Copyright 2010, SIL International All rights reserved.
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of 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 Lesser General Public License for more details.
You should also have received a copy of the GNU Lesser General Public License along with this library in the file named "LICENSE". If not, write to the Free Software Foundation, 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA or visit their web page on the internet at http://www.fsf.org/licenses/lgpl.html.
Alternatively, the contents of this file may be used under the terms of the Mozilla Public License (http://mozilla.org/MPL) or 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.
*/ /*--------------------------------------------------------------------*//*:Ignore this sentence.
File: TtfUtil.cpp
Responsibility: Alan Ward
Last reviewed: Not yet.
Description
Implements the methods for TtfUtil class. This file should remain portable to any C++
environment by only using standard C++ and the TTF structurs defined in Tt.h.
-------------------------------------------------------------------------------*//*:End Ignore*/
/*********************************************************************************************** Local Constants and static variables
***********************************************************************************************/ namespace
{ #ifdef ALL_TTFUTILS // max number of components allowed in composite glyphs constint kMaxGlyphComponents = 8; #endif
/*---------------------------------------------------------------------------------------------- Table of standard Postscript glyph names. From Martin Hosken. Disagress with ttfdump.exe
---------------------------------------------------------------------------------------------*/ #ifdef ALL_TTFUTILS constint kcPostNames = 258;
/* Note on error processing: The code guards against bad glyph ids being used to look up data in open ended tables (loca, hmtx). If the glyph id comes from a cmap this shouldn't happen but it seems prudent to check for user errors here. The code does assume that data obtained from the TTF file is valid otherwise (though the CheckTable method seeks to check for obvious problems that might accompany a change in table versions). For example an invalid offset in the loca table which could exceed the size of the glyf table is NOT trapped. Likewise if numberOf_LongHorMetrics in the hhea table is wrong, this will NOT be trapped, which could cause a lookup in the hmtx table to exceed the table length. Of course, TTF tables
that are completely corrupt will cause unpredictable results. */
/* Note on composite glyphs: Glyphs that have components that are themselves composites are not supported. IsDeepComposite can be used to test for this. False is returned from many of the methods in this cases. It is unclear how to build composite glyphs in some cases, so this code represents my best guess until test cases can be found. See notes on the high-
level GlyfPoints method. */ namespace graphite2
{ namespace TtfUtil
{
/*---------------------------------------------------------------------------------------------- Get offset and size of the offset table needed to find table directory. Return true if success, false otherwise. lSize excludes any table directory entries.
----------------------------------------------------------------------------------------------*/ bool GetHeaderInfo(size_t & lOffset, size_t & lSize)
{
lOffset = 0;
lSize = offsetof(Sfnt::OffsetSubTable, table_directory);
assert(sizeof(uint32) + 4*sizeof (uint16) == lSize); returntrue;
}
/*---------------------------------------------------------------------------------------------- Check the offset table for expected data. Return true if success, false otherwise.
----------------------------------------------------------------------------------------------*/ bool CheckHeader(constvoid * pHdr)
{ const Sfnt::OffsetSubTable * pOffsetTable
= reinterpret_cast<const Sfnt::OffsetSubTable *>(pHdr);
case Tag::post: // post
{ const Sfnt::PostScriptGlyphName * const pPost
= reinterpret_cast<const Sfnt::PostScriptGlyphName *>(pTable); if (lTableSize < sizeof(Sfnt::PostScriptGlyphName)) returnfalse; const fixed format = be::swap(pPost->format); bool r = format == PostScriptGlyphName::Format1
|| format == PostScriptGlyphName::Format2
|| format == PostScriptGlyphName::Format3
|| format == PostScriptGlyphName::Format25; return r;
}
case Tag::glyf:
{ return (lTableSize >= sizeof(Sfnt::Glyph));
}
default: break;
}
returntrue;
}
/*---------------------------------------------------------------------------------------------- Return the number of glyphs in the font. Should never be less than zero.
Note: this method is not currently used by the Graphite engine.
----------------------------------------------------------------------------------------------*/
size_t GlyphCount(constvoid * pMaxp)
{ const Sfnt::MaximumProfile * pTable = reinterpret_cast<const Sfnt::MaximumProfile *>(pMaxp); return be::swap(pTable->num_glyphs);
}
#ifdef ALL_TTFUTILS /*---------------------------------------------------------------------------------------------- Return the maximum number of components for any composite glyph in the font.
Note: this method is not currently used by the Graphite engine.
----------------------------------------------------------------------------------------------*/
size_t MaxCompositeComponentCount(constvoid * pMaxp)
{ const Sfnt::MaximumProfile * pTable = reinterpret_cast<const Sfnt::MaximumProfile *>(pMaxp); return be::swap(pTable->max_component_elements);
}
/*---------------------------------------------------------------------------------------------- Composite glyphs can be composed of glyphs that are themselves composites. This method returns the maximum number of levels like this for any glyph in the font. A non-composite glyph has a level of 1.
Note: this method is not currently used by the Graphite engine.
----------------------------------------------------------------------------------------------*/
size_t MaxCompositeLevelCount(constvoid * pMaxp)
{ const Sfnt::MaximumProfile * pTable = reinterpret_cast<const Sfnt::MaximumProfile *>(pMaxp); return be::swap(pTable->max_component_depth);
}
/*---------------------------------------------------------------------------------------------- Return the number of glyphs in the font according to a differt source. Should never be less than zero. Return -1 on failure.
Note: this method is not currently used by the Graphite engine.
----------------------------------------------------------------------------------------------*/
size_t LocaGlyphCount(size_t lLocaSize, constvoid * pHead) //throw(std::domain_error)
{
if (be::swap(pTable->index_to_loc_format)
== Sfnt::FontHeader::ShortIndexLocFormat) // loca entries are two bytes and have been divided by two return (lLocaSize >> 1) - 1;
if (be::swap(pTable->index_to_loc_format)
== Sfnt::FontHeader::LongIndexLocFormat) // loca entries are four bytes return (lLocaSize >> 2) - 1;
return -1; //throw std::domain_error("head table in inconsistent state. The font may be corrupted");
} #endif
/*---------------------------------------------------------------------------------------------- Return the design units the font is designed with
----------------------------------------------------------------------------------------------*/ int DesignUnits(constvoid * pHead)
{ const Sfnt::FontHeader * pTable = reinterpret_cast<const Sfnt::FontHeader *>(pHead);
return be::swap(pTable->units_per_em);
}
#ifdef ALL_TTFUTILS /*---------------------------------------------------------------------------------------------- Return the checksum from the head table, which serves as a unique identifer for the font.
----------------------------------------------------------------------------------------------*/ int HeadTableCheckSum(constvoid * pHead)
{ const Sfnt::FontHeader * pTable = reinterpret_cast<const Sfnt::FontHeader *>(pHead);
return be::swap(pTable->check_sum_adjustment);
}
/*---------------------------------------------------------------------------------------------- Return the create time from the head table. This consists of a 64-bit integer, which we return here as two 32-bit integers.
Note: this method is not currently used by the Graphite engine.
----------------------------------------------------------------------------------------------*/ void HeadTableCreateTime(constvoid * pHead, unsignedint * pnDateBC, unsignedint * pnDateAD)
{ const Sfnt::FontHeader * pTable = reinterpret_cast<const Sfnt::FontHeader *>(pHead);
/*---------------------------------------------------------------------------------------------- Return the modify time from the head table.This consists of a 64-bit integer, which we return here as two 32-bit integers.
Note: this method is not currently used by the Graphite engine.
----------------------------------------------------------------------------------------------*/ void HeadTableModifyTime(constvoid * pHead, unsignedint * pnDateBC, unsignedint *pnDateAD)
{ const Sfnt::FontHeader * pTable = reinterpret_cast<const Sfnt::FontHeader *>(pHead);
;
*pnDateBC = be::swap(pTable->modified[0]);
*pnDateAD = be::swap(pTable->modified[1]);
}
/*---------------------------------------------------------------------------------------------- Return true if the font is italic.
----------------------------------------------------------------------------------------------*/ bool IsItalic(constvoid * pHead)
{ const Sfnt::FontHeader * pTable = reinterpret_cast<const Sfnt::FontHeader *>(pHead);
/*---------------------------------------------------------------------------------------------- Return the ascent for the font
----------------------------------------------------------------------------------------------*/ int FontAscent(constvoid * pOs2)
{ const Sfnt::Compatibility * pTable = reinterpret_cast<const Sfnt::Compatibility *>(pOs2);
return be::swap(pTable->win_ascent);
}
/*---------------------------------------------------------------------------------------------- Return the descent for the font
----------------------------------------------------------------------------------------------*/ int FontDescent(constvoid * pOs2)
{ const Sfnt::Compatibility * pTable = reinterpret_cast<const Sfnt::Compatibility *>(pOs2);
return be::swap(pTable->win_descent);
}
/*---------------------------------------------------------------------------------------------- Get the bold and italic style bits. Return true if successful. false otherwise. In addition to checking the OS/2 table, one could also check the head table's macStyle field (overridden by the OS/2 table on Win) the sub-family name in the name table (though this can contain oblique, dark, etc too)
----------------------------------------------------------------------------------------------*/ bool FontOs2Style(constvoid *pOs2, bool & fBold, bool & fItalic)
{ const Sfnt::Compatibility * pTable = reinterpret_cast<const Sfnt::Compatibility *>(pOs2);
for (int i = 0; i < cRecord; ++i)
{ if (be::swap(pRecord->platform_id) == nPlatformId &&
be::swap(pRecord->platform_specific_id) == nEncodingId &&
be::swap(pRecord->language_id) == nLangId &&
be::swap(pRecord->name_id) == nNameId)
{
lOffset = be::swap(pRecord->offset) + nRecordOffset;
lSize = be::swap(pRecord->length); returntrue;
}
pRecord++;
}
returnfalse;
}
#ifdef ALL_TTFUTILS /*---------------------------------------------------------------------------------------------- Return all the lang-IDs that have data for the given name-IDs. Assume that there is room in the return array (langIdList) for 128 items. The purpose of this method is to return a list of all possible lang-IDs.
----------------------------------------------------------------------------------------------*/ int GetLangsForNames(constvoid * pName, int nPlatformId, int nEncodingId, int * nameIdList, int cNameIds, short * langIdList)
{ const Sfnt::FontNames * pTable = reinterpret_cast<const Sfnt::FontNames *>(pName); int cLangIds = 0;
uint16 cRecord = be::swap(pTable->count); if (cRecord > 127) return cLangIds; //uint16 nRecordOffset = swapw(pTable->stringOffset); const Sfnt::NameRecord * pRecord = reinterpret_cast<const Sfnt::NameRecord *>(pTable + 1);
for (int i = 0; i < cRecord; ++i)
{ if (be::swap(pRecord->platform_id) == nPlatformId &&
be::swap(pRecord->platform_specific_id) == nEncodingId)
{ bool fNameFound = false; int nLangId = be::swap(pRecord->language_id); int nNameId = be::swap(pRecord->name_id); for (int j = 0; j < cNameIds; j++)
{ if (nNameId == nameIdList[j])
{
fNameFound = true; break;
}
} if (fNameFound)
{ // Add it if it's not there. int ilang; for (ilang = 0; ilang < cLangIds; ilang++) if (langIdList[ilang] == nLangId) break; if (ilang >= cLangIds)
{
langIdList[cLangIds] = short(nLangId);
cLangIds++;
} if (cLangIds == 128) return cLangIds;
}
}
pRecord++;
}
return cLangIds;
}
/*---------------------------------------------------------------------------------------------- Get the offset and size of the font family name in English for the MS Platform with Unicode writing system. The offset is within the pName data. The string is double byte with MSB first.
----------------------------------------------------------------------------------------------*/ bool Get31EngFamilyInfo(constvoid * pName, size_t & lOffset, size_t & lSize)
{ return GetNameInfo(pName, Sfnt::NameRecord::Microsoft, 1, 1033,
Sfnt::NameRecord::Family, lOffset, lSize);
}
/*---------------------------------------------------------------------------------------------- Get the offset and size of the full font name in English for the MS Platform with Unicode writing system. The offset is within the pName data. The string is double byte with MSB first.
Note: this method is not currently used by the Graphite engine.
----------------------------------------------------------------------------------------------*/ bool Get31EngFullFontInfo(constvoid * pName, size_t & lOffset, size_t & lSize)
{ return GetNameInfo(pName, Sfnt::NameRecord::Microsoft, 1, 1033,
Sfnt::NameRecord::Fullname, lOffset, lSize);
}
/*---------------------------------------------------------------------------------------------- Get the offset and size of the font family name in English for the MS Platform with Symbol writing system. The offset is within the pName data. The string is double byte with MSB first.
----------------------------------------------------------------------------------------------*/ bool Get30EngFamilyInfo(constvoid * pName, size_t & lOffset, size_t & lSize)
{ return GetNameInfo(pName, Sfnt::NameRecord::Microsoft, 0, 1033,
Sfnt::NameRecord::Family, lOffset, lSize);
}
/*---------------------------------------------------------------------------------------------- Get the offset and size of the full font name in English for the MS Platform with Symbol writing system. The offset is within the pName data. The string is double byte with MSB first.
Note: this method is not currently used by the Graphite engine.
----------------------------------------------------------------------------------------------*/ bool Get30EngFullFontInfo(constvoid * pName, size_t & lOffset, size_t & lSize)
{ return GetNameInfo(pName, Sfnt::NameRecord::Microsoft, 0, 1033,
Sfnt::NameRecord::Fullname, lOffset, lSize);
}
/*---------------------------------------------------------------------------------------------- Return the Glyph ID for a given Postscript name. This method finds the first glyph which matches the requested Postscript name. Ideally every glyph should have a unique Postscript name (except for special names such as .notdef), but this is not always true. On failure return value less than zero. -1 - table search failed -2 - format 3 table (no Postscript glyph info) -3 - other failures
Note: this method is not currently used by the Graphite engine.
----------------------------------------------------------------------------------------------*/ int PostLookup(constvoid * pPost, size_t lPostSize, constvoid * pMaxp, constchar * pPostName)
{ usingnamespace Sfnt;
if (format == PostScriptGlyphName::Format3)
{ // format 3 - no Postscript glyph info in font return -2;
}
// search for given Postscript name among the standard names int iPostName = -1; // index in standard names for (int i = 0; i < kcPostNames; i++)
{ if (!strcmp(pPostName, rgPostName[i]))
{
iPostName = i; break;
}
}
if (format == PostScriptGlyphName::Format1)
{ // format 1 - use standard Postscript names return iPostName;
}
if (format == PostScriptGlyphName::Format25)
{ if (iPostName == -1) return -1;
const PostScriptGlyphName25 * pTable25
= static_cast<const PostScriptGlyphName25 *>(pTable); int cnGlyphs = GlyphCount(pMaxp); for (gid16 nGlyphId = 0; nGlyphId < cnGlyphs && nGlyphId < kcPostNames;
nGlyphId++)
{ // glyph_name_index25 contains bytes so no byte swapping needed // search for first glyph id that uses the standard name if (nGlyphId + pTable25->offset[nGlyphId] == iPostName) return nGlyphId;
}
}
if (format == PostScriptGlyphName::Format2)
{ // format 2 const PostScriptGlyphName2 * pTable2
= static_cast<const PostScriptGlyphName2 *>(pTable);
int cnGlyphs = be::swap(pTable2->number_of_glyphs);
if (iPostName != -1)
{ // did match a standard name, look for first glyph id mapped to that name for (gid16 nGlyphId = 0; nGlyphId < cnGlyphs; nGlyphId++)
{ if (be::swap(pTable2->glyph_name_index[nGlyphId]) == iPostName) return nGlyphId;
}
}
{ // did not match a standard name, search font specific names
size_t nStrSizeGoal = strlen(pPostName); constchar * pFirstGlyphName = reinterpret_cast<constchar *>(
&pTable2->glyph_name_index[0] + cnGlyphs); constchar * pGlyphName = pFirstGlyphName; int iInNames = 0; // index in font specific names bool fFound = false; constchar * const endOfTable
= reinterpret_cast<constchar *>(pTable2) + lPostSize; while (pGlyphName < endOfTable && !fFound)
{ // search Pascal strings for first matching name
size_t nStringSize = size_t(*pGlyphName); if (nStrSizeGoal != nStringSize ||
strncmp(pGlyphName + 1, pPostName, nStringSize))
{ // did not match
++iInNames;
pGlyphName += nStringSize + 1;
} else
{ // did match
fFound = true;
}
} if (!fFound) return -1; // no font specific name matches request
iInNames += kcPostNames; for (gid16 nGlyphId = 0; nGlyphId < cnGlyphs; nGlyphId++)
{ // search for first glyph id that maps to the found string index if (be::swap(pTable2->glyph_name_index[nGlyphId]) == iInNames) return nGlyphId;
} return -1; // no glyph mapped to this index (very strange)
}
}
return -3;
}
/*---------------------------------------------------------------------------------------------- Convert a Unicode character string from big endian (MSB first, Motorola) format to little endian (LSB first, Intel) format. nSize is the number of Unicode characters in the string. It should not include any terminating null. If nSize is 0, it is assumed the string is null terminated. nSize defaults to 0. Return true if successful, false otherwise.
----------------------------------------------------------------------------------------------*/ void SwapWString(void * pWStr, size_t nSize /* = 0 */) //throw (std::invalid_argument)
{ if (pWStr == 0)
{ // throw std::invalid_argument("null pointer given"); return;
}
// for (int i = 0; i < nSize; i++) // { // swap the wide characters in the string // pStr[i] = utf16(be::swap(uint16(pStr[i]))); // }
} #endif
/*---------------------------------------------------------------------------------------------- Get the left-side bearing and and advance width based on the given tables and Glyph ID Return true if successful, false otherwise. On false, one or both value could be INT_MIN
----------------------------------------------------------------------------------------------*/ bool HorMetrics(gid16 nGlyphId, constvoid * pHmtx, size_t lHmtxSize, constvoid * pHhea, int & nLsb, unsignedint & nAdvWid)
{ const Sfnt::HorizontalMetric * phmtx = reinterpret_cast<const Sfnt::HorizontalMetric *>(pHmtx);
size_t cLongHorMetrics = be::swap(phhea->num_long_hor_metrics); if (nGlyphId < cLongHorMetrics)
{ // glyph id is acceptable if ((nGlyphId + 1) * sizeof(Sfnt::HorizontalMetric) > lHmtxSize) returnfalse;
nAdvWid = be::swap(phmtx[nGlyphId].advance_width);
nLsb = be::swap(phmtx[nGlyphId].left_side_bearing);
} else
{ // guard against bad glyph id
size_t lLsbOffset = sizeof(Sfnt::HorizontalMetric) * cLongHorMetrics + sizeof(int16) * (nGlyphId - cLongHorMetrics); // offset in bytes // We test like this as LsbOffset is an offset not a length. if (lLsbOffset >= lHmtxSize - sizeof(int16) || cLongHorMetrics == 0)
{
nLsb = 0; returnfalse;
}
nAdvWid = be::swap(phmtx[cLongHorMetrics - 1].advance_width);
nLsb = be::peek<int16>(reinterpret_cast<const byte *>(phmtx) + lLsbOffset);
}
returntrue;
}
/*---------------------------------------------------------------------------------------------- Return a pointer to the requested cmap subtable. By default find the Microsoft Unicode subtable. Pass nEncoding as -1 to find first table that matches only nPlatformId. Return NULL if the subtable cannot be found.
----------------------------------------------------------------------------------------------*/ constvoid * FindCmapSubtable(constvoid * pCmap, int nPlatformId, /* =3 */ int nEncodingId, /* = 1 */ size_t length)
{ const Sfnt::CharacterCodeMap * pTable = reinterpret_cast<const Sfnt::CharacterCodeMap *>(pCmap);
uint16 csuPlatforms = be::swap(pTable->num_subtables); if (length && (sizeof(Sfnt::CharacterCodeMap) + 8 * (csuPlatforms - 1) > length)) return NULL; for (int i = 0; i < csuPlatforms; i++)
{ if (be::swap(pTable->encoding[i].platform_id) == nPlatformId &&
(nEncodingId == -1 || be::swap(pTable->encoding[i].platform_specific_id) == nEncodingId))
{
uint32 offset = be::swap(pTable->encoding[i].offset); const uint8 * pRtn = reinterpret_cast<const uint8 *>(pCmap) + offset; if (length)
{ if (offset > length - 2) return NULL;
uint16 format = be::read<uint16>(pRtn); if (format == 4)
{ if (offset > length - 4) return NULL;
uint16 subTableLength = be::peek<uint16>(pRtn); if (i + 1 == csuPlatforms)
{ if (subTableLength > length - offset) return NULL;
} elseif (subTableLength > be::swap(pTable->encoding[i+1].offset)) return NULL;
} if (format == 12)
{ if (offset > length - 6) return NULL;
uint32 subTableLength = be::peek<uint32>(pRtn); if (i + 1 == csuPlatforms)
{ if (subTableLength > length - offset) return NULL;
} elseif (subTableLength > be::swap(pTable->encoding[i+1].offset)) return NULL;
}
} returnreinterpret_cast<const uint8 *>(pCmap) + offset;
}
}
return 0;
}
/*---------------------------------------------------------------------------------------------- Check the Microsoft Unicode subtable for expected values
----------------------------------------------------------------------------------------------*/ bool CheckCmapSubtable4(constvoid * pCmapSubtable4, constvoid * pCmapEnd /*, unsigned int maxgid*/)
{
size_t table_len = (const byte *)pCmapEnd - (const byte *)pCmapSubtable4; if (!pCmapSubtable4) returnfalse; const Sfnt::CmapSubTable * pTable = reinterpret_cast<const Sfnt::CmapSubTable *>(pCmapSubtable4); // Bob H say some freeware TT fonts have version 1 (eg, CALIGULA.TTF) // so don't check subtable version. 21 Mar 2002 spec changes version to language. if (table_len < sizeof(*pTable) || be::swap(pTable->format) != 4) returnfalse; const Sfnt::CmapSubTableFormat4 * pTable4 = reinterpret_cast<const Sfnt::CmapSubTableFormat4 *>(pCmapSubtable4); if (table_len < sizeof(*pTable4)) returnfalse;
uint16 length = be::swap(pTable4->length); if (length > table_len) returnfalse; if (length < sizeof(Sfnt::CmapSubTableFormat4)) returnfalse;
uint16 nRanges = be::swap(pTable4->seg_count_x2) >> 1; if (!nRanges || length < sizeof(Sfnt::CmapSubTableFormat4) + 4 * nRanges * sizeof(uint16)) returnfalse; // check last range is properly terminated
uint16 chEnd = be::peek<uint16>(pTable4->end_code + nRanges - 1); if (chEnd != 0xFFFF) returnfalse; #if 0 int lastend = -1; for (int i = 0; i < nRanges; ++i)
{
uint16 end = be::peek<uint16>(pTable4->end_code + i);
uint16 start = be::peek<uint16>(pTable4->end_code + nRanges + 1 + i);
int16 delta = be::peek<int16>(pTable4->end_code + 2*nRanges + 1 + i);
uint16 offset = be::peek<uint16>(pTable4->end_code + 3*nRanges + 1 + i); if (lastend >= end || lastend >= start) returnfalse; if (offset)
{ const uint16 *gstart = pTable4->end_code + 3*nRanges + 1 + i + (offset >> 1); const uint16 *gend = gstart + end - start; if ((char *)gend >= (char *)pCmapSubtable4 + length) returnfalse; while (gstart <= gend)
{
uint16 g = be::peek<uint16>(gstart++); if (g && ((g + delta) & 0xFFFF) > maxgid) returnfalse;
}
} elseif (((delta + end) & 0xFFFF) > maxgid) returnfalse;
lastend = end;
} #endif returntrue;
}
/*---------------------------------------------------------------------------------------------- Return the Glyph ID for the given Unicode ID in the Microsoft Unicode subtable. (Actually this code only depends on subtable being format 4.) Return 0 if the Unicode ID is not in the subtable.
----------------------------------------------------------------------------------------------*/
gid16 CmapSubtable4Lookup(constvoid * pCmapSubtabel4, unsignedint nUnicodeId, int rangeKey)
{ const Sfnt::CmapSubTableFormat4 * pTable = reinterpret_cast<const Sfnt::CmapSubTableFormat4 *>(pCmapSubtabel4);
if (rangeKey)
{
pMid = &(pTable->end_code[rangeKey]);
chEnd = be::peek<uint16>(pMid);
} else
{ // Binary search of the endCode[] array
pLeft = &(pTable->end_code[0]);
n = nSeg; while (n > 0)
{
cMid = n >> 1; // Pick an element in the middle
pMid = pLeft + cMid;
chEnd = be::peek<uint16>(pMid); if (nUnicodeId <= chEnd)
{ if (cMid == 0 || nUnicodeId > be::peek<uint16>(pMid -1)) break; // Must be this seg or none!
n = cMid; // Continue on left side, omitting mid point
} else
{
pLeft = pMid + 1; // Continue on right side, omitting mid point
n -= (cMid + 1);
}
}
if (!n) return 0;
}
// Ok, we're down to one segment and pMid points to the endCode element // Either this is it or none is.
if (idRangeOffset == 0) return (uint16)(idDelta + nUnicodeId); // must use modulus 2^16
// Look up value in glyphIdArray const ptrdiff_t offset = (nUnicodeId - chStart) + (idRangeOffset >> 1) +
(pMid - reinterpret_cast<const uint16 *>(pTable)); if (offset * 2 + 1 >= be::swap<uint16>(pTable->length)) return 0;
gid16 nGlyphId = be::peek<uint16>(reinterpret_cast<const uint16 *>(pTable)+offset); // If this value is 0, return 0. Else add the idDelta return nGlyphId ? nGlyphId + idDelta : 0;
}
return 0;
}
/*---------------------------------------------------------------------------------------------- Return the next Unicode value in the cmap. Pass 0 to obtain the first item. Returns 0xFFFF as the last item. pRangeKey is an optional key that is used to optimize the search; its value is the range in which the character is found.
----------------------------------------------------------------------------------------------*/ unsignedint CmapSubtable4NextCodepoint(constvoid *pCmap31, unsignedint nUnicodeId, int * pRangeKey)
{ const Sfnt::CmapSubTableFormat4 * pTable = reinterpret_cast<const Sfnt::CmapSubTableFormat4 *>(pCmap31);
const uint16 * pStartCode = &(pTable->end_code[0])
+ nRange // length of end code array
+ 1; // reserved word
if (nUnicodePrev == 0)
{ // return the first codepoint. if (pRangeKey)
*pRangeKey = 0; return be::peek<uint16>(pStartCode);
} elseif (nUnicodePrev >= 0xFFFF)
{ if (pRangeKey)
*pRangeKey = nRange - 1; return 0xFFFF;
}
int iRange = (pRangeKey) ? *pRangeKey : 0; // Just in case we have a bad key: while (iRange > 0 && be::peek<uint16>(pStartCode + iRange) > nUnicodePrev)
iRange--; while (iRange < nRange - 1 && be::peek<uint16>(pTable->end_code + iRange) < nUnicodePrev)
iRange++;
// Now iRange is the range containing nUnicodePrev. unsignedint nStartCode = be::peek<uint16>(pStartCode + iRange); unsignedint nEndCode = be::peek<uint16>(pTable->end_code + iRange);
if (nStartCode > nUnicodePrev) // Oops, nUnicodePrev is not in the cmap! Adjust so we get a reasonable // answer this time around.
nUnicodePrev = nStartCode - 1;
if (nEndCode > nUnicodePrev)
{ // Next is in the same range; it is the next successive codepoint. if (pRangeKey)
*pRangeKey = iRange; return nUnicodePrev + 1;
}
// Otherwise the next codepoint is the first one in the next range. // There is guaranteed to be a next range because there must be one that // ends with 0xFFFF. if (pRangeKey)
*pRangeKey = iRange + 1; return (iRange + 1 >= nRange) ? 0xFFFF : be::peek<uint16>(pStartCode + iRange + 1);
}
/*---------------------------------------------------------------------------------------------- Check the Microsoft UCS-4 subtable for expected values.
----------------------------------------------------------------------------------------------*/ bool CheckCmapSubtable12(constvoid *pCmapSubtable12, constvoid *pCmapEnd /*, unsigned int maxgid*/)
{
size_t table_len = (const byte *)pCmapEnd - (const byte *)pCmapSubtable12; if (!pCmapSubtable12) returnfalse; const Sfnt::CmapSubTable * pTable = reinterpret_cast<const Sfnt::CmapSubTable *>(pCmapSubtable12); if (table_len < sizeof(*pTable) || be::swap(pTable->format) != 12) returnfalse; const Sfnt::CmapSubTableFormat12 * pTable12 = reinterpret_cast<const Sfnt::CmapSubTableFormat12 *>(pCmapSubtable12); if (table_len < sizeof(*pTable12)) returnfalse;
uint32 length = be::swap(pTable12->length); if (length > table_len) returnfalse; if (length < sizeof(Sfnt::CmapSubTableFormat12)) returnfalse;
uint32 num_groups = be::swap(pTable12->num_groups); if (num_groups > 0x10000000 || length != (sizeof(Sfnt::CmapSubTableFormat12) + (num_groups - 1) * sizeof(uint32) * 3)) returnfalse; #if 0 for (unsignedint i = 0; i < num_groups; ++i)
{ if (be::swap(pTable12->group[i].end_char_code) - be::swap(pTable12->group[i].start_char_code) + be::swap(pTable12->group[i].start_glyph_id) > maxgid) returnfalse; if (i > 0 && be::swap(pTable12->group[i].start_char_code) <= be::swap(pTable12->group[i-1].end_char_code)) returnfalse;
} #endif returntrue;
}
/*---------------------------------------------------------------------------------------------- Return the Glyph ID for the given Unicode ID in the Microsoft UCS-4 subtable. (Actually this code only depends on subtable being format 12.) Return 0 if the Unicode ID is not in the subtable.
----------------------------------------------------------------------------------------------*/
gid16 CmapSubtable12Lookup(constvoid * pCmap310, unsignedint uUnicodeId, int rangeKey)
{ const Sfnt::CmapSubTableFormat12 * pTable = reinterpret_cast<const Sfnt::CmapSubTableFormat12 *>(pCmap310);
//uint32 uLength = be::swap(pTable->length); //could use to test for premature end of table
uint32 ucGroups = be::swap(pTable->num_groups);
/*---------------------------------------------------------------------------------------------- Return the next Unicode value in the cmap. Pass 0 to obtain the first item. Returns 0x10FFFF as the last item. pRangeKey is an optional key that is used to optimize the search; its value is the range in which the character is found.
----------------------------------------------------------------------------------------------*/ unsignedint CmapSubtable12NextCodepoint(constvoid *pCmap310, unsignedint nUnicodeId, int * pRangeKey)
{ const Sfnt::CmapSubTableFormat12 * pTable = reinterpret_cast<const Sfnt::CmapSubTableFormat12 *>(pCmap310);
int nRange = be::swap(pTable->num_groups);
uint32 nUnicodePrev = (uint32)nUnicodeId;
if (nUnicodePrev == 0)
{ // return the first codepoint. if (pRangeKey)
*pRangeKey = 0; return be::swap(pTable->group[0].start_char_code);
} elseif (nUnicodePrev >= 0x10FFFF)
{ if (pRangeKey)
*pRangeKey = nRange; return 0x10FFFF;
}
int iRange = (pRangeKey) ? *pRangeKey : 0; // Just in case we have a bad key: while (iRange > 0 && be::swap(pTable->group[iRange].start_char_code) > nUnicodePrev)
iRange--; while (iRange < nRange - 1 && be::swap(pTable->group[iRange].end_char_code) < nUnicodePrev)
iRange++;
// Now iRange is the range containing nUnicodePrev.
if (nStartCode > nUnicodePrev) // Oops, nUnicodePrev is not in the cmap! Adjust so we get a reasonable // answer this time around.
nUnicodePrev = nStartCode - 1;
if (nEndCode > nUnicodePrev)
{ // Next is in the same range; it is the next successive codepoint. if (pRangeKey)
*pRangeKey = iRange; return nUnicodePrev + 1;
}
// Otherwise the next codepoint is the first one in the next range, or 10FFFF if we're done. if (pRangeKey)
*pRangeKey = iRange + 1; return (iRange + 1 >= nRange) ? 0x10FFFF : be::swap(pTable->group[iRange + 1].start_char_code);
}
/*---------------------------------------------------------------------------------------------- Return the offset stored in the loca table for the given Glyph ID. (This offset is into the glyf table.) Return -1 if the lookup failed. Technically this method should return an unsigned long but it is unlikely the offset will exceed 2^31.
----------------------------------------------------------------------------------------------*/
size_t LocaLookup(gid16 nGlyphId, constvoid * pLoca, size_t lLocaSize, constvoid * pHead) // throw (std::out_of_range)
{ const Sfnt::FontHeader * pTable = reinterpret_cast<const Sfnt::FontHeader *>(pHead);
size_t res = -2;
// CheckTable verifies the index_to_loc_format is valid if (be::swap(pTable->index_to_loc_format) == Sfnt::FontHeader::ShortIndexLocFormat)
{ // loca entries are two bytes and have been divided by two if (lLocaSize > 1 && nGlyphId + 1u < lLocaSize >> 1) // allow sentinel value to be accessed
{ const uint16 * pShortTable = reinterpret_cast<const uint16 *>(pLoca);
res = be::peek<uint16>(pShortTable + nGlyphId) << 1; if (res == static_cast<size_t>(be::peek<uint16>(pShortTable + nGlyphId + 1) << 1)) return -1;
}
} elseif (be::swap(pTable->index_to_loc_format) == Sfnt::FontHeader::LongIndexLocFormat)
{ // loca entries are four bytes if (lLocaSize > 3 && nGlyphId + 1u < lLocaSize >> 2)
{ const uint32 * pLongTable = reinterpret_cast<const uint32 *>(pLoca);
res = be::peek<uint32>(pLongTable + nGlyphId); if (res == static_cast<size_t>(be::peek<uint32>(pLongTable + nGlyphId + 1))) return -1;
}
}
// only get here if glyph id was bad return res; //throw std::out_of_range("glyph id out of range for font");
}
/*---------------------------------------------------------------------------------------------- Return a pointer into the glyf table based on the given offset (from LocaLookup). Return NULL on error.
----------------------------------------------------------------------------------------------*/ void * GlyfLookup(constvoid * pGlyf, size_t nGlyfOffset, size_t nTableLen)
{ const uint8 * pByte = reinterpret_cast<const uint8 *>(pGlyf); if (OVERFLOW_OFFSET_CHECK(pByte, nGlyfOffset) || nGlyfOffset >= nTableLen - sizeof(Sfnt::Glyph)) return NULL; returnconst_cast<uint8 *>(pByte + nGlyfOffset);
}
/*---------------------------------------------------------------------------------------------- Get the bounding box coordinates for a simple glyf entry (non-composite). Return true if successful, false otherwise.
----------------------------------------------------------------------------------------------*/ bool GlyfBox(constvoid * pSimpleGlyf, int & xMin, int & yMin, int & xMax, int & yMax)
{ const Sfnt::Glyph * pGlyph = reinterpret_cast<const Sfnt::Glyph *>(pSimpleGlyf);
#ifdef ALL_TTFUTILS /*---------------------------------------------------------------------------------------------- Return the number of contours for a simple glyf entry (non-composite) Returning -1 means this is a composite glyph
----------------------------------------------------------------------------------------------*/ int GlyfContourCount(constvoid * pSimpleGlyf)
{ const Sfnt::Glyph * pGlyph = reinterpret_cast<const Sfnt::Glyph *>(pSimpleGlyf); return be::swap(pGlyph->number_of_contours); // -1 means composite glyph
}
/*---------------------------------------------------------------------------------------------- Get the point numbers for the end points of the glyph contours for a simple glyf entry (non-composite). cnPointsTotal - count of contours from GlyfContourCount(); (same as number of end points) prgnContourEndPoints - should point to a buffer large enough to hold cnPoints integers cnPoints - count of points placed in above range Return true if successful, false otherwise. False could indicate a multi-level composite glyphs.
----------------------------------------------------------------------------------------------*/ bool GlyfContourEndPoints(constvoid * pSimpleGlyf, int * prgnContourEndPoint, int cnPointsTotal, int & cnPoints)
{ const Sfnt::SimpleGlyph * pGlyph = reinterpret_cast<const Sfnt::SimpleGlyph *>(pSimpleGlyf);
int cContours = be::swap(pGlyph->number_of_contours); if (cContours < 0) returnfalse; // this method isn't supposed handle composite glyphs
for (int i = 0; i < cContours && i < cnPointsTotal; i++)
{
prgnContourEndPoint[i] = be::swap(pGlyph->end_pts_of_contours[i]);
}
cnPoints = cContours; returntrue;
}
/*---------------------------------------------------------------------------------------------- Get the points for a simple glyf entry (non-composite) cnPointsTotal - count of points from largest end point obtained from GlyfContourEndPoints prgnX & prgnY - should point to buffers large enough to hold cnPointsTotal integers The ranges are parallel so that coordinates for point(n) are found at offset n in both ranges. This is raw point data with relative coordinates. prgbFlag - should point to a buffer a large enough to hold cnPointsTotal bytes This range is parallel to the prgnX & prgnY cnPoints - count of points placed in above ranges Return true if successful, false otherwise. False could indicate a composite glyph
----------------------------------------------------------------------------------------------*/ bool GlyfPoints(constvoid * pSimpleGlyf, int * prgnX, int * prgnY, char * prgbFlag, int cnPointsTotal, int & cnPoints)
{ usingnamespace Sfnt;
const Sfnt::SimpleGlyph * pGlyph = reinterpret_cast<const Sfnt::SimpleGlyph *>(pSimpleGlyf); int cContours = be::swap(pGlyph->number_of_contours); // return false for composite glyph if (cContours <= 0) returnfalse; int cPts = be::swap(pGlyph->end_pts_of_contours[cContours - 1]) + 1; if (cPts > cnPointsTotal) returnfalse;
// skip over bounding box data & point to byte count of instructions (hints) const uint8 * pbGlyph = reinterpret_cast<const uint8 *>
(&pGlyph->end_pts_of_contours[cContours]);
// skip over hints & point to first flag int cbHints = be::swap(*(uint16 *)pbGlyph);
pbGlyph += sizeof(uint16);
pbGlyph += cbHints;
// load flags & point to first x coordinate int iFlag = 0; while (iFlag < cPts)
{ if (!(*pbGlyph & SimpleGlyph::Repeat))
{ // flag isn't repeated
prgbFlag[iFlag] = (char)*pbGlyph;
pbGlyph++;
iFlag++;
} else
{ // flag is repeated; count specified by next byte char chFlag = (char)*pbGlyph;
pbGlyph++; int cFlags = (int)*pbGlyph;
pbGlyph++;
prgbFlag[iFlag] = chFlag;
iFlag++; for (int i = 0; i < cFlags; i++)
{
prgbFlag[iFlag + i] = chFlag;
}
iFlag += cFlags;
}
} if (iFlag != cPts) returnfalse;
// load x coordinates
iFlag = 0; while (iFlag < cPts)
{ if (prgbFlag[iFlag] & SimpleGlyph::XShort)
{
prgnX[iFlag] = *pbGlyph; if (!(prgbFlag[iFlag] & SimpleGlyph::XIsPos))
{
prgnX[iFlag] = -prgnX[iFlag];
}
pbGlyph++;
} else
{ if (prgbFlag[iFlag] & SimpleGlyph::XIsSame)
{
prgnX[iFlag] = 0; // do NOT increment pbGlyph
} else
{
prgnX[iFlag] = be::swap(*(int16 *)pbGlyph);
pbGlyph += sizeof(int16);
}
}
iFlag++;
}
// load y coordinates
iFlag = 0; while (iFlag < cPts)
{ if (prgbFlag[iFlag] & SimpleGlyph::YShort)
{
prgnY[iFlag] = *pbGlyph; if (!(prgbFlag[iFlag] & SimpleGlyph::YIsPos))
{
prgnY[iFlag] = -prgnY[iFlag];
}
pbGlyph++;
} else
{ if (prgbFlag[iFlag] & SimpleGlyph::YIsSame)
{
prgnY[iFlag] = 0; // do NOT increment pbGlyph
} else
{
prgnY[iFlag] = be::swap(*(int16 *)pbGlyph);
pbGlyph += sizeof(int16);
}
}
iFlag++;
}
cnPoints = cPts; returntrue;
}
/*---------------------------------------------------------------------------------------------- Fill prgnCompId with the component Glyph IDs from pSimpleGlyf. Client must allocate space before calling. pSimpleGlyf - assumed to point to a composite glyph cCompIdTotal - the number of elements in prgnCompId cCompId - the total number of Glyph IDs stored in prgnCompId Return true if successful, false otherwise False could indicate a non-composite glyph or the input array was not big enough
----------------------------------------------------------------------------------------------*/ bool GetComponentGlyphIds(constvoid * pSimpleGlyf, int * prgnCompId,
size_t cnCompIdTotal, size_t & cnCompId)
{ usingnamespace Sfnt;
if (GlyfContourCount(pSimpleGlyf) >= 0) returnfalse;
const Sfnt::SimpleGlyph * pGlyph = reinterpret_cast<const Sfnt::SimpleGlyph *>(pSimpleGlyf); // for a composite glyph, the special data begins here const uint8 * pbGlyph = reinterpret_cast<const uint8 *>(&pGlyph->end_pts_of_contours[0]);
/*---------------------------------------------------------------------------------------------- Return info on how a component glyph is to be placed pSimpleGlyph - assumed to point to a composite glyph nCompId - glyph id for component of interest bOffset - if true, a & b are the x & y offsets for this component if false, b is the point on this component that is attaching to point a on the preceding glyph Return true if successful, false otherwise False could indicate a non-composite glyph or that component wasn't found
----------------------------------------------------------------------------------------------*/ bool GetComponentPlacement(constvoid * pSimpleGlyf, int nCompId, bool fOffset, int & a, int & b)
{ usingnamespace Sfnt;
if (GlyfContourCount(pSimpleGlyf) >= 0) returnfalse;
const Sfnt::SimpleGlyph * pGlyph = reinterpret_cast<const Sfnt::SimpleGlyph *>(pSimpleGlyf); // for a composite glyph, the special data begins here const uint8 * pbGlyph = reinterpret_cast<const uint8 *>(&pGlyph->end_pts_of_contours[0]);
uint16 GlyphFlags; do
{
GlyphFlags = be::swap(*((uint16 *)pbGlyph));
pbGlyph += sizeof(uint16); if (be::swap(*((uint16 *)pbGlyph)) == nCompId)
{
pbGlyph += sizeof(uint16); // skip over glyph id of component
fOffset = (GlyphFlags & CompoundGlyph::ArgsAreXYValues) == CompoundGlyph::ArgsAreXYValues;
if (GlyphFlags & CompoundGlyph::Arg1Arg2Words )
{
a = be::swap(*(int16 *)pbGlyph);
pbGlyph += sizeof(int16);
b = be::swap(*(int16 *)pbGlyph);
pbGlyph += sizeof(int16);
} else
{ // args are signed bytes
a = *pbGlyph++;
b = *pbGlyph++;
} returntrue;
}
pbGlyph += sizeof(uint16); // skip over glyph id of component int nOffset = 0;
nOffset += GlyphFlags & CompoundGlyph::Arg1Arg2Words ? 4 : 2;
nOffset += GlyphFlags & CompoundGlyph::HaveScale ? 2 : 0;
nOffset += GlyphFlags & CompoundGlyph::HaveXAndYScale ? 4 : 0;
nOffset += GlyphFlags & CompoundGlyph::HaveTwoByTwo ? 8 : 0;
pbGlyph += nOffset;
} while (GlyphFlags & CompoundGlyph::MoreComponents);
// didn't find requested component
fOffset = true;
a = 0;
b = 0; returnfalse;
}
/*---------------------------------------------------------------------------------------------- Return info on how a component glyph is to be transformed pSimpleGlyph - assumed to point to a composite glyph nCompId - glyph id for component of interest flt11, flt11, flt11, flt11 - a 2x2 matrix giving the transform bTransOffset - whether to transform the offset from above method The spec is unclear about the meaning of this flag Currently - initialize to true for MS rasterizer and false for Mac rasterizer, then on return it will indicate whether transform should apply to offset (MSDN CD 10/99) Return true if successful, false otherwise False could indicate a non-composite glyph or that component wasn't found
----------------------------------------------------------------------------------------------*/ bool GetComponentTransform(constvoid * pSimpleGlyf, int nCompId, float & flt11, float & flt12, float & flt21, float & flt22, bool & fTransOffset)
{ usingnamespace Sfnt;
if (GlyfContourCount(pSimpleGlyf) >= 0) returnfalse;
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