SpriteBatches can be overwritten in prepare_sprite_image_bind_groups

[ickshonpe]

Bevy version

Main + 0.15

What you did

fn main() {
    App::new()
        .add_plugins(DefaultPlugins.set(WindowPlugin {
            primary_window: Some(Window {
                resolution: WindowResolution::new(1000., 1000.).with_scale_factor_override(1.),
                title: "Window 1".to_string(),
                ..default()
            }),
            ..default()
        }))
        .add_systems(Startup, setup)
        .run();
}

fn setup(mut commands: Commands) {
    // The primary window is the default camera target and 0 is the default render layer, there's no need to set these normally
    // the explicitness is just to make this example as clear as possible.

    commands.spawn((
        Camera2d::default(),
        Camera {
            target: RenderTarget::Window(WindowRef::Primary),
            ..default()
        },
        RenderLayers::layer(0),
    ));

    // Spawn a second window
    let window_2 = commands
        .spawn(Window {
            title: "Window 2".to_owned(),
            resolution: WindowResolution::new(1000., 1000.).with_scale_factor_override(1.),
            ..default()
        })
        .id();

    commands.spawn((
        Camera2d::default(),
        Camera {
            target: RenderTarget::Window(WindowRef::Entity(window_2)),
            ..default()
        },
        RenderLayers::layer(1),
    ));

    // Text drawn to window 1
    commands.spawn((Text2d::new("1"), RenderLayers::layer(0)));

    // Text drawn to window 2
    commands.spawn((Text2d::new("2"), RenderLayers::layer(1)));

    commands.spawn((
        Text2d::new("3"),
        Transform::from_translation(-25. * Vec3::Y),
        RenderLayers::from_layers(&[0, 1]),
    ));
}

What went wrong

In the second window it should display 2 and 3, but sometimes it displays the wrong glyphs.

Additional information

Font's use a texture atlas, so there is only one texture.
So each render phase generates a single SpriteBatch.
Then each SpriteBatch is inserted on the render entity for the first phase item in that batch.
This means that if the phase item corresponding to the "3" glyph is the first item in each batch, both SpriteBatchs will be inserted on the same render entity, overwriting one of the batches.
The "3" glyph sprite is visible in both views so that single SpriteBatch is then drawn for both views.

It also seems odd how the same sprite batch goes to each view as well.

[ickshonpe]

Needs someone more comfortable with the rendering abstractions to take a look, it's not difficult to fix but I'm not sure how to get it done without some ugly hacks