"SfR Fresh" - the SfR Freeware/Shareware Archive

Member "freetype-2.3.7/src/bdf/README" of archive freetype-2.3.7.tar.gz:

    1                   FreeType font driver for BDF fonts
    2 
    3                        Francesco Zappa Nardelli
    4                   <francesco.zappa.nardelli@ens.fr>
    5 
    6 
    7 Introduction
    8 ************
    9 
   10 BDF (Bitmap Distribution Format) is a bitmap font format defined by Adobe,
   11 which is intended to be easily understood by both humans and computers.
   12 This code implements a BDF driver for the FreeType library, following the
   13 Adobe Specification V 2.2.  The specification of the BDF font format is
   14 available from Adobe's web site:
   15 
   16   http://partners.adobe.com/asn/developer/PDFS/TN/5005.BDF_Spec.pdf
   17 
   18 Many good bitmap fonts in bdf format come with XFree86 (www.XFree86.org).
   19 They do not define vertical metrics, because the X Consortium BDF
   20 specification has removed them.
   21 
   22 
   23 Encodings
   24 *********
   25 
   26 The variety of encodings that accompanies bdf fonts appears to encompass the
   27 small set defined in freetype.h.  On the other hand, two properties that
   28 specify encoding and registry are usually defined in bdf fonts.
   29 
   30 I decided to make these two properties directly accessible, leaving to the
   31 client application the work of interpreting them.  For instance:
   32 
   33 
   34   #include FT_INTERNAL_BDF_TYPES_H
   35 
   36   FT_Face          face;
   37   BDF_Public_Face  bdfface;
   38 
   39 
   40   FT_New_Face( library, ..., &face );
   41 
   42   bdfface = (BDF_Public_Face)face;
   43 
   44   if ( ( bdfface->charset_registry == "ISO10646" ) &&
   45        ( bdfface->charset_encoding == "1" )        )
   46     [..]
   47 
   48 
   49 Thus the driver always exports `ft_encoding_none' as face->charmap.encoding.
   50 FT_Get_Char_Index's behavior is unmodified, that is, it converts the ULong
   51 value given as argument into the corresponding glyph number.
   52 
   53 If the two properties are not available, Adobe Standard Encoding should be
   54 assumed.
   55 
   56 
   57 Anti-Aliased Bitmaps
   58 ********************
   59 
   60 The driver supports an extension to the BDF format as used in Mark Leisher's
   61 xmbdfed bitmap font editor.  Microsoft's SBIT tool expects bitmap fonts in
   62 that format for adding anti-aliased them to TrueType fonts.  It introduces a
   63 fourth field to the `SIZE' keyword which gives the bpp value (bits per
   64 pixel) of the glyph data in the font.  Possible values are 1 (the default),
   65 2 (four gray levels), 4 (16 gray levels), and 8 (256 gray levels).  The
   66 driver returns either a bitmap with 1 bit per pixel or a pixmap with 8bits
   67 per pixel (using 4, 16, and 256 gray levels, respectively).
   68 
   69 
   70 Known problems
   71 **************
   72 
   73 - A font is entirely loaded into memory.  Obviously, this is not the Right
   74   Thing(TM).  If you have big fonts I suggest you convert them into PCF
   75   format (using the bdftopcf utility): the PCF font drive of FreeType can
   76   perform incremental glyph loading.
   77 
   78 When I have some time, I will implement on-demand glyph parsing.
   79 
   80 - Except for encodings properties, client applications have no visibility of
   81   the PCF_Face object.  This means that applications cannot directly access
   82   font tables and must trust FreeType.
   83 
   84 - Currently, glyph names are ignored.
   85 
   86   I plan to give full visibility of the BDF_Face object in an upcoming
   87   revision of the driver, thus implementing also glyph names.
   88 
   89 - As I have never seen a BDF font that defines vertical metrics, vertical
   90   metrics are (parsed and) discarded.  If you own a BDF font that defines
   91   vertical metrics, please let me know (I will implement them in 5-10
   92   minutes).
   93 
   94 
   95 License
   96 *******
   97 
   98 Copyright (C) 2001-2002 by Francesco Zappa Nardelli
   99 
  100 Permission is hereby granted, free of charge, to any person obtaining
  101 a copy of this software and associated documentation files (the
  102 "Software"), to deal in the Software without restriction, including
  103 without limitation the rights to use, copy, modify, merge, publish,
  104 distribute, sublicense, and/or sell copies of the Software, and to
  105 permit persons to whom the Software is furnished to do so, subject to
  106 the following conditions:
  107 
  108 The above copyright notice and this permission notice shall be
  109 included in all copies or substantial portions of the Software.
  110 
  111 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  112 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  113 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  114 IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
  115 CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  116 TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  117 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  118 
  119 *** Portions of the driver (that is, bdflib.c and bdf.h):
  120 
  121 Copyright 2000 Computing Research Labs, New Mexico State University
  122 Copyright 2001-2002 Francesco Zappa Nardelli
  123 
  124 Permission is hereby granted, free of charge, to any person obtaining a
  125 copy of this software and associated documentation files (the "Software"),
  126 to deal in the Software without restriction, including without limitation
  127 the rights to use, copy, modify, merge, publish, distribute, sublicense,
  128 and/or sell copies of the Software, and to permit persons to whom the
  129 Software is furnished to do so, subject to the following conditions:
  130 
  131 The above copyright notice and this permission notice shall be included in
  132 all copies or substantial portions of the Software.
  133 
  134 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  135 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  136 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  137 THE COMPUTING RESEARCH LAB OR NEW MEXICO STATE UNIVERSITY BE LIABLE FOR ANY
  138 CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT
  139 OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
  140 THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  141 
  142 
  143 Credits
  144 *******
  145 
  146 This driver is based on excellent Mark Leisher's bdf library.  If you
  147 find something good in this driver you should probably thank him, not
  148 me.