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update crc

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iikorni
2026-08-31 18:59:54 -05:00
parent da2a9a8fbc
commit 01a368e019
2 changed files with 67 additions and 71 deletions
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Quake/crc.cpp
+21 -22
View File
@@ -1,6 +1,7 @@
/*
Copyright (C) 1996-2001 Id Software, Inc.
Copyright (C) 2002-2009 John Fitzgibbons and others
Copyright (C) 2026 iikorni
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
@@ -18,7 +19,6 @@ along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* crc.c */
#include "quakedef.hpp"
#include "crc.hpp"
@@ -27,10 +27,10 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
// and the initial and final xor values shown below... in other words, the
// CCITT standard CRC used by XMODEM
#define CRC_INIT_VALUE 0xffff
#define CRC_XOR_VALUE 0x0000
constexpr unsigned short CRC_INIT_VALUE = 0xFFFF;
constexpr unsigned short CRC_XOR_VALUE = 0x0000;
static const unsigned short crctable[256] =
constexpr unsigned short CRC_TABLE[256] =
{
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
@@ -66,29 +66,28 @@ static const unsigned short crctable[256] =
0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
};
void CRC_Init(unsigned short *crcvalue)
{
*crcvalue = CRC_INIT_VALUE;
}
namespace crc {
void init(unsigned short *val) {
*val = CRC_INIT_VALUE;
}
void CRC_ProcessByte(unsigned short *crcvalue, byte data)
{
*crcvalue = (*crcvalue << 8) ^ crctable[(*crcvalue >> 8) ^ data];
}
void process_byte(unsigned short *val, const byte data) {
*val = (*val << 8) ^ CRC_TABLE[(*val >> 8) ^ data];
}
unsigned short CRC_Value(unsigned short crcvalue)
{
return crcvalue ^ CRC_XOR_VALUE;
}
unsigned short value(const unsigned short val) {
return val ^ CRC_XOR_VALUE;
}
//johnfitz -- texture crc
unsigned short CRC_Block (const byte *start, int count)
{
unsigned short block(const byte *start, int count) {
unsigned short crc;
CRC_Init (&crc);
while (count--)
crc = (crc << 8) ^ crctable[(crc >> 8) ^ *start++];
init(&crc);
while (count--) {
crc = (crc << 8) ^ CRC_TABLE[(crc >> 8) ^ *start++];
}
return crc;
}
}
Quake/crc.hpp
+8 -11
View File
@@ -1,6 +1,7 @@
/*
Copyright (C) 1996-2001 Id Software, Inc.
Copyright (C) 2002-2009 John Fitzgibbons and others
Copyright (C) 2026 iikorni
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
@@ -19,15 +20,11 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef _QUAKE_CRC_H
#define _QUAKE_CRC_H
/* crc.h */
void CRC_Init(unsigned short *crcvalue);
void CRC_ProcessByte(unsigned short *crcvalue, byte data);
unsigned short CRC_Value(unsigned short crcvalue);
unsigned short CRC_Block (const byte *start, int count); //johnfitz -- texture crc
#endif /* _QUAKE_CRC_H */
#pragma once
namespace crc {
void init(unsigned short *val);
void process_byte(unsigned short *val, byte data);
unsigned short value(unsigned short val);
unsigned short block(const byte *start, int count);
}