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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 <qstring.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 QString &encName);
+
+ // Full name of the encoding, as read from the encoding file
+ QString 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
+ QString 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