * be at least as large as <CODE>size</CODE> + the corresponding <CODE>offset</CODE>.
168 * There must be an entry in the <CODE>offset</CODE> array for each <CODE>dataArray</CODE>
169 * entry. For each bank, only elements <CODE>offset</CODE> through
170 * <CODE>offset</CODE> + <CODE>size</CODE> - 1 should be used by accessors of this
171 * <CODE>DataBuffer</CODE>.
172 * <p>
173 * Note that {@code DataBuffer} objects created by this constructor
174 * may be incompatible with <a href="#optimizations">performance
175 * optimizations</a> used by some implementations (such as caching
176 * an associated image in video memory).
177 *
178 * @param dataArray The byte arrays for the <CODE>DataBuffer</CODE>.
179 * @param size The size of the banks in the <CODE>DataBuffer</CODE>.
180 * @param offsets The offsets into each array.
181 */
182 public DataBufferByte(byte dataArray[][], int size, int offsets[]) {
183 super(UNTRACKABLE, TYPE_BYTE, size, dataArray.length, offsets);
184 bankdata = (byte[][]) dataArray.clone();
185 data = bankdata[0];
186 }
187
188 /**
189 * Returns the default (first) byte data array.
190 * <p>
191 * Note that calling this method may cause this {@code DataBuffer}
192 * object to be incompatible with <a href="#optimizations">performance
193 * optimizations</a> used by some implementations (such as caching
194 * an associated image in video memory).
195 *
196 * @return The first byte data array.
197 */
198 public byte[] getData() {
199 theTrackable.setUntrackable();
200 return data;
201 }
202
203 /**
204 * Returns the data array for the specified bank.
205 * <p>
206 * Note that calling this method may cause this {@code DataBuffer}
207 * object to be incompatible with <a href="#optimizations">performance
208 * optimizations</a> used by some implementations (such as caching
209 * an associated image in video memory).
210 *
211 * @param bank The bank whose data array you want to get.
212 * @return The data array for the specified bank.
213 */
214 public byte[] getData(int bank) {
215 theTrackable.setUntrackable();
216 return bankdata[bank];
217 }
218
219 /**
220 * Returns the data arrays for all banks.
221 * <p>
222 * Note that calling this method may cause this {@code DataBuffer}
223 * object to be incompatible with <a href="#optimizations">performance
224 * optimizations</a> used by some implementations (such as caching
225 * an associated image in video memory).
226 *
227 * @return All of the data arrays.
228 */
229 public byte[][] getBankData() {
230 theTrackable.setUntrackable();
231 return (byte[][]) bankdata.clone();
232 }
233
234 /**
235 * Returns the requested data array element from the first (default) bank.
236 *
237 * @param i The data array element you want to get.
238 * @return The requested data array element as an integer.
239 * @see #setElem(int, int)
240 * @see #setElem(int, int, int)
241 */
242 public int getElem(int i) {
243 return (int)(data[i+offset]) & 0xff;
244 }
245
246 /**
247 * Returns the requested data array element from the specified bank.
248 *
249 * @param bank The bank from which you want to get a data array element.
250 * @param i The data array element you want to get.
251 * @return The requested data array element as an integer.
252 * @see #setElem(int, int)
253 * @see #setElem(int, int, int)
254 */
255 public int getElem(int bank, int i) {
256 return (int)(bankdata[bank][i+offsets[bank]]) & 0xff;
257 }
258
259 /**
260 * Sets the requested data array element in the first (default) bank
261 * to the specified value.
262 *
263 * @param i The data array element you want to set.
264 * @param val The integer value to which you want to set the data array element.
265 * @see #getElem(int)
266 * @see #getElem(int, int)
267 */
268 public void setElem(int i, int val) {
269 data[i+offset] = (byte)val;
270 theTrackable.markDirty();
271 }
272
273 /**
274 * Sets the requested data array element in the specified bank
275 * from the given integer.
276 * @param bank The bank in which you want to set the data array element.
277 * @param i The data array element you want to set.
278 * @param val The integer value to which you want to set the specified data array element.
279 * @see #getElem(int)
280 * @see #getElem(int, int)
281 */
282 public void setElem(int bank, int i, int val) {
283 bankdata[bank][i+offsets[bank]] = (byte)val;
284 theTrackable.markDirty();
285 }
286 }