[cairo] Is Cairo able to fit my needs?

Bill Spitzak spitzak at thefoundry.co.uk
Thu Oct 4 06:45:06 PDT 2007

Carl Worth wrote:
> On Wed, 3 Oct 2007 22:01:32 +0200, "Innova-Studios - Juergen Ladstaetter" wrote:
>> Ad 2) doesn’t that function set the whole graphic to that color?
> No. cairo_fill just fills the current path, (just like the equivalent
> operation in PostScript).
>> Ad 3) normally when painting two things over each other, a logical function
>> "COPY" is used. For displaying postscript there are also other functions
>> needed.
>> A small list of functions:
>> wxAND                 src AND dst
>> wxAND_INVERT          (NOT src) AND dst
>> wxAND_REVERSE         src AND (NOT dst)
> ...
> OK, if you want bitwise logical operators then you won't find them in
> cairo. Many cairo output targets, (such as PostScript!), don't have
> any notion of "bits" so such operations are not well-defined at all.
> Cairo does have various operators, but they are the Porter/Duff
> compositing operators, not bitwise arithmetic operators.
> I hope that helps.

I'm not sure he was talking about bitwise operators. Actually I think he 
is asking for the Porter/Duff operations.

Bill Spitzak, Senior Software Engineer
The Foundry, 1 Wardour Street, London, W1D 6PA, UK
Tel: +44 (0)20 7434 0449 * Fax: +44 (0)20 7434 1550 * Web: 
The Foundry Visionmongers Ltd * Registered in England and Wales No: 4642027

More information about the cairo mailing list