bugThe FreeType Project - Bugs: bug #34432, Hinting problem...

 
 

bug #34432: Hinting problem TimesNewRomanItalic_EB at specific hi-res resolution

Submitted by:  John Tytgat <joty>
Submitted on:  Thu 29 Sep 2011 09:10:27 AM UTC  
 
Severity: 3 - NormalItem Group: None
Status: InvalidPrivacy: Public
Assigned to: Werner LEMBERG <wl>Open/Closed: Closed
Planned Release: None

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Fri 30 Sep 2011 12:27:13 PM UTC, comment #2:

Now I can confirm that it is a bug in the font: CVT index 897 is correctly initialized and adjusted for ppem values <= 2047, but hinting is disabled (via bytecode) for ppem values >= 2049. In other words, ppem value 2048 is omitted somehow, causing the artifact you've experienced.

Is this an MS core font? Then it probably makes sense to submit a bug report.

Werner LEMBERG <wl>
Project AdministratorIn charge of this item.
Thu 29 Sep 2011 09:45:58 PM UTC, comment #1:

I suspect this is the same problem as Savannah bug #33215. To verify this, please send me the font privately.

Werner LEMBERG <wl>
Project AdministratorIn charge of this item.
Thu 29 Sep 2011 09:10:27 AM UTC, original submission:

I have a hinting problem with the font TimesNewRomanItalic_EB (available on request) at a specific high resolution (FT_Set_PixelSizes(face, 2048, 2048)). E.g. for the glyph 'o', the inner subpath is significantly different. Taking any other value than 2048 (even one higher or less), the outline is as expected.

Attached a C99 test program showing this problem (using FT's git version of today). This outputs a simple PS file which can then be viewed (or converted to PDF). I attach the resulting PDF as reference (green outline is for pixel size 2047, the red (wrong) outline is for pixel size 2048).

I'm unable to determine whether this is due to wrong/bad hinting in the TT font, or whether this is due to FT's hinting implementation. I'm also unable to reproduce this problem in FontForge when creating a bitmap with pixel size 2048 but I'm well aware that this might be due to lots of other reasons/differences.

John Tytgat <joty>

 

(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach File(s):
   
   
Comment:
   

Attached Files
file #24045:  test.c added by joty (4KiB - text/plain)
file #24046:  output.pdf added by joty (8KiB - application/unknown)

 

Depends on the following items: None found

Items that depend on this one: None found

 

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  • -unavailable- added by wl (Posted a comment)
  • -unavailable- added by joty (Submitted the item)
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    Follow 6 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Fri 30 Sep 2011 12:27:13 PM UTCwlStatusNeed Info=>Invalid
      Open/ClosedOpen=>Closed
    Thu 29 Sep 2011 09:45:58 PM UTCwlStatusNone=>Need Info
      Assigned toNone=>wl
    Thu 29 Sep 2011 09:10:27 AM UTCjotyAttached File-=>Added test.c, #24045
      Attached File-=>Added output.pdf, #24046

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