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. |