[cairo] Semantics of transparent objects on opaque targets (image vs. PostScript)

Michael Sweet mike at easysw.com
Fri Jan 13 12:16:22 PST 2006


Carl Worth wrote:
> ...
> To me, this seems like the right thing to do, but it is a change
> compared to what the PostScript result has been up until now, so I
> wanted to confirm the decision here on the list before I updated the
> reference images for the PostScript output in the test suite.

I agree that this is the right thing to do - basically, if you don't
draw a background then you'll get an implementation/surface-defined
default background, which for PostScript output is white.

.....

On a separate, nit-picky note, your PS output does not conform to
the Adobe Document Structuring Conventions:

     1. No Pages: comment in the header (you need at least a
        "%%Pages: (atend)" in the header)
     2. The header comments indicate ASCII (Clean7Bit) data, but
        you are embedding binary data.
     3. There is no %%EndPage comment defined by the DSC.
     4. Presumably you'll want a %%Pages comment after the
        %%Trailer...
     5. Unless you are really using Level 3 language elements,
        the %%LanguageLevel comment should specify version 2.
        (this one is not really a DSC problem, but a general nit)

Once I have finished up CUPS 1.2 (probably sometime in March), I'll
be happy to work with you on this part of Cairo...

-- 
______________________________________________________________________
Michael Sweet, Easy Software Products           mike at easysw dot com
Internet Printing and Document Software          http://www.easysw.com


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