001    /* DataBufferUShort.java --
002       Copyright (C) 2000, 2002, 2004, 2005 Free Software Foundation
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package java.awt.image;
039    
040    /* This is one of several classes that are nearly identical. Maybe we
041       should have a central template and generate all these files. This
042       is one of the cases where templates or macros would have been
043       useful to have in Java.
044    
045       This file has been created using search-replace. My only fear is
046       that these classes will grow out-of-sync as of a result of changes
047       that are not propagated to the other files. As always, mirroring
048       code is a maintenance nightmare.  */
049    
050    /**
051     * A {@link DataBuffer} that uses an array of <code>short</code> primitives
052     * to represent each of its banks.
053     *
054     * @author Rolf W. Rasmussen (rolfwr@ii.uib.no)
055     */
056    public final class DataBufferUShort extends DataBuffer
057    {
058      private short[] data;
059      private short[][] bankData;
060    
061      /**
062       * Creates a new data buffer with a single data bank containing the
063       * specified number of <code>short</code> elements.
064       *
065       * @param size the number of elements in the data bank.
066       */
067      public DataBufferUShort(int size)
068      {
069        super(TYPE_USHORT, size, 1, 0);
070        bankData = new short[1][];
071        data = new short[size];
072        bankData[0] = data;
073      }
074    
075      /**
076       * Creates a new data buffer with the specified number of data banks,
077       * each containing the specified number of <code>short</code> elements.
078       *
079       * @param size the number of elements in the data bank.
080       * @param numBanks the number of data banks.
081       */
082      public DataBufferUShort(int size, int numBanks)
083      {
084        super(TYPE_USHORT, size, numBanks);
085        bankData = new short[numBanks][size];
086        data = bankData[0];
087      }
088    
089      /**
090       * Creates a new data buffer backed by the specified data bank.
091       *
092       * @param dataArray the data bank.
093       * @param size the number of elements in the data bank.
094       *
095       * @throws NullPointerException if dataArray is null
096       */
097      public DataBufferUShort(short[] dataArray, int size)
098      {
099        super(TYPE_USHORT, size, 1, 0);
100        if (dataArray == null)
101          throw new NullPointerException();
102        bankData = new short[1][];
103        data = dataArray;
104        bankData[0] = data;
105      }
106    
107      /**
108       * Creates a new data buffer backed by the specified data bank, with
109       * the specified offset to the first element.
110       *
111       * @param dataArray the data bank.
112       * @param size the number of elements in the data bank.
113       * @param offset the offset to the first element in the array.
114       *
115       * @throws NullPointerException if dataArray is null
116       */
117      public DataBufferUShort(short[] dataArray, int size, int offset)
118      {
119        super(TYPE_USHORT, size, 1, offset);
120        if (dataArray == null)
121          throw new NullPointerException();
122        bankData = new short[1][];
123        data = dataArray;
124        bankData[0] = data;
125      }
126    
127      /**
128       * Creates a new data buffer backed by the specified data banks.
129       *
130       * @param dataArray the data banks.
131       * @param size the number of elements in the data bank.
132       *
133       * @throws NullPointerException if <code>dataArray</code> is
134       *         <code>null</code>.
135       */
136      public DataBufferUShort(short[][] dataArray, int size)
137      {
138        super(TYPE_USHORT, size, dataArray.length);
139        bankData = dataArray;
140        data = bankData[0];
141      }
142    
143      /**
144       * Creates a new data buffer backed by the specified data banks, with
145       * the specified offsets to the first element in each bank.
146       *
147       * @param dataArray the data banks.
148       * @param size the number of elements in the data bank.
149       * @param offsets the offsets to the first element in each data bank.
150       *
151       * @throws NullPointerException if <code>dataArray</code> is
152       *         <code>null</code>.
153       */
154      public DataBufferUShort(short[][] dataArray, int size, int[] offsets)
155      {
156        super(TYPE_USHORT, size, dataArray.length, offsets);
157        bankData = dataArray;
158        data = bankData[0];
159      }
160    
161      /**
162       * Returns the first data bank.
163       *
164       * @return The first data bank.
165       */
166      public short[] getData()
167      {
168        return data;
169      }
170    
171      /**
172       * Returns a data bank.
173       *
174       * @param bank the bank index.
175       * @return A data bank.
176       */
177      public short[] getData(int bank)
178      {
179        return bankData[bank];
180      }
181    
182      /**
183       * Returns the array underlying this <code>DataBuffer</code>.
184       *
185       * @return The data banks.
186       */
187      public short[][] getBankData()
188      {
189        return bankData;
190      }
191    
192      /**
193       * Returns an element from the first data bank.  The offset (specified in
194       * the constructor) is added to <code>i</code> before accessing the
195       * underlying data array.
196       *
197       * @param i the element index.
198       * @return The element.
199       */
200      public int getElem(int i)
201      {
202        return data[i+offset] & 0xffff; // get unsigned short as int
203      }
204    
205      /**
206       * Returns an element from a particular data bank.  The offset (specified in
207       * the constructor) is added to <code>i</code> before accessing the
208       * underlying data array.
209       *
210       * @param bank the bank index.
211       * @param i the element index.
212       * @return The element.
213       */
214      public int getElem(int bank, int i)
215      {
216        // get unsigned short as int
217        return bankData[bank][i+offsets[bank]] & 0xffff;
218      }
219    
220      /**
221       * Sets an element in the first data bank.  The offset (specified in the
222       * constructor) is added to <code>i</code> before updating the underlying
223       * data array.
224       *
225       * @param i the element index.
226       * @param val the new element value.
227       */
228      public void setElem(int i, int val)
229      {
230        data[i+offset] = (short) val;
231      }
232    
233      /**
234       * Sets an element in a particular data bank.  The offset (specified in the
235       * constructor) is added to <code>i</code> before updating the underlying
236       * data array.
237       *
238       * @param bank the data bank index.
239       * @param i the element index.
240       * @param val the new element value.
241       */
242      public void setElem(int bank, int i, int val)
243      {
244        bankData[bank][i+offsets[bank]] = (short) val;
245      }
246    }