Fix Window feedback loop between the OS and Bevy (#7517)

# Objective

Fix #7377
Fix #7513

## Solution

Record the changes made to the Bevy `Window` from `winit` as 'canon' to avoid Bevy sending those changes back to `winit` again, causing a feedback loop.

## Changelog

* Removed `ModifiesWindows` system label.
  Neither `despawn_window` nor `changed_window` actually modify the `Window` component so all the `.after(ModifiesWindows)` shouldn't be necessary.
* Moved `changed_window` and `despawn_window` systems to `CoreStage::Last` to avoid systems making changes to the `Window` between `changed_window` and the end of the frame as they would be ignored.

## Migration Guide
The `ModifiesWindows` system label was removed.


Co-authored-by: devil-ira <justthecooldude@gmail.com>

Author: tim-blackbird

crates/bevy_pbr/src/lib.rs

@@ -11,7 +11,6 @@ mod render;
 
 pub use alpha::*;
 use bevy_transform::TransformSystem;
-use bevy_window::ModifiesWindows;
 pub use bundle::*;
 pub use fog::*;
 pub use light::*;
@@ -199,8 +198,7 @@ impl Plugin for PbrPlugin {
                     .in_set(SimulationLightSystems::AssignLightsToClusters)
                     .after(TransformSystem::TransformPropagate)
                     .after(VisibilitySystems::CheckVisibility)
-                    .after(CameraUpdateSystem)
-                    .after(ModifiesWindows),
+                    .after(CameraUpdateSystem),
             )
             .add_system(
                 update_directional_light_cascades

crates/bevy_render/src/camera/projection.rs

@@ -7,7 +7,6 @@ use bevy_reflect::{
     std_traits::ReflectDefault, FromReflect, GetTypeRegistration, Reflect, ReflectDeserialize,
     ReflectSerialize,
 };
-use bevy_window::ModifiesWindows;
 use serde::{Deserialize, Serialize};
 
 /// Adds [`Camera`](crate::camera::Camera) driver systems for a given projection type.
@@ -43,7 +42,6 @@ impl<T: CameraProjection + Component + GetTypeRegistration> Plugin for CameraPro
             .add_system(
                 crate::camera::camera_system::<T>
                     .in_set(CameraUpdateSystem)
-                    .after(ModifiesWindows)
                     // We assume that each camera will only have one projection,
                     // so we can ignore ambiguities with all other monomorphizations.
                     // FIXME: Add an archetype invariant for this https://github.com/bevyengine/bevy/issues/1481.

crates/bevy_text/src/lib.rs

@@ -28,7 +28,6 @@ use bevy_asset::AddAsset;
 use bevy_ecs::prelude::*;
 use bevy_render::{camera::CameraUpdateSystem, ExtractSchedule, RenderApp};
 use bevy_sprite::SpriteSystem;
-use bevy_window::ModifiesWindows;
 use std::num::NonZeroUsize;
 
 #[derive(Default)]
@@ -83,7 +82,6 @@ impl Plugin for TextPlugin {
             .add_system(
                 update_text2d_layout
                     .in_base_set(CoreSet::PostUpdate)
-                    .after(ModifiesWindows)
                     // Potential conflict: `Assets<Image>`
                     // In practice, they run independently since `bevy_render::camera_update_system`
                     // will only ever observe its own render target, and `update_text2d_layout`

crates/bevy_ui/src/lib.rs

@@ -34,7 +34,6 @@ use bevy_app::prelude::*;
 use bevy_ecs::prelude::*;
 use bevy_input::InputSystem;
 use bevy_transform::TransformSystem;
-use bevy_window::ModifiesWindows;
 use stack::ui_stack_system;
 pub use stack::UiStack;
 use update::update_clipping_system;
@@ -110,7 +109,6 @@ impl Plugin for UiPlugin {
                 widget::text_system
                     .in_base_set(CoreSet::PostUpdate)
                     .before(UiSystem::Flex)
-                    .after(ModifiesWindows)
                     // Potential conflict: `Assets<Image>`
                     // In practice, they run independently since `bevy_render::camera_update_system`
                     // will only ever observe its own render target, and `widget::text_system`
@@ -135,8 +133,7 @@ impl Plugin for UiPlugin {
             .add_system(
                 flex_node_system
                     .in_set(UiSystem::Flex)
-                    .before(TransformSystem::TransformPropagate)
-                    .after(ModifiesWindows),
+                    .before(TransformSystem::TransformPropagate),
             )
             .add_system(ui_stack_system.in_set(UiSystem::Stack))
             .add_system(

crates/bevy_window/src/lib.rs

@@ -137,9 +137,6 @@ impl Plugin for WindowPlugin {
     }
 }
 
-#[derive(Debug, Hash, PartialEq, Eq, Clone, SystemSet)]
-pub struct ModifiesWindows;
-
 /// Defines the specific conditions the application should exit on
 #[derive(Clone)]
 pub enum ExitCondition {

crates/bevy_winit/src/lib.rs

@@ -6,7 +6,7 @@ mod winit_config;
 mod winit_windows;
 
 use bevy_ecs::system::{SystemParam, SystemState};
-use system::{changed_window, create_window, despawn_window};
+use system::{changed_window, create_window, despawn_window, CachedWindow};
 
 pub use winit_config::*;
 pub use winit_windows::*;
@@ -26,7 +26,7 @@ use bevy_utils::{
 };
 use bevy_window::{
     exit_on_all_closed, CursorEntered, CursorLeft, CursorMoved, FileDragAndDrop, Ime,
-    ModifiesWindows, ReceivedCharacter, RequestRedraw, Window, WindowBackendScaleFactorChanged,
+    ReceivedCharacter, RequestRedraw, Window, WindowBackendScaleFactorChanged,
     WindowCloseRequested, WindowCreated, WindowFocused, WindowMoved, WindowResized,
     WindowScaleFactorChanged,
 };
@@ -39,7 +39,6 @@ use winit::{
     event_loop::{ControlFlow, EventLoop, EventLoopBuilder, EventLoopWindowTarget},
 };
 
-use crate::system::WinitWindowInfo;
 #[cfg(target_arch = "wasm32")]
 use crate::web_resize::{CanvasParentResizeEventChannel, CanvasParentResizePlugin};
 
@@ -70,7 +69,6 @@ impl Plugin for WinitPlugin {
         app.init_non_send_resource::<WinitWindows>()
             .init_resource::<WinitSettings>()
             .set_runner(winit_runner)
-            .configure_set(ModifiesWindows.in_base_set(CoreSet::PostUpdate))
             // exit_on_all_closed only uses the query to determine if the query is empty,
             // and so doesn't care about ordering relative to changed_window
             .add_systems(
@@ -79,7 +77,7 @@ impl Plugin for WinitPlugin {
                     // Update the state of the window before attempting to despawn to ensure consistent event ordering
                     despawn_window.after(changed_window),
                 )
-                    .in_set(ModifiesWindows),
+                    .in_base_set(CoreSet::Last),
             );
 
         #[cfg(target_arch = "wasm32")]
@@ -349,7 +347,7 @@ pub fn winit_runner(mut app: App) {
                 // Fetch and prepare details from the world
                 let mut system_state: SystemState<(
                     NonSend<WinitWindows>,
-                    Query<(&mut Window, &mut WinitWindowInfo)>,
+                    Query<(&mut Window, &mut CachedWindow)>,
                     WindowEvents,
                     InputEvents,
                     CursorEvents,
@@ -376,7 +374,7 @@ pub fn winit_runner(mut app: App) {
                         return;
                     };
 
-                let (mut window, mut info) =
+                let (mut window, mut cache) =
                     if let Ok((window, info)) = window_query.get_mut(window_entity) {
                         (window, info)
                     } else {
@@ -394,7 +392,6 @@ pub fn winit_runner(mut app: App) {
                         window
                             .resolution
                             .set_physical_resolution(size.width, size.height);
-                        info.last_winit_size = size;
 
                         window_events.window_resized.send(WindowResized {
                             window: window_entity,
@@ -421,11 +418,7 @@ pub fn winit_runner(mut app: App) {
                             window.resolution.physical_height() as f64 - position.y,
                         );
 
-                        // bypassing change detection to not trigger feedback loop with system `changed_window`
-                        // this system change the cursor position in winit
-                        window
-                            .bypass_change_detection()
-                            .set_physical_cursor_position(Some(physical_position));
+                        window.set_physical_cursor_position(Some(physical_position));
 
                         cursor_events.cursor_moved.send(CursorMoved {
                             window: window_entity,
@@ -439,14 +432,7 @@ pub fn winit_runner(mut app: App) {
                         });
                     }
                     WindowEvent::CursorLeft { .. } => {
-                        // Component
-                        if let Ok((mut window, _)) = window_query.get_mut(window_entity) {
-                            // bypassing change detection to not trigger feedback loop with system `changed_window`
-                            // this system change the cursor position in winit
-                            window
-                                .bypass_change_detection()
-                                .set_physical_cursor_position(None);
-                        }
+                        window.set_physical_cursor_position(None);
 
                         cursor_events.cursor_left.send(CursorLeft {
                             window: window_entity,
@@ -594,6 +580,10 @@ pub fn winit_runner(mut app: App) {
                     },
                     _ => {}
                 }
+
+                if window.is_changed() {
+                    cache.window = window.clone();
+                }
             }
             event::Event::DeviceEvent {
                 event: DeviceEvent::MouseMotion { delta: (x, y) },