[gs-devel] Fwd: revised font api

[Tor Andersson]

Apparently something went wrong with the mailing list so the original
didn't get sent out. Here it is again.

---------- Forwarded message ----------
From: Tor Andersson <tor.andersson at artifex.com>
Date: Thu, 21 May 2009 20:41:16 +0200
Subject: revised font api
To: Ken Sharp <ken.sharp at artifex.com>
Cc: gs-devel at ghostscript.com

Hi Ken!

This is a rough draft of our revised font API. This covers all that MuPDF and
GhostXPS will need, and I am fairly confident it covers what GhostPCL needs
for TrueType.

I believe it will work for our rasterizer, and probably not too well
for pdfwrite :)
Comments will be appreciated.

The revised API project has two main goals:

1) A saner interface for interpreters to use.
2) A separation between the font parsing and font rendering.
3) Pluggable font libraries (freetype, ufst, font fusion, and the
artifex scaler)

We should possibly be able to use a different font parser and
rasterizer (i.e. freetype parser with artifex rasterizing).

The encoding stuff is a direct access to the actual truetype font data,
and does no voodoo since the mojo juice is different for every PDL.
We're hiding it behind our API since we want to be able to use
different font libraries, and code duplication is black mag...ehh... bad (TM).

For opentype layout, the layout engine will have to parse its own fonts,
there's no good common API to expose OpenType (or Graphite, or AAT or
whatever the flavor of the year is) and the problem is bigger than our scope
at the moment. This is good enough for existing PDLs (except SVG).

Tor & Ralph