[cairo] Cairo PDF output broken with Noto Nastaliq Urdu font

[Behdad Esfahbod]

On 14-11-19 04:04 PM, Adrian Johnson wrote:
> On 20/11/14 08:28, Behdad Esfahbod wrote:
>> On 14-11-19 03:33 AM, Adrian Johnson wrote:
>>> Yes, I can have a look when I get time. The best way to ensure this does
>>> not get overlooked is to file a bug. I've done this for you at:
>>>
>>> https://bugs.freedesktop.org/show_bug.cgi?id=86461
>>
>> Thanks Adrian.  Really appreciate it.
>>
> 
> So it turned out to be an easy fix.

Thanks.  Confirmed that it was indeed fixed.


> Something I noticed while debugging
> this is hb-view appears to be emitting a lot of empty glyphs. In large
> documents this will unnecessarily increase the file size and increase
> rendering time.

I can confirm this also.  This seems to be an issue in the font.  We will make
sure it is cleaned up in the final version.

That said, text extraction is completely broken with this font...  I expected
that, but just bringing it up.

Cheers,
behdad


> Adding some debug to cairo_show_text_glyphs and using the sample text:
> 
> کے
> 
> I get:
> 
> cairo_show_text_glyphs   num_glyphs: 5
>    glyph 0: 1005
>    glyph 1: 1006
>    glyph 2: 1007
>    glyph 3: 248
>    glyph 4: 409
> 
> Using ttx I can see that
> 
>  <mtx name="glyph01005" width="0" lsb="0"/>
>  <mtx name="glyph01006" width="0" lsb="0"/>
>  <mtx name="glyph01007" width="0" lsb="0"/>
> 
> and
> 
> <TTGlyph name="glyph01005" xMin="0" yMin="0" xMax="0" yMax="0">
>   <contour>
>     <pt x="0" y="0" on="1"/>
>   </contour>
>   <instructions><assembly>
>   </assembly></instructions>
> </TTGlyph>
> 
> <TTGlyph name="glyph01006" xMin="0" yMin="0" xMax="0" yMax="0">
>   <contour>
>     <pt x="0" y="0" on="1"/>
>   </contour>
>   <instructions><assembly>
>     </assembly></instructions>
> </TTGlyph>
> 
> <TTGlyph name="glyph01007" xMin="0" yMin="0" xMax="0" yMax="0">
>   <contour>
>     <pt x="0" y="0" on="1"/>
>   </contour>
>   <instructions><assembly>
>   </assembly></instructions>
> </TTGlyph>
> 
> 
> The cairo PS output is:
> 
> 24 0 0 24 30.973638 24.414763 Tm
> /f-0-1 1 Tf
> -0.268014 0.635325 Td
> <01>Tj
> -0.355888 -0.420035 Td
> <02>Tj
> 1.287346 -0.18717 Td
> <03>Tj
> -0.317223 -0.114236 Td
> <04>Tj
> -0.346221 0.086116 Td
> <05>Tj
> 
> 
> 

-- 
behdad
http://behdad.org/