Re: Drawing with cairo

["Diego A. Fons" <diegofons apexar com>]

Paul Davis wrote:
> On Thu, 2008-05-15 at 12:05 -0300, Diego A. Fons wrote:
>
>   
> > Like Theodore I'm using gtkmm. This is an extrac of the code which 
> > doesn't work:
> > void Plotter::on_realize( void )
> > {
> >     // Create the GDK window
> >     refGdkWindow = Gdk::Window::create(get_window(), &attributes,
> >             GDK_WA_X | GDK_WA_Y);
> >
> >     // Create Cairo context
> >     Cairo::RefPtr<Cairo::Context> cr = refGdkWindow->create_cairo_context();
> > }
> >     
>
> you're all thinking too hard. Cairo drawing contexts are supposed to be
> created as necessary. They are cheap. Don't try to cache them. Create
> them in an expose handler and get rid of them.
>
> my attitude towards Cairo is to assume that its been handcoded in SSE9
> assembler unless i come across particular hotspots.
>
>
>   
So you are saying I create the Cairo context in the expose event and 
don't care about performance of redrawing the whole plot? OK, I'm trying 
that. I'm also going to try the image buffer approach, it is, drawing in 
a buffer as a member variable and write the buffer's content to the 
Cairo context in the expose event.

Still I don't understand why can't get a context and store it in a 
member variable.

Regards,
Diego A. Fons.