FreeType font driver for PCF fonts

                       Francesco Zappa Nardelli

                  <francesco.zappa.nardelli@ens.fr>

Introduction

************

PCF (Portable Compiled Format) is a binary bitmap font format, largely used

in X world. This code implements a PCF driver for the FreeType library.

Glyph images are loaded into memory only on demand, thus leading to a small

memory footprint.

Information on the PCF font format can only be worked out from

`pcfread.c', and `pcfwrite.c', to be found, for instance, in the XFree86

(www.xfree86.org) source tree (xc/lib/font/bitmap/).

Many good bitmap fonts in bdf format come with XFree86: they can be

compiled into the pcf format using the `bdftopcf' utility.

Supported hardware

******************

The driver has been tested on linux/x86 and sunos5.5/sparc.  In both

cases the compiler was gcc.  When back in Paris, I will test it also

on linux/alpha.

Encodings

*********

Use `FT_Get_BDF_Charset_ID' to access the encoding and registry.

The driver always exports `ft_encoding_none' as face->charmap.encoding. 

FT_Get_Char_Index() behavior is unmodified, that is, it converts the ULong

value given as argument into the corresponding glyph number.

Known problems

**************

- dealing explicitly with encodings breaks the uniformity of freetype2

  api.

- except for encodings properties, client applications have no

  visibility of the PCF_Face object.  This means that applications

  cannot directly access font tables and are obliged to trust

  FreeType.

- currently, glyph names and ink_metrics are ignored.

I plan to give full visibility of the PCF_Face object in the next

release of the driver, thus implementing also glyph names and

ink_metrics.

- height is defined as (ascent - descent).  Is this correct?

- if unable to read size information from the font, PCF_Init_Face

  sets available_size->width and available_size->height to 12.

- too many english grammar errors in the readme file :-(

License

*******

Copyright (C) 2000 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.

Credits

*******

Keith Packard wrote the pcf driver found in XFree86.  His work is at

the same time the specification and the sample implementation of the

PCF format.  Undoubtedly, this driver is inspired from his work.