add fps counter plugin

src/fps_counter.rs

@@ -0,0 +1,63 @@
+use bevy::{
+    dev_tools::fps_overlay::{FpsOverlayConfig, FpsOverlayPlugin},
+    prelude::*,
+    text::FontSmoothing,
+};
+struct OverlayColor;
+impl OverlayColor {
+    const RED: Color = Color::srgb(1.0, 0.0, 0.0);
+    const GREEN: Color = Color::srgb(0.0, 1.0, 0.0);
+}
+
+pub struct FpsCounterPlugin;
+impl Plugin for FpsCounterPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_plugins(FpsOverlayPlugin {
+            config: FpsOverlayConfig {
+                text_config: TextFont {
+                    font_size: 42.0,
+                    ..default()
+                },
+                text_color: OverlayColor::RED,
+                enabled: true,
+            },
+        })
+        .add_systems(Startup, setup)
+        .add_systems(Update, customize_config);
+    }
+}
+fn setup(mut commands: Commands) {
+    commands.spawn((
+        Text::new(concat!(
+            "Press 1 to toggle the overlay color.\n",
+            "Press 2 to decrease the overlay size.\n",
+            "Press 3 to increase the overlay size.\n",
+            "Press 4 to toggle the overlay visibility.",
+        )),
+        Node {
+            position_type: PositionType::Absolute,
+            bottom: Val::Px(12.0),
+            left: Val::Px(12.0),
+            ..default()
+        },
+    ));
+}
+fn customize_config(input: Res<ButtonInput<KeyCode>>, mut overlay: ResMut<FpsOverlayConfig>) {
+    if input.just_pressed(KeyCode::Digit1) {
+        // Changing resource will affect overlay
+        if overlay.text_color == OverlayColor::GREEN {
+            overlay.text_color = OverlayColor::RED;
+        } else {
+            overlay.text_color = OverlayColor::GREEN;
+        }
+    }
+    if input.just_pressed(KeyCode::Digit2) {
+        overlay.text_config.font_size -= 2.0;
+    }
+    if input.just_pressed(KeyCode::Digit3) {
+        overlay.text_config.font_size += 2.0;
+    }
+    if input.just_pressed(KeyCode::Digit4) {
+        overlay.enabled = !overlay.enabled;
+    }
+}

src/main.rs

@@ -1,9 +1,12 @@
 use bevy::prelude::*;
 
+mod fps_counter;
 fn main() {
     App::new()
-        .add_plugins(DefaultPlugins)
-        .add_plugins(HelloPlugin)
+        .add_plugins((
+            DefaultPlugins,
+            fps_counter::FpsCounterPlugin,
+        ))
         .run();
 }
 //region first app