1 | // SPDX-License-Identifier: MIT OR MPL-2.0 OR LGPL-2.1-or-later OR GPL-2.0-or-later |
2 | // Copyright 2010, SIL International, All rights reserved. |
3 | /* |
4 | Responsibility: Alan Ward |
5 | Last reviewed: Not yet. |
6 | |
7 | Description: |
8 | Utility class for handling TrueType font files. |
9 | */ |
10 | #pragma once |
11 | |
12 | |
13 | #include <cstddef> |
14 | |
15 | namespace graphite2 |
16 | { |
17 | namespace TtfUtil |
18 | { |
19 | |
20 | #define OVERFLOW_OFFSET_CHECK(p, o) (o + reinterpret_cast<size_t>(p) < reinterpret_cast<size_t>(p)) |
21 | |
22 | typedef long fontTableId32; |
23 | typedef unsigned short gid16; |
24 | |
25 | #define TTF_TAG(a,b,c,d) ((a << 24UL) + (b << 16UL) + (c << 8UL) + (d)) |
26 | |
27 | // Enumeration used to specify a table in a TTF file |
28 | class Tag |
29 | { |
30 | unsigned int _v; |
31 | public: |
32 | Tag(const char n[5]) throw() : _v(TTF_TAG(n[0],n[1],n[2],n[3])) {} |
33 | Tag(const unsigned int tag) throw() : _v(tag) {} |
34 | |
35 | operator unsigned int () const throw () { return _v; } |
36 | |
37 | enum |
38 | { |
39 | Feat = TTF_TAG('F','e','a','t'), |
40 | Glat = TTF_TAG('G','l','a','t'), |
41 | Gloc = TTF_TAG('G','l','o','c'), |
42 | Sile = TTF_TAG('S','i','l','e'), |
43 | Silf = TTF_TAG('S','i','l','f'), |
44 | Sill = TTF_TAG('S','i','l','l'), |
45 | cmap = TTF_TAG('c','m','a','p'), |
46 | cvt = TTF_TAG('c','v','t',' '), |
47 | cryp = TTF_TAG('c','r','y','p'), |
48 | head = TTF_TAG('h','e','a','d'), |
49 | fpgm = TTF_TAG('f','p','g','m'), |
50 | gdir = TTF_TAG('g','d','i','r'), |
51 | glyf = TTF_TAG('g','l','y','f'), |
52 | hdmx = TTF_TAG('h','d','m','x'), |
53 | hhea = TTF_TAG('h','h','e','a'), |
54 | hmtx = TTF_TAG('h','m','t','x'), |
55 | loca = TTF_TAG('l','o','c','a'), |
56 | kern = TTF_TAG('k','e','r','n'), |
57 | LTSH = TTF_TAG('L','T','S','H'), |
58 | maxp = TTF_TAG('m','a','x','p'), |
59 | name = TTF_TAG('n','a','m','e'), |
60 | OS_2 = TTF_TAG('O','S','/','2'), |
61 | post = TTF_TAG('p','o','s','t'), |
62 | prep = TTF_TAG('p','r','e','p') |
63 | }; |
64 | }; |
65 | |
66 | /*---------------------------------------------------------------------------------------------- |
67 | Class providing utility methods to parse a TrueType font file (TTF). |
68 | Callling application handles all file input and memory allocation. |
69 | Assumes minimal knowledge of TTF file format. |
70 | ----------------------------------------------------------------------------------------------*/ |
71 | ////////////////////////////////// tools to find & check TTF tables |
72 | bool (size_t & lOffset, size_t & lSize); |
73 | bool (const void * pHdr); |
74 | bool GetTableDirInfo(const void * pHdr, size_t & lOffset, size_t & lSize); |
75 | bool GetTableInfo(const Tag TableTag, const void * pHdr, const void * pTableDir, |
76 | size_t & lOffset, size_t & lSize); |
77 | bool CheckTable(const Tag TableId, const void * pTable, size_t lTableSize); |
78 | |
79 | ////////////////////////////////// simple font wide info |
80 | size_t GlyphCount(const void * pMaxp); |
81 | #ifdef ALL_TTFUTILS |
82 | size_t MaxCompositeComponentCount(const void * pMaxp); |
83 | size_t MaxCompositeLevelCount(const void * pMaxp); |
84 | size_t LocaGlyphCount(size_t lLocaSize, const void * pHead); // throw (std::domain_error); |
85 | #endif |
86 | int DesignUnits(const void * pHead); |
87 | #ifdef ALL_TTFUTILS |
88 | int HeadTableCheckSum(const void * pHead); |
89 | void HeadTableCreateTime(const void * pHead, unsigned int * pnDateBC, unsigned int * pnDateAD); |
90 | void HeadTableModifyTime(const void * pHead, unsigned int * pnDateBC, unsigned int * pnDateAD); |
91 | bool IsItalic(const void * pHead); |
92 | int FontAscent(const void * pOs2); |
93 | int FontDescent(const void * pOs2); |
94 | bool FontOs2Style(const void *pOs2, bool & fBold, bool & fItalic); |
95 | bool Get31EngFamilyInfo(const void * pName, size_t & lOffset, size_t & lSize); |
96 | bool Get31EngFullFontInfo(const void * pName, size_t & lOffset, size_t & lSize); |
97 | bool Get30EngFamilyInfo(const void * pName, size_t & lOffset, size_t & lSize); |
98 | bool Get30EngFullFontInfo(const void * pName, size_t & lOffset, size_t & lSize); |
99 | int PostLookup(const void * pPost, size_t lPostSize, const void * pMaxp, |
100 | const char * pPostName); |
101 | #endif |
102 | |
103 | ////////////////////////////////// utility methods helpful for name table |
104 | bool GetNameInfo(const void * pName, int nPlatformId, int nEncodingId, |
105 | int nLangId, int nNameId, size_t & lOffset, size_t & lSize); |
106 | //size_t NameTableLength(const byte * pTable); |
107 | #ifdef ALL_TTFUTILS |
108 | int GetLangsForNames(const void * pName, int nPlatformId, int nEncodingId, |
109 | int *nameIdList, int cNameIds, short *langIdList); |
110 | void SwapWString(void * pWStr, size_t nSize = 0); // throw (std::invalid_argument); |
111 | #endif |
112 | |
113 | ////////////////////////////////// cmap lookup tools |
114 | const void * FindCmapSubtable(const void * pCmap, int nPlatformId = 3, |
115 | int nEncodingId = 1, size_t length = 0); |
116 | bool CheckCmapSubtable4(const void * pCmap31, const void * pCmapEnd /*, unsigned int maxgid*/); |
117 | gid16 CmapSubtable4Lookup(const void * pCmapSubtabel4, unsigned int nUnicodeId, int rangeKey = 0); |
118 | unsigned int CmapSubtable4NextCodepoint(const void *pCmap31, unsigned int nUnicodeId, |
119 | int * pRangeKey = 0); |
120 | bool CheckCmapSubtable12(const void *pCmap310, const void * pCmapEnd /*, unsigned int maxgid*/); |
121 | gid16 CmapSubtable12Lookup(const void * pCmap310, unsigned int uUnicodeId, int rangeKey = 0); |
122 | unsigned int CmapSubtable12NextCodepoint(const void *pCmap310, unsigned int nUnicodeId, |
123 | int * pRangeKey = 0); |
124 | |
125 | ///////////////////////////////// horizontal metric data for a glyph |
126 | bool HorMetrics(gid16 nGlyphId, const void * pHmtx, size_t lHmtxSize, |
127 | const void * pHhea, int & nLsb, unsigned int & nAdvWid); |
128 | |
129 | ////////////////////////////////// primitives for loca and glyf lookup |
130 | size_t LocaLookup(gid16 nGlyphId, const void * pLoca, size_t lLocaSize, |
131 | const void * pHead); // throw (std::out_of_range); |
132 | void * GlyfLookup(const void * pGlyf, size_t lGlyfOffset, size_t lTableLen); |
133 | |
134 | ////////////////////////////////// primitves for simple glyph data |
135 | bool GlyfBox(const void * pSimpleGlyf, int & xMin, int & yMin, |
136 | int & xMax, int & yMax); |
137 | |
138 | #ifdef ALL_TTFUTILS |
139 | int GlyfContourCount(const void * pSimpleGlyf); |
140 | bool GlyfContourEndPoints(const void * pSimpleGlyf, int * prgnContourEndPoint, |
141 | int cnPointsTotal, size_t & cnPoints); |
142 | bool GlyfPoints(const void * pSimpleGlyf, int * prgnX, int * prgnY, |
143 | char * prgbFlag, int cnPointsTotal, int & cnPoints); |
144 | |
145 | // primitive to find the glyph ids in a composite glyph |
146 | bool GetComponentGlyphIds(const void * pSimpleGlyf, int * prgnCompId, |
147 | size_t cnCompIdTotal, size_t & cnCompId); |
148 | // primitive to find the placement data for a component in a composite glyph |
149 | bool GetComponentPlacement(const void * pSimpleGlyf, int nCompId, |
150 | bool fOffset, int & a, int & b); |
151 | // primitive to find the transform data for a component in a composite glyph |
152 | bool GetComponentTransform(const void * pSimpleGlyf, int nCompId, |
153 | float & flt11, float & flt12, float & flt21, float & flt22, bool & fTransOffset); |
154 | #endif |
155 | |
156 | ////////////////////////////////// operate on composite or simple glyph (auto glyf lookup) |
157 | void * GlyfLookup(gid16 nGlyphId, const void * pGlyf, const void * pLoca, |
158 | size_t lGlyfSize, size_t lLocaSize, const void * pHead); // primitive used by below methods |
159 | |
160 | #ifdef ALL_TTFUTILS |
161 | // below are primary user methods for handling glyf data |
162 | bool IsSpace(gid16 nGlyphId, const void * pLoca, size_t lLocaSize, const void * pHead); |
163 | bool IsDeepComposite(gid16 nGlyphId, const void * pGlyf, const void * pLoca, |
164 | size_t lGlyfSize, size_t lLocaSize, const void * pHead); |
165 | |
166 | bool GlyfBox(gid16 nGlyphId, const void * pGlyf, const void * pLoca, size_t lGlyfSize, size_t lLocaSize, |
167 | const void * pHead, int & xMin, int & yMin, int & xMax, int & yMax); |
168 | bool GlyfContourCount(gid16 nGlyphId, const void * pGlyf, const void * pLoca, |
169 | size_t lGlyfSize, size_t lLocaSize, const void *pHead, size_t & cnContours); |
170 | bool GlyfContourEndPoints(gid16 nGlyphId, const void * pGlyf, const void * pLoca, |
171 | size_t lGlyfSize, size_t lLocaSize, const void * pHead, int * prgnContourEndPoint, size_t cnPoints); |
172 | bool GlyfPoints(gid16 nGlyphId, const void * pGlyf, const void * pLoca, |
173 | size_t lGlyfSize, size_t lLocaSize, const void * pHead, const int * prgnContourEndPoint, size_t cnEndPoints, |
174 | int * prgnX, int * prgnY, bool * prgfOnCurve, size_t cnPoints); |
175 | |
176 | // utitily method used by high-level GlyfPoints |
177 | bool SimplifyFlags(char * prgbFlags, int cnPoints); |
178 | bool CalcAbsolutePoints(int * prgnX, int * prgnY, int cnPoints); |
179 | #endif |
180 | |
181 | } // end of namespace TtfUtil |
182 | } // end of namespace graphite2 |
183 | |