1 files changed, 148 insertions, 0 deletions
diff --git a/src/bdf/README b/src/bdf/README
new file mode 100644
index 0000000..e3f2ae3
--- /dev/null
+++ b/src/bdf/README
@@ -0,0 +1,148 @@
+                  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 the
+Adobe Specification V 2.2.  The specification of the BDF font format is
+available from Adobe's web site:
+
+  http://partners.adobe.com/asn/developer/PDFS/TN/5005.BDF_Spec.pdf
+
+Many good bitmap fonts in bdf format come with XFree86 (www.XFree86.org).
+They do not define vertical metrics, because the X Consortium BDF
+specification has removed them.
+
+
+Encodings
+*********
+
+The variety of encodings that accompanies bdf fonts appears to encompass the
+small set defined in freetype.h.  On the other hand, two properties that
+specify encoding and registry are usually defined in bdf fonts.
+
+I decided to make these two properties directly accessible, leaving to the
+client 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 ULong
+value given as argument into the corresponding glyph number.
+
+If the two properties are not available, Adobe Standard Encoding should be
+assumed.
+
+
+Anti-Aliased Bitmaps
+********************
+
+The driver supports an extension to the BDF format as used in Mark Leisher's
+xmbdfed bitmap font editor.  Microsoft's SBIT tool expects bitmap fonts in
+that format for adding anti-aliased them to TrueType fonts.  It introduces a
+fourth field to the `SIZE' keyword which gives the bpp value (bits per
+pixel) 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).  The
+driver returns either a bitmap with 1 bit per pixel or a pixmap with 8bits
+per 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 Nardelli
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included 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 OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE 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 University
+Copyright 2001-2002 Francesco Zappa Nardelli
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included 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 OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+THE COMPUTING RESEARCH LAB OR NEW MEXICO STATE UNIVERSITY BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT
+OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
+THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+
+Credits
+*******
+
+This driver is based on excellent Mark Leisher's bdf library.  If you
+find something good in this driver you should probably thank him, not
+me.