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// -*- C++ -*-
// fontEncoding.h
//
// Part of KDVI - A DVI previewer for the KDE desktop environemt
//
// (C) 2003 Stefan Kebekus
// Distributed under the GPL
#ifndef _FONTENCODING_H
#define _FONTENCODING_H
#include <tqstring.h>
/**
* This class represents the contents of a font encoding file,
* e.g. "8r.enc"
*
* Explanation of font encodings: TeX was designed to only use
* MetaFont fonts. A DVI file referres to a MetaFont font by giving an
* at-most-8-character name, such as 'cmr10'. The DVI previewer would
* then locate the associated PK font file (e.g. cmr10.600pk), load
* it, and retrieve the character shaped.
*
* Today TeX is also used to access Type1 and TrueType fonts, which it
* was never designed to do. As in the case of MetaFont font, the DVI
* file specifies the name of a font, e.g. 'rpbkd', and the DVI
* previewer finds the associated font file 'ubkd8a.pfb' by means of a
* map file (see fontMap.h). The font map file also specifies an
* encoding (e.g. '8r', to be found in a file '8r.enc'). Font
* encodings are necessary because TeX can only use the first 256
* characters of a font, while modern PostScript fonts often contain
* more.
*
* In a PostScript font, glyphs can often be accessed in two ways:
*
* (a) by an integer, the 'glyph index', which need not be
* positive. Glyph indices can be found in every font.
*
* (b) by the name of the glyph, such as 'A', 'plusminus' or
* 'ogonek'. Note: Not all fonts contain glyph names, and if a font
* contains glyph names, they are not always reliable.
*
* An encoding file is essentially a list of 256 names of glyphs that
* TeX wishes to use from a certain font. If the font contains more
* than 256 glyphs, TeX is still limited to use at most 256 glyphs. If
* more glyphs are required, TeX can probably use the same font under
* a different name and with a different encoding ---the map file
* (fontMap.h) can probably see to that.
*
* Summing up: this class contains 256 glyph names read from an
* encoding file during the construction of this class.
*
* @author Stefan Kebekus <kebekus@kde.org>
*
**/
class fontEncoding {
public:
// The constructor takes the name of an encoding file, such as
// '8r.enc', locate the file on the hard disk using the 'kpsewhich'
// command, reads it in and parses it. If the file cannot be
// located, opened or parsed, errors are printed using the kdError()
// channel, and the array glyphNameVector will contain empty
// strings.
fontEncoding(const TQString &encName);
// Full name of the encoding, as read from the encoding file
TQString encodingFullName;
// List of 256 glyph names. The name can be '.notdef' to indicate
// that a certain position is left open, or empty, if the encoding
// file did not contain 256 characters or could not be properly read
TQString glyphNameVector[256];
// Returns 'true' if the encoding file was found and could
// successfully be loaded.
bool isValid() {return _isValid;}
private:
// Set by the constructor to 'true', if the encoding file was found
// and could be loaded successfully.
bool _isValid;
};
#endif
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