ref: b4b96260e475cf55f594443b156ae04afb036880
dir: /docs/BUGS/
List of known FreeType 2 Bugs
-----------------------------
"Identifier" is a unique string used to uniquely identify the bug
A more complete description of the bug is found below the table of
opened bugs..
"Date" is the date where the bug was first reported or entered
in this document. Dates are in _european_ format, i.e day/month/year
"Opened By" is the name of the people who first spotted the bug.
Note that we can use abbreviations here, like:
"David" for David Turner
"Werner" for Werner Lemberg
etc..
"Reproducable" indicates wether the bug could be reproduced by the
development team or not (it can be specific to a given platform),
wether it always happen, or only sporadically, etc..
I. Opened bugs:
===============
Identifier Date Opened by Reproducable
------------------------------------------------------------------------------
NO-CID-CMAPS 13-09-2001 David always
AUTOHINT-NO-SBITS 13-09-2001 David always
BAD-TT-RENDERING 12-09-2001 Paul Pedriana ?
BAD-THIN-LINES 13-09-2001 David ?
NOT-WINDOWS-METRICS 07-10-2001 David always
--------------------END-OF-OPENED-BUGS-TABLE----------------------------------
II. Table of closed bugs:
=========================
Identifier Date Closed by Closure date
------------------------------------------------------------------------------
BAD-TTNAMEID.H 12-09-2001 Antoine N/A
--------------------END-OF-CLOSED-BUGS-TABLE----------------------------------
II. Bug descriptions:
=====================
NO-CID-CMAPS:
Not exactly a bug, but the CFF font driver doesn't build a Unicode
charmap from the content of font files, which prevents efficiently
using fonts in this format..
BAD-TTNAMEID.H
the file "ttnameid.h" contains various constant macro definitions
corresponding to important values defined by the TrueType specification.
Joe Man <[email protected]> reports that:
According to the information from
TrueType v1.66
Platform ID = 3 (Microsoft)
the Encoding ID of GB2312 = 4
the Encoding ID of big5 = 3
However, I have found that
in ttnameid.h
TT_MS_ID_GB2312 = 3
TT_MS_ID_BIG_5 = 4
Which one is correct?
Antoine replied that this was a bug in the TT 1.66 specification, and
that FreeType followed the most recent TrueType/OpenType specification
here !!
AUTOHINT-SBITS
when trying to load a glyph, with the auto-hinter activated (i.e.
when using FT_LOAD_FORCE_AUTOHINT, or when the font driver doesn't
provide its own hinter), embedded bitmaps are _never_ loaded, unlike
the default behaviour described by the API specification.
this seems to be a bug in FT_Load_Glyph, but there is no way to solve it
efficiently without making a few important internal changes to the library's
design (more importantly, to the font driver interface)
BAD-TT-RENDERING
according to Paul Pedriana <[email protected]>, there is a rather
important difference between the rendering of TrueType-hinted glyphs
of current FT2 and old betas..
Tests and comparisons show a _major_ discrepancy of monochrome truetype
bytecode-hinted glyphs !! Something seems to be really fucked here !!
BAD-THIN-LINES
it seems that the anti-aliased renderer in FreeType has problems
rendering extremely thin straight lines correctly, at least when using
the FT_Outline_Render functions..
NOT-WINDOWS-METRICS
FreeType doesn't always return the same metrics as Windows for ascender,
descender and text height, depending on character pixel sizes. A lot of
testing on Windows is needed to debug this properly. It might be due to
a rounding bug when computing the "x_scale" and "y_scale" values.