blob: 98187a1c5bd4a3f3035671f70d1f74f9abbc395f [file] [log] [blame]
// Copyright 2014 The PDFium Authors
// 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
#include "core/fpdfapi/cmaps/fpdf_cmaps.h"
#include <algorithm>
#include "third_party/base/check.h"
namespace fxcmap {
namespace {
struct SingleCmap {
uint16_t code;
uint16_t cid;
};
struct RangeCmap {
uint16_t low;
uint16_t high;
uint16_t cid;
};
const CMap* FindNextCMap(const CMap* pMap) {
return pMap->m_UseOffset ? pMap + pMap->m_UseOffset : nullptr;
}
} // namespace
uint16_t CIDFromCharCode(const CMap* pMap, uint32_t charcode) {
DCHECK(pMap);
const uint16_t loword = static_cast<uint16_t>(charcode);
if (charcode >> 16) {
while (pMap) {
if (pMap->m_pDWordMap) {
const DWordCIDMap* begin = pMap->m_pDWordMap;
const auto* end = begin + pMap->m_DWordCount;
const auto* found = std::lower_bound(
begin, end, charcode,
[](const DWordCIDMap& element, uint32_t charcode) {
uint16_t hiword = static_cast<uint16_t>(charcode >> 16);
if (element.m_HiWord != hiword)
return element.m_HiWord < hiword;
return element.m_LoWordHigh < static_cast<uint16_t>(charcode);
});
if (found != end && loword >= found->m_LoWordLow &&
loword <= found->m_LoWordHigh) {
return found->m_CID + loword - found->m_LoWordLow;
}
}
pMap = FindNextCMap(pMap);
}
return 0;
}
while (pMap && pMap->m_pWordMap) {
switch (pMap->m_WordMapType) {
case CMap::Type::kSingle: {
const auto* begin =
reinterpret_cast<const SingleCmap*>(pMap->m_pWordMap);
const auto* end = begin + pMap->m_WordCount;
const auto* found = std::lower_bound(
begin, end, loword, [](const SingleCmap& element, uint16_t code) {
return element.code < code;
});
if (found != end && found->code == loword)
return found->cid;
break;
}
case CMap::Type::kRange: {
const auto* begin =
reinterpret_cast<const RangeCmap*>(pMap->m_pWordMap);
const auto* end = begin + pMap->m_WordCount;
const auto* found = std::lower_bound(
begin, end, loword, [](const RangeCmap& element, uint16_t code) {
return element.high < code;
});
if (found != end && loword >= found->low && loword <= found->high)
return found->cid + loword - found->low;
break;
}
}
pMap = FindNextCMap(pMap);
}
return 0;
}
uint32_t CharCodeFromCID(const CMap* pMap, uint16_t cid) {
// TODO(dsinclair): This should be checking both pMap->m_WordMap and
// pMap->m_DWordMap. There was a second while() but it was never reached as
// the first always returns. Investigate and determine how this should
// really be working. (https://codereview.chromium.org/2235743003 removed the
// second while loop.)
DCHECK(pMap);
while (pMap) {
switch (pMap->m_WordMapType) {
case CMap::Type::kSingle: {
const auto* pCur =
reinterpret_cast<const SingleCmap*>(pMap->m_pWordMap);
const auto* pEnd = pCur + pMap->m_WordCount;
while (pCur < pEnd) {
if (pCur->cid == cid)
return pCur->code;
++pCur;
}
break;
}
case CMap::Type::kRange: {
const auto* pCur = reinterpret_cast<const RangeCmap*>(pMap->m_pWordMap);
const auto* pEnd = pCur + pMap->m_WordCount;
while (pCur < pEnd) {
if (cid >= pCur->cid && cid <= pCur->cid + pCur->high - pCur->low)
return pCur->low + cid - pCur->cid;
++pCur;
}
break;
}
}
pMap = FindNextCMap(pMap);
}
return 0;
}
} // namespace fxcmap