RE: [ft] Differences between FT 2.3.9 & 2.4.4 that may cause poor rendering quality

[John C. Turnbull]

Great, that should be very helpful and thanks for the very prompt reply!

-JCT

-----Original Message-----
From: Werner LEMBERG [mailto:address@hidden 
Sent: Sunday, 6 March 2011 17:57
To: address@hidden
Cc: address@hidden
Subject: Re: [ft] Differences between FT 2.3.9 & 2.4.4 that may cause poor
rendering quality


> I use an OpenGL library called Visualization Library which utilises
> FreeType in providing the font rendering information in its text
> renderer.  In upgrading to their latest version I noticed a
> significant degradation in the quality of the rendered text and the
> only difference in this area with respect to VL was that they
> started using FreeType 2.4.4 instead of 2.3.9 that they had used
> previously.

In version 2.4.0 the bytecode interpreter (for TTFs) has been
activated as the default.  Looking at the large rendering differences
of your images, I suppose this is what you experience.

> Does anyone know if any special compiler flags or options need to be
> set when compiling FT 2.4.4 or some other reason why text rendering
> quality would be worse under the latest version?  It looks as though
> some degree of antialiasing has been lost perhaps.

The right way IMHO is to call FT_Load_Glyph with
FT_LOAD_FORCE_AUTOHINT.  If that is not possible for you, undefine
TT_CONFIG_OPTION_BYTECODE_INTERPRETER while compiling FreeType.


    Werner