Default to wgpu renderer

[emilk]

Unfortunately, just switching glow to wgpu causes build errors for web, and runtime errors on native.
Apparently we also need to turn on some wgpu features, but that… sucks. And it is not obvious from the eframe docs.
This needs fixing.

Native

> cargo run
thread 'main' panicked at /Users/emilk/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/wgpu-27.0.1/src/api/instance.rs:65:13:
No wgpu backend feature that is implemented for the target platform was enabled. See `wgpu::Instance::enabled_backend_features()` for more information.

Web

error[E0433]: failed to resolve: could not find `web_sys` in `wgpu`
   --> /Users/emilk/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/egui-wgpu-0.33.0/src/setup.rs:58:31
    |
58  |                         wgpu::web_sys::window().is_some_and(|w| w.is_secure_context());
    |                               ^^^^^^^ could not find `web_sys` in `wgpu`
    |
note: found an item that was configured out
   --> /Users/emilk/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/wgpu-27.0.1/src/lib.rs:143:9
    |
143 | pub use web_sys;
    |         ^^^^^^^
note: the item is gated here
   --> /Users/emilk/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/wgpu-27.0.1/src/lib.rs:142:1
    |
142 | #[cfg(web)]
    | ^^^^^^^^^^^

[kasper64]

Maybe it's stupid question, but is there a workaround for this?
I looked for the possibility to enable feature of dependencies's dependences, but that doesn't seem possible.

[emilk]

The work-around is as simple as adding an extra dependency on wgpu with default features enabled:

wgpu = { version = "27.0.1", default-features = true }

I'll see if we could/should do that in eframe already somehow to make this easier

[Resonanz]

Hey there @emilk , frame_template (with rust 1.88 and egui 0.33.0) with wgpu crashes on my M4 Mac (26.0.1). It has been doing this for a while. Glow works fine. Wgpu used to work.

Steps:

1. Clone eframe_template
2. Change feature "glow" to "wgpu"
3. cargo run
4. Crash.

thread 'main' panicked at /Users/me/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/wgpu-27.0.1/src/api/instance.rs:65:13:
No wgpu backend feature that is implemented for the target platform was enabled. See `wgpu::Instance::enabled_backend_features()` for more information.