// Copyright 2014 PDFium Authors. All rights reserved. | |
// Use of this source code is governed by a BSD-style license that can be | |
// found in the LICENSE file. | |
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com | |
// Original code is licensed as follows: | |
/* | |
* Copyright 2007 ZXing authors | |
* | |
* Licensed under the Apache License, Version 2.0 (the "License"); | |
* you may not use this file except in compliance with the License. | |
* You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, software | |
* distributed under the License is distributed on an "AS IS" BASIS, | |
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
* See the License for the specific language governing permissions and | |
* limitations under the License. | |
*/ | |
#include "../barcode.h" | |
#include "BC_CommonBitSource.h" | |
CBC_CommonBitSource::CBC_CommonBitSource(CFX_ByteArray* bytes) | |
{ | |
m_bytes.Copy((*bytes)); | |
m_bitOffset = 0; | |
m_byteOffset = 0; | |
} | |
CBC_CommonBitSource::~CBC_CommonBitSource() | |
{ | |
} | |
FX_INT32 CBC_CommonBitSource::ReadBits(FX_INT32 numBits, FX_INT32 &e) | |
{ | |
if (numBits < 1 || numBits > 32) { | |
e = BCExceptionIllegalArgument; | |
return 0; | |
} | |
FX_INT32 result = 0; | |
if (m_bitOffset > 0) { | |
FX_INT32 bitsLeft = 8 - m_bitOffset; | |
FX_INT32 toRead = numBits < bitsLeft ? numBits : bitsLeft; | |
FX_INT32 bitsToNotRead = bitsLeft - toRead; | |
FX_INT32 mask = (0xff >> (8 - toRead)) << bitsToNotRead; | |
result = (m_bytes[m_byteOffset] & mask) >> bitsToNotRead; | |
numBits -= toRead; | |
m_bitOffset += toRead; | |
if (m_bitOffset == 8) { | |
m_bitOffset = 0; | |
m_byteOffset++; | |
} | |
} | |
if (numBits > 0) { | |
while(numBits >= 8) { | |
result = (result << 8) | (m_bytes[m_byteOffset] & 0xff); | |
m_byteOffset++; | |
numBits -= 8; | |
} | |
if (numBits > 0) { | |
FX_INT32 bitsToNotRead = 8 - numBits; | |
FX_INT32 mask = (0xff >> bitsToNotRead) << bitsToNotRead; | |
result = (result << numBits) | ((m_bytes[m_byteOffset] & mask) >> bitsToNotRead); | |
m_bitOffset += numBits; | |
} | |
} | |
return result; | |
} | |
FX_INT32 CBC_CommonBitSource::Available() | |
{ | |
return 8 * (m_bytes.GetSize() - m_byteOffset) - m_bitOffset; | |
} | |
FX_INT32 CBC_CommonBitSource::getByteOffset() | |
{ | |
return m_byteOffset; | |
} |