[poppler] Patch proposal: Implementation for real gouraud shaded triangles

[Thomas Freitag]

  Hi Christian!

Sorry, I just subscribed to the poppler mailing list, so I didn't get 
Your patch and haven't seen the complete discussion.
As far as I understand, You speed up matrix and triangle patch shadings, 
but only with RGB colorspaces. I would be interested in having that at 
least for CMYK, too, and I would be able to test that. So can You send 
me the patch and a hint what I should do to have it in CMYK? In the past 
I speed that up in increasing the gouraudColorDelta value, which also 
gave sufficient results, but Your solution seems to be better.

Best regards,
Thomas

Am 05.10.2010 22:59, schrieb Albert Astals Cid:
> A Dijous, 15 de juliol de 2010, Christian Feuersaenger va escriure:
>>>>>> Dear poppler developers,
>>>>>>
>>>>>> hereby I propose a new patch for a high quality, fast gouraud
>>>>>> shader for
>>>>>> triangle shadings.
>>>>>>
>>>>>> The patch provides
>>>>>> - scalable triangle shadings (in contrast to the old approach),
>>>>>> - correct shading, no approximation using flat triangles,
>>>>>> - greatly (!) improved rendering speed,
>>>>>> - support for opacity (in contrast to the previous approach).
>>>>>>
>>>>>> This patch is relative to the master branch,
>>>>>> git show poppler-0.14.0-91-g31ac578 .
>>>>>>
>>>>>> It is unrelated to my previous patch proposals concerning shadings;
>>>>>> the
>>>>>> other patch proposal (my mail several weeks ago) is still important
>>>>>> and
>>>>>> relevant. The patch in this mail is independent and does not
>>>>>> include my
>>>>>> previous patch proposals.
>>>>>>
>>>>>> I tested the new patch with pdftoppm and with the xpdf-poppler fork of
>>>>>> Rogerio Brito; it appears to work reliable. I tested
>>>>>> - matrix shadings and triangle patch shadings (Types 4 and 5),
>>>>>> - degenerated triangles,
>>>>>> - clipping,
>>>>>> - opacity,
>>>>>> - RGB color spaces.
>>>>>>
>>>>>> The implementation now supports these shadings on a display driver
>>>>>> level
>>>>>> and is implemented directly in the splash device (using scanline
>>>>>> sweeps).
>>>>>>
>>>>>> I've been defensive: I have no test cases for other color spaces and I
>>>>>> have no test data for non-parametric shadings. Consequently, I
>>>>>> disabled
>>>>>> the shader for these cases; it will fall back to the existing
>>>>>> solutions
>>>>>> (approximate shading by means of many flat triangles).
>>>>>>
>>>>>> I hope you find my patch proposal useful. I believe it is worthy of
>>>>>> being part of libpoppler.
>>>>> Do you have a pdf where we can see the improvement this patch gives?
>>>>>
>>>>> Albert
>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Christian
>>>>> _______________________________________________
>>>>> poppler mailing list
>>>>> poppler at lists.freedesktop.org
>>>>> http://lists.freedesktop.org/mailman/listinfo/poppler
>>> _______________________________________________
>>> poppler mailing list
>>> poppler at lists.freedesktop.org
>>> http://lists.freedesktop.org/mailman/listinfo/poppler
>> _______________________________________________
>> poppler mailing list
>> poppler at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/poppler
> _______________________________________________
> poppler mailing list
> poppler at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/poppler
>
> .
>