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source: code/trunk/src/libraries/util/CRC32.cc @ 12227

Last change on this file since 12227 was 5738, checked in by landauf, 15 years ago

merged libraries2 back to trunk

  • Property svn:eol-style set to native
File size: 1.9 KB
RevLine 
[1742]1/*
2 *   ORXONOX - the hottest 3D action shooter ever to exist
3 *                    > www.orxonox.net <
4 *
5 *
6 *   License notice:
7 *
8 *   This program is free software; you can redistribute it and/or
9 *   modify it under the terms of the GNU General Public License
10 *   as published by the Free Software Foundation; either version 2
11 *   of the License, or (at your option) any later version.
12 *
13 *   This program is distributed in the hope that it will be useful,
14 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
15 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 *   GNU General Public License for more details.
17 *
18 *   You should have received a copy of the GNU General Public License
19 *   along with this program; if not, write to the Free Software
20 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
21 *
22 *   Author:
[1791]23 *      ...
[1742]24 *   Co-authors:
25 *      ...
26 *
27 */
28
29#include "CRC32.h"
30
[2171]31namespace orxonox
32{
33    void calcCRCBit(uint32_t &crc32, int bit)
34    {
35        int hbit = (crc32 & 0x80000000) ? 1 : 0;
36        if (hbit != bit)
37            crc32 = (crc32 << 1) ^ UTIL_CRC32POLY;
38        else
39            crc32 = crc32 << 1;
40      }
[1742]41
[2171]42    uint32_t calcCRC(unsigned char *data, unsigned int dataLength)
43    {
44        uint32_t crc32 = 0;
45        for(unsigned int i = 0; i < dataLength; i++)
46        {
47            calcCRCBit(crc32, (data[i] & 0x1) >> 0); // 1st bit
48            calcCRCBit(crc32, (data[i] & 0x2) >> 1); // 2nd bit
49            calcCRCBit(crc32, (data[i] & 0x3) >> 2); // 3rd bit
50            calcCRCBit(crc32, (data[i] & 0x4) >> 3); // 4th bit
51            calcCRCBit(crc32, (data[i] & 0x5) >> 4); // 5th bit
52            calcCRCBit(crc32, (data[i] & 0x6) >> 5); // 6th bit
53            calcCRCBit(crc32, (data[i] & 0x7) >> 6); // 7th bit
54            calcCRCBit(crc32, (data[i] & 0x8) >> 7); // 8th bit
55        }
56        return crc32;
[1742]57    }
[2171]58}
[1742]59
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