mirror of
https://github.com/libretro/scummvm.git
synced 2024-12-02 23:26:44 +00:00
87 lines
2.5 KiB
C++
87 lines
2.5 KiB
C++
/* ScummVM - Graphic Adventure Engine
|
|
*
|
|
* ScummVM is the legal property of its developers, whose names
|
|
* are too numerous to list here. Please refer to the COPYRIGHT
|
|
* file distributed with this source distribution.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
*
|
|
*/
|
|
|
|
// Based on eos' Huffman code
|
|
|
|
#include "common/huffman.h"
|
|
#include "common/util.h"
|
|
#include "common/textconsole.h"
|
|
#include "common/bitstream.h"
|
|
|
|
namespace Common {
|
|
|
|
Huffman::Symbol::Symbol(uint32 c, uint32 s) : code(c), symbol(s) {
|
|
}
|
|
|
|
|
|
Huffman::Huffman(uint8 maxLength, uint32 codeCount, const uint32 *codes, const uint8 *lengths, const uint32 *symbols) {
|
|
assert(codeCount > 0);
|
|
|
|
assert(codes);
|
|
assert(lengths);
|
|
|
|
if (maxLength == 0)
|
|
for (uint32 i = 0; i < codeCount; i++)
|
|
maxLength = MAX(maxLength, lengths[i]);
|
|
|
|
assert(maxLength <= 32);
|
|
|
|
_codes.resize(maxLength);
|
|
_symbols.resize(codeCount);
|
|
|
|
for (uint32 i = 0; i < codeCount; i++) {
|
|
// The symbol. If none were specified, just assume it's identical to the code index
|
|
uint32 symbol = symbols ? symbols[i] : i;
|
|
|
|
// Put the code and symbol into the correct list
|
|
_codes[lengths[i] - 1].push_back(Symbol(codes[i], symbol));
|
|
|
|
// And put the pointer to the symbol/code struct into the symbol list.
|
|
_symbols[i] = &_codes[lengths[i] - 1].back();
|
|
}
|
|
}
|
|
|
|
Huffman::~Huffman() {
|
|
}
|
|
|
|
void Huffman::setSymbols(const uint32 *symbols) {
|
|
for (uint32 i = 0; i < _symbols.size(); i++)
|
|
_symbols[i]->symbol = symbols ? *symbols++ : i;
|
|
}
|
|
|
|
uint32 Huffman::getSymbol(BitStream &bits) const {
|
|
uint32 code = 0;
|
|
|
|
for (uint32 i = 0; i < _codes.size(); i++) {
|
|
bits.addBit(code, i);
|
|
|
|
for (CodeList::const_iterator cCode = _codes[i].begin(); cCode != _codes[i].end(); ++cCode)
|
|
if (code == cCode->code)
|
|
return cCode->symbol;
|
|
}
|
|
|
|
error("Unknown Huffman code");
|
|
return 0;
|
|
}
|
|
|
|
} // End of namespace Common
|