// SPDX-License-Identifier: MIT OR MPL-2.0 OR LGPL-2.1-or-later OR GPL-2.0-or-later
// Copyright 2010, SIL International, All rights reserved.
/*
Responsibility: Alan Ward
Last reviewed: Not yet.
Description:
Utility class for handling TrueType font files.
*/
#pragma once
#include <cstddef>
namespace graphite2
{
namespace TtfUtil
{
#define OVERFLOW_OFFSET_CHECK(p, o) (o + reinterpret_cast<size_t>(p) < reinterpret_cast<size_t>(p))
typedef long fontTableId32;
typedef unsigned short gid16;
#define TTF_TAG(a,b,c,d) ((a << 24UL) + (b << 16UL) + (c << 8UL) + (d))
// Enumeration used to specify a table in a TTF file
class Tag
{
unsigned int _v;
public:
Tag(const char n[5]) throw() : _v(TTF_TAG(n[0],n[1],n[2],n[3])) {}
Tag(const unsigned int tag) throw() : _v(tag) {}
operator unsigned int () const throw () { return _v; }
enum
{
Feat = TTF_TAG('F','e','a','t'),
Glat = TTF_TAG('G','l','a','t'),
Gloc = TTF_TAG('G','l','o','c'),
Sile = TTF_TAG('S','i','l','e'),
Silf = TTF_TAG('S','i','l','f'),
Sill = TTF_TAG('S','i','l','l'),
cmap = TTF_TAG('c','m','a','p'),
cvt = TTF_TAG('c','v','t',' '),
cryp = TTF_TAG('c','r','y','p'),
head = TTF_TAG('h','e','a','d'),
fpgm = TTF_TAG('f','p','g','m'),
gdir = TTF_TAG('g','d','i','r'),
glyf = TTF_TAG('g','l','y','f'),
hdmx = TTF_TAG('h','d','m','x'),
hhea = TTF_TAG('h','h','e','a'),
hmtx = TTF_TAG('h','m','t','x'),
loca = TTF_TAG('l','o','c','a'),
kern = TTF_TAG('k','e','r','n'),
LTSH = TTF_TAG('L','T','S','H'),
maxp = TTF_TAG('m','a','x','p'),
name = TTF_TAG('n','a','m','e'),
OS_2 = TTF_TAG('O','S','/','2'),
post = TTF_TAG('p','o','s','t'),
prep = TTF_TAG('p','r','e','p')
};
};
/*----------------------------------------------------------------------------------------------
Class providing utility methods to parse a TrueType font file (TTF).
Callling application handles all file input and memory allocation.
Assumes minimal knowledge of TTF file format.
----------------------------------------------------------------------------------------------*/
////////////////////////////////// tools to find & check TTF tables
bool GetHeaderInfo(size_t & lOffset, size_t & lSize);
bool CheckHeader(const void * pHdr);
bool GetTableDirInfo(const void * pHdr, size_t & lOffset, size_t & lSize);
bool GetTableInfo(const Tag TableTag, const void * pHdr, const void * pTableDir,
size_t & lOffset, size_t & lSize);
bool CheckTable(const Tag TableId, const void * pTable, size_t lTableSize);
////////////////////////////////// simple font wide info
size_t GlyphCount(const void * pMaxp);
#ifdef ALL_TTFUTILS
size_t MaxCompositeComponentCount(const void * pMaxp);
size_t MaxCompositeLevelCount(const void * pMaxp);
size_t LocaGlyphCount(size_t lLocaSize, const void * pHead); // throw (std::domain_error);
#endif
int DesignUnits(const void * pHead);
#ifdef ALL_TTFUTILS
int HeadTableCheckSum(const void * pHead);
void HeadTableCreateTime(const void * pHead, unsigned int * pnDateBC, unsigned int * pnDateAD);
void HeadTableModifyTime(const void * pHead, unsigned int * pnDateBC, unsigned int * pnDateAD);
bool IsItalic(const void * pHead);
int FontAscent(const void * pOs2);
int FontDescent(const void * pOs2);
bool FontOs2Style(const void *pOs2, bool & fBold, bool & fItalic);
bool Get31EngFamilyInfo(const void * pName, size_t & lOffset, size_t & lSize);
bool Get31EngFullFontInfo(const void * pName, size_t & lOffset, size_t & lSize);
bool Get30EngFamilyInfo(const void * pName, size_t & lOffset, size_t & lSize);
bool Get30EngFullFontInfo(const void * pName, size_t & lOffset, size_t & lSize);
int PostLookup(const void * pPost, size_t lPostSize, const void * pMaxp,
const char * pPostName);
#endif
////////////////////////////////// utility methods helpful for name table
bool GetNameInfo(const void * pName, int nPlatformId, int nEncodingId,
int nLangId, int nNameId, size_t & lOffset, size_t & lSize);
//size_t NameTableLength(const byte * pTable);
#ifdef ALL_TTFUTILS
int GetLangsForNames(const void * pName, int nPlatformId, int nEncodingId,
int *nameIdList, int cNameIds, short *langIdList);
void SwapWString(void * pWStr, size_t nSize = 0); // throw (std::invalid_argument);
#endif
////////////////////////////////// cmap lookup tools
const void * FindCmapSubtable(const void * pCmap, int nPlatformId = 3,
int nEncodingId = 1, size_t length = 0);
bool CheckCmapSubtable4(const void * pCmap31, const void * pCmapEnd /*, unsigned int maxgid*/);
gid16 CmapSubtable4Lookup(const void * pCmapSubtabel4, unsigned int nUnicodeId, int rangeKey = 0);
unsigned int CmapSubtable4NextCodepoint(const void *pCmap31, unsigned int nUnicodeId,
int * pRangeKey = 0);
bool CheckCmapSubtable12(const void *pCmap310, const void * pCmapEnd /*, unsigned int maxgid*/);
gid16 CmapSubtable12Lookup(const void * pCmap310, unsigned int uUnicodeId, int rangeKey = 0);
unsigned int CmapSubtable12NextCodepoint(const void *pCmap310, unsigned int nUnicodeId,
int * pRangeKey = 0);
///////////////////////////////// horizontal metric data for a glyph
bool HorMetrics(gid16 nGlyphId, const void * pHmtx, size_t lHmtxSize,
const void * pHhea, int & nLsb, unsigned int & nAdvWid);
////////////////////////////////// primitives for loca and glyf lookup
size_t LocaLookup(gid16 nGlyphId, const void * pLoca, size_t lLocaSize,
const void * pHead); // throw (std::out_of_range);
void * GlyfLookup(const void * pGlyf, size_t lGlyfOffset, size_t lTableLen);
////////////////////////////////// primitves for simple glyph data
bool GlyfBox(const void * pSimpleGlyf, int & xMin, int & yMin,
int & xMax, int & yMax);
#ifdef ALL_TTFUTILS
int GlyfContourCount(const void * pSimpleGlyf);
bool GlyfContourEndPoints(const void * pSimpleGlyf, int * prgnContourEndPoint,
int cnPointsTotal, size_t & cnPoints);
bool GlyfPoints(const void * pSimpleGlyf, int * prgnX, int * prgnY,
char * prgbFlag, int cnPointsTotal, int & cnPoints);
// primitive to find the glyph ids in a composite glyph
bool GetComponentGlyphIds(const void * pSimpleGlyf, int * prgnCompId,
size_t cnCompIdTotal, size_t & cnCompId);
// primitive to find the placement data for a component in a composite glyph
bool GetComponentPlacement(const void * pSimpleGlyf, int nCompId,
bool fOffset, int & a, int & b);
// primitive to find the transform data for a component in a composite glyph
bool GetComponentTransform(const void * pSimpleGlyf, int nCompId,
float & flt11, float & flt12, float & flt21, float & flt22, bool & fTransOffset);
#endif
////////////////////////////////// operate on composite or simple glyph (auto glyf lookup)
void * GlyfLookup(gid16 nGlyphId, const void * pGlyf, const void * pLoca,
size_t lGlyfSize, size_t lLocaSize, const void * pHead); // primitive used by below methods
#ifdef ALL_TTFUTILS
// below are primary user methods for handling glyf data
bool IsSpace(gid16 nGlyphId, const void * pLoca, size_t lLocaSize, const void * pHead);
bool IsDeepComposite(gid16 nGlyphId, const void * pGlyf, const void * pLoca,
size_t lGlyfSize, size_t lLocaSize, const void * pHead);
bool GlyfBox(gid16 nGlyphId, const void * pGlyf, const void * pLoca, size_t lGlyfSize, size_t lLocaSize,
const void * pHead, int & xMin, int & yMin, int & xMax, int & yMax);
bool GlyfContourCount(gid16 nGlyphId, const void * pGlyf, const void * pLoca,
size_t lGlyfSize, size_t lLocaSize, const void *pHead, size_t & cnContours);
bool GlyfContourEndPoints(gid16 nGlyphId, const void * pGlyf, const void * pLoca,
size_t lGlyfSize, size_t lLocaSize, const void * pHead, int * prgnContourEndPoint, size_t cnPoints);
bool GlyfPoints(gid16 nGlyphId, const void * pGlyf, const void * pLoca,
size_t lGlyfSize, size_t lLocaSize, const void * pHead, const int * prgnContourEndPoint, size_t cnEndPoints,
int * prgnX, int * prgnY, bool * prgfOnCurve, size_t cnPoints);
// utitily method used by high-level GlyfPoints
bool SimplifyFlags(char * prgbFlags, int cnPoints);
bool CalcAbsolutePoints(int * prgnX, int * prgnY, int cnPoints);
#endif
} // end of namespace TtfUtil
} // end of namespace graphite2