Line data Source code
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 : typedef long fontTableId32;
47 : typedef unsigned short gid16;
48 :
49 : #define TTF_TAG(a,b,c,d) ((a << 24UL) + (b << 16UL) + (c << 8UL) + (d))
50 :
51 : // Enumeration used to specify a table in a TTF file
52 : class Tag
53 : {
54 : unsigned long _v;
55 : public:
56 : Tag(const char n[5]) throw() : _v(TTF_TAG(n[0],n[1],n[2],n[3])) {}
57 0 : Tag(const unsigned long tag) throw() : _v(tag) {}
58 :
59 0 : operator unsigned long () const throw () { return _v; }
60 :
61 : enum
62 : {
63 : Feat = TTF_TAG('F','e','a','t'),
64 : Glat = TTF_TAG('G','l','a','t'),
65 : Gloc = TTF_TAG('G','l','o','c'),
66 : Sile = TTF_TAG('S','i','l','e'),
67 : Silf = TTF_TAG('S','i','l','f'),
68 : Sill = TTF_TAG('S','i','l','l'),
69 : cmap = TTF_TAG('c','m','a','p'),
70 : cvt = TTF_TAG('c','v','t',' '),
71 : cryp = TTF_TAG('c','r','y','p'),
72 : head = TTF_TAG('h','e','a','d'),
73 : fpgm = TTF_TAG('f','p','g','m'),
74 : gdir = TTF_TAG('g','d','i','r'),
75 : glyf = TTF_TAG('g','l','y','f'),
76 : hdmx = TTF_TAG('h','d','m','x'),
77 : hhea = TTF_TAG('h','h','e','a'),
78 : hmtx = TTF_TAG('h','m','t','x'),
79 : loca = TTF_TAG('l','o','c','a'),
80 : kern = TTF_TAG('k','e','r','n'),
81 : LTSH = TTF_TAG('L','T','S','H'),
82 : maxp = TTF_TAG('m','a','x','p'),
83 : name = TTF_TAG('n','a','m','e'),
84 : OS_2 = TTF_TAG('O','S','/','2'),
85 : post = TTF_TAG('p','o','s','t'),
86 : prep = TTF_TAG('p','r','e','p')
87 : };
88 : };
89 :
90 : /*----------------------------------------------------------------------------------------------
91 : Class providing utility methods to parse a TrueType font file (TTF).
92 : Callling application handles all file input and memory allocation.
93 : Assumes minimal knowledge of TTF file format.
94 : ----------------------------------------------------------------------------------------------*/
95 : ////////////////////////////////// tools to find & check TTF tables
96 : bool GetHeaderInfo(size_t & lOffset, size_t & lSize);
97 : bool CheckHeader(const void * pHdr);
98 : bool GetTableDirInfo(const void * pHdr, size_t & lOffset, size_t & lSize);
99 : bool GetTableInfo(const Tag TableTag, const void * pHdr, const void * pTableDir,
100 : size_t & lOffset, size_t & lSize);
101 : bool CheckTable(const Tag TableId, const void * pTable, size_t lTableSize);
102 :
103 : ////////////////////////////////// simple font wide info
104 : size_t GlyphCount(const void * pMaxp);
105 : #ifdef ALL_TTFUTILS
106 : size_t MaxCompositeComponentCount(const void * pMaxp);
107 : size_t MaxCompositeLevelCount(const void * pMaxp);
108 : size_t LocaGlyphCount(size_t lLocaSize, const void * pHead); // throw (std::domain_error);
109 : #endif
110 : int DesignUnits(const void * pHead);
111 : #ifdef ALL_TTFUTILS
112 : int HeadTableCheckSum(const void * pHead);
113 : void HeadTableCreateTime(const void * pHead, unsigned int * pnDateBC, unsigned int * pnDateAD);
114 : void HeadTableModifyTime(const void * pHead, unsigned int * pnDateBC, unsigned int * pnDateAD);
115 : bool IsItalic(const void * pHead);
116 : int FontAscent(const void * pOs2);
117 : int FontDescent(const void * pOs2);
118 : bool FontOs2Style(const void *pOs2, bool & fBold, bool & fItalic);
119 : bool Get31EngFamilyInfo(const void * pName, size_t & lOffset, size_t & lSize);
120 : bool Get31EngFullFontInfo(const void * pName, size_t & lOffset, size_t & lSize);
121 : bool Get30EngFamilyInfo(const void * pName, size_t & lOffset, size_t & lSize);
122 : bool Get30EngFullFontInfo(const void * pName, size_t & lOffset, size_t & lSize);
123 : int PostLookup(const void * pPost, size_t lPostSize, const void * pMaxp,
124 : const char * pPostName);
125 : #endif
126 :
127 : ////////////////////////////////// utility methods helpful for name table
128 : bool GetNameInfo(const void * pName, int nPlatformId, int nEncodingId,
129 : int nLangId, int nNameId, size_t & lOffset, size_t & lSize);
130 : //size_t NameTableLength(const byte * pTable);
131 : #ifdef ALL_TTFUTILS
132 : int GetLangsForNames(const void * pName, int nPlatformId, int nEncodingId,
133 : int *nameIdList, int cNameIds, short *langIdList);
134 : void SwapWString(void * pWStr, size_t nSize = 0); // throw (std::invalid_argument);
135 : #endif
136 :
137 : ////////////////////////////////// cmap lookup tools
138 : const void * FindCmapSubtable(const void * pCmap, int nPlatformId = 3,
139 : int nEncodingId = 1, size_t length = 0);
140 : bool CheckCmapSubtable4(const void * pCmap31, const void * pCmapEnd /*, unsigned int maxgid*/);
141 : gid16 CmapSubtable4Lookup(const void * pCmapSubtabel4, unsigned int nUnicodeId, int rangeKey = 0);
142 : unsigned int CmapSubtable4NextCodepoint(const void *pCmap31, unsigned int nUnicodeId,
143 : int * pRangeKey = 0);
144 : bool CheckCmapSubtable12(const void *pCmap310, const void * pCmapEnd /*, unsigned int maxgid*/);
145 : gid16 CmapSubtable12Lookup(const void * pCmap310, unsigned int uUnicodeId, int rangeKey = 0);
146 : unsigned int CmapSubtable12NextCodepoint(const void *pCmap310, unsigned int nUnicodeId,
147 : int * pRangeKey = 0);
148 :
149 : ///////////////////////////////// horizontal metric data for a glyph
150 : bool HorMetrics(gid16 nGlyphId, const void * pHmtx, size_t lHmtxSize,
151 : const void * pHhea, int & nLsb, unsigned int & nAdvWid);
152 :
153 : ////////////////////////////////// primitives for loca and glyf lookup
154 : size_t LocaLookup(gid16 nGlyphId, const void * pLoca, size_t lLocaSize,
155 : const void * pHead); // throw (std::out_of_range);
156 : void * GlyfLookup(const void * pGlyf, size_t lGlyfOffset, size_t lTableLen);
157 :
158 : ////////////////////////////////// primitves for simple glyph data
159 : bool GlyfBox(const void * pSimpleGlyf, int & xMin, int & yMin,
160 : int & xMax, int & yMax);
161 :
162 : #ifdef ALL_TTFUTILS
163 : int GlyfContourCount(const void * pSimpleGlyf);
164 : bool GlyfContourEndPoints(const void * pSimpleGlyf, int * prgnContourEndPoint,
165 : int cnPointsTotal, size_t & cnPoints);
166 : bool GlyfPoints(const void * pSimpleGlyf, int * prgnX, int * prgnY,
167 : char * prgbFlag, int cnPointsTotal, int & cnPoints);
168 :
169 : // primitive to find the glyph ids in a composite glyph
170 : bool GetComponentGlyphIds(const void * pSimpleGlyf, int * prgnCompId,
171 : size_t cnCompIdTotal, size_t & cnCompId);
172 : // primitive to find the placement data for a component in a composite glyph
173 : bool GetComponentPlacement(const void * pSimpleGlyf, int nCompId,
174 : bool fOffset, int & a, int & b);
175 : // primitive to find the transform data for a component in a composite glyph
176 : bool GetComponentTransform(const void * pSimpleGlyf, int nCompId,
177 : float & flt11, float & flt12, float & flt21, float & flt22, bool & fTransOffset);
178 : #endif
179 :
180 : ////////////////////////////////// operate on composite or simple glyph (auto glyf lookup)
181 : void * GlyfLookup(gid16 nGlyphId, const void * pGlyf, const void * pLoca,
182 : size_t lGlyfSize, size_t lLocaSize, const void * pHead); // primitive used by below methods
183 :
184 : #ifdef ALL_TTFUTILS
185 : // below are primary user methods for handling glyf data
186 : bool IsSpace(gid16 nGlyphId, const void * pLoca, size_t lLocaSize, const void * pHead);
187 : bool IsDeepComposite(gid16 nGlyphId, const void * pGlyf, const void * pLoca,
188 : size_t lGlyfSize, size_t lLocaSize, const void * pHead);
189 :
190 : bool GlyfBox(gid16 nGlyphId, const void * pGlyf, const void * pLoca, size_t lGlyfSize, size_t lLocaSize,
191 : const void * pHead, int & xMin, int & yMin, int & xMax, int & yMax);
192 : bool GlyfContourCount(gid16 nGlyphId, const void * pGlyf, const void * pLoca,
193 : size_t lGlyfSize, size_t lLocaSize, const void *pHead, size_t & cnContours);
194 : bool GlyfContourEndPoints(gid16 nGlyphId, const void * pGlyf, const void * pLoca,
195 : size_t lGlyfSize, size_t lLocaSize, const void * pHead, int * prgnContourEndPoint, size_t cnPoints);
196 : bool GlyfPoints(gid16 nGlyphId, const void * pGlyf, const void * pLoca,
197 : size_t lGlyfSize, size_t lLocaSize, const void * pHead, const int * prgnContourEndPoint, size_t cnEndPoints,
198 : int * prgnX, int * prgnY, bool * prgfOnCurve, size_t cnPoints);
199 :
200 : // utitily method used by high-level GlyfPoints
201 : bool SimplifyFlags(char * prgbFlags, int cnPoints);
202 : bool CalcAbsolutePoints(int * prgnX, int * prgnY, int cnPoints);
203 : #endif
204 :
205 : } // end of namespace TtfUtil
206 : } // end of namespace graphite2
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