[texworks] Problem with TW viewer : asymptote and layers

[Charlie Sharpsteen]

On Sun, Jun 19, 2011 at 3:02 PM,  <site4000 at free.fr> wrote:
> Hello,
>
> I use Windows Seven 64 bits, TL2010 up to date with TLContrib and run
> TeXworks 0.4.0 (r.759).
>
> I got the following Asymptote code here :
> http://asymptote.sourceforge.net/gallery/spectrum.asy
>
> Here it is :

<snip>

> When I compile this code with pdflatex (pdflatex+asy+pdflatex), there's non
> problem (I fact there is a problem because there is no more layers but that
> another problem and it doesn't come from TeXworks) but if you uncomment the
> fifth line (%\usepackage{ocg})
> and then compile again with pdflatex (pdflatex+asy+pdflatex), everything
> disappear. However, if you read the pdf with acrobat, there's no problem
> with it.
>
>
> Arthur

TeXworks uses the Poppler library to render PDF files:

    http://poppler.freedesktop.org

At the moment, TeXworks does not make use of Poppler's support for
optional content groups. There is a feature request open for adding
layer support:

    http://code.google.com/p/texworks/issues/detail?id=498

However, it looks like there may be some barriers to supporting
Asymptote layers. I loaded up your example PDF in Poppler's demo
viewer and got:

"Error: Could not find a OCG with Ref (12:0)"
"Error: Could not find a OCG with Ref (13:0)"
"Error: Could not find a OCG with Ref (14:0)"
"Error: Could not find a OCG with Ref (15:0)"
"Error: Could not find a OCG with Ref (16:0)"
"Error: Could not find a OCG with Ref (17:0)"
"Error: Could not find a OCG with Ref (18:0)"
"Error: Could not find a OCG with Ref (12:0)"
"Error: Could not find a OCG with Ref (13:0)"
"Error: Could not find a OCG with Ref (14:0)"
"Error: Could not find a OCG with Ref (15:0)"
"Error: Could not find a OCG with Ref (16:0)"
"Error: Could not find a OCG with Ref (17:0)"
"Error: Could not find a OCG with Ref (18:0)"

So, Poppler may not be able to work with the layers produced by
Asymptote and the OCG package. Someone may need to put in
some serious development time in order to fix this.

-Charlie