61 lines
2 KiB
C#
61 lines
2 KiB
C#
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//
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// Copyright 2020 Electronic Arts Inc.
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//
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// The Command & Conquer Map Editor and corresponding source code is free
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// software: you can redistribute it and/or modify it under the terms of
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// the GNU General Public License as published by the Free Software Foundation,
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// either version 3 of the License, or (at your option) any later version.
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// The Command & Conquer Map Editor and corresponding source code is distributed
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// in the hope that it will be useful, but with permitted additional restrictions
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// under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT
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// distributed with this program. You should have received a copy of the
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// GNU General Public License along with permitted additional restrictions
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// with this program. If not, see https://github.com/electronicarts/CnC_Remastered_Collection
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using System;
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namespace MobiusEditor.Utility
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{
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public class CRC
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{
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static CRC()
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{
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for (var i = 0U; i < 256U; ++i)
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{
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uint crc = i;
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for (var j = 0U; j < 8U; ++j)
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{
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if ((crc & 1U) != 0U)
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{
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crc = (crc >> 1) ^ polynomial;
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}
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else
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{
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crc >>= 1;
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}
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}
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crcTable[i] = crc;
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}
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}
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public static uint Calculate(byte[] bytes)
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{
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if (bytes == null)
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{
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throw new ArgumentNullException("bytes");
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}
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uint remainder = 0xFFFFFFFFU;
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for (var i = 0; i < bytes.Length; ++i)
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{
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uint index = (remainder & 0xFF) ^ bytes[i];
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remainder = (remainder >> 8) ^ crcTable[index];
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}
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return ~remainder;
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}
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private static readonly uint[] crcTable = new uint[256];
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private const uint polynomial = 0xEDB88320;
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}
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}
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