[cairo] How to create and redraw canvas?

[Stefan Salewski]

On Wed, 2019-03-06 at 20:04 +0100, Радомир Хаџић wrote:
> What actually I can't
> figure out is how can I display this saved surface, and that's what
> I'd like you to explain.
> 
> I tried using Cairo::Context::set_source() since it looked like it
> might work

As you may have noticed your source code has not been shipped.

I am not sure if I fully understand your desire, but I have tried to do
similar tasks some years ago, that time in ruby language.

Maybe a recent post of Uli Schlachter can help you (in cairo world
recent is less than a few years ago), it is a C example which improves
system load while doing animations. The trick is to reuse already drawn
parts of the display, so it should be similar to our intents. (My guess
is that you just forgot the paint() call after set_source()...

https://lists.cairographics.org/archives/cairo/2016-October/027796.html