Re: [gtkmm] the canvas

[Ole Laursen <olau hardworking dk>]

Paul Davis <paul linuxaudiosystems com> writes:

> >Still, I think it's much better than people hand-coding graphics with
> >a drawing area. 
> 
> for some things, that's still very appropriate. the canvas only really
> comes into its own where z-order stacking changes during the life of
> the application. then the canvas really starts to shine.

Yes - it just seems silly to use a drawing area manually when you
could spend your time on more interesting stuff, like programming your
application. :-) But of course, it depends on the situation.

> >		 I've had a brief look at FooCanvas, and from the
> >outside it seems to be using almost exactly the same interface as the
> >ordinary canvas.
> 
> it does, in all but one key aspect. what they did was to remove all
> the AA support, which isn't really about anti-aliasing per se, but is
> really about client side rendering ie. drawing directly into an RGB
> buffer rather than using gdk_draw_foo(). the claim is that because
> GTK+2 is now double-buffered, its better to do leave the "draw into
> RGB buffer" to the core GTK code. the problem is that the gdk_draw_*
> functions don't provide support for some of the things you can do if
> you can draw the individual pixels yourself. the most obvious issue:
> you want to use alpha-blending without requiring that the X server
> supports the Render extension.

Ah, thanks for the explanation.

-- 
Ole Laursen
http://www.cs.auc.dk/~olau/