first circle try

src/bin/circle.rs

@@ -0,0 +1,32 @@
+use std::f32::consts::PI;
+
+use bevy::prelude::*;
+use bevy_prototype_lyon::prelude::*;
+
+fn main() {
+    App::new()
+        .insert_resource(Msaa { samples: 4 })
+        .add_plugins(DefaultPlugins)
+        .add_plugin(ShapePlugin)
+        .add_startup_system(setup_system)
+        .run();
+}
+
+fn setup_system(mut commands: Commands) {
+    let mut path_builder = PathBuilder::new();
+    path_builder.move_to(Vec2::new(100., 0.));
+    path_builder.arc(
+        100.0 * Vec2::ZERO,
+        100.0 * Vec2::ONE,
+        90f32.to_radians(),
+        0.,
+    );
+    let line = path_builder.build();
+
+    commands.spawn_bundle(Camera2dBundle::default());
+    commands.spawn_bundle(GeometryBuilder::build_as(
+        &line,
+        DrawMode::Stroke(StrokeMode::new(Color::BLACK, 10.0)),
+        Transform::default(),
+    ));
+}