rapier engine testing (don't like)

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

@@ -1,9 +1,17 @@
 mod drawable;
+mod engine;
 mod particle;
 
 use drawable::DrawShape;
+use engine::{PhysicsEngine, PhysicsState};
+
+use nalgebra::vector;
 use nannou::prelude::*;
 use particle::Particle;
+use rapier2d::{
+    dynamics::{RigidBodyBuilder, RigidBodyHandle},
+    geometry::ColliderBuilder,
+};
 
 const PARTICLE_COUNT: u32 = 200;
 const PARTICLE_SIZE: f32 = 10.0;
@@ -12,6 +20,8 @@ struct Model {
     // Store the window ID so we can refer to this specific window later if needed.
     _window: WindowId,
     particles: Vec<Particle>,
+    engine: PhysicsEngine,
+    handles: Vec<RigidBodyHandle>,
 }
 
 fn fill_particles(app: &App, particles: &mut Vec<Particle>) {
@@ -42,11 +52,45 @@ fn model(app: &App) -> Model {
         .build()
         .unwrap();
 
+    let mut engine = PhysicsEngine {
+        state: PhysicsState {
+            gravity: vector![0.0, -9.81 * 10.0],
+            ..Default::default()
+        },
+        ..Default::default()
+    };
+
+    let mut handles = Vec::new();
+
+    /* Create the ground. */
+    let collider = ColliderBuilder::cuboid(100.0, 0.1)
+        .translation(vector![0.0, -200.0])
+        .build();
+    engine.state.colliders.insert(collider);
+
+    /* Create the bouncing ball. */
+    let rigid_body = RigidBodyBuilder::dynamic()
+        .translation(vector![0.0, 10.0])
+        .build();
+    let collider = ColliderBuilder::ball(10.0).restitution(0.7).build();
+    let ball_body_handle = engine.state.bodies.insert(rigid_body);
+    engine
+        .state
+        .colliders
+        .insert_with_parent(collider, ball_body_handle, &mut engine.state.bodies);
+
+    handles.push(ball_body_handle);
+
     let mut particles = Vec::new();
 
     fill_particles(app, &mut particles);
 
-    Model { _window, particles }
+    Model {
+        _window,
+        particles,
+        engine,
+        handles,
+    }
 }
 
 // Handle events related to the window and update the model if necessary
@@ -66,10 +110,12 @@ fn event(app: &App, model: &mut Model, event: WindowEvent) {
 
 // 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.particles.iter_mut().for_each(|particle| {
-        let offset = (_app.time + particle.time_offset).sin() * 100.0;
-        particle.pos.x = particle.start_pos.x + offset
-    });
+    // _model.particles.iter_mut().for_each(|particle| {
+    //     let offset = (_app.time + particle.time_offset).sin() * 100.0;
+    //     particle.pos.x = particle.start_pos.x + offset
+    // });
+
+    _model.engine.step();
 }
 
 // Draw the state of your `Model` into the given `Frame` here.
@@ -77,7 +123,17 @@ fn view(app: &App, model: &Model, frame: Frame) {
     let canvas = app.draw();
     canvas.background().color(CORNFLOWERBLUE);
 
-    canvas.draw(&model.particles);
+    // canvas.draw(&model.particles);
+    model
+        .handles
+        .iter()
+        .map(|handle| model.engine.state.bodies.get(*handle).unwrap())
+        .for_each(|body| {
+            canvas
+                .ellipse()
+                .radius(10.0)
+                .xy(std::convert::Into::<Vec2>::into(*body.translation()));
+        });
 
     // I don't think there is even a fail condition in this function, but it returns a result?
     canvas.to_frame(app, &frame).unwrap();