Re: [gtkmm] the canvas

[Paul Davis <paul linuxaudiosystems com>]

>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.

>		 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.

--p