mirror of
https://github.com/dhewm/dhewm3.git
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155 lines
4.1 KiB
C++
155 lines
4.1 KiB
C++
/*
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===========================================================================
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Doom 3 GPL Source Code
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Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
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This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).
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Doom 3 Source Code is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Doom 3 Source Code is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
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In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
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If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
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===========================================================================
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*/
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#include "../precompiled.h"
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#pragma hdrstop
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int idHashIndex::INVALID_INDEX[1] = { -1 };
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/*
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================
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idHashIndex::Init
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================
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*/
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void idHashIndex::Init( const int initialHashSize, const int initialIndexSize ) {
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assert( idMath::IsPowerOfTwo( initialHashSize ) );
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hashSize = initialHashSize;
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hash = INVALID_INDEX;
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indexSize = initialIndexSize;
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indexChain = INVALID_INDEX;
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granularity = DEFAULT_HASH_GRANULARITY;
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hashMask = hashSize - 1;
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lookupMask = 0;
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}
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/*
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================
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idHashIndex::Allocate
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================
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*/
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void idHashIndex::Allocate( const int newHashSize, const int newIndexSize ) {
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assert( idMath::IsPowerOfTwo( newHashSize ) );
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Free();
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hashSize = newHashSize;
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hash = new int[hashSize];
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memset( hash, 0xff, hashSize * sizeof( hash[0] ) );
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indexSize = newIndexSize;
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indexChain = new int[indexSize];
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memset( indexChain, 0xff, indexSize * sizeof( indexChain[0] ) );
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hashMask = hashSize - 1;
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lookupMask = -1;
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}
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/*
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================
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idHashIndex::Free
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================
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*/
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void idHashIndex::Free( void ) {
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if ( hash != INVALID_INDEX ) {
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delete[] hash;
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hash = INVALID_INDEX;
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}
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if ( indexChain != INVALID_INDEX ) {
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delete[] indexChain;
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indexChain = INVALID_INDEX;
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}
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lookupMask = 0;
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}
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/*
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================
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idHashIndex::ResizeIndex
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================
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*/
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void idHashIndex::ResizeIndex( const int newIndexSize ) {
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int *oldIndexChain, mod, newSize;
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if ( newIndexSize <= indexSize ) {
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return;
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}
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mod = newIndexSize % granularity;
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if ( !mod ) {
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newSize = newIndexSize;
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} else {
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newSize = newIndexSize + granularity - mod;
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}
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if ( indexChain == INVALID_INDEX ) {
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indexSize = newSize;
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return;
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}
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oldIndexChain = indexChain;
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indexChain = new int[newSize];
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memcpy( indexChain, oldIndexChain, indexSize * sizeof(int) );
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memset( indexChain + indexSize, 0xff, (newSize - indexSize) * sizeof(int) );
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delete[] oldIndexChain;
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indexSize = newSize;
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}
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/*
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================
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idHashIndex::GetSpread
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================
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*/
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int idHashIndex::GetSpread( void ) const {
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int i, index, totalItems, *numHashItems, average, error, e;
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if ( hash == INVALID_INDEX ) {
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return 100;
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}
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totalItems = 0;
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numHashItems = new int[hashSize];
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for ( i = 0; i < hashSize; i++ ) {
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numHashItems[i] = 0;
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for ( index = hash[i]; index >= 0; index = indexChain[index] ) {
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numHashItems[i]++;
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}
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totalItems += numHashItems[i];
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}
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// if no items in hash
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if ( totalItems <= 1 ) {
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delete[] numHashItems;
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return 100;
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}
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average = totalItems / hashSize;
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error = 0;
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for ( i = 0; i < hashSize; i++ ) {
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e = abs( numHashItems[i] - average );
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if ( e > 1 ) {
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error += e - 1;
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}
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}
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delete[] numHashItems;
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return 100 - (error * 100 / totalItems);
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}
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