Simple example doesn't work on web.

[simbleau]

The simple example doesn't run on web, it panicks expecting there to be at least 1 GPU canvas.

Do we expect all examples to work with web?

[DJMcNab]

The messiness which is proper platform support is one of the motivating reasons for the simple example

I'm intending to close this as not planned

[simbleau]

Why not stuff all the platform support messiness into a new crate similar to scenes, e.g.
demo_driver? That would keep the simple example actually simple and dually make it easy to be imported from velato and vello_svg, and third - allow us to keep all examples running on every platform.

Passing some basic info, like draw requests, should be enough for all of the demos, but I'm just brainstorming.

e.g.

/// Doesn't return and continues to draw the next frame in a demo window with profiling and benchmarks.
fn run_demo(draw_fn: F) -> ! 
where F: FnMut(&mut Scene) + Send + Sync + 'static {
    todo!()
}