better window bounding boxes

I also switch to using generalized Rect instead of an app for places where i was using the window boundary

Cargo.toml

@@ -6,12 +6,9 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-bevy = { version = "0.12.1" }
-bevy_dylib = "0.12.1"
-bevy_rapier2d = "*"
-
-[profile.dev]
-opt-level = 1
+nalgebra = { version = "0.32.3", features = ["glam017"] }
+nannou = "0.19.0"
+rapier2d = "0.18.0"
 
 [profile.dev.package."*"]
 opt-level = 3

rust-toolchain.toml

@@ -1,2 +0,0 @@
-[toolchain]
-channel = "nightly"

src/drawable.rs

@@ -0,0 +1,56 @@
+use nannou::prelude::*;
+use rapier2d::geometry::{Collider, ColliderSet, TypedShape};
+
+pub(crate) trait Drawable {
+    fn draw(&self, draw: &Draw);
+}
+
+impl<T> Drawable for Vec<T>
+where
+    T: Drawable,
+{
+    fn draw(&self, draw: &Draw) {
+        self.iter().for_each(|s| s.draw(draw))
+    }
+}
+
+impl Drawable for Collider {
+    fn draw(&self, draw: &Draw) {
+        match self.shape().as_typed_shape() {
+            TypedShape::Ball(ball) => {
+                draw.ellipse()
+                    .radius(ball.radius)
+                    .xy((*self.translation()).into());
+            }
+            TypedShape::Cuboid(cube) => {
+                draw.rect()
+                    .w(cube.half_extents.x * 2.0)
+                    .h(cube.half_extents.y * 2.0)
+                    .xy((*self.translation()).into());
+            }
+            _ => eprintln!("Attempted to draw a shape with no draw impl"),
+        }
+    }
+}
+
+impl Drawable for ColliderSet {
+    fn draw(&self, draw: &Draw) {
+        self.iter().for_each(|(_, collider)| draw.draw(collider))
+    }
+}
+
+pub(crate) trait DrawShape<T>
+where
+    T: Drawable,
+{
+    fn draw(&self, drawable: &T);
+}
+
+impl<T> DrawShape<T> for Draw
+where
+    T: Drawable,
+{
+    fn draw(&self, drawable: &T) {
+        drawable.draw(self);
+    }
+}

src/engine.rs

@@ -0,0 +1,50 @@
+use rapier2d::{
+    dynamics::{
+        CCDSolver, ImpulseJointSet, IntegrationParameters, IslandManager, MultibodyJointSet,
+        RigidBodySet,
+    },
+    geometry::{BroadPhase, ColliderSet, NarrowPhase},
+    math::Vector,
+    pipeline::{PhysicsPipeline, QueryPipeline},
+};
+
+#[derive(Default)]
+pub struct PhysicsEngine {
+    pub state: PhysicsState,
+    pub pipeline: PhysicsPipeline,
+}
+
+#[derive(Default)]
+pub struct PhysicsState {
+    pub islands: IslandManager,
+    pub broad_phase: BroadPhase,
+    pub narrow_phase: NarrowPhase,
+    pub bodies: RigidBodySet,
+    pub colliders: ColliderSet,
+    pub joints: ImpulseJointSet,
+    pub multibody_joints: MultibodyJointSet,
+    pub ccd_solver: CCDSolver,
+    pub query_pipeline: QueryPipeline,
+    pub integration_parameters: IntegrationParameters,
+    pub gravity: Vector<f32>,
+}
+
+impl PhysicsEngine {
+    pub fn step(&mut self) {
+        self.pipeline.step(
+            &self.state.gravity,
+            &self.state.integration_parameters,
+            &mut self.state.islands,
+            &mut self.state.broad_phase,
+            &mut self.state.narrow_phase,
+            &mut self.state.bodies,
+            &mut self.state.colliders,
+            &mut self.state.joints,
+            &mut self.state.multibody_joints,
+            &mut self.state.ccd_solver,
+            Some(&mut self.state.query_pipeline),
+            &(),
+            &(),
+        )
+    }
+}

src/main.rs

@@ -1,44 +1,168 @@
-use bevy::prelude::*;
-use bevy_rapier2d::prelude::*;
+mod drawable;
+mod engine;
 
-fn main() {
-    App::new()
-        .add_plugins(DefaultPlugins)
-        .add_plugins(RapierPhysicsPlugin::<NoUserData>::pixels_per_meter(100.0))
-        .add_plugins(RapierDebugRenderPlugin::default())
-        .add_systems(Startup, setup_graphics)
-        .add_systems(Startup, setup_physics)
-        .add_systems(Update, print_ball_altitude)
-        .run();
+use drawable::DrawShape;
+use engine::{PhysicsEngine, PhysicsState};
+
+use nalgebra::vector;
+use nannou::prelude::*;
+use rapier2d::{
+    dynamics::{RigidBodyBuilder, RigidBodyHandle, RigidBodySet},
+    geometry::{ColliderBuilder, ColliderSet},
+};
+
+const WINDOW_WIDTH: u32 = 512;
+const WINDOW_HEIGHT: u32 = WINDOW_WIDTH;
+const PARTICLE_COUNT: u32 = 200;
+const PARTICLE_SIZE: f32 = 5.;
+
+struct Model {
+    // Store the window ID so we can refer to this specific window later if needed.
+    window: WindowId,
+    // particles: Vec<Particle>,
+    engine: PhysicsEngine,
 }
 
-fn setup_graphics(mut commands: Commands) {
-    // Add a camera so we can see the debug-render.
-    commands.spawn(Camera2dBundle::default());
+fn random_vec_in_rect(boundary: &Rect) -> nalgebra::Vector2<f32> {
+    let x = random_range(-100., 100.);
+    let y = random_range(-150., boundary.top());
+
+    vector![x, y]
 }
 
-fn setup_physics(mut commands: Commands) {
-    /* Create the ground. */
-    commands
-        .spawn(Collider::cuboid(500.0, 50.0))
-        .insert(TransformBundle::from(Transform::from_xyz(0.0, -100.0, 0.0)));
+fn fill_particles(boundary: &Rect, colliders: &mut ColliderSet, bodies: &mut RigidBodySet) {
+    // Keeping track of already placed balls to avoid overlap
+    // Need to look into a way to do this with rapier directly
+    let mut positions: Vec<nalgebra::Vector2<f32>> = Vec::new();
 
-    /* Create the bouncing ball. */
-    commands
-        .spawn(RigidBody::Dynamic)
-        .insert(Collider::ball(10.0))
-        .insert(Restitution::coefficient(2.0))
-        .insert(TransformBundle::from(Transform::from_xyz(0.0, 400.0, 0.0)));
+    for _ in 0..PARTICLE_COUNT {
+        let mut xy = random_vec_in_rect(boundary);
+        while !positions
+            .iter()
+            .all(|pos| pos.metric_distance(&xy) > PARTICLE_SIZE * 2.)
+        {
+            xy = random_vec_in_rect(boundary)
+        }
+        positions.push(xy);
 
-    commands
-        .spawn(RigidBody::Dynamic)
-        .insert(Collider::ball(10.0))
-        .insert(Restitution::coefficient(2.0))
-        .insert(TransformBundle::from(Transform::from_xyz(0.0, 600.0, 0.0)));
-}
-
-fn print_ball_altitude(positions: Query<&Transform, With<RigidBody>>) {
-    for transform in positions.iter() {
-        println!("Ball altitude: {}", transform.translation.y);
+        /* Create the bouncing ball. */
+        let rigid_body = RigidBodyBuilder::dynamic().translation(xy).build();
+        let collider = ColliderBuilder::ball(PARTICLE_SIZE)
+            .restitution(0.1)
+            .build();
+        let ball_body_handle = bodies.insert(rigid_body);
+        colliders.insert_with_parent(collider, ball_body_handle, bodies);
     }
 }
+
+fn model(app: &App) -> Model {
+    // One thing that tripped me up when begginning nannou was realizing
+    // that view and event methods are per window, and update functions are
+    // per app
+
+    // Create a new window! Store the ID so we can refer to it later.
+    let window = app
+        .new_window()
+        .size(WINDOW_WIDTH, WINDOW_HEIGHT)
+        .title("nannou")
+        .view(view) // The function that will be called for presenting graphics to a frame.
+        .event(event) // The function that will be called when the window receives events.
+        .build()
+        .unwrap();
+
+    let mut engine = PhysicsEngine {
+        state: PhysicsState {
+            gravity: vector![0., -9.81 * 10.],
+            ..Default::default()
+        },
+        ..Default::default()
+    };
+
+    let boundary = app.window(window).unwrap().rect();
+
+    /* Create the ground. */
+    let collider = ColliderBuilder::cuboid(boundary.w(), 4.)
+        .translation(vector![0., boundary.bottom()])
+        .build();
+    engine.state.colliders.insert(collider);
+
+    /* Create the walls. */
+    let collider = ColliderBuilder::cuboid(4., boundary.h())
+        .translation(vector![boundary.left(), 0.])
+        .build();
+    engine.state.colliders.insert(collider);
+    let collider = ColliderBuilder::cuboid(4., boundary.h())
+        .translation(vector![boundary.right(), 0.])
+        .build();
+    engine.state.colliders.insert(collider);
+
+    /* Create the ceiling. */
+    let collider = ColliderBuilder::cuboid(boundary.w(), 4.)
+        .translation(vector![0., boundary.top()])
+        .build();
+    engine.state.colliders.insert(collider);
+
+    fill_particles(
+        &boundary,
+        &mut engine.state.colliders,
+        &mut engine.state.bodies,
+    );
+
+    Model { window, engine }
+}
+
+// Handle events related to the window and update the model if necessary
+fn event(app: &App, model: &mut Model, event: WindowEvent) {
+    if let KeyReleased(Key::Escape) = event {
+        app.quit()
+    }
+
+    if let Resized(_) = event {
+        // Rust borrowing rules means I need to first gather a list of handles,
+        // then delete them all
+        let handles: Vec<RigidBodyHandle> = model
+            .engine
+            .state
+            .bodies
+            .iter()
+            .map(|(handle, _)| handle)
+            .collect();
+
+        for handle in handles {
+            model.engine.state.bodies.remove(
+                handle,
+                &mut model.engine.state.islands,
+                &mut model.engine.state.colliders,
+                &mut model.engine.state.joints,
+                &mut model.engine.state.multibody_joints,
+                true,
+            );
+        }
+
+        fill_particles(
+            &app.window(model.window).unwrap().rect(),
+            &mut model.engine.state.colliders,
+            &mut model.engine.state.bodies,
+        );
+    }
+}
+
+// Update the state of your application here. By default, this gets called right before `view`.
+fn update(_app: &App, model: &mut Model, _update: Update) {
+    model.engine.step();
+}
+
+// Draw the state of your `Model` into the given `Frame` here.
+fn view(app: &App, model: &Model, frame: Frame) {
+    let canvas = app.draw();
+    canvas.background().color(CORNFLOWERBLUE);
+
+    canvas.draw(&model.engine.state.colliders);
+
+    // I don't think there is even a fail condition in this function, but it returns a result?
+    canvas.to_frame(app, &frame).unwrap();
+}
+
+fn main() {
+    nannou::app(model).update(update).run();
+}