[cairo] Cairo on Symbian OS. Help!

iwanj i_junianto at yahoo.co.uk
Mon Jan 5 09:54:34 PST 2009


Thanks for the clarification. I guess I'll drop the idea of double buffering to make it consistent with other backends.

iwanj

--- On Mon, 5/1/09, Gerdus van Zyl <gerdusvanzyl at gmail.com> wrote:

> From: Gerdus van Zyl <gerdusvanzyl at gmail.com>
> Subject: Re: [cairo] Cairo on Symbian OS. Help!
> To: cairo at cairographics.org
> Date: Monday, 5 January, 2009, 8:41 AM
> The API I use for double buffering is the following sequence
> push_group_with_content, [draw on ctx],
> pop_group_to_source, paint
> which creates a temporary surface of the right
> type(create_similar)
> behind the scenes
> 
> Generally surfaces are long lived while contexts are short
> lived. GTK
> is a bad example since it brings another level of
> indirection since
> widgets receive an offscreen surface and the real cairo
> surface type
> is hidden by GDK, etc.
> 
> How to implement animation is really dependant on the type
> of
> animation and the program structure. Eg. Multiple surfaces,
> parametric
> drawing function, etc. Cairo just provides a nice way to
> draw and blit
> things.
> 
> I am not sure if you should build the double buffering into
> your
> symbian backend since AFAIK it's not how it works with
> the other
> backends (win32).
> 
> ~G
> 
> On Mon, Jan 5, 2009 at 9:15 AM, iwanj
> <i_junianto at yahoo.co.uk> wrote:
> > (My previous email ended up as a single line due
> > to missing CR/LF)
> >
> > Hi all,
> >
> > I've just started playing with Cairo on Symbian OS
> > (http://code.google.com/p/cairo-for-symbian) and
> currently
> > working on implementing Symbian OS surface backend to
> allow
> > Cairo rendering to a window.
> >
> > From looking at cairo-tutorial-gtk.h it seems that
> Cairo
> > surface is created and destroyed everytime the window
> is
> > being redraw/exposed. Is it how Cairo is intended to
> be
> > used? What is the common practice when we want to use
> Cairo
> > to render some animated contents?
> >
> > I'm planning to use double buffering for my window
> > surface implementation, but couldn't find any
> suitable
> > Cairo API to do the actual swap buffer. Can we rely on
> > application to call cairo_surface_flush instead?
> >
> > Cheers,
> > iwanj
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > cairo mailing list
> > cairo at cairographics.org
> > http://lists.cairographics.org/mailman/listinfo/cairo
> >
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