[Galene] Re: Blur background

[Francis Bolduc <fbolduc@gmail.com>]

Thank you, I did not notice the init method. I will use that one.

Regards,
Francis


On Sun, May 5, 2024 at 4:47 PM Juliusz Chroboczek <jch@irif.fr> wrote:
>
> > Yes, loading 3rdparty libraries is conceptually insecure. I initially
> > tried to download the Javascript libraries and wasm modules to serve
> > them via Galene, but failed because they refer to each other via full
> > URL instead of relative paths when you load them.  I also tried to
> > download their source code and build them myself, but my head exploded
> > when I saw the kind of build system those libraries have.
>
> Yeah, these are the two reasons I've been waiting for Chrome to implement
> native background blur [1], but that effort appears to have been abandoned.
>
> [1] https://chromestatus.com/feature/5077577782263808
>
> >>> +    offscreen = new OffscreenCanvas(1920, 1080);
>
> >> This should be done lazily, in the filter, not at startup.
>
> > Not sure what you mean. How would you do this?
>
> Two ways.  One is to add a function 'init' to your filter definition:
>
>     'blur-background':
>         description: "Blur Background",
>         init: initBlurBackground,
>         f: blurBackground,
>     },
>
> and then, in initBlurBackground, instantiate a new field in your filter:
>
>     function initBlurBackground(ctx) {
>         this.offscreen = new OffscreenCanvas(...)
>         ...
>
> The other solution is to simply do the initialisation in the main function
> of the filter:
>
>     if(!(offscreen in this)) {
>         this.offscreen = new OffscreenCanvas(...)
>         ...
>
> In either case, the data structures are only created when the filter is
> first invoked, which means that only users who use your filter pay the
> cost of initialisation.
>
> -- Juliusz