bugThe FreeType Project - Bugs: bug #54565, Upside down transform and...

 
 

bug #54565: Upside down transform and FT_GlyphSlot_Oblique made opposite angle

Submitted by:  Toshio Nakamura <tnakamura>
Submitted on:  Fri 24 Aug 2018 06:19:11 AM UTC  
 
Severity:  3 - Normal Item Group:  Incorrect behaviour
Status:  None Privacy:  Public
Assigned to:  Alexei Podtelezhnikov <podtelez> Open/Closed:  Open
Planned Release:  None

Add a New Comment(Rich Markup)
   

You are not logged in

Please log in, so followups can be emailed to you.

 

Wed 05 Sep 2018 01:49:05 AM UTC, comment #5:

Hi Werner,
I opened JDK-8210058, but no update yet.
https://bugs.openjdk.java.net/browse/JDK-8210058

Toshio Nakamura <tnakamura>
Tue 04 Sep 2018 07:06:54 PM UTC, comment #4:

Toshio-san, any comments from the OpenJDK people?

Werner LEMBERG <wl>
Project Administrator
Mon 27 Aug 2018 01:48:52 AM UTC, comment #3:

Thank you for the quick replys. I'll report this issue to OpenJDK community.

Toshio Nakamura <tnakamura>
Fri 24 Aug 2018 01:21:36 PM UTC, comment #2:

I also think that everything is fine. Both transformations applied correctly: first reflection then slant. In the mirror world both slanting angle and text direction would appear opposite. Are you sure you want mirror reflection and not rotation by 180 degrees? In the rotated world you would indeed preserve slanting angle and text direction.

Alexei Podtelezhnikov <podtelez>
Project MemberIn charge of this item.
Fri 24 Aug 2018 06:57:33 AM UTC, comment #1:

Thanks for the report and the code example.

I think what you see is correct behaviour, according to the documentation. `FT_Set_Transform' only sets the transformation for `FT_Load_Glyph', i.e., creating the data for an `FT_GlyphSlot' object. However, `FT_GlyphSlot_Oblique' acts on an `FT_GlyphSlot' object; it is thus not controlled by the transformation set up with `FT_Set_Transform'.

Alexei, I'm assigning this issue to you. Do you think it would be beneficial to change `FT_GlyphSlot_Oblique' to obey `face->internal->transformation_matrix'? Contrary to `FT_Glyph' objects, `FT_GlyphSLot' has still a connection to its parent face...

Werner LEMBERG <wl>
Project Administrator
Fri 24 Aug 2018 06:19:11 AM UTC, original submission:

When we transformed upside down by FT_Set_Transform() and to set italic style by FT_GlyphSlot_Oblique(), The angle of italic shape is opposite.
It seems transforming upside down is ignored.

This problem occurred with OpenJDK and some conditions (creating PS data with AlphaComposite or Texture)
OpenJDK creates printing image upside down, and characters with italic attribute calls FT_GlyphSlot_Oblique(), then hit this problem.

Attached C++ sample code and the output SVG file.

Toshio Nakamura <tnakamura>

 

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

Attach Files:
   
   
Comment:
   

Attached Files
file #44845:  invItalic.cpp added by tnakamura (3KiB - application/octet-stream)
file #44846:  Out.svg added by tnakamura (609B - image/svg+xml)

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -email is unavailable- added by podtelez (Posted a comment)
  • -email is unavailable- added by wl (Posted a comment)
  • -email is unavailable- added by tnakamura
  • -email is unavailable- added by tnakamura (Submitted the item)
  •  

    Do you think this task is very important?
    If so, you can add your encouragement to it.
    This task has 0 encouragements so far.

    Only logged-in users can vote.

     

     

     

    Follow 4 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2018-08-24 wl Assigned toNone => podtelez
    2018-08-24 tnakamura Attached File- => Added invItalic.cpp, #44845
        Attached File- => Added Out.svg, #44846
        Carbon-Copy- => Added tnakamura

    Back to the top


    Powered by Savane 3.4