/vcl/source/fontsubset/gsub.cxx
C++ | 349 lines | 273 code | 46 blank | 30 comment | 75 complexity | 75383746b60f3d3156ac0f0e729c16e3 MD5 | raw file
Possible License(s): GPL-3.0, LGPL-3.0, MPL-2.0-no-copyleft-exception, LGPL-2.1, BSD-3-Clause-No-Nuclear-License-2014
- /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
- /*
- * This file is part of the LibreOffice project.
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/.
- *
- * This file incorporates work covered by the following license notice:
- *
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed
- * with this work for additional information regarding copyright
- * ownership. The ASF licenses this file to you 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 .
- */
- #include "sft.hxx"
- #include "gsub.h"
- #include <osl/diagnose.h>
- #include <vector>
- #include <map>
- #include <algorithm>
- namespace vcl
- {
- typedef sal_uIntPtr sal_uLong;
- typedef sal_uInt8 FT_Byte;
- typedef std::map<sal_uInt16,sal_uInt16> GlyphSubstitution;
- inline sal_uInt32 NEXT_Long( const unsigned char* &p )
- {
- sal_uInt32 nVal = (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3];
- p += 4;
- return nVal;
- }
- inline sal_uInt16 NEXT_UShort( const unsigned char* &p )
- {
- sal_uInt16 nVal = (p[0]<<8) + p[1];
- p += 2;
- return nVal;
- }
- #define MKTAG(s) ((((((s[0]<<8)+s[1])<<8)+s[2])<<8)+s[3])
- int ReadGSUB( struct _TrueTypeFont* pTTFile,
- int nRequestedScript, int nRequestedLangsys )
- {
- const FT_Byte* pGsubBase = (FT_Byte*)pTTFile->tables[ O_gsub ];
- if( !pGsubBase )
- return -1;
- // #129682# check offsets inside GSUB table
- const FT_Byte* pGsubLimit = pGsubBase + pTTFile->tlens[ O_gsub ];
- // parse GSUB header
- const FT_Byte* pGsubHeader = pGsubBase;
- const sal_uLong nVersion = NEXT_Long( pGsubHeader );
- const sal_uInt16 nOfsScriptList = NEXT_UShort( pGsubHeader );
- const sal_uInt16 nOfsFeatureTable = NEXT_UShort( pGsubHeader );
- const sal_uInt16 nOfsLookupList = NEXT_UShort( pGsubHeader );
- // sanity check the GSUB header
- if( nVersion != 0x00010000 )
- if( nVersion != 0x00001000 ) // workaround for SunBatang etc.
- return -1; // unknown format or broken
- typedef std::vector<sal_uLong> ReqFeatureTagList;
- ReqFeatureTagList aReqFeatureTagList;
- aReqFeatureTagList.push_back( MKTAG("vert") );
- typedef std::vector<sal_uInt16> UshortList;
- UshortList aFeatureIndexList;
- // parse Script Table
- const FT_Byte* pScriptHeader = pGsubBase + nOfsScriptList;
- const sal_uInt16 nCntScript = NEXT_UShort( pScriptHeader );
- if( pGsubLimit < pScriptHeader + 6 * nCntScript )
- return false;
- for( sal_uInt16 nScriptIndex = 0; nScriptIndex < nCntScript; ++nScriptIndex )
- {
- const sal_uLong nTag = NEXT_Long( pScriptHeader ); // e.g. hani/arab/kana/hang
- const sal_uInt16 nOfsScriptTable= NEXT_UShort( pScriptHeader );
- if( (nTag != (sal_uInt16)nRequestedScript) && (nRequestedScript != 0) )
- continue;
- const FT_Byte* pScriptTable = pGsubBase + nOfsScriptList + nOfsScriptTable;
- if( pGsubLimit < pScriptTable + 4 )
- return false;
- const sal_uInt16 nDefaultLangsysOfs = NEXT_UShort( pScriptTable );
- const sal_uInt16 nCntLangSystem = NEXT_UShort( pScriptTable );
- sal_uInt16 nLangsysOffset = 0;
- if( pGsubLimit < pScriptTable + 6 * nCntLangSystem )
- return false;
- for( sal_uInt16 nLangsysIndex = 0; nLangsysIndex < nCntLangSystem; ++nLangsysIndex )
- {
- const sal_uLong nInnerTag = NEXT_Long( pScriptTable ); // e.g. KOR/ZHS/ZHT/JAN
- const sal_uInt16 nOffset= NEXT_UShort( pScriptTable );
- if( (nInnerTag != (sal_uInt16)nRequestedLangsys) && (nRequestedLangsys != 0) )
- continue;
- nLangsysOffset = nOffset;
- break;
- }
- if( (nDefaultLangsysOfs != 0) && (nDefaultLangsysOfs != nLangsysOffset) )
- {
- const FT_Byte* pLangSys = pGsubBase + nOfsScriptList + nOfsScriptTable + nDefaultLangsysOfs;
- if( pGsubLimit < pLangSys + 6 )
- return false;
- /*const sal_uInt16 nLookupOrder =*/ NEXT_UShort( pLangSys );
- const sal_uInt16 nReqFeatureIdx = NEXT_UShort( pLangSys );
- const sal_uInt16 nCntFeature = NEXT_UShort( pLangSys );
- if( pGsubLimit < pLangSys + 2 * nCntFeature )
- return false;
- aFeatureIndexList.push_back( nReqFeatureIdx );
- for( sal_uInt16 i = 0; i < nCntFeature; ++i )
- {
- const sal_uInt16 nFeatureIndex = NEXT_UShort( pLangSys );
- aFeatureIndexList.push_back( nFeatureIndex );
- }
- }
- if( nLangsysOffset != 0 )
- {
- const FT_Byte* pLangSys = pGsubBase + nOfsScriptList + nOfsScriptTable + nLangsysOffset;
- if( pGsubLimit < pLangSys + 6 )
- return false;
- /*const sal_uInt16 nLookupOrder =*/ NEXT_UShort( pLangSys );
- const sal_uInt16 nReqFeatureIdx = NEXT_UShort( pLangSys );
- const sal_uInt16 nCntFeature = NEXT_UShort( pLangSys );
- if( pGsubLimit < pLangSys + 2 * nCntFeature )
- return false;
- aFeatureIndexList.push_back( nReqFeatureIdx );
- for( sal_uInt16 i = 0; i < nCntFeature; ++i )
- {
- const sal_uInt16 nFeatureIndex = NEXT_UShort( pLangSys );
- aFeatureIndexList.push_back( nFeatureIndex );
- }
- }
- }
- if( aFeatureIndexList.empty() )
- return true;
- UshortList aLookupIndexList;
- UshortList aLookupOffsetList;
- // parse Feature Table
- const FT_Byte* pFeatureHeader = pGsubBase + nOfsFeatureTable;
- if( pGsubLimit < pFeatureHeader + 2 )
- return false;
- const sal_uInt16 nCntFeature = NEXT_UShort( pFeatureHeader );
- if( pGsubLimit < pFeatureHeader + 6 * nCntFeature )
- return false;
- for( sal_uInt16 nFeatureIndex = 0; nFeatureIndex < nCntFeature; ++nFeatureIndex )
- {
- const sal_uLong nTag = NEXT_Long( pFeatureHeader ); // e.g. locl/vert/trad/smpl/liga/fina/...
- const sal_uInt16 nOffset= NEXT_UShort( pFeatureHeader );
- // ignore unneeded feature lookups
- if( aFeatureIndexList[0] != nFeatureIndex ) // do not ignore the required feature
- {
- const int nRequested = std::count( aFeatureIndexList.begin(), aFeatureIndexList.end(), nFeatureIndex);
- if( !nRequested ) // ignore features that are not requested
- continue;
- const int nAvailable = std::count( aReqFeatureTagList.begin(), aReqFeatureTagList.end(), nTag);
- if( !nAvailable ) // some fonts don't provide features they request!
- continue;
- }
- const FT_Byte* pFeatureTable = pGsubBase + nOfsFeatureTable + nOffset;
- if( pGsubLimit < pFeatureTable + 2 )
- return false;
- const sal_uInt16 nCntLookups = NEXT_UShort( pFeatureTable );
- if( pGsubLimit < pFeatureTable + 2 * nCntLookups )
- return false;
- for( sal_uInt16 i = 0; i < nCntLookups; ++i )
- {
- const sal_uInt16 nLookupIndex = NEXT_UShort( pFeatureTable );
- aLookupIndexList.push_back( nLookupIndex );
- }
- if( nCntLookups == 0 ) //### hack needed by Mincho/Gothic/Mingliu/Simsun/...
- aLookupIndexList.push_back( 0 );
- }
- // parse Lookup List
- const FT_Byte* pLookupHeader = pGsubBase + nOfsLookupList;
- if( pGsubLimit < pLookupHeader + 2 )
- return false;
- const sal_uInt16 nCntLookupTable = NEXT_UShort( pLookupHeader );
- if( pGsubLimit < pLookupHeader + 2 * nCntLookupTable )
- return false;
- for( sal_uInt16 nLookupIdx = 0; nLookupIdx < nCntLookupTable; ++nLookupIdx )
- {
- const sal_uInt16 nOffset = NEXT_UShort( pLookupHeader );
- if( std::count( aLookupIndexList.begin(), aLookupIndexList.end(), nLookupIdx ) )
- aLookupOffsetList.push_back( nOffset );
- }
- UshortList::const_iterator it = aLookupOffsetList.begin();
- for(; it != aLookupOffsetList.end(); ++it )
- {
- const sal_uInt16 nOfsLookupTable = *it;
- const FT_Byte* pLookupTable = pGsubBase + nOfsLookupList + nOfsLookupTable;
- if( pGsubLimit < pLookupTable + 6 )
- return false;
- const sal_uInt16 eLookupType = NEXT_UShort( pLookupTable );
- /*const sal_uInt16 eLookupFlag =*/ NEXT_UShort( pLookupTable );
- const sal_uInt16 nCntLookupSubtable = NEXT_UShort( pLookupTable );
- // TODO: switch( eLookupType )
- if( eLookupType != 1 ) // TODO: once we go beyond SingleSubst
- continue;
- if( pGsubLimit < pLookupTable + 2 * nCntLookupSubtable )
- return false;
- for( sal_uInt16 nSubTableIdx = 0; nSubTableIdx < nCntLookupSubtable; ++nSubTableIdx )
- {
- const sal_uInt16 nOfsSubLookupTable = NEXT_UShort( pLookupTable );
- const FT_Byte* pSubLookup = pGsubBase + nOfsLookupList + nOfsLookupTable + nOfsSubLookupTable;
- if( pGsubLimit < pSubLookup + 6 )
- return false;
- const sal_uInt16 nFmtSubstitution = NEXT_UShort( pSubLookup );
- const sal_uInt16 nOfsCoverage = NEXT_UShort( pSubLookup );
- typedef std::pair<sal_uInt16,sal_uInt16> GlyphSubst;
- typedef std::vector<GlyphSubst> SubstVector;
- SubstVector aSubstVector;
- const FT_Byte* pCoverage = pGsubBase
- + nOfsLookupList + nOfsLookupTable + nOfsSubLookupTable + nOfsCoverage;
- if( pGsubLimit < pCoverage + 4 )
- return false;
- const sal_uInt16 nFmtCoverage = NEXT_UShort( pCoverage );
- switch( nFmtCoverage )
- {
- case 1: // Coverage Format 1
- {
- const sal_uInt16 nCntGlyph = NEXT_UShort( pCoverage );
- if( pGsubLimit < pCoverage + 2 * nCntGlyph )
- // TODO? nCntGlyph = (pGsubLimit - pCoverage) / 2;
- return false;
- aSubstVector.reserve( nCntGlyph );
- for( sal_uInt16 i = 0; i < nCntGlyph; ++i )
- {
- const sal_uInt16 nGlyphId = NEXT_UShort( pCoverage );
- aSubstVector.push_back( GlyphSubst( nGlyphId, 0 ) );
- }
- }
- break;
- case 2: // Coverage Format 2
- {
- const sal_uInt16 nCntRange = NEXT_UShort( pCoverage );
- if( pGsubLimit < pCoverage + 6 * nCntRange )
- // TODO? nCntGlyph = (pGsubLimit - pCoverage) / 6;
- return false;
- for( int i = nCntRange; --i >= 0; )
- {
- const sal_uInt32 nGlyph0 = NEXT_UShort( pCoverage );
- const sal_uInt32 nGlyph1 = NEXT_UShort( pCoverage );
- const sal_uInt16 nCovIdx = NEXT_UShort( pCoverage );
- for( sal_uInt32 j = nGlyph0; j <= nGlyph1; ++j )
- aSubstVector.push_back( GlyphSubst( static_cast<sal_uInt16>(j + nCovIdx), 0 ) );
- }
- }
- break;
- }
- SubstVector::iterator subst_it( aSubstVector.begin() );
- switch( nFmtSubstitution )
- {
- case 1: // Single Substitution Format 1
- {
- const sal_uInt16 nDeltaGlyphId = NEXT_UShort( pSubLookup );
- for(; subst_it != aSubstVector.end(); ++subst_it )
- (*subst_it).second = (*subst_it).first + nDeltaGlyphId;
- }
- break;
- case 2: // Single Substitution Format 2
- {
- const sal_uInt16 nCntGlyph = NEXT_UShort( pSubLookup );
- for( int i = nCntGlyph; (subst_it != aSubstVector.end()) && (--i>=0); ++subst_it )
- {
- if( pGsubLimit < pSubLookup + 2 )
- return false;
- const sal_uInt16 nGlyphId = NEXT_UShort( pSubLookup );
- (*subst_it).second = nGlyphId;
- }
- }
- break;
- }
- // now apply the glyph substitutions that have been collected in this subtable
- if( !aSubstVector.empty() )
- {
- GlyphSubstitution* pGSubstitution = new GlyphSubstitution;
- pTTFile->pGSubstitution = (void*)pGSubstitution;
- for( subst_it = aSubstVector.begin(); subst_it != aSubstVector.end(); ++subst_it )
- (*pGSubstitution)[ (*subst_it).first ] = (*subst_it).second;
- }
- }
- }
- return true;
- }
- void ReleaseGSUB(struct _TrueTypeFont* pTTFile)
- {
- GlyphSubstitution* pGlyphSubstitution = (GlyphSubstitution*)pTTFile->pGSubstitution;
- if( pGlyphSubstitution )
- delete pGlyphSubstitution;
- }
- int UseGSUB( struct _TrueTypeFont* pTTFile, int nGlyph, int /*wmode*/ )
- {
- GlyphSubstitution* pGlyphSubstitution = (GlyphSubstitution*)pTTFile->pGSubstitution;
- if( pGlyphSubstitution != 0 )
- {
- GlyphSubstitution::const_iterator it( pGlyphSubstitution->find( sal::static_int_cast<sal_uInt16>(nGlyph) ) );
- if( it != pGlyphSubstitution->end() )
- nGlyph = (*it).second;
- }
- return nGlyph;
- }
- int HasVerticalGSUB( struct _TrueTypeFont* pTTFile )
- {
- GlyphSubstitution* pGlyphSubstitution = (GlyphSubstitution*)pTTFile->pGSubstitution;
- return pGlyphSubstitution ? +1 : 0;
- }
- }
- /* vim:set shiftwidth=4 softtabstop=4 expandtab: */