TtfUtil.h (9955B)
1 /* GRAPHITE2 LICENSING 2 3 Copyright 2010, SIL International 4 All rights reserved. 5 6 This library is free software; you can redistribute it and/or modify 7 it under the terms of the GNU Lesser General Public License as published 8 by the Free Software Foundation; either version 2.1 of License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should also have received a copy of the GNU Lesser General Public 17 License along with this library in the file named "LICENSE". 18 If not, write to the Free Software Foundation, 51 Franklin Street, 19 Suite 500, Boston, MA 02110-1335, USA or visit their web page on the 20 internet at http://www.fsf.org/licenses/lgpl.html. 21 22 Alternatively, the contents of this file may be used under the terms of the 23 Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public 24 License, as published by the Free Software Foundation, either version 2 25 of the License or (at your option) any later version. 26 */ 27 #pragma once 28 /*--------------------------------------------------------------------*//*:Ignore this sentence. 29 30 File: TtfUtil.h 31 Responsibility: Alan Ward 32 Last reviewed: Not yet. 33 34 Description: 35 Utility class for handling TrueType font files. 36 ----------------------------------------------------------------------------------------------*/ 37 38 39 #include <cstddef> 40 41 namespace graphite2 42 { 43 namespace TtfUtil 44 { 45 46 #define OVERFLOW_OFFSET_CHECK(p, o) (o + reinterpret_cast<size_t>(p) < reinterpret_cast<size_t>(p)) 47 48 typedef long fontTableId32; 49 typedef unsigned short gid16; 50 51 #define TTF_TAG(a,b,c,d) ((a << 24UL) + (b << 16UL) + (c << 8UL) + (d)) 52 53 // Enumeration used to specify a table in a TTF file 54 class Tag 55 { 56 unsigned int _v; 57 public: 58 Tag(const char n[5]) throw() : _v(TTF_TAG(n[0],n[1],n[2],n[3])) {} 59 Tag(const unsigned int tag) throw() : _v(tag) {} 60 61 operator unsigned int () const throw () { return _v; } 62 63 enum 64 { 65 Feat = TTF_TAG('F','e','a','t'), 66 Glat = TTF_TAG('G','l','a','t'), 67 Gloc = TTF_TAG('G','l','o','c'), 68 Sile = TTF_TAG('S','i','l','e'), 69 Silf = TTF_TAG('S','i','l','f'), 70 Sill = TTF_TAG('S','i','l','l'), 71 cmap = TTF_TAG('c','m','a','p'), 72 cvt = TTF_TAG('c','v','t',' '), 73 cryp = TTF_TAG('c','r','y','p'), 74 head = TTF_TAG('h','e','a','d'), 75 fpgm = TTF_TAG('f','p','g','m'), 76 gdir = TTF_TAG('g','d','i','r'), 77 glyf = TTF_TAG('g','l','y','f'), 78 hdmx = TTF_TAG('h','d','m','x'), 79 hhea = TTF_TAG('h','h','e','a'), 80 hmtx = TTF_TAG('h','m','t','x'), 81 loca = TTF_TAG('l','o','c','a'), 82 kern = TTF_TAG('k','e','r','n'), 83 LTSH = TTF_TAG('L','T','S','H'), 84 maxp = TTF_TAG('m','a','x','p'), 85 name = TTF_TAG('n','a','m','e'), 86 OS_2 = TTF_TAG('O','S','/','2'), 87 post = TTF_TAG('p','o','s','t'), 88 prep = TTF_TAG('p','r','e','p') 89 }; 90 }; 91 92 /*---------------------------------------------------------------------------------------------- 93 Class providing utility methods to parse a TrueType font file (TTF). 94 Callling application handles all file input and memory allocation. 95 Assumes minimal knowledge of TTF file format. 96 ----------------------------------------------------------------------------------------------*/ 97 ////////////////////////////////// tools to find & check TTF tables 98 bool GetHeaderInfo(size_t & lOffset, size_t & lSize); 99 bool CheckHeader(const void * pHdr); 100 bool GetTableDirInfo(const void * pHdr, size_t & lOffset, size_t & lSize); 101 bool GetTableInfo(const Tag TableTag, const void * pHdr, const void * pTableDir, 102 size_t & lOffset, size_t & lSize); 103 bool CheckTable(const Tag TableId, const void * pTable, size_t lTableSize); 104 105 ////////////////////////////////// simple font wide info 106 size_t GlyphCount(const void * pMaxp); 107 #ifdef ALL_TTFUTILS 108 size_t MaxCompositeComponentCount(const void * pMaxp); 109 size_t MaxCompositeLevelCount(const void * pMaxp); 110 size_t LocaGlyphCount(size_t lLocaSize, const void * pHead); // throw (std::domain_error); 111 #endif 112 int DesignUnits(const void * pHead); 113 #ifdef ALL_TTFUTILS 114 int HeadTableCheckSum(const void * pHead); 115 void HeadTableCreateTime(const void * pHead, unsigned int * pnDateBC, unsigned int * pnDateAD); 116 void HeadTableModifyTime(const void * pHead, unsigned int * pnDateBC, unsigned int * pnDateAD); 117 bool IsItalic(const void * pHead); 118 int FontAscent(const void * pOs2); 119 int FontDescent(const void * pOs2); 120 bool FontOs2Style(const void *pOs2, bool & fBold, bool & fItalic); 121 bool Get31EngFamilyInfo(const void * pName, size_t & lOffset, size_t & lSize); 122 bool Get31EngFullFontInfo(const void * pName, size_t & lOffset, size_t & lSize); 123 bool Get30EngFamilyInfo(const void * pName, size_t & lOffset, size_t & lSize); 124 bool Get30EngFullFontInfo(const void * pName, size_t & lOffset, size_t & lSize); 125 int PostLookup(const void * pPost, size_t lPostSize, const void * pMaxp, 126 const char * pPostName); 127 #endif 128 129 ////////////////////////////////// utility methods helpful for name table 130 bool GetNameInfo(const void * pName, int nPlatformId, int nEncodingId, 131 int nLangId, int nNameId, size_t & lOffset, size_t & lSize); 132 //size_t NameTableLength(const byte * pTable); 133 #ifdef ALL_TTFUTILS 134 int GetLangsForNames(const void * pName, int nPlatformId, int nEncodingId, 135 int *nameIdList, int cNameIds, short *langIdList); 136 void SwapWString(void * pWStr, size_t nSize = 0); // throw (std::invalid_argument); 137 #endif 138 139 ////////////////////////////////// cmap lookup tools 140 const void * FindCmapSubtable(const void * pCmap, int nPlatformId = 3, 141 int nEncodingId = 1, size_t length = 0); 142 bool CheckCmapSubtable4(const void * pCmap31, const void * pCmapEnd /*, unsigned int maxgid*/); 143 gid16 CmapSubtable4Lookup(const void * pCmapSubtabel4, unsigned int nUnicodeId, int rangeKey = 0); 144 unsigned int CmapSubtable4NextCodepoint(const void *pCmap31, unsigned int nUnicodeId, 145 int * pRangeKey = 0); 146 bool CheckCmapSubtable12(const void *pCmap310, const void * pCmapEnd /*, unsigned int maxgid*/); 147 gid16 CmapSubtable12Lookup(const void * pCmap310, unsigned int uUnicodeId, int rangeKey = 0); 148 unsigned int CmapSubtable12NextCodepoint(const void *pCmap310, unsigned int nUnicodeId, 149 int * pRangeKey = 0); 150 151 ///////////////////////////////// horizontal metric data for a glyph 152 bool HorMetrics(gid16 nGlyphId, const void * pHmtx, size_t lHmtxSize, 153 const void * pHhea, int & nLsb, unsigned int & nAdvWid); 154 155 ////////////////////////////////// primitives for loca and glyf lookup 156 size_t LocaLookup(gid16 nGlyphId, const void * pLoca, size_t lLocaSize, 157 const void * pHead); // throw (std::out_of_range); 158 void * GlyfLookup(const void * pGlyf, size_t lGlyfOffset, size_t lTableLen); 159 160 ////////////////////////////////// primitves for simple glyph data 161 bool GlyfBox(const void * pSimpleGlyf, int & xMin, int & yMin, 162 int & xMax, int & yMax); 163 164 #ifdef ALL_TTFUTILS 165 int GlyfContourCount(const void * pSimpleGlyf); 166 bool GlyfContourEndPoints(const void * pSimpleGlyf, int * prgnContourEndPoint, 167 int cnPointsTotal, size_t & cnPoints); 168 bool GlyfPoints(const void * pSimpleGlyf, int * prgnX, int * prgnY, 169 char * prgbFlag, int cnPointsTotal, int & cnPoints); 170 171 // primitive to find the glyph ids in a composite glyph 172 bool GetComponentGlyphIds(const void * pSimpleGlyf, int * prgnCompId, 173 size_t cnCompIdTotal, size_t & cnCompId); 174 // primitive to find the placement data for a component in a composite glyph 175 bool GetComponentPlacement(const void * pSimpleGlyf, int nCompId, 176 bool fOffset, int & a, int & b); 177 // primitive to find the transform data for a component in a composite glyph 178 bool GetComponentTransform(const void * pSimpleGlyf, int nCompId, 179 float & flt11, float & flt12, float & flt21, float & flt22, bool & fTransOffset); 180 #endif 181 182 ////////////////////////////////// operate on composite or simple glyph (auto glyf lookup) 183 void * GlyfLookup(gid16 nGlyphId, const void * pGlyf, const void * pLoca, 184 size_t lGlyfSize, size_t lLocaSize, const void * pHead); // primitive used by below methods 185 186 #ifdef ALL_TTFUTILS 187 // below are primary user methods for handling glyf data 188 bool IsSpace(gid16 nGlyphId, const void * pLoca, size_t lLocaSize, const void * pHead); 189 bool IsDeepComposite(gid16 nGlyphId, const void * pGlyf, const void * pLoca, 190 size_t lGlyfSize, size_t lLocaSize, const void * pHead); 191 192 bool GlyfBox(gid16 nGlyphId, const void * pGlyf, const void * pLoca, size_t lGlyfSize, size_t lLocaSize, 193 const void * pHead, int & xMin, int & yMin, int & xMax, int & yMax); 194 bool GlyfContourCount(gid16 nGlyphId, const void * pGlyf, const void * pLoca, 195 size_t lGlyfSize, size_t lLocaSize, const void *pHead, size_t & cnContours); 196 bool GlyfContourEndPoints(gid16 nGlyphId, const void * pGlyf, const void * pLoca, 197 size_t lGlyfSize, size_t lLocaSize, const void * pHead, int * prgnContourEndPoint, size_t cnPoints); 198 bool GlyfPoints(gid16 nGlyphId, const void * pGlyf, const void * pLoca, 199 size_t lGlyfSize, size_t lLocaSize, const void * pHead, const int * prgnContourEndPoint, size_t cnEndPoints, 200 int * prgnX, int * prgnY, bool * prgfOnCurve, size_t cnPoints); 201 202 // utitily method used by high-level GlyfPoints 203 bool SimplifyFlags(char * prgbFlags, int cnPoints); 204 bool CalcAbsolutePoints(int * prgnX, int * prgnY, int cnPoints); 205 #endif 206 207 } // end of namespace TtfUtil 208 } // end of namespace graphite2