RE: [ft] Bytecode enabled rendering

[Ian Brown]

David, I'm not sure that your arguments below are valid. From what I can
divine, ClearType and Avalon are only concerned with sub-pixel rendering
and anti-aliasing. The original issue, however, is about non-aliased
rendering ... i.e. monochrome rendering.
When using freetype to render bitmaps for printing, the discrepancy with
the Microsoft output can be problematic.

Snip from the original post:
> >>I am experiencing problems with aliasing-disabled rendering, and if
> >>you look at Kaya's screenshot (my system, and any other will
> >>probably do, shows just the same behaviour)

So.... making changes to optionally implement the 'broken' Microsoft
rounding implementation should not infringe any more patents than are
currently infringed when byte code processing is enabled. The problem is
figuring out what the MS processor is actually doing. Granted this is no
easy task - but I don't see how the clear-type patents are involved.

Ian

-----Original Message-----
From: address@hidden
[mailto:address@hidden On Behalf Of
Turner, David
Sent: 16 November 2005 13:37
To: Anton Danilov; address@hidden
Subject: RE: [ft] Bytecode enabled rendering

I've already spoken about this in a previous e-mail.

Microsoft holds a large number of patents covering specific
parts of the ClearType technology, see the bottom of this
page for a non-exhaustive list:

  http://www.microsoft.com/mscorp/ip/tech/cleartype.asp

For the moment, we're not going to implement Microsoft's
rendering techniques (which are also documented in a document
named "Avalon Text", that you'll find with a search engine).

Don't expect to have identical rendering in the case of
anti-aliased text with FreeType on Linux.

We could implement it, just like bytecode interpretation,
by disabling it by default in the sources. But very frankly,
I don't care enough about this to spend my time on it.

If you happen to take the time to provide patches to FreeType
and/or libXft to support that, we may even *not* be interested
in integrating them to the official FreeType sources.

You could still distribute a patch however, that distributions
could pick if they want to.

Case closed.

- David Turner
- The FreeType Project  (www.freetype.org)

> 
> Werner LEMBERG wrote:
> >>I am experiencing problems with aliasing-disabled rendering, and if
> >>you look at Kaya's screenshot (my system, and any other will
> >>probably do, shows just the same behaviour)