Exposed a CursorPosition resource

crates/bevy_window/src/cursor.rs

@@ -1,3 +1,35 @@
+use crate::WindowId;
+use bevy_math::Vec2;
+use bevy_utils::HashMap;
+
+#[derive(Debug, Clone, Default)]
+/// Resource storing the cursor position on the app windows
+pub struct CursorPositions {
+    pub(crate) positions: HashMap<WindowId, Vec2>,
+}
+
+impl CursorPositions {
+    /// Retrieves the cursor position from the given [`WindowId`]
+    pub fn get(&self, id: WindowId) -> Option<Vec2> {
+        self.positions.get(&id).copied()
+    }
+
+    /// Retrieves the cursor position from the *primary* window
+    pub fn primary_position(&self) -> Option<Vec2> {
+        self.get(WindowId::primary())
+    }
+
+    /// Returns an iterator on cursor positions
+    pub fn positions_iter(&self) -> impl Iterator<Item = &Vec2> {
+        self.positions.values()
+    }
+
+    /// Returns an iterator on window ids and cursor positions
+    pub fn iter(&self) -> impl Iterator<Item = (&WindowId, &Vec2)> {
+        self.positions.iter()
+    }
+}
+
 /// The icon to display for a window's cursor.
 ///
 /// Examples of all of these cursors can be found [here](https://www.w3schools.com/cssref/playit.asp?filename=playcss_cursor).

crates/bevy_window/src/lib.rs

@@ -47,6 +47,8 @@ pub struct WindowPlugin {
     /// If this system (or a replacement) is not running, the close button will have no effect.
     /// This may surprise your users. It is recommended to leave this setting as `true`.
     pub close_when_requested: bool,
+    /// Whether the plugin will update a [`CursorPositions`] resource every frame.
+    pub update_cursor_position: bool,
 }
 
 impl Default for WindowPlugin {
@@ -55,6 +57,7 @@ impl Default for WindowPlugin {
             add_primary_window: true,
             exit_on_all_closed: true,
             close_when_requested: true,
+            update_cursor_position: true,
         }
     }
 }
@@ -91,6 +94,11 @@ impl Plugin for WindowPlugin {
             });
         }
 
+        if self.update_cursor_position {
+            app.init_resource::<CursorPositions>();
+            app.add_system(update_cursor_positions);
+        }
+
         if self.exit_on_all_closed {
             app.add_system(exit_on_all_closed);
         }

crates/bevy_window/src/system.rs

@@ -1,9 +1,17 @@
-use crate::{Window, WindowCloseRequested, WindowFocused, WindowId, Windows};
+use crate::{CursorPositions, Window, WindowCloseRequested, WindowFocused, WindowId, Windows};
 
 use bevy_app::AppExit;
 use bevy_ecs::prelude::*;
 use bevy_input::{keyboard::KeyCode, Input};
 
+/// Updates the [`CursorPositions`] resource
+pub fn update_cursor_positions(mut positions: ResMut<CursorPositions>, windows: Res<Windows>) {
+    positions.positions = windows
+        .iter()
+        .flat_map(|w| w.cursor_position().map(|p| (w.id(), p)))
+        .collect();
+}
+
 /// Exit the application when there are no open windows.
 ///
 /// This system is added by the [`WindowPlugin`] in the default configuration.