001    /**
002     * ===========================================
003     * LibFonts : a free Java font reading library
004     * ===========================================
005     *
006     * Project Info:  http://reporting.pentaho.org/libfonts/
007     *
008     * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
009     *
010     * This library is free software; you can redistribute it and/or modify it under the terms
011     * of the GNU Lesser General Public License as published by the Free Software Foundation;
012     * either version 2.1 of the License, or (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015     * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016     * See the GNU Lesser General Public License for more details.
017     *
018     * You should have received a copy of the GNU Lesser General Public License along with this
019     * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020     * Boston, MA 02111-1307, USA.
021     *
022     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023     * in the United States and other countries.]
024     *
025     * ------------
026     * $Id: ByteAccessUtilities.java 3523 2007-10-16 11:03:09Z tmorgner $
027     * ------------
028     * (C) Copyright 2006-2007, by Pentaho Corporation.
029     */
030    package org.jfree.fonts;
031    
032    import org.jfree.fonts.encoding.ByteBuffer;
033    import org.jfree.fonts.encoding.CodePointBuffer;
034    import org.jfree.fonts.encoding.Encoding;
035    import org.jfree.fonts.encoding.EncodingException;
036    import org.jfree.fonts.encoding.EncodingRegistry;
037    import org.jfree.fonts.encoding.manual.Utf16LE;
038    
039    /**
040     * Reads byte-data using a Big-Endian access schema. Big-Endian is used for TrueType fonts.
041     *
042     * @author Thomas Morgner
043     */
044    public class ByteAccessUtilities
045    {
046      private ByteAccessUtilities()
047      {
048      }
049    
050      public static int readUShort (final byte[] data, final int pos)
051      {
052        return ((data[pos] & 0xff) << 8) | (data[pos + 1] & 0xff);
053      }
054    
055      public static long readULong (final byte[] data, final int pos)
056      {
057        final int c1 = (data[pos] & 0xff);
058        final int c2 = (data[pos + 1] & 0xff);
059        final int c3 = (data[pos + 2] & 0xff);
060        final int c4 = (data[pos + 3] & 0xff);
061    
062        long retval = ((long) c1 << 24);
063        retval |= (long)c2 << 16;
064        retval |= (long)c3 << 8;
065        retval |= (long)c4;
066        return retval;
067      }
068    
069      public static float readFixed (final byte[] data, final int pos)
070      {
071        final short mantissa = readShort(data, pos);
072        final int fraction = readUShort(data, pos + 2);
073        if (fraction == 0 || mantissa == 0)
074        {
075          return 0;
076        }
077        return (float) mantissa / (fraction / 16384.0f);
078      }
079    
080      public static long readLongDateTime (final byte[] data, final int pos)
081      {
082        final int c1 = (data[pos] & 0xff);
083        final int c2 = (data[pos + 1] & 0xff);
084        final int c3 = (data[pos + 2] & 0xff);
085        final int c4 = (data[pos + 3] & 0xff);
086        final int c5 = (data[pos + 4] & 0xff);
087        final int c6 = (data[pos + 5] & 0xff);
088        final int c7 = (data[pos + 6] & 0xff);
089        final int c8 = (data[pos + 7] & 0xff);
090    
091        long retval = ((long) c1 << 56);
092        retval |= (long)c2 << 48;
093        retval |= (long)c3 << 40;
094        retval |= (long)c4 << 32;
095        retval |= (long)c5 << 24;
096        retval |= (long)c6 << 16;
097        retval |= (long)c7 << 8;
098        retval |= (long)c8;
099        return retval;
100      }
101    
102      public static byte[] readBytes (final byte[] data,
103                                      final int pos, final int length)
104      {
105        final byte[] retval = new byte[length];
106        System.arraycopy(data, pos, retval, 0, length);
107        return retval;
108      }
109    
110      public static short readShort (final byte[] data, final int pos)
111      {
112        return (short) ((data[pos] & 0xff) << 8 | (data[pos + 1] & 0xff));
113      }
114    
115      public static int readLong (final byte[] data, final int pos)
116      {
117        int retval = 0;
118        retval |= (long)(data[pos] & 0xff) << 24;
119        retval |= (long)(data[pos + 1] & 0xff) << 16;
120        retval |= (long)(data[pos + 2] & 0xff) << 8;
121        retval |= (long)(data[pos + 3] & 0xff);
122        return retval;
123      }
124    
125      public static int readZStringOffset (final byte[] data, final int pos, final int maxLength)
126      {
127        final int lastPos = Math.min (pos + maxLength, pos + data.length);
128        for (int i = pos; i < lastPos; i++)
129        {
130          if (data[i] == 0)
131          {
132            return i;
133          }
134        }
135    
136        return lastPos;
137      }
138    
139      public static String readZString (final byte[] data, final int pos, final int maxLength, final String encoding)
140          throws EncodingException
141      {
142        final int lastPos = Math.min (pos + maxLength, pos + data.length);
143        for (int i = pos; i < lastPos; i++)
144        {
145          if (data[i] == 0)
146          {
147            return readString(data, pos, i - pos, encoding);
148          }
149        }
150    
151        return readString(data, pos, lastPos, encoding);
152      }
153    
154      public static String readString (final byte[] data, final int pos,
155                                       final int length, final String encoding)
156              throws EncodingException
157      {
158        final Encoding enc;
159        if ("UTF-16".equals(encoding))
160        {
161          enc = EncodingRegistry.getInstance().getEncoding("UTF-16LE");
162        }
163        else
164        {
165          enc = EncodingRegistry.getInstance().getEncoding(encoding);
166        }
167        final ByteBuffer byteBuffer = new ByteBuffer(data, pos, length);
168        final CodePointBuffer cp = enc.decode(byteBuffer, null);
169        return Utf16LE.getInstance().encodeString(cp);
170      }
171    }