[gs-devel] GS and fonts

[Ray Johnston]

Steve,

Steve Claridge wrote:

> I've been asked to add a new driver to Ghostscript and have a few questions:
> 
> 1) Why does GS use the Fontmap file to load fonts from external sources if the
>    PS or PDF input file has embedded fonts? Is this purely to avoid any
>    problems with font licensing or a technical issue?

The PDF spec requires that there are 14 Base Fonts always available, so you
need a Fontmap to define where these fonts can be found and usually to map
the 'standard' name to the equivalent font that you have (alias).

Most PostScript drivers also assume that there will be the standard Level 2
set of 35 fonts always available.

This has nothing to do with licensing.

Note that you don't need a Fontmap if you compile in the standard 35 fonts.
See the documentation on compiled fonts.

> 2) We already have a custom driver which I'm using as a base, it was written
>    by someone who no longer works here, looking at this it seems that if the
>    char_xglyph function cannot match to an xglyph_code the copy_mono func is
>    called rather than render_char. copy_mono has a bitmap of the char to be
>    printed, but the character on the bitmap is very 'rough' and does not look
>    nice, why is this?

Ghostscript will render fonts is the Xfont logic doesn't. The resolution of the
rendering is the device resolution. You may want to enable anti-aliasing of the
rendering using -dTextAlphaBits=4 or increase the resolution of the device.

We don't support your driver so can't really help.

Regards,
Ray Johnston
Artifex Software Inc.
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