michael@0: /*  GRAPHITE2 LICENSING
michael@0: 
michael@0:     Copyright 2010, SIL International
michael@0:     All rights reserved.
michael@0: 
michael@0:     This library is free software; you can redistribute it and/or modify
michael@0:     it under the terms of the GNU Lesser General Public License as published
michael@0:     by the Free Software Foundation; either version 2.1 of License, or
michael@0:     (at your option) any later version.
michael@0: 
michael@0:     This program is distributed in the hope that it will be useful,
michael@0:     but WITHOUT ANY WARRANTY; without even the implied warranty of
michael@0:     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
michael@0:     Lesser General Public License for more details.
michael@0: 
michael@0:     You should also have received a copy of the GNU Lesser General Public
michael@0:     License along with this library in the file named "LICENSE".
michael@0:     If not, write to the Free Software Foundation, 51 Franklin Street, 
michael@0:     Suite 500, Boston, MA 02110-1335, USA or visit their web page on the 
michael@0:     internet at http://www.fsf.org/licenses/lgpl.html.
michael@0: 
michael@0: Alternatively, the contents of this file may be used under the terms of the
michael@0: Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
michael@0: License, as published by the Free Software Foundation, either version 2
michael@0: of the License or (at your option) any later version.
michael@0: */
michael@0: #pragma once
michael@0: /*--------------------------------------------------------------------*//*:Ignore this sentence.
michael@0: 
michael@0: File: TtfUtil.h
michael@0: Responsibility: Alan Ward
michael@0: Last reviewed: Not yet.
michael@0: 
michael@0: Description:
michael@0:     Utility class for handling TrueType font files.
michael@0: ----------------------------------------------------------------------------------------------*/
michael@0: 
michael@0: 
michael@0: #include <cstddef>
michael@0: 
michael@0: namespace graphite2
michael@0: {
michael@0: namespace TtfUtil
michael@0: {
michael@0: 
michael@0: typedef long fontTableId32;
michael@0: typedef unsigned short gid16;
michael@0: 
michael@0: #define TTF_TAG(a,b,c,d) ((a << 24UL) + (b << 16UL) + (c << 8UL) + (d))
michael@0: 
michael@0: // Enumeration used to specify a table in a TTF file
michael@0: class Tag
michael@0: {
michael@0:     unsigned long _v;
michael@0: public:
michael@0:     Tag(const char n[5]) throw()            : _v(TTF_TAG(n[0],n[1],n[2],n[3])) {}
michael@0:     Tag(const unsigned long tag) throw()    : _v(tag) {}
michael@0: 
michael@0:     operator unsigned long () const throw () { return _v; }
michael@0: 
michael@0:     enum
michael@0:     {
michael@0:         Feat = TTF_TAG('F','e','a','t'),
michael@0:         Glat = TTF_TAG('G','l','a','t'),
michael@0:         Gloc = TTF_TAG('G','l','o','c'),
michael@0:         Sile = TTF_TAG('S','i','l','e'),
michael@0:         Silf = TTF_TAG('S','i','l','f'),
michael@0:         Sill = TTF_TAG('S','i','l','l'),
michael@0:         cmap = TTF_TAG('c','m','a','p'),
michael@0:         cvt  = TTF_TAG('c','v','t',' '),
michael@0:         cryp = TTF_TAG('c','r','y','p'),
michael@0:         head = TTF_TAG('h','e','a','d'),
michael@0:         fpgm = TTF_TAG('f','p','g','m'),
michael@0:         gdir = TTF_TAG('g','d','i','r'),
michael@0:         glyf = TTF_TAG('g','l','y','f'),
michael@0:         hdmx = TTF_TAG('h','d','m','x'),
michael@0:         hhea = TTF_TAG('h','h','e','a'),
michael@0:         hmtx = TTF_TAG('h','m','t','x'),
michael@0:         loca = TTF_TAG('l','o','c','a'),
michael@0:         kern = TTF_TAG('k','e','r','n'),
michael@0:         LTSH = TTF_TAG('L','T','S','H'),
michael@0:         maxp = TTF_TAG('m','a','x','p'),
michael@0:         name = TTF_TAG('n','a','m','e'),
michael@0:         OS_2 = TTF_TAG('O','S','/','2'),
michael@0:         post = TTF_TAG('p','o','s','t'),
michael@0:         prep = TTF_TAG('p','r','e','p')
michael@0:     };
michael@0: };
michael@0: 
michael@0: /*----------------------------------------------------------------------------------------------
michael@0:     Class providing utility methods to parse a TrueType font file (TTF).
michael@0:     Callling application handles all file input and memory allocation.
michael@0:     Assumes minimal knowledge of TTF file format.
michael@0: ----------------------------------------------------------------------------------------------*/
michael@0:     ////////////////////////////////// tools to find & check TTF tables
michael@0:     bool GetHeaderInfo(size_t & lOffset, size_t & lSize);
michael@0:     bool CheckHeader(const void * pHdr);
michael@0:     bool GetTableDirInfo(const void * pHdr, size_t & lOffset, size_t & lSize);
michael@0:     bool GetTableInfo(const Tag TableTag, const void * pHdr, const void * pTableDir,
michael@0:         size_t & lOffset, size_t & lSize);
michael@0:     bool CheckTable(const Tag TableId, const void * pTable, size_t lTableSize);
michael@0: 
michael@0:     ////////////////////////////////// simple font wide info 
michael@0:     size_t  GlyphCount(const void * pMaxp); 
michael@0: #ifdef ALL_TTFUTILS
michael@0:     size_t  MaxCompositeComponentCount(const void * pMaxp);
michael@0:     size_t  MaxCompositeLevelCount(const void * pMaxp);
michael@0:     size_t  LocaGlyphCount(size_t lLocaSize, const void * pHead); // throw (std::domain_error); 
michael@0: #endif
michael@0:     int DesignUnits(const void * pHead);
michael@0: #ifdef ALL_TTFUTILS
michael@0:     int HeadTableCheckSum(const void * pHead);
michael@0:     void HeadTableCreateTime(const void * pHead, unsigned int * pnDateBC, unsigned int * pnDateAD);
michael@0:     void HeadTableModifyTime(const void * pHead, unsigned int * pnDateBC, unsigned int * pnDateAD);
michael@0:     bool IsItalic(const void * pHead);
michael@0:     int FontAscent(const void * pOs2);
michael@0:     int FontDescent(const void * pOs2);
michael@0:     bool FontOs2Style(const void *pOs2, bool & fBold, bool & fItalic);
michael@0:     bool Get31EngFamilyInfo(const void * pName, size_t & lOffset, size_t & lSize);
michael@0:     bool Get31EngFullFontInfo(const void * pName, size_t & lOffset, size_t & lSize);
michael@0:     bool Get30EngFamilyInfo(const void * pName, size_t & lOffset, size_t & lSize);
michael@0:     bool Get30EngFullFontInfo(const void * pName, size_t & lOffset, size_t & lSize);
michael@0:     int PostLookup(const void * pPost, size_t lPostSize, const void * pMaxp, 
michael@0:         const char * pPostName);
michael@0: #endif
michael@0: 
michael@0:     ////////////////////////////////// utility methods helpful for name table
michael@0:     bool GetNameInfo(const void * pName, int nPlatformId, int nEncodingId,
michael@0:         int nLangId, int nNameId, size_t & lOffset, size_t & lSize);
michael@0:     //size_t NameTableLength(const byte * pTable);
michael@0: #ifdef ALL_TTFUTILS
michael@0:     int GetLangsForNames(const void * pName, int nPlatformId, int nEncodingId,
michael@0:         int *nameIdList, int cNameIds, short *langIdList);
michael@0:     void SwapWString(void * pWStr, size_t nSize = 0); // throw (std::invalid_argument);
michael@0: #endif
michael@0: 
michael@0:     ////////////////////////////////// cmap lookup tools 
michael@0:     const void * FindCmapSubtable(const void * pCmap, int nPlatformId = 3, 
michael@0:         int nEncodingId = 1, size_t length = 0);
michael@0:     bool CheckCmapSubtable4(const void * pCmap31);
michael@0:     gid16 CmapSubtable4Lookup(const void * pCmapSubtabel4, unsigned int nUnicodeId, int rangeKey = 0);
michael@0:     unsigned int CmapSubtable4NextCodepoint(const void *pCmap31, unsigned int nUnicodeId,
michael@0:         int * pRangeKey = 0);
michael@0:     bool CheckCmapSubtable12(const void *pCmap310);
michael@0:     gid16 CmapSubtable12Lookup(const void * pCmap310, unsigned int uUnicodeId, int rangeKey = 0);
michael@0:     unsigned int CmapSubtable12NextCodepoint(const void *pCmap310, unsigned int nUnicodeId,
michael@0:         int * pRangeKey = 0);
michael@0: 
michael@0:     ///////////////////////////////// horizontal metric data for a glyph
michael@0:     bool HorMetrics(gid16 nGlyphId, const void * pHmtx, size_t lHmtxSize, 
michael@0:         const void * pHhea, int & nLsb, unsigned int & nAdvWid);
michael@0: 
michael@0:     ////////////////////////////////// primitives for loca and glyf lookup 
michael@0:     size_t LocaLookup(gid16 nGlyphId, const void * pLoca, size_t lLocaSize, 
michael@0:         const void * pHead); // throw (std::out_of_range); 
michael@0:     void * GlyfLookup(const void * pGlyf, size_t lGlyfOffset, size_t lTableLen);
michael@0: 
michael@0:     ////////////////////////////////// primitves for simple glyph data
michael@0:     bool GlyfBox(const void * pSimpleGlyf, int & xMin, int & yMin, 
michael@0:         int & xMax, int & yMax);
michael@0: 
michael@0: #ifdef ALL_TTFUTILS
michael@0:     int GlyfContourCount(const void * pSimpleGlyf); 
michael@0:     bool GlyfContourEndPoints(const void * pSimpleGlyf, int * prgnContourEndPoint, 
michael@0:         int cnPointsTotal, size_t & cnPoints);
michael@0:     bool GlyfPoints(const void * pSimpleGlyf, int * prgnX, int * prgnY, 
michael@0:         char * prgbFlag, int cnPointsTotal, int & cnPoints);
michael@0:     
michael@0:     // primitive to find the glyph ids in a composite glyph
michael@0:     bool GetComponentGlyphIds(const void * pSimpleGlyf, int * prgnCompId, 
michael@0:         size_t cnCompIdTotal, size_t & cnCompId);
michael@0:     // primitive to find the placement data for a component in a composite glyph
michael@0:     bool GetComponentPlacement(const void * pSimpleGlyf, int nCompId,
michael@0:         bool fOffset, int & a, int & b);                        
michael@0:     // primitive to find the transform data for a component in a composite glyph
michael@0:     bool GetComponentTransform(const void * pSimpleGlyf, int nCompId,
michael@0:         float & flt11, float & flt12, float & flt21, float & flt22, bool & fTransOffset);
michael@0: #endif
michael@0: 
michael@0:     ////////////////////////////////// operate on composite or simple glyph (auto glyf lookup)
michael@0:     void * GlyfLookup(gid16 nGlyphId, const void * pGlyf, const void * pLoca, 
michael@0:         size_t lGlyfSize, size_t lLocaSize, const void * pHead); // primitive used by below methods
michael@0: 
michael@0: #ifdef ALL_TTFUTILS
michael@0:     // below are primary user methods for handling glyf data
michael@0:     bool IsSpace(gid16 nGlyphId, const void * pLoca, size_t lLocaSize, const void * pHead);
michael@0:     bool IsDeepComposite(gid16 nGlyphId, const void * pGlyf, const void * pLoca, 
michael@0:         size_t lGlyfSize, size_t lLocaSize, const void * pHead);
michael@0: 
michael@0:     bool GlyfBox(gid16 nGlyphId, const void * pGlyf, const void * pLoca, size_t lGlyfSize, size_t lLocaSize, 
michael@0:         const void * pHead, int & xMin, int & yMin, int & xMax, int & yMax);
michael@0:     bool GlyfContourCount(gid16 nGlyphId, const void * pGlyf, const void * pLoca, 
michael@0:         size_t lGlyfSize, size_t lLocaSize, const void *pHead, size_t & cnContours);
michael@0:     bool GlyfContourEndPoints(gid16 nGlyphId, const void * pGlyf, const void * pLoca, 
michael@0:         size_t lGlyfSize, size_t lLocaSize, const void * pHead, int * prgnContourEndPoint, size_t cnPoints); 
michael@0:     bool GlyfPoints(gid16 nGlyphId, const void * pGlyf, const void * pLoca, 
michael@0:         size_t lGlyfSize, size_t lLocaSize, const void * pHead, const int * prgnContourEndPoint, size_t cnEndPoints, 
michael@0:         int * prgnX, int * prgnY, bool * prgfOnCurve, size_t cnPoints);
michael@0: 
michael@0:     // utitily method used by high-level GlyfPoints 
michael@0:     bool SimplifyFlags(char * prgbFlags, int cnPoints);
michael@0:     bool CalcAbsolutePoints(int * prgnX, int * prgnY, int cnPoints);
michael@0: #endif
michael@0: 
michael@0: } // end of namespace TtfUtil
michael@0: } // end of namespace graphite2