Allow Bevy to start from non-main threads on supported platforms (#10020)

# Objective

Allow Bevy apps to run without requiring to start from the main thread.
This allows other projects and applications to do things like spawning a
normal or scoped
thread and run Bevy applications there.

The current behaviour if you try this is a panic.

## Solution

Allow this by default on platforms winit supports this behaviour on
(x11, Wayland, Windows).

---

## Changelog

### Added

- Added the ability to start Bevy apps outside of the main thread on
x11, Wayland, Windows

---------

Signed-off-by: Torstein Grindvik <torstein.grindvik@nordicsemi.no>
Signed-off-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
Co-authored-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
Co-authored-by: James Liu <contact@jamessliu.com>
This commit is contained in:
Torstein Grindvik 2023-10-06 15:26:06 +02:00 committed by GitHub
parent dd46fd3aee
commit 8b21ee45c0
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2 changed files with 42 additions and 2 deletions

View File

@ -64,7 +64,7 @@ impl PluginGroup for DefaultPlugins {
#[cfg(feature = "bevy_winit")]
{
group = group.add(bevy_winit::WinitPlugin);
group = group.add(bevy_winit::WinitPlugin::default());
}
#[cfg(feature = "bevy_render")]

View File

@ -72,11 +72,51 @@ pub static ANDROID_APP: std::sync::OnceLock<AndroidApp> = std::sync::OnceLock::n
/// replace the existing [`App`] runner with one that constructs an [event loop](EventLoop) to
/// receive window and input events from the OS.
#[derive(Default)]
pub struct WinitPlugin;
pub struct WinitPlugin {
/// Allows the window (and the event loop) to be created on any thread
/// instead of only the main thread.
///
/// See [`EventLoopBuilder::build`] for more information on this.
///
/// # Supported platforms
///
/// Only works on Linux (X11/Wayland) and Windows.
/// This field is ignored on other platforms.
pub run_on_any_thread: bool,
}
impl Plugin for WinitPlugin {
fn build(&self, app: &mut App) {
let mut event_loop_builder = EventLoopBuilder::<()>::with_user_event();
// This is needed because the features checked in the inner
// block might be enabled on other platforms than linux.
#[cfg(target_os = "linux")]
{
#[cfg(feature = "x11")]
{
use winit::platform::x11::EventLoopBuilderExtX11;
// This allows a Bevy app to be started and ran outside of the main thread.
// A use case for this is to allow external applications to spawn a thread
// which runs a Bevy app without requiring the Bevy app to need to reside on
// the main thread, which can be problematic.
event_loop_builder.with_any_thread(self.run_on_any_thread);
}
#[cfg(feature = "wayland")]
{
use winit::platform::wayland::EventLoopBuilderExtWayland;
event_loop_builder.with_any_thread(self.run_on_any_thread);
}
}
#[cfg(target_os = "windows")]
{
use winit::platform::windows::EventLoopBuilderExtWindows;
event_loop_builder.with_any_thread(self.run_on_any_thread);
}
#[cfg(target_os = "android")]
{
use winit::platform::android::EventLoopBuilderExtAndroid;