rebase

examples/hello_world.rs

@@ -19,6 +19,7 @@ fn render_shapes(mut commands: Commands) {
     // Line
     let line = (
         VelloLine::new(DVec2::new(0.0, 100.0), DVec2::new(0.0, -100.0)),
+        Head::new(DVec2::new(0.0, 100.0), DVec2::new(0.0, -100.0)),
         Stroke::new(5.0).with_color(Color::WHITE),
         Transform::from_xyz(-300.0, 0.0, 0.0),
     );

src/head.rs

@@ -15,7 +15,11 @@ pub struct Head {
     pub rotation_offset: f32,
 }
 
-#[derive(Resource)]
+// impl Head {
+//     pub fn new()
+// }
+
+#[derive(Resource, Default)]
 pub struct Shapes {
     pub scenes: std::collections::HashMap<ShapeId, &'static mut vello::Scene>,
 }

src/lib.rs

@@ -32,15 +32,17 @@ pub struct VelloGraphicsPlugin;
 
 impl Plugin for VelloGraphicsPlugin {
     fn build(&self, app: &mut App) {
-        app.add_plugins(VelloPlugin).add_systems(
-            Update,
-            (
-                build_vector::<VelloRect>(),
-                build_vector::<VelloCircle>(),
-                build_vector::<VelloLine>(),
-                build_vector::<VelloBezPath>(),
-            ),
-        );
+        app.add_plugins(VelloPlugin)
+            .init_resource::<Shapes>()
+            .add_systems(
+                Update,
+                (
+                    build_vector::<VelloRect>(),
+                    build_vector::<VelloCircle>(),
+                    build_vector::<VelloLine>(),
+                    build_vector::<VelloBezPath>(),
+                ),
+            );
     }
 }
 
@@ -88,8 +90,10 @@ fn append_heads<HeadEquipt: VelloVector + VectorBorder + Component>(
         (&HeadEquipt, &Head, &mut VelloScene),
         (Without<Stroke>, Or<(Changed<HeadEquipt>, Changed<Fill>)>),
     >,
-    shapes: Res<Shapes>,
+    shapes: Option<Res<Shapes>>,
 ) {
+    let Some(shapes) = shapes else { return };
+
     for (vector, head, mut scene) in q_vectors.iter_mut() {
         let translation = vector.border_translation(head.time);
         let translation = kurbo::Vec2::new(translation.x, translation.y);

src/line.rs

@@ -49,6 +49,6 @@ impl VectorBorder for VelloLine {
     }
 
     fn border_tangent(&self, _time: f64) -> f64 {
-        (self.p1.y - self.p0.y) / (self.p1.x - self.p0.x)
+        ((self.p1.y - self.p0.y) / (self.p1.x - self.p0.x)).atan()
     }
 }