bugThe FreeType Project - Bugs: bug #30859, TTF Rendering inconsistency...

 
 

bug #30859: TTF Rendering inconsistency between 2.3.12 and 2.4.{1,2}

Submitted by:  None
Submitted on:  Mon 23 Aug 2010 09:39:42 PM UTC  
 
Severity: 3 - NormalItem Group: Incorrect behaviour
Status: InvalidPrivacy: Public
Assigned to: Werner LEMBERG <wl>Open/Closed: Closed
Planned Release: None

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Tue 24 Aug 2010 09:47:58 AM UTC, comment #3:

You might do a debugging session of one of the glyphs with FontForge, then you can see the hinting engine in action. And indeed, the `f' becomes one pixel higher than `T'.

BTW, I was testing with version 1.10.

Werner LEMBERG <wl>
Project AdministratorIn charge of this item.
Tue 24 Aug 2010 06:58:34 AM UTC, comment #2:

Right: disabling the bytecode interpreter in 2.4.2 gives the older results back. Thanks for the hint.

Still, I'm puzzled by the result of this bytecode interpreter. For instance, looking at the word "This" or "If", you can see that the capital T or I is actually smaller than the lower case h or f. I find this a bit odd, and initially I tought it was some kind of rounding problem. If you say that I should be happy with this, then I will tweak my fontconfig configuration :)

Thanks again,
Anthony

Anonymous
Tue 24 Aug 2010 06:26:39 AM UTC, comment #1:

Starting with version 2.4.0, the bytecode interpreter has been activated by default. The image you provide shows the font using the font rendered with the autohinter (old) and with the bytecode interpreter (new). You might play around with the `ftview' demo program to verify that, assuming that it has been linked again 2.4.0 or newer.

This is not a bug. Assuming a GNU/Linux box, you can write rules for the FontConfig library so that this particular font is still autohinted by the operating system, then you have you previous result back.

Werner LEMBERG <wl>
Project AdministratorIn charge of this item.
Mon 23 Aug 2010 09:39:42 PM UTC, original submission:

Hi,

I observe a visual rendering issue betweem 2.3.12 (that is correct for me) and 2.4.1 or 2.4.2 (that looks incorrect, but see attached image).

Before I investigate further (like checking the git version etc.), I would like to know what do you guys think about the screenshot attached.

The screenshot is with emacs (tough all apps do the same rendering), Bitsream Vera Sans Mono (TTF), size 9. They are for sure different: the version at the top is with freetype 2.3.12, the version at the bottom freetype 2.4.1 and 2.4.2 (both with and without subpixel hinting option, no change). In both case exactly the same setup except the freetype library.

So... is this a bug? :)

Anonymous

 

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file #21286:  freetype-2.4-bug.jpg added by None (27KiB - image/jpeg)

 

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    Follow 4 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Tue 24 Aug 2010 06:26:39 AM UTCwlAssigned toNone=>wl
      Open/ClosedOpen=>Closed
    Tue 24 Aug 2010 06:26:38 AM UTCwlStatusNone=>Invalid
    Mon 23 Aug 2010 09:39:42 PM UTCNoneAttached File-=>Added freetype-2.4-bug.jpg, #21286

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