[cairo] Blurry page when printing pdf on windows

[Adrian Johnson]

On 10/06/16 23:09, Juan Garcia wrote:
> Hi everybody!
> 
> First of all, thank you very much for creating such an awesome library!
> 
> I've encountered a small problem while using it and would really
> appreciate if you could give me a hand with it. If you find the time and
> feel like it, of course!
> 
> I created the following pdf
> (eu-data-protection-authorities-demand-privacy-shield-clarification)
> with firefox:
> 
> https://owncloud.m-privacy.de/index.php/s/RK88qQpaUXHN5Vg
> (password is 'save')
> 
> 
> With some copy paste from different sources (mostly examples from your
> page and poppler) I managed to implement a small cairo_pdfprinter.exe to
> print pdfs with windows (I actually use the code somewhere else but I
> created it to test and the code I am using elsewhere is exactly the same).
> 
> Please find the source here (cairo_pdfprinter.c):
> 
> https://owncloud.m-privacy.de/index.php/s/oY8zB0qqD5le1hd
> (password is also 'save')
> 
> It probably has to do with
> cairo_surface_t* surface = cairo_win32_printing_surface_create
> (print_dlg->hDC);
> 
> in the do_print function.
> 
> Most of the time it works, but with some pdfs created with certain web
> pages with firefox it prints some of the pages blurred (normally not all
> of them). The pdf is ok. See the attached xps which I printed with the
> standard windows printer (this also happens with actual printers).
> 
> Here the blurry xps example:
> https://owncloud.m-privacy.de/index.php/s/RhisnVdNhBuwa9n
> (password is also 'save')
> 
> In the example, just the first page that appears blurry. I believe it
> somehow might have to do with alpha channels and was very excited when I
> saw there was a new version that seems to solve *exactly* my problem :)
> 
> Unfortunately, after compiling the newest cairo (1.15.2), and
> recompiling the example I get an error which says:
> 
> Assertion failed!
> 
> Program: Z:\cairo_pdfprinter.exe
> File: cairo-recording-surface.c, Line 599
> 
> Expression: ! surface->unbounded
> 
> If I happen to *not* print the first page, the file *does* print.
> 
> Am I doing something wrong here? Do you have any idea what could be wrong?

No idea. Does it work using the latest cairo git and pdftocairo? Does it
work with a different printer eg a pdf printer? How did you build it?

> 
> Once again, thanks for the cool software and thank you very much for
> your help!
> 
> Kind regards,
> Juanito
> 
>