build: print scenes in top left

examples/diagnostics/src/main.rs

@@ -1,57 +1,85 @@
 use bevy::{diagnostic::DiagnosticsStore, prelude::*};
 use bevy_vello::{diagnostics::VelloDiagnosticsPlugin, prelude::*, VelloPlugin};
-use std::ops::DerefMut;
+
+const SCENE_COUNT: usize = 5;
 
 fn main() {
     let mut app = App::new();
     app.add_plugins(DefaultPlugins)
         .add_plugins(VelloPlugin::default())
         .add_plugins(VelloDiagnosticsPlugin)
-        .add_systems(Startup, setup_vector_graphics)
+        .add_systems(Startup, setup)
         .add_systems(Update, simple_animation)
-        .add_systems(Update, print_diagnostics);
+        .add_systems(Update, update_scene_count_ui);
 
     app.run();
 }
 
-fn setup_vector_graphics(mut commands: Commands) {
+fn setup(mut commands: Commands) {
     commands.spawn((Camera2d, VelloView));
-    commands.spawn(VelloScene::new());
+    for i in 0..SCENE_COUNT {
+        commands.spawn((
+            VelloScene::new(),
+            Transform::from_translation(Vec3::new(i as f32 * 100.0 - 200.0, 0.0, 0.0)),
+        ));
+    }
+
+    // UI Text displaying the scene count
+    commands.spawn((
+        Text::new("Total Scenes: 0"),
+        TextFont {
+            font_size: 30.0,
+            ..default()
+        },
+        TextColor(Color::WHITE),
+        Node {
+            position_type: PositionType::Absolute,
+            left: Val::Px(10.0),
+            top: Val::Px(10.0),
+            ..default()
+        },
+        SceneCounterText,
+    ));
 }
 
-fn simple_animation(mut query_scene: Single<(&mut Transform, &mut VelloScene)>, time: Res<Time>) {
+#[derive(Component)]
+struct SceneCounterText;
+
+fn simple_animation(mut query: Query<(&mut Transform, &mut VelloScene)>, time: Res<Time>) {
     let sin_time = time.elapsed_secs().sin().mul_add(0.5, 0.5);
-    let (ref mut transform, ref mut scene) = query_scene.deref_mut();
-    // Reset scene every frame
-    scene.reset();
-
-    // Animate color green to blue
-    let c = Vec3::lerp(
-        Vec3::new(-1.0, 1.0, -1.0),
-        Vec3::new(-1.0, 1.0, 1.0),
-        sin_time + 0.5,
-    );
-
-    // Animate the corner radius
-    scene.fill(
-        peniko::Fill::NonZero,
-        kurbo::Affine::default(),
-        peniko::Color::new([c.x, c.y, c.z, 1.]),
-        None,
-        &kurbo::RoundedRect::new(-50.0, -50.0, 50.0, 50.0, (sin_time as f64) * 50.0),
-    );
-
-    transform.scale = Vec3::lerp(Vec3::ONE * 0.5, Vec3::ONE * 1.0, sin_time);
-    transform.translation = Vec3::lerp(Vec3::X * -100.0, Vec3::X * 100.0, sin_time);
-    transform.rotation = Quat::from_rotation_z(-std::f32::consts::TAU * sin_time);
-}
 
-fn print_diagnostics(diagnostics: Res<DiagnosticsStore>) {
-    let diagnostic = diagnostics
-        .get(&VelloDiagnosticsPlugin::SCENE_COUNT)
-        .unwrap();
+    for (mut transform, mut scene) in query.iter_mut() {
+        scene.reset();
+
+        let c = Vec3::lerp(
+            Vec3::new(-1.0, 1.0, -1.0),
+            Vec3::new(-1.0, 1.0, 1.0),
+            sin_time + 0.5,
+        );
+
+        scene.fill(
+            peniko::Fill::NonZero,
+            kurbo::Affine::default(),
+            peniko::Color::new([c.x, c.y, c.z, 1.]),
+            None,
+            &kurbo::RoundedRect::new(-50.0, -50.0, 50.0, 50.0, (sin_time as f64) * 50.0),
+        );
+
+        transform.scale = Vec3::lerp(Vec3::ONE * 0.5, Vec3::ONE * 1.0, sin_time);
+        transform.translation.y = sin_time * 50.0;
+        transform.rotation = Quat::from_rotation_z(-std::f32::consts::TAU * sin_time);
+    }
+}
 
-    if let Some(scene_count) = diagnostic.measurement() {
-        info!("Total scenes: {}", scene_count.value);
+fn update_scene_count_ui(
+    diagnostics: Res<DiagnosticsStore>,
+    mut query: Query<&mut Text, With<SceneCounterText>>,
+) {
+    if let Some(diagnostic) = diagnostics.get(&VelloDiagnosticsPlugin::SCENE_COUNT) {
+        if let Some(scene_count) = diagnostic.measurement() {
+            for mut text in query.iter_mut() {
+                text.0 = format!("Total Scenes: {}", scene_count.value);
+            }
+        }
     }
 }