--- a/sources/huffman/bitreader.cpp Fri May 15 20:10:44 2015 +0300
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,144 +0,0 @@
-/*
- * skulltag::BitReader class - Allows reading arbitrary bit lengths of data.
- * Version 1 - Revsion 0
- *
- * Copyright 2009 Timothy Landers
- * email: code.vortexcortex@gmail.com
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-#include "bitreader.h"
-/** Prevents naming convention problems via encapsulation. */
-namespace skulltag {
- // BitReader class implementation
-
- int BitReader::intBitSize = 0;
- int BitReader::intSize = 0;
- int BitReader::mask[32] = {0};
-
- /** Creates a new BitReader. */
- BitReader::BitReader(){
- init();
- }
-
- /** Creates a new BitReader.
- * @param input Source of data that bits will be read from.
- * @param max Maximum number of chars to read. */
- BitReader::BitReader( unsigned char const * input, int const &max ){
- inputBuffer( input, max );
- }
-
- /** Sets the input buffer that bytes will be read from.
- * @param input Source of data that bits will be read from.
- * @param max Maximum number of chars to input.
- * @return true if successful, false if an error occurs. */
- bool BitReader::inputBuffer( unsigned char const * input, int const &max ){
- init(); // zero the vars.
- currentByte = input;
- if ( input == 0 ) return false;
- if ( max < 1 ) return false;
- bytesAvailable = max;
- bitsAvailable = max << 3;
- maximumBytes = max;
- return true;
- }
-
- /** Initializes this BitReader */
- void BitReader::init(){
- // initialize static variables if not initialized yet.
- if ( intSize == 0 ){
- intSize = sizeof maximumBytes;
- mask[0] = 0;
-
- // fill mask such that m = { 0, 1, 3, 7, 15, etc. }
- for ( int i = 1; i < 32; i++ ) mask[i] = (mask[i-1] << 1) | 1;
-
- intBitSize = intSize << 3;
- }
-
- // initialize member variables.
- bitsAvailable = 0;
- bytesAvailable = 0;
- bufferBits = 0;
- currentByte = 0;
- maximumBytes = 0;
- bitsUsed = 0;
- }
-
- /** Fills the internal bit buffer.
- * @return true if successful, false if an error occurs. */
- bool BitReader::fill(){
- if ( (currentByte == 0) || (bytesAvailable <= 0) ) return false;
-
- // while there's at least one octet free in the buffer, and one byte to read.
- while ( (bitsUsed < (intBitSize - 8)) && (bytesAvailable > 0) ){
-
- // put a byte into the bottom end of the buffer.
- bufferBits |= (*currentByte & mask[8]) << (intBitSize - bitsUsed - 8);
-
- // Set variables to reflect the change.
- currentByte++;
- bytesAvailable--;
- bitsUsed += 8;
- }
- return true;
- }
-
- /** Fetches a specified number of bits and stores them in an int.
- * @param bits destination of the retrieved bits. <br>
- * The bits will be stored in the least significant portion of the int.
- * @param count the number of bits to fetch.
- * @return the number of bits read -- may not be equal to the amount requested. */
- int BitReader::get( int &bits, int const &count ){
- bits = 0;
- // Requesting more bits than are available.
- if ( count > bitsAvailable ) return 0;
- if ( (count > bitsUsed) && (!fill()) ) return 0;
- bits = (bufferBits >> (intBitSize - count)) & mask[count];
- // lesser of bits in buffer or requested bits.
- int got = (bitsUsed < count) ? bitsUsed : count;
- // get as many bits from the buffer as we can.
- if ( got > 0 ){
- bufferBits <<= got;
- bitsUsed -= got;
- bitsAvailable -= got;
- }
- // if more bits are requested.
- if ( count > got ){
- if (!fill()) {
- bits = (bits >> (count - got)) & mask[count - got];
- return got;
- }
- got = count - got;
- // avoid reading more bits than available.
- if ( got <= bitsAvailable ){
- bits |= (bufferBits >> (intBitSize - got)) & mask[got];
- bufferBits <<= got;
- bitsUsed -= got;
- bitsAvailable -= got;
- }
- }
- return count;
- }
-
- /** @return Amount of bits that can be read from this BitReader. */
- int BitReader::availableBits(){ return bitsAvailable; }
-
-} // end namespace skulltag