FreeType font driver for BDF fonts                       Francesco Zappa Nardelli                  <francesco.zappa.nardelli@ens.fr>Introduction************BDF (Bitmap Distribution Format) is a bitmap font format defined by Adobe,which is intended to be easily understood by both humans and computers. This code implements a BDF driver for the FreeType library, following theAdobe Specification V 2.2.  The specification of the BDF font format isavailable from Adobe's web site:  http://partners.adobe.com/asn/developer/PDFS/TN/5005.BDF_Spec.pdfMany good bitmap fonts in bdf format come with XFree86 (www.XFree86.org). They do not define vertical metrics, because the X Consortium BDFspecification has removed them.Encodings*********The variety of encodings that accompanies bdf fonts appears to encompass thesmall set defined in freetype.h.  On the other hand, two properties thatspecify encoding and registry are usually defined in bdf fonts.I decided to make these two properties directly accessible, leaving to theclient application the work of interpreting them.  For instance:  #include FT_INTERNAL_BDF_TYPES_H  FT_Face          face;  BDF_Public_Face  bdfface;  FT_New_Face( library, ..., &face );  bdfface = (BDF_Public_Face)face;    if ( ( bdfface->charset_registry == "ISO10646" ) &&        ( bdfface->charset_encoding == "1" )        )    [..]Thus the driver always exports `ft_encoding_none' as face->charmap.encoding. FT_Get_Char_Index's behavior is unmodified, that is, it converts the ULongvalue given as argument into the corresponding glyph number.If the two properties are not available, Adobe Standard Encoding should beassumed.Anti-Aliased Bitmaps********************The driver supports an extension to the BDF format as used in Mark Leisher'sxmbdfed bitmap font editor.  Microsoft's SBIT tool expects bitmap fonts inthat format for adding anti-aliased them to TrueType fonts.  It introduces afourth field to the `SIZE' keyword which gives the bpp value (bits perpixel) of the glyph data in the font.  Possible values are 1 (the default),2 (four gray levels), 4 (16 gray levels), and 8 (256 gray levels).  Thedriver returns either a bitmap with 1 bit per pixel or a pixmap with 8bitsper pixel (using 4, 16, and 256 gray levels, respectively).Known problems**************- A font is entirely loaded into memory.  Obviously, this is not the Right  Thing(TM).  If you have big fonts I suggest you convert them into PCF  format (using the bdftopcf utility): the PCF font drive of FreeType can  perform incremental glyph loading.When I have some time, I will implement on-demand glyph parsing.- Except for encodings properties, client applications have no visibility of  the PCF_Face object.  This means that applications cannot directly access  font tables and must trust FreeType.- Currently, glyph names are ignored.  I plan to give full visibility of the BDF_Face object in an upcoming  revision of the driver, thus implementing also glyph names.- As I have never seen a BDF font that defines vertical metrics, vertical  metrics are (parsed and) discarded.  If you own a BDF font that defines  vertical metrics, please let me know (I will implement them in 5-10  minutes).License*******Copyright (C) 2001-2002 by Francesco Zappa NardelliPermission is hereby granted, free of charge, to any person obtaininga copy of this software and associated documentation files (the"Software"), to deal in the Software without restriction, includingwithout limitation the rights to use, copy, modify, merge, publish,distribute, sublicense, and/or sell copies of the Software, and topermit persons to whom the Software is furnished to do so, subject tothe following conditions:The above copyright notice and this permission notice shall beincluded in all copies or substantial portions of the Software.THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OFMERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANYCLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THESOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.*** Portions of the driver (that is, bdflib.c and bdf.h):Copyright 2000 Computing Research Labs, New Mexico State UniversityCopyright 2001-2002 Francesco Zappa NardelliPermission is hereby granted, free of charge, to any person obtaining acopy of this software and associated documentation files (the "Software"),to deal in the Software without restriction, including without limitationthe rights to use, copy, modify, merge, publish, distribute, sublicense,and/or sell copies of the Software, and to permit persons to whom theSoftware is furnished to do so, subject to the following conditions:The above copyright notice and this permission notice shall be included inall copies or substantial portions of the Software.THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS ORIMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALLTHE COMPUTING RESEARCH LAB OR NEW MEXICO STATE UNIVERSITY BE LIABLE FOR ANYCLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORTOR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE ORTHE USE OR OTHER DEALINGS IN THE SOFTWARE.Credits*******This driver is based on excellent Mark Leisher's bdf library.  If youfind something good in this driver you should probably thank him, notme.