first circle try

Cargo.lock

@@ -110,9 +110,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.60"
+version = "1.0.62"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c794e162a5eff65c72ef524dfe393eb923c354e350bb78b9c7383df13f3bc142"
+checksum = "1485d4d2cc45e7b201ee3767015c96faa5904387c9d87c6efdd0fb511f12d305"
 
 [[package]]
 name = "approx"
@@ -165,9 +165,9 @@ dependencies = [
 
 [[package]]
 name = "async-channel"
-version = "1.6.1"
+version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2114d64672151c0c5eaa5e131ec84a74f06e1e559830dabba01ca30605d66319"
+checksum = "e14485364214912d3b19cc3435dde4df66065127f05fa0d75c712f36f12c2f28"
 dependencies = [
  "concurrent-queue",
  "event-listener",
@@ -422,9 +422,9 @@ dependencies = [
 
 [[package]]
 name = "bevy_egui"
-version = "0.15.0"
+version = "0.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4ab46f07c3f360507fae9bc3b9c000c583e0d67661f0dd6dd5a24a709775b1e"
+checksum = "acbf44ff770566dca66b805a6829df783f64700bd01d35aec1034dff31b531a4"
 dependencies = [
  "arboard",
  "bevy",
@@ -875,7 +875,7 @@ checksum = "8bda6dada53e546845887ae7357eec57b8d547ef71627b716b33839b4a98b687"
 dependencies = [
  "ahash",
  "getrandom",
- "hashbrown 0.12.3",
+ "hashbrown",
  "instant",
  "tracing",
  "uuid",
@@ -964,24 +964,24 @@ checksum = "0d8c1fef690941d3e7788d328517591fecc684c084084702d6ff1641e993699a"
 
 [[package]]
 name = "bumpalo"
-version = "3.10.0"
+version = "3.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37ccbd214614c6783386c1af30caf03192f17891059cecc394b4fb119e363de3"
+checksum = "c1ad822118d20d2c234f427000d5acc36eabe1e29a348c89b63dd60b13f28e5d"
 
 [[package]]
 name = "bytemuck"
-version = "1.11.0"
+version = "1.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a5377c8865e74a160d21f29c2d40669f53286db6eab59b88540cbb12ffc8b835"
+checksum = "2f5715e491b5a1598fc2bef5a606847b5dc1d48ea625bd3c02c00de8285591da"
 dependencies = [
  "bytemuck_derive",
 ]
 
 [[package]]
 name = "bytemuck_derive"
-version = "1.1.1"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cfd2f4180c5721da6335cc9e9061cce522b87a35e51cc57636d28d22a9863c80"
+checksum = "1b9e1f5fa78f69496407a27ae9ed989e3c3b072310286f5ef385525e4cbc24a9"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1119,9 +1119,9 @@ checksum = "3d7b894f5411737b7867f4827955924d7c254fc9f4d91a6aad6b097804b1018b"
 
 [[package]]
 name = "combine"
-version = "4.6.4"
+version = "4.6.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2a604e93b79d1808327a6fca85a6f2d69de66461e7620f5a4cbf5fb4d1d7c948"
+checksum = "35ed6e9d84f0b51a7f52daf1c7d71dd136fd7a3f41a8462b8cdb8c78d920fad4"
 dependencies = [
  "bytes",
  "memchr",
@@ -1592,15 +1592,15 @@ dependencies = [
 
 [[package]]
 name = "futures-core"
-version = "0.3.21"
+version = "0.3.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c09fd04b7e4073ac7156a9539b57a484a8ea920f79c7c675d05d289ab6110d3"
+checksum = "d2acedae88d38235936c3922476b10fced7b2b68136f5e3c03c2d5be348a1115"
 
 [[package]]
 name = "futures-io"
-version = "0.3.21"
+version = "0.3.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc4045962a5a5e935ee2fdedaa4e08284547402885ab326734432bed5d12966b"
+checksum = "93a66fc6d035a26a3ae255a6d2bca35eda63ae4c5512bef54449113f7a1228e5"
 
 [[package]]
 name = "futures-lite"
@@ -1778,13 +1778,13 @@ dependencies = [
 
 [[package]]
 name = "gpu-descriptor"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a538f217be4d405ff4719a283ca68323cc2384003eca5baaa87501e821c81dda"
+checksum = "0b0c02e1ba0bdb14e965058ca34e09c020f8e507a760df1121728e0aef68d57a"
 dependencies = [
  "bitflags",
  "gpu-descriptor-types",
- "hashbrown 0.11.2",
+ "hashbrown",
 ]
 
 [[package]]
@@ -1826,15 +1826,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "hashbrown"
-version = "0.11.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab5ef0d4909ef3724cc8cce6ccc8572c5c817592e9285f5464f8e86f8bd3726e"
-dependencies = [
- "ahash",
-]
-
 [[package]]
 name = "hashbrown"
 version = "0.12.3"
@@ -1931,7 +1922,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "10a35a97730320ffe8e2d410b5d3b69279b98d2c14bdb8b70ea89ecf7888d41e"
 dependencies = [
  "autocfg",
- "hashbrown 0.12.3",
+ "hashbrown",
 ]
 
 [[package]]
@@ -1996,9 +1987,9 @@ dependencies = [
 
 [[package]]
 name = "itoa"
-version = "1.0.2"
+version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "112c678d4050afce233f4f2852bb2eb519230b3cf12f33585275537d7e41578d"
+checksum = "6c8af84674fe1f223a982c933a0ee1086ac4d4052aa0fb8060c12c6ad838e754"
 
 [[package]]
 name = "jni"
@@ -2100,9 +2091,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.126"
+version = "0.2.132"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "349d5a591cd28b49e1d1037471617a32ddcda5731b99419008085f72d5a53836"
+checksum = "8371e4e5341c3a96db127eb2465ac681ced4c433e01dd0e938adbef26ba93ba5"
 
 [[package]]
 name = "libloading"
@@ -2632,9 +2623,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.13.0"
+version = "1.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18a6dbe30758c9f83eb00cbea4ac95966305f5a7772f3f42ebfc7fc7eddbd8e1"
+checksum = "074864da206b4973b84eb91683020dbefd6a8c3f0f38e054d93954e891935e4e"
 
 [[package]]
 name = "owned_ttf_parser"
@@ -2774,9 +2765,9 @@ checksum = "a8815d101cfb4cb491154896bdab292a395a7ac9ab185a9941a2f5be0135900d"
 
 [[package]]
 name = "proc-macro-crate"
-version = "1.2.0"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26d50bfb8c23f23915855a00d98b5a35ef2e0b871bb52937bacadb798fbb66c8"
+checksum = "eda0fc3b0fb7c975631757e14d9049da17374063edb6ebbcbc54d880d4fe94e9"
 dependencies = [
  "once_cell",
  "thiserror",
@@ -2942,18 +2933,18 @@ checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
 [[package]]
 name = "serde"
-version = "1.0.141"
+version = "1.0.143"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7af873f2c95b99fcb0bd0fe622a43e29514658873c8ceba88c4cb88833a22500"
+checksum = "53e8e5d5b70924f74ff5c6d64d9a5acd91422117c60f48c4e07855238a254553"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.141"
+version = "1.0.143"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "75743a150d003dd863b51dc809bcad0d73f2102c53632f1e954e738192a3413f"
+checksum = "d3d8e8de557aee63c26b85b947f5e59b690d0454c753f3adeb5cd7835ab88391"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2962,9 +2953,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.82"
+version = "1.0.83"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "82c2c1fdcd807d1098552c5b9a36e425e42e9fbd7c6a37a8425f390f781f7fa7"
+checksum = "38dd04e3c8279e75b31ef29dbdceebfe5ad89f4d0937213c53f7d49d01b3d5a7"
 dependencies = [
  "itoa",
  "ryu",
@@ -3263,9 +3254,9 @@ checksum = "099b7128301d285f79ddd55b9a83d5e6b9e97c92e0ea0daebee7263e932de992"
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.2"
+version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "15c61ba63f9235225a22310255a29b806b907c9b8c964bcbd0a2c70f3f2deea7"
+checksum = "c4f5b37a154999a8f3f98cc23a628d850e154479cd94decf3414696e12e31aaf"
 
 [[package]]
 name = "unicode-normalization"
@@ -3662,9 +3653,9 @@ dependencies = [
 
 [[package]]
 name = "x11-dl"
-version = "2.19.1"
+version = "2.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ea26926b4ce81a6f5d9d0f3a0bc401e5a37c6ae14a1bfaa8ff6099ca80038c59"
+checksum = "0c83627bc137605acc00bb399c7b908ef460b621fc37c953db2b09f88c449ea6"
 dependencies = [
  "lazy_static",
  "libc",

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(),
+    ));
+}

src/main.rs

@@ -1,4 +1,5 @@
 mod debug;
+mod primitives;
 mod turtle;
 mod turtle_movement;
 mod turtle_shapes;

src/primitives.rs

@@ -0,0 +1,110 @@
+use bevy::prelude::{Bundle, Color, Component, Name, Transform, Vec2};
+use bevy_prototype_lyon::{
+    entity::ShapeBundle,
+    prelude::{DrawMode, FillMode, GeometryBuilder, Path, PathBuilder, ShapePath, StrokeMode},
+    shapes::{self, Line},
+};
+use bevy_tweening::Lens;
+
+use crate::turtle::Angle;
+
+pub(crate) struct LineAnimationLens {
+    start: Vec2,
+    end: Vec2,
+}
+
+impl LineAnimationLens {
+    pub(crate) fn new(start: Vec2, end: Vec2) -> Self {
+        Self { start, end }
+    }
+}
+
+impl Lens<Path> for LineAnimationLens {
+    fn lerp(&mut self, target: &mut Path, ratio: f32) {
+        let line = shapes::Line(self.start, self.start + ((self.end - self.start) * ratio));
+        *target = ShapePath::build_as(&line);
+    }
+}
+
+#[derive(Bundle)]
+pub(crate) struct TurtleDrawLine {
+    #[bundle]
+    line: ShapeBundle,
+    name: Name,
+    marker: LineMarker,
+}
+
+#[derive(Component, Default)]
+struct LineMarker;
+
+impl TurtleDrawLine {
+    pub(crate) fn new(start: Vec2, _end: Vec2, index: u64) -> Self {
+        Self {
+            line: GeometryBuilder::build_as(
+                &Line(start, start),
+                DrawMode::Outlined {
+                    fill_mode: FillMode::color(Color::MIDNIGHT_BLUE),
+                    outline_mode: StrokeMode::new(Color::BLACK, 1.0),
+                },
+                Transform::identity(),
+            ),
+            name: Name::new(format!("Line {}", index)),
+            marker: LineMarker,
+        }
+    }
+}
+
+pub(crate) struct CircleAnimationLens {
+    start: Vec2,
+    end: Vec2,
+}
+
+impl Lens<Path> for CircleAnimationLens {
+    fn lerp(&mut self, target: &mut Path, ratio: f32) {
+        let line = shapes::Line(self.start, self.start + ((self.end - self.start) * ratio));
+        *target = ShapePath::build_as(&line);
+    }
+}
+
+#[derive(Bundle)]
+
+pub(crate) struct TurtleDrawCircle {
+    #[bundle]
+    line: ShapeBundle,
+    name: Name,
+    marker: CircleMarker,
+}
+
+#[derive(Component, Default)]
+struct CircleMarker;
+
+impl TurtleDrawCircle {
+    pub(crate) fn new(
+        center: Vec2,
+        radii: Vec2,
+        angle: Angle,
+        index: u64,
+        start: Vec2,
+        end: Vec2,
+    ) -> Self {
+        let mut path_builder = PathBuilder::new();
+        path_builder.move_to(start);
+        // The center point of the radius, then the radii in x and y direction, then the angle that will be drawn, then the x_rotation ?
+        path_builder.arc(center, radii, angle.0.to_radians(), 0.);
+        let line = path_builder.build();
+        println!("Draw Circle: {} {} {:?}", center, radii, angle);
+
+        Self {
+            line: GeometryBuilder::build_as(
+                &line,
+                DrawMode::Outlined {
+                    fill_mode: FillMode::color(Color::rgba(0., 0., 0., 0.)),
+                    outline_mode: StrokeMode::new(Color::BLACK, 1.0),
+                },
+                Transform::identity(),
+            ),
+            name: Name::new(format!("Circle {}", index)),
+            marker: CircleMarker,
+        }
+    }
+}

src/turtle.rs

@@ -2,13 +2,16 @@ use std::time::Duration;
 
 use bevy::prelude::*;
 use bevy_inspector_egui::{Inspectable, RegisterInspectable};
-use bevy_prototype_lyon::{entity::ShapeBundle, prelude::*, shapes::Line};
+use bevy_prototype_lyon::prelude::*;
 use bevy_tweening::{
-    component_animator_system, lens::TransformPositionLens, Animator, EaseFunction, Lens, Tween,
+    component_animator_system, lens::TransformScaleLens, Animator, EaseFunction, Tween,
     TweenCompleted, TweeningPlugin, TweeningType,
 };
 
-use crate::turtle_shapes;
+use crate::{
+    primitives::{LineAnimationLens, TurtleDrawCircle, TurtleDrawLine},
+    turtle_shapes,
+};
 
 pub struct TurtlePlugin;
 
@@ -39,12 +42,26 @@ impl Default for Turtle {
             },
             commands: TurtleCommands::new(vec![
                 TurtleCommand::Forward(Length(100.)),
+                TurtleCommand::Circle {
+                    radius: Length(150.),
+                    angle: Angle(180.),
+                },
                 TurtleCommand::Right(Angle(90.)),
+                TurtleCommand::Circle {
+                    radius: Length(15.),
+                    angle: Angle(180.),
+                },
                 TurtleCommand::Backward(Length(100.)),
                 TurtleCommand::Right(Angle(90.)),
                 TurtleCommand::Forward(Length(100.)),
                 TurtleCommand::Right(Angle(45.)),
+                //TurtleCommand::PenUp,
                 TurtleCommand::Forward(Length(100.)),
+                //TurtleCommand::PenDown,
+                TurtleCommand::Circle {
+                    radius: Length(-30.),
+                    angle: Angle(90.),
+                },
                 TurtleCommand::Right(Angle(90.)),
                 TurtleCommand::Forward(Length(50.)),
                 TurtleCommand::Right(Angle(90.)),
@@ -94,6 +111,7 @@ pub struct TurtleState {
     pub start: Vec2,
     pub heading: f32,
     pub index: u64,
+    pub drawing: bool,
 }
 
 impl TurtleCommands {
@@ -105,13 +123,14 @@ impl TurtleCommands {
                 start: Vec2::ZERO,
                 heading: 0f32.to_radians(),
                 index: 0,
+                drawing: true,
             },
         }
     }
 }
 
 impl TurtleCommands {
-    fn get_next(&mut self) -> Option<(Tween<Transform>, TurtleGraphElement)> {
+    fn get_next(&mut self) -> Option<(Option<Tween<Transform>>, Option<TurtleGraphElement>)> {
         let index = self.state.index;
         let next_index = index + 1;
 
@@ -129,9 +148,17 @@ impl TurtleCommands {
                 TurtleCommand::Right(Angle(x)) => {
                     crate::turtle_movement::turtle_turn(&mut self.state, -*x as f32)
                 }
-                TurtleCommand::PenUp => todo!(),
+                TurtleCommand::PenUp => {
-                TurtleCommand::PenDown => todo!(),
+                    self.state.drawing = false;
-                TurtleCommand::Circle => todo!(),
+                    (None, None)
+                }
+                TurtleCommand::PenDown => {
+                    self.state.drawing = true;
+                    (None, None)
+                }
+                TurtleCommand::Circle { radius, angle } => {
+                    crate::turtle_movement::turtle_circle(&mut self.state, radius.0 as f32, *angle)
+                }
                 TurtleCommand::Pause => todo!(),
             };
             self.state.index = next_index;
@@ -148,6 +175,13 @@ pub enum TurtleGraphElement {
         start: Vec2,
         end: Vec2,
     },
+    TurtleCircle {
+        start: Vec2,
+        end: Vec2,
+        center: Vec2,
+        radii: Vec2,
+        angle: Angle,
+    },
     #[default]
     Noop,
 }
@@ -161,10 +195,10 @@ pub struct Colors {
     fill_color: Color,
 }
 
-#[derive(Inspectable, Default)]
+#[derive(Inspectable, Default, Copy, Clone, Debug)]
-pub struct Length(f64);
+pub struct Length(f32);
-#[derive(Inspectable, Default)]
+#[derive(Inspectable, Default, Copy, Clone, Debug)]
-pub struct Angle(f64);
+pub struct Angle(pub f32);
 
 #[derive(Component, Inspectable, Default)]
 pub enum TurtleCommand {
@@ -176,24 +210,20 @@ pub enum TurtleCommand {
     PenDown,
     #[default]
     Pause,
-    Circle,
+    Circle {
+        radius: Length,
+        angle: Angle,
+    },
 }
 
 fn setup(mut commands: Commands) {
     let animator = Animator::new(Tween::new(
-        // Use a quadratic easing on both endpoints.
         EaseFunction::QuadraticInOut,
-        // Loop animation back and forth.
         TweeningType::PingPong,
-        // Animation time (one way only; for ping-pong it takes 2 seconds
-        // to come back to start).
         Duration::from_millis(500),
-        // The lens gives access to the Transform component of the Entity,
+        TransformScaleLens {
-        // for the Animator to animate it. It also contains the start and
+            start: Vec3::new(1., 1., 0.),
-        // end values respectively associated with the progress ratios 0. and 1.
+            end: Vec3::new(1.3, 1.3, 0.),
-        TransformPositionLens {
-            start: Vec3::ZERO,
-            end: Vec3::new(40., 40., 0.),
         },
     ));
     commands.spawn_bundle(Camera2dBundle::default());
@@ -211,82 +241,62 @@ fn setup(mut commands: Commands) {
         .insert(TurtleShape);
 }
 
-struct MyCustomLens {
-    start: Vec2,
-    end: Vec2,
-}
-
-impl Lens<Path> for MyCustomLens {
-    fn lerp(&mut self, target: &mut Path, ratio: f32) {
-        let line = shapes::Line(self.start, self.start + ((self.end - self.start) * ratio));
-        *target = ShapePath::build_as(&line);
-    }
-}
-
-#[derive(Bundle)]
-struct TurtleDrawLine {
-    #[bundle]
-    line: ShapeBundle,
-    name: Name,
-    marker: LineMarker,
-}
-
-#[derive(Component, Default)]
-struct LineMarker;
-
-impl TurtleDrawLine {
-    fn new(start: Vec2, _end: Vec2, index: u64) -> Self {
-        Self {
-            line: GeometryBuilder::build_as(
-                &Line(start, start),
-                DrawMode::Outlined {
-                    fill_mode: FillMode::color(Color::MIDNIGHT_BLUE),
-                    outline_mode: StrokeMode::new(Color::BLACK, 1.0),
-                },
-                Transform::identity(),
-            ),
-            name: Name::new(format!("Line {}", index)),
-            marker: LineMarker,
-        }
-    }
-}
-
 fn draw_lines(
     mut commands: Commands,
     mut tcmd: Query<&mut TurtleCommands>,
     mut turtle: Query<&mut Animator<Transform>, With<TurtleShape>>,
     mut query_event: EventReader<TweenCompleted>, // TODO: howto attach only to the right event?
 ) {
-    for _ev in query_event.iter() {
+    for ev in query_event.iter() {
         let mut tcmd = tcmd.single_mut();
-        if let Some((turtle_animation, graph_element_to_draw)) = tcmd.get_next() {
+        loop {
+            match tcmd.get_next() {
+                Some((Some(turtle_animation), Some(graph_element_to_draw))) => {
                     let mut turtle = turtle.single_mut();
                     turtle.set_tweenable(turtle_animation);
                     match graph_element_to_draw {
                         TurtleGraphElement::TurtleLine { start, end } => {
                             let line_animator = Animator::new(Tween::new(
-                        // Use a quadratic easing on both endpoints.
                                 EaseFunction::QuadraticInOut,
-                        // Loop animation back and forth.
                                 TweeningType::Once,
-                        // Animation time (one way only; for ping-pong it takes 2 seconds
-                        // to come back to start).
                                 Duration::from_millis(500),
-                        // The lens gives access to the Transform component of the Entity,
+                                LineAnimationLens::new(start, end),
-                        // for the Animator to animate it. It also contains the start and
-                        // end values respectively associated with the progress ratios 0. and 1.
-                        MyCustomLens { start, end },
                             ));
                             commands
                                 .spawn_bundle(TurtleDrawLine::new(start, end, tcmd.state.index))
                                 .insert(line_animator);
                         }
                         TurtleGraphElement::Noop => println!("No drawing!"),
+                        TurtleGraphElement::TurtleCircle {
+                            center,
+                            radii,
+                            angle,
+                            start,
+                            end,
+                        } => {
+                            // let circle_animator = todo!();
+                            commands.spawn_bundle(TurtleDrawCircle::new(
+                                center,
+                                radii,
+                                angle,
+                                tcmd.state.index,
+                                start,
+                                end,
+                            ));
+                        }
+                    }
+                    return;
+                }
+                Some((_, _)) => {
+                    println!("without animation");
+                }
+                None => {
+                    println!("nothing to draw");
+                    return;
                 }
-        } else {
-            println!("nothing to draw")
             };
         }
+    }
 }
 
 fn keypresses(
@@ -301,30 +311,40 @@ fn keypresses(
             start: Vec2::ZERO,
             heading: 0.,
             index: 0,
+            drawing: true,
         };
-        if let Some((turtle_animation, graph_element_to_draw)) = tcmd.get_next() {
+        if let Some((Some(turtle_animation), Some(graph_element_to_draw))) = tcmd.get_next() {
             let mut shap = qry.single_mut();
             shap.set_tweenable(turtle_animation);
             match graph_element_to_draw {
                 TurtleGraphElement::TurtleLine { start, end } => {
                     let line_animator = Animator::new(Tween::new(
-                        // Use a quadratic easing on both endpoints.
                         EaseFunction::QuadraticInOut,
-                        // Loop animation back and forth.
                         TweeningType::Once,
-                        // Animation time (one way only; for ping-pong it takes 2 seconds
-                        // to come back to start).
                         Duration::from_millis(500),
-                        // The lens gives access to the Transform component of the Entity,
+                        LineAnimationLens::new(start, end),
-                        // for the Animator to animate it. It also contains the start and
-                        // end values respectively associated with the progress ratios 0. and 1.
-                        MyCustomLens { start, end },
                     ));
                     commands
                         .spawn_bundle(TurtleDrawLine::new(start, end, tcmd.state.index))
                         .insert(line_animator);
                 }
                 TurtleGraphElement::Noop => (),
+                TurtleGraphElement::TurtleCircle {
+                    center,
+                    radii,
+                    angle,
+                    start,
+                    end,
+                } => {
+                    commands.spawn_bundle(TurtleDrawCircle::new(
+                        center,
+                        radii,
+                        angle,
+                        tcmd.state.index,
+                        start,
+                        end,
+                    ));
+                }
             }
         };
     }

src/turtle_movement.rs

@@ -6,40 +6,40 @@ use bevy_tweening::{
     EaseFunction, Tween, TweeningType,
 };
 
-use crate::turtle::{TurtleGraphElement, TurtleState};
+use crate::turtle::{Angle, TurtleGraphElement, TurtleState};
 
 pub fn turtle_turn(
     state: &mut TurtleState,
     angle_to_turn: f32,
-) -> (Tween<Transform>, TurtleGraphElement) {
+) -> (Option<Tween<Transform>>, Option<TurtleGraphElement>) {
     let start = state.heading;
     let end = state.heading + (angle_to_turn * PI / 180.);
     let animation = Tween::new(
-        // Use a quadratic easing on both endpoints.
+        // Use a quadratic easing on both endpoints
         EaseFunction::QuadraticInOut,
-        // Loop animation back and forth.
         TweeningType::Once,
-        // Animation time (one way only; for ping-pong it takes 2 seconds
+        // Animation time
-        // to come back to start).
         Duration::from_millis(500),
-        // The lens gives access to the Transform component of the Entity,
+        // Rotate the turtle
-        // for the Animator to animate it. It also contains the start and
-        // end values respectively associated with the progress ratios 0. and 1.
         TransformRotateZLens { start, end },
     )
     .with_completed_event(state.index as u64);
+    // Dont move and draw
     let line = TurtleGraphElement::Noop;
+    // Update the state
     state.heading = end % (2. * PI);
-    (animation, line)
+    (Some(animation), Some(line))
 }
 
-pub fn turtle_move(state: &mut TurtleState, length: f32) -> (Tween<Transform>, TurtleGraphElement) {
+pub fn turtle_move(
+    state: &mut TurtleState,
+    length: f32,
+) -> (Option<Tween<Transform>>, Option<TurtleGraphElement>) {
     let start = state.start;
     let end = state.start + (Vec2::from_angle(state.heading) * length);
     let turtle_movement_animation = Tween::new(
         // accelerate and decelerate
         EaseFunction::QuadraticInOut,
-        // Loop animation back and forth.
         TweeningType::Once,
         // later to be controlled by speed
         Duration::from_millis(500),
@@ -50,7 +50,51 @@ pub fn turtle_move(state: &mut TurtleState, length: f32) -> (Tween<Transform>, T
         },
     )
     .with_completed_event(state.index as u64);
-    let line = TurtleGraphElement::TurtleLine { start, end };
+    // The line for animating and drawing
+    let line = if state.drawing {
+        TurtleGraphElement::TurtleLine { start, end }
+    } else {
+        TurtleGraphElement::Noop
+    };
     state.start = end;
-    (turtle_movement_animation, line)
+    (Some(turtle_movement_animation), Some(line))
+}
+
+pub fn turtle_circle(
+    state: &mut TurtleState,
+    radius: f32,
+    angle: Angle,
+) -> (Option<Tween<Transform>>, Option<TurtleGraphElement>) {
+    let radius_tuple = Vec2::ONE * radius.abs();
+    dbg!(state.start, radius_tuple);
+    let center = state.start
+        + (Vec2::new(radius, 0.).rotate(Vec2::from_angle((state.heading + 90.).to_radians())));
+    dbg!(center);
+    let turtle_movement_animation = Tween::new(
+        // accelerate and decelerate
+        EaseFunction::QuadraticInOut,
+        TweeningType::Once,
+        // later to be controlled by speed
+        Duration::from_millis(500),
+        // set the start and end of the animation
+        TransformPositionLens {
+            start: center.extend(0.),
+            end: center.extend(0.),
+        },
+    )
+    .with_completed_event(state.index as u64);
+    // The line for animating and drawing
+    let line = if state.drawing {
+        TurtleGraphElement::TurtleCircle {
+            center,
+            radii: radius_tuple,
+            angle,
+            start: state.start,
+            end: state.start + 200.,
+        }
+    } else {
+        TurtleGraphElement::Noop
+    };
+    // TODO update end_position : state.start = end;
+    (Some(turtle_movement_animation), Some(line))
 }