19fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream/* 29fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamCopyright (C) 1996-1997 Id Software, Inc. 39fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 49fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamThis program is free software; you can redistribute it and/or 59fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreammodify it under the terms of the GNU General Public License 69fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamas published by the Free Software Foundation; either version 2 79fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamof the License, or (at your option) any later version. 89fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 99fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamThis program is distributed in the hope that it will be useful, 109fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreambut WITHOUT ANY WARRANTY; without even the implied warranty of 119fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 129fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 139fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamSee the GNU General Public License for more details. 149fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 159fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamYou should have received a copy of the GNU General Public License 169fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamalong with this program; if not, write to the Free Software 179fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamFoundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 189fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 199fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream*/ 209fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream/* crc.c */ 219fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 229fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream#include "quakedef.h" 239fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream#include "crc.h" 249fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 259fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream// this is a 16 bit, non-reflected CRC using the polynomial 0x1021 269fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream// and the initial and final xor values shown below... in other words, the 279fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream// CCITT standard CRC used by XMODEM 289fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 299fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream#define CRC_INIT_VALUE 0xffff 309fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream#define CRC_XOR_VALUE 0x0000 319fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 329fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamstatic unsigned short crctable[256] = 339fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream{ 349fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 359fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, 369fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, 379fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, 389fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485, 399fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, 409fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4, 419fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc, 429fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823, 439fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b, 449fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, 459fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, 469fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41, 479fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, 489fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70, 499fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78, 509fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, 519fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067, 529fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, 539fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256, 549fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, 559fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 569fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c, 579fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634, 589fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, 599fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3, 609fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, 619fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92, 629fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, 639fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, 649fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, 659fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0 669fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream}; 679fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 689fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamvoid CRC_Init(unsigned short *crcvalue) 699fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream{ 709fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream *crcvalue = CRC_INIT_VALUE; 719fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream} 729fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 739fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamvoid CRC_ProcessByte(unsigned short *crcvalue, byte data) 749fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream{ 759fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream *crcvalue = (*crcvalue << 8) ^ crctable[(*crcvalue >> 8) ^ data]; 769fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream} 779fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 789fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamunsigned short CRC_Value(unsigned short crcvalue) 799fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream{ 809fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream return crcvalue ^ CRC_XOR_VALUE; 819fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream} 829fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 839fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstreamunsigned short CRC_Block (byte *start, int count) 849fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream{ 859fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream unsigned short crc; 869fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 879fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream CRC_Init (&crc); 889fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream while (count--) 899fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream crc = (crc << 8) ^ crctable[(crc >> 8) ^ *start++]; 909fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 919fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream return crc; 929fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream} 939fd67c44777b350dc56f3e70c88963b0d966ffc7quake upstream 94