Re: [ft] Problem rendering V and Y less than 12 pixel text

[Francesco Panicucci]

>It looks like a font problem.  In particular, I see that you are
>rendering without anti-aliasing, and many TrueType fonts support
>bitmap rendering only in a PPEM small range (if at all).  Use a font
>editor or font dumper to check the `gasp' table of the font to find
>out the supported ranges.

 

Thanks for reply,

 

our problem is that we can’t render with anti-aliasing because we have not the alpha so we use 1-bit monochrome bitmap glyphs.

We found that the bad rendering issue is due to the update of  the freetype reference library used in our system from version 2.4.4 to 2.4.5 and later.

 

The documentation reports into the “CHANGES BETWEEN 2.4.4 and 2.4.5” section the following note: “If autohinting is not explicitly disabled, FreeType now uses

the autohinter if a TrueType based font doesn't contain native hints.”

We tested several configuration using the latest version of the library (2.4.8) in order to obtain the same result as that we had using 2.4.4 version .

We set both FT_LOAD_NO_AUTOHINT and  FT_LOAD_NO_HINTING flags but we didn’t obtain any improvements.

Using the 2.4.8 library and the FT_LOAD_NO_AUTOHINT flag the “v” and  ”y” glyphs are bad rendered. Than, setting FT_LOAD_NO_HINTING flag we have the problem with “t” glyph and finally using both the flags the “t” and “y” glyphs are not perfectly aligned and “J” is missing.

 

https://docs.google.com/open?id=0B0eADBsvqd19ZGFiODBjNmMtYjY1NC00NDA3LWE0YzEtNzJmYmIwZGU2N2U1

 

Our question is, how can we set any flags or parameters in order to obtain with 2.4.8 version of the library the same behavior we had using 2.44 version?

 

Francesco