/************************************************************************* ** TFM.cpp ** ** ** ** This file is part of dvisvgm -- the DVI to SVG converter ** ** Copyright (C) 2005-2010 Martin Gieseking ** ** ** ** This program is free software; you can redistribute it and/or ** ** modify it under the terms of the GNU General Public License as ** ** published by the Free Software Foundation; either version 3 of ** ** the License, or (at your option) any later version. ** ** ** ** This program is distributed in the hope that it will be useful, but ** ** WITHOUT ANY WARRANTY; without even the implied warranty of ** ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ** ** GNU General Public License for more details. ** ** ** ** You should have received a copy of the GNU General Public License ** ** along with this program; if not, see . ** *************************************************************************/ #include #include #include #include "FileFinder.h" #include "Message.h" #include "MetafontWrapper.h" #include "StreamReader.h" #include "TFM.h" using namespace std; /** Reads a sequence of n TFM words (4 Bytes each). * @param[in] is reads from this stream * @param[out] v the read words * @param[in] n number of words to be read * @return dynamically allocated array containing the read words * (must be deleted by the caller) */ template static void read_words (StreamReader &sr, vector &v, unsigned n) { v.clear(); v.resize(n); for (unsigned i=0; i < n; i++) v[i] = sr.readUnsigned(4); } /** Converts a TFM fix point value to double. */ static double fix2double (FixWord fix) { return double(fix)/(1 << 20); } TFM::TFM () : _checksum(0), _firstChar(0), _lastChar(0), _designSize(0) { } TFM::TFM (istream &is) { readFromStream(is); } TFM* TFM::createFromFile (const char *fontname) { string filename = string(fontname) + ".tfm"; const char *path = FileFinder::lookup(filename); ifstream ifs(path, ios_base::binary); if (ifs) return new TFM(ifs); return 0; } bool TFM::readFromStream (istream &is) { StreamReader sr(is); is.seekg(2, ios_base::beg); // skip file size UInt16 lh = UInt16(sr.readUnsigned(2)); // length of header in 4 byte words _firstChar= UInt16(sr.readUnsigned(2)); // smalles character code in font _lastChar = UInt16(sr.readUnsigned(2)); // largest character code in font UInt16 nw = UInt16(sr.readUnsigned(2)); // number of words in width table UInt16 nh = UInt16(sr.readUnsigned(2)); // number of words in height table UInt16 nd = UInt16(sr.readUnsigned(2)); // number of words in depth table UInt16 ni = UInt16(sr.readUnsigned(2)); // number of words in italic corr. table // UInt16 nl = UInt16(sr.readUnsigned(2)); // number of words in lig/kern table // UInt16 nk = UInt16(sr.readUnsigned(2)); // number of words in kern table // UInt16 ne = UInt16(sr.readUnsigned(2)); // number of words in ext. char table // UInt16 np = UInt16(sr.readUnsigned(2)); // number of font parameter words is.seekg(8, ios_base::cur); // move to header (skip above commented bytes) _checksum = sr.readUnsigned(4); _designSize = sr.readUnsigned(4); is.seekg(24+lh*4, ios_base::beg); // move to char info table read_words(sr, _charInfoTable, _lastChar-_firstChar+1); read_words(sr, _widthTable, nw); read_words(sr, _heightTable, nh); read_words(sr, _depthTable, nd); read_words(sr, _italicTable, ni); return true; } /** Returns the design size of this font in TeX point units. */ double TFM::getDesignSize () const { return fix2double(_designSize); } // the char info word for each character consists of 4 bytes holding the following information: // width index w, height index (h), depth index (d), italic correction index (it), // tag (tg) and a remainder: // // byte 1 | byte 2 | byte 3 | byte 4 // xxxxxxxx | xxxx xxxx | xxxxxx xx | xxxxxxxx // w | h d | it tg | remainder /** Returns the width of char c in TeX point units. */ double TFM::getCharWidth (int c) const { if (c < _firstChar || c > _lastChar || unsigned(c-_firstChar) >= _charInfoTable.size()) return 0; int index = (_charInfoTable[c-_firstChar] >> 24) & 0xFF; return fix2double(_widthTable[index]) * fix2double(_designSize); } /** Returns the height of char c in TeX point units. */ double TFM::getCharHeight (int c) const { if (c < _firstChar || c > _lastChar || unsigned(c-_firstChar) >= _charInfoTable.size()) return 0; int index = (_charInfoTable[c-_firstChar] >> 20) & 0x0F; return fix2double(_heightTable[index]) * fix2double(_designSize); } /** Returns the depth of char c in TeX point units. */ double TFM::getCharDepth (int c) const { if (c < _firstChar || c > _lastChar || unsigned(c-_firstChar) >= _charInfoTable.size()) return 0; int index = (_charInfoTable[c-_firstChar] >> 16) & 0x0F; return fix2double(_depthTable[index]) * fix2double(_designSize); } /** Returns the italic correction of char c in TeX point units. */ double TFM::getItalicCorr (int c) const { if (c < _firstChar || c > _lastChar || unsigned(c-_firstChar) >= _charInfoTable.size()) return 0; int index = (_charInfoTable[c-_firstChar] >> 10) & 0x3F; return fix2double(_italicTable[index]) * fix2double(_designSize); }