mirror of
https://github.com/electronicarts/CnC_Remastered_Collection
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03416d24e1
Initial commit of original Tiberian Dawn and Red Alert source code converted to build as DLLs, and compatible with the release version of Command & Conquer Remastered.
119 lines
4.7 KiB
C++
119 lines
4.7 KiB
C++
//
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// Copyright 2020 Electronic Arts Inc.
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//
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// TiberianDawn.DLL and RedAlert.dll 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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// TiberianDawn.DLL and RedAlert.dll 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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/* $Header: /CounterStrike/CRC.H 1 3/03/97 10:24a Joe_bostic $ */
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/***********************************************************************************************
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*** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S ***
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***********************************************************************************************
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* *
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* Project Name : Command & Conquer *
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* *
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* File Name : CRC.H *
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* *
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* Programmer : Joe L. Bostic *
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* *
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* Start Date : 03/02/96 *
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* *
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* Last Update : March 2, 1996 [JLB] *
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* *
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*---------------------------------------------------------------------------------------------*
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* Functions: *
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* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
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#ifndef CRC_H
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#define CRC_H
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#include <stdlib.h>
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/*
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** The "bool" integral type was defined by the C++ comittee in
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** November of '94. Until the compiler supports this, use the following
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** definition.
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*/
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#ifndef __BORLANDC__
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#ifndef TRUE_FALSE_DEFINED
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#define TRUE_FALSE_DEFINED
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enum {false=0,true=1};
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typedef int bool;
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#endif
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#endif
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/*
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** This is a CRC engine class. It will process submitted data and generate a CRC from it.
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** Well, actually, the value returned is not a true CRC. However, it shares the same strength
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** characteristic and is faster to generate than the traditional CRC. This object is treated like
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** a method class. If it is called as a function (using the function operator), it will return
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** the CRC value. There are other function operators to submit data for processing.
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*/
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class CRCEngine {
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public:
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// Constructor for CRC engine (it can have an override initial CRC value).
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CRCEngine(long initial=0) : CRC(initial), Index(0) {
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StagingBuffer.Composite = 0;
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};
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// Fetches CRC value.
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long operator() (void) const {return(Value());};
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// Submits one byte sized datum to the CRC accumulator.
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void operator() (char datum);
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// Submits an arbitrary buffer to the CRC accumulator.
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long operator() (void const * buffer, int length);
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// Implicit conversion operator so this object appears like a 'long integer'.
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operator long(void) const {return(Value());};
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protected:
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bool Buffer_Needs_Data(void) const {
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return(Index != 0);
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};
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long Value(void) const {
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if (Buffer_Needs_Data()) {
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return(_lrotl(CRC, 1) + StagingBuffer.Composite);
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}
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return(CRC);
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};
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/*
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** Current accumulator of the CRC value. This value doesn't take into
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** consideration any pending data in the staging buffer.
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*/
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long CRC;
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/*
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** This is the sub index into the staging buffer used to keep track of
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** partial data blocks as they are submitted to the CRC engine.
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*/
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int Index;
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/*
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** This is the buffer that holds the incoming partial data. When the buffer
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** is filled, the value is transformed into the CRC and the buffer is flushed
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** in preparation for additional data.
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*/
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union {
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long Composite;
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char Buffer[sizeof(long)];
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} StagingBuffer;
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};
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#endif
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