user controlled window visibility

Cargo.toml

@@ -2017,6 +2017,16 @@ description = "Creates a solid color window"
 category = "Window"
 wasm = true
 
+[[example]]
+name = "invisible_window"
+path = "examples/window/invisible_window.rs"
+
+[package.metadata.example.invisible_window]
+name = "Invisible Window"
+description = "Demonstrates how to spawn an invisible window"
+category = "Window"
+wasm = false
+
 [[example]]
 name = "low_power"
 path = "examples/window/low_power.rs"

crates/bevy_window/src/window.rs

@@ -213,6 +213,14 @@ pub struct Window {
     ///
     /// - iOS / Android / Web: Unsupported.
     pub window_theme: Option<WindowTheme>,
+    /// Sets the window's visibility.
+    ///
+    /// If `false`, this will hide the window. If `true`, this will show the window.
+    ///
+    /// ## Platform-specific
+    ///
+    /// - **Android / Wayland / Web:** Unsupported.
+    pub visible: bool,
 }
 
 impl Default for Window {
@@ -239,6 +247,7 @@ impl Default for Window {
             prevent_default_event_handling: true,
             canvas: None,
             window_theme: None,
+            visible: true,
         }
     }
 }
@@ -1016,7 +1025,7 @@ pub enum WindowTheme {
 ///
 /// ## Platform-specific
 ///
-/// **`iOS`**, **`Android`**, and the **`Web`** do not have window control buttons.  
+/// **`iOS`**, **`Android`**, and the **`Web`** do not have window control buttons.
 ///
 /// On some **`Linux`** environments these values have no effect.
 #[derive(Debug, Copy, Clone, PartialEq, Reflect)]

crates/bevy_winit/src/system.rs

@@ -314,6 +314,10 @@ pub(crate) fn changed_windows(
                 winit_window.set_theme(window.window_theme.map(convert_window_theme));
             }
 
+            if window.visible != cache.window.visible {
+                winit_window.set_visible(window.visible);
+            }
+
             cache.window = window.clone();
         }
     }

crates/bevy_winit/src/winit_windows.rs

@@ -167,7 +167,7 @@ impl WinitWindows {
         );
         adapters.insert(entity, adapter);
         handlers.insert(entity, handler);
-        winit_window.set_visible(true);
+        winit_window.set_visible(window.visible);
 
         // Do not set the grab mode on window creation if it's none. It can fail on mobile.
         if window.cursor.grab_mode != CursorGrabMode::None {

examples/README.md

@@ -365,6 +365,7 @@ Example | Description
 Example | Description
 --- | ---
 [Clear Color](../examples/window/clear_color.rs) | Creates a solid color window
+[Invisible Window](../examples/window/invisible_window.rs) | Demonstrates how to spawn an invisible window
 [Low Power](../examples/window/low_power.rs) | Demonstrates settings to reduce power use for bevy applications
 [Multiple Windows](../examples/window/multiple_windows.rs) | Demonstrates creating multiple windows, and rendering to them
 [Scale Factor Override](../examples/window/scale_factor_override.rs) | Illustrates how to customize the default window settings

examples/window/invisible_window.rs

@@ -0,0 +1,26 @@
+//! This shows how to spawn an invisible window and turn it visible once it's ready to display.
+//! This is useful when you want to avoid the white window that shows up before the GPU is ready to render the app.
+
+use bevy::prelude::*;
+use bevy_internal::window::PrimaryWindow;
+
+fn main() {
+    App::new()
+        .add_plugins(DefaultPlugins.set(WindowPlugin {
+            primary_window: Some(Window {
+                // This will spawn an invisible window
+                visible: false,
+                ..default()
+            }),
+            ..default()
+        }))
+        .add_systems(Startup, setup)
+        .run();
+}
+
+fn setup(mut primary_window: Query<&mut Window, With<PrimaryWindow>>) {
+    // At this point the gpu is ready to show the app so we can make the window visible
+    // There might still be a white frame when doing it in startup.
+    // Alternatively, you could have a system that waits a few seconds before making the window visible.
+    primary_window.single_mut().visible = true;
+}