[Freetype] Badly rendered characters

[Axel Stoltenberg]

Hello,

We would appreciate any help for a problem that we have with freetype 2.1.9.

We are a font producing company and we have created TrueType fonts for
one of our customers. Now we got reports about badly rendered characters. 
The customer uses freetype to render the fonts. 

In order to reproduce the problem we tested the fonts under Windows,  
here the characters are OK. 

We than wrote a small test application based on the sample code in 
ft2demos-2.1.9/src. This test program runs under linux. It calls freetype to 
render some sample strings in different point sizes and creates
a (greyscale) gif file as output.

We compiled the freetype library using 
#define  TT_CONFIG_OPTION_BYTECODE_INTERPRETER
and 
#define TT_CONFIG_OPTION_UNPATENTED_HINTING
in ./freetype-2.1.9/include/freetype/config/ftoption.h .

We were able to reproduce the problem. 

Just to give two small examples: the latin uppercase character "A" at 12
pixel bodysize 
appears like a triangle , such like 
   .
   *
 .***.
 .****.
 **  **
.**  **.
********
********.

instead of 
   .
   *
 .***.
 .****
 **  **
********
********
**    **.

The character "E" looks like 

******
******
**  
**
******
******
******
******

instead of 

******
******
**  
******
******
**
******
******

It appears as if the horizontal stem hinting is not interpreted as expected.
We use standard Y-Stems and Y-delta-hints. 

For test purpose we modified all the hinting of the letter "E" so that
all hints were relativ to the baseline: we could see a much better result.

Did anyone make a similar experience ?

We would appreciate any comment or suggestion.

Thanks,

Axel Stoltenberg