add ui to example

examples/3d/wireframe.rs

@@ -14,13 +14,13 @@ fn main() {
                 ..default()
             },
         }))
-        .add_plugin(WireframePlugin)
-        // Wireframes can be configured with this resource
+        // Wireframes can be configured with this resource. This can be changed at runtime.
         // See the associated docs for more details
         .insert_resource(WireframeConfig {
             global: true,
             color: Color::GREEN,
         })
+        .add_plugin(WireframePlugin)
         .add_startup_system(setup)
         .add_system(update_colors)
         .run();
@@ -31,6 +31,7 @@ fn setup(
     mut commands: Commands,
     mut meshes: ResMut<Assets<Mesh>>,
     mut materials: ResMut<Assets<StandardMaterial>>,
+    asset_server: Res<AssetServer>,
 ) {
     // plane
     commands.spawn(PbrBundle {
@@ -78,14 +79,57 @@ fn setup(
         transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
         ..default()
     });
+
+    // Text used to show controls
+    commands.spawn(
+        TextBundle::from_section(
+            "",
+            TextStyle {
+                font: asset_server.load("fonts/FiraMono-Medium.ttf"),
+                font_size: 18.0,
+                color: Color::WHITE,
+            },
+        )
+        .with_style(Style {
+            position_type: PositionType::Absolute,
+            position: UiRect {
+                top: Val::Px(10.0),
+                left: Val::Px(10.0),
+                ..default()
+            },
+            ..default()
+        }),
+    );
 }
 
 /// This system let's you toggle various wireframe settings
 fn update_colors(
     keyboard_input: Res<Input<KeyCode>>,
     mut config: ResMut<WireframeConfig>,
     mut wireframe_colors: Query<&mut WireframeColor>,
+    mut text: Query<&mut Text>,
 ) {
+    let mut text = text.single_mut();
+    let text = &mut text.sections[0].value;
+
+    *text = "WireframeConfig\n".to_string();
+    text.push_str("-------------\n");
+    text.push_str(&format!("Global: {}\n", config.global));
+    text.push_str(&format!(
+        "Color: r={} g={} b={}\n",
+        config.color.r(),
+        config.color.g(),
+        config.color.b()
+    ));
+
+    text.push_str("\n\n");
+
+    text.push_str("Controls\n");
+    text.push_str("---------------\n");
+    text.push_str("Z - Toggle global\n");
+    text.push_str("X - Change global color\n");
+    text.push_str("X - Change color of the center cube wireframe\n");
+
     // Toggle showing a wireframe on all meshes
     if keyboard_input.just_pressed(KeyCode::Z) {
         info!("toggle global");