UI render layers

crates/bevy_ui/src/entity.rs

@@ -4,14 +4,10 @@ use crate::{
     widget::{Button, ImageMode},
     CalculatedSize, FocusPolicy, Interaction, Node, Style, UiColor, UiImage,
 };
-use bevy_ecs::{
-    bundle::Bundle,
-    prelude::{Component, With},
-    query::QueryItem,
-};
+use bevy_ecs::{bundle::Bundle, prelude::Component};
 use bevy_render::{
-    camera::Camera, extract_component::ExtractComponent, prelude::ComputedVisibility,
-    view::Visibility,
+    prelude::ComputedVisibility,
+    view::{RenderLayers, Visibility},
 };
 use bevy_text::{Text, TextAlignment, TextSection, TextStyle};
 use bevy_transform::prelude::{GlobalTransform, Transform};
@@ -37,6 +33,8 @@ pub struct NodeBundle {
     pub visibility: Visibility,
     /// Algorithmically-computed indication of whether an entity is visible and should be extracted for rendering
     pub computed_visibility: ComputedVisibility,
+    /// The UI camera layers this node is visible in.
+    pub render_layers: RenderLayers,
 }
 
 /// A UI node that is an image
@@ -64,6 +62,8 @@ pub struct ImageBundle {
     pub visibility: Visibility,
     /// Algorithmically-computed indication of whether an entity is visible and should be extracted for rendering
     pub computed_visibility: ComputedVisibility,
+    /// The ui camera layers this image is visible in.
+    pub render_layers: RenderLayers,
 }
 
 /// A UI node that is text
@@ -87,6 +87,8 @@ pub struct TextBundle {
     pub visibility: Visibility,
     /// Algorithmically-computed indication of whether an entity is visible and should be extracted for rendering
     pub computed_visibility: ComputedVisibility,
+    /// The ui camera layers this text is visible in.
+    pub render_layers: RenderLayers,
 }
 
 impl TextBundle {
@@ -135,12 +137,13 @@ impl Default for TextBundle {
             global_transform: Default::default(),
             visibility: Default::default(),
             computed_visibility: Default::default(),
+            render_layers: Default::default(),
         }
     }
 }
 
 /// A UI node that is a button
-#[derive(Bundle, Clone, Debug)]
+#[derive(Bundle, Clone, Debug, Default)]
 pub struct ButtonBundle {
     /// Describes the size of the node
     pub node: Node,
@@ -164,51 +167,32 @@ pub struct ButtonBundle {
     pub visibility: Visibility,
     /// Algorithmically-computed indication of whether an entity is visible and should be extracted for rendering
     pub computed_visibility: ComputedVisibility,
+    /// The ui camera layers this button is visible in.
+    pub render_layers: RenderLayers,
 }
 
-impl Default for ButtonBundle {
-    fn default() -> Self {
-        ButtonBundle {
-            button: Button,
-            interaction: Default::default(),
-            focus_policy: Default::default(),
-            node: Default::default(),
-            style: Default::default(),
-            color: Default::default(),
-            image: Default::default(),
-            transform: Default::default(),
-            global_transform: Default::default(),
-            visibility: Default::default(),
-            computed_visibility: Default::default(),
-        }
-    }
-}
 /// Configuration for cameras related to UI.
 ///
 /// When a [`Camera`] doesn't have the [`UiCameraConfig`] component,
 /// it will display the UI by default.
 ///
 /// [`Camera`]: bevy_render::camera::Camera
-#[derive(Component, Clone)]
+#[derive(Component, Debug, Clone)]
 pub struct UiCameraConfig {
     /// Whether to output UI to this camera view.
     ///
     /// When a `Camera` doesn't have the [`UiCameraConfig`] component,
     /// it will display the UI by default.
     pub show_ui: bool,
+    /// The ui camera layers this camera can see.
+    pub ui_render_layers: RenderLayers,
 }
 
 impl Default for UiCameraConfig {
     fn default() -> Self {
-        Self { show_ui: true }
-    }
-}
-
-impl ExtractComponent for UiCameraConfig {
-    type Query = &'static Self;
-    type Filter = With<Camera>;
-
-    fn extract_component(item: QueryItem<Self::Query>) -> Self {
-        item.clone()
+        Self {
+            show_ui: true,
+            ui_render_layers: Default::default(),
+        }
     }
 }

crates/bevy_ui/src/lib.rs

@@ -12,7 +12,6 @@ pub mod entity;
 pub mod update;
 pub mod widget;
 
-use bevy_render::extract_component::ExtractComponentPlugin;
 pub use flex::*;
 pub use focus::*;
 pub use geometry::*;
@@ -28,11 +27,10 @@ pub mod prelude {
 use bevy_app::prelude::*;
 use bevy_ecs::schedule::{ParallelSystemDescriptorCoercion, SystemLabel};
 use bevy_input::InputSystem;
+use bevy_render::view::VisibilitySystems;
 use bevy_transform::TransformSystem;
 use bevy_window::ModifiesWindows;
-use update::{ui_z_system, update_clipping_system};
-
-use crate::prelude::UiCameraConfig;
+use update::{ui_z_system, update_clipping_system, update_layer_visibility};
 
 /// The basic plugin for Bevy UI
 #[derive(Default)]
@@ -45,12 +43,16 @@ pub enum UiSystem {
     Flex,
     /// After this label, input interactions with UI entities have been updated for this frame
     Focus,
+    /// Update the [`ComputedVisibility`] component of [`Node`] entities to reflect
+    /// their visibility in accordance to UI cameras.
+    ///
+    /// [`ComputedVisibility`]: bevy_render::view::ComputedVisibility
+    LayerVisibility,
 }
 
 impl Plugin for UiPlugin {
     fn build(&self, app: &mut App) {
-        app.add_plugin(ExtractComponentPlugin::<UiCameraConfig>::default())
-            .init_resource::<FlexSurface>()
+        app.init_resource::<FlexSurface>()
             .register_type::<AlignContent>()
             .register_type::<AlignItems>()
             .register_type::<AlignSelf>()
@@ -98,6 +100,12 @@ impl Plugin for UiPlugin {
                     .before(TransformSystem::TransformPropagate)
                     .after(ModifiesWindows),
             )
+            .add_system_to_stage(
+                CoreStage::PostUpdate,
+                update_layer_visibility
+                    .label(UiSystem::LayerVisibility)
+                    .after(VisibilitySystems::CheckVisibility),
+            )
             .add_system_to_stage(
                 CoreStage::PostUpdate,
                 ui_z_system