14 files changed, 1005 insertions, 0 deletions

diff --git a/examples2d/Cargo.toml b/examples2d/Cargo.toml
new file mode 100644
index 0000000..7e97948
--- /dev/null
+++ b/examples2d/Cargo.toml
@@ -0,0 +1,27 @@
+[package]
+name    = "nphysics-examples-2d"
+version = "0.1.0"
+authors = [ "Sébastien Crozet <developer@crozet.re>" ]
+edition = "2018"
+
+[features]
+parallel = [ "rapier2d/parallel", "rapier_testbed2d/parallel" ]
+simd-stable = [ "rapier2d/simd-stable" ]
+simd-nightly = [ "rapier2d/simd-nightly" ]
+other-backends = [ "rapier_testbed2d/other-backends" ]
+enhanced-determinism = [ "rapier2d/enhanced-determinism" ]
+
+[dependencies]
+rand       = "0.7"
+Inflector  = "0.11"
+nalgebra = "0.22"
+
+[dependencies.rapier_testbed2d]
+path = "../build/rapier_testbed2d"
+
+[dependencies.rapier2d]
+path = "../build/rapier2d"
+
+[[bin]]
+name = "all_examples2"
+path = "./all_examples2.rs"
\ No newline at end of file
diff --git a/examples2d/all_examples2.rs b/examples2d/all_examples2.rs
new file mode 100644
index 0000000..7b8bf09
--- /dev/null
+++ b/examples2d/all_examples2.rs
@@ -0,0 +1,90 @@
+#![allow(dead_code)]
+
+extern crate nalgebra as na;
+
+#[cfg(target_arch = "wasm32")]
+use wasm_bindgen::prelude::*;
+
+use inflector::Inflector;
+
+use rapier_testbed2d::Testbed;
+use std::cmp::Ordering;
+
+mod balls2;
+mod boxes2;
+mod capsules2;
+mod debug_box_ball2;
+mod heightfield2;
+mod joints2;
+mod kinematic2;
+mod pyramid2;
+mod sensor2;
+mod stress_joint_ball2;
+mod stress_joint_fixed2;
+mod stress_joint_prismatic2;
+
+fn demo_name_from_command_line() -> Option<String> {
+    let mut args = std::env::args();
+
+    while let Some(arg) = args.next() {
+        if &arg[..] == "--example" {
+            return args.next();
+        }
+    }
+
+    None
+}
+
+#[cfg(any(target_arch = "wasm32", target_arch = "asmjs"))]
+fn demo_name_from_url() -> Option<String> {
+    None
+    //    let window = stdweb::web::window();
+    //    let hash = window.location()?.search().ok()?;
+    //    Some(hash[1..].to_string())
+}
+
+#[cfg(not(any(target_arch = "wasm32", target_arch = "asmjs")))]
+fn demo_name_from_url() -> Option<String> {
+    None
+}
+
+#[cfg_attr(target_arch = "wasm32", wasm_bindgen(start))]
+pub fn main() {
+    let demo = demo_name_from_command_line()
+        .or_else(|| demo_name_from_url())
+        .unwrap_or(String::new())
+        .to_camel_case();
+
+    let mut builders: Vec<(_, fn(&mut Testbed))> = vec![
+        ("Balls", balls2::init_world),
+        ("Boxes", boxes2::init_world),
+        ("Capsules", capsules2::init_world),
+        ("Heightfield", heightfield2::init_world),
+        ("Joints", joints2::init_world),
+        ("Kinematic", kinematic2::init_world),
+        ("Pyramid", pyramid2::init_world),
+        ("Sensor", sensor2::init_world),
+        ("(Debug) box ball", debug_box_ball2::init_world),
+        ("(Stress test) joint ball", stress_joint_ball2::init_world),
+        ("(Stress test) joint fixed", stress_joint_fixed2::init_world),
+        (
+            "(Stress test) joint prismatic",
+            stress_joint_prismatic2::init_world,
+        ),
+    ];
+
+    // Lexicographic sort, with stress tests moved at the end of the list.
+    builders.sort_by(|a, b| match (a.0.starts_with("("), b.0.starts_with("(")) {
+        (true, true) | (false, false) => a.0.cmp(b.0),
+        (true, false) => Ordering::Greater,
+        (false, true) => Ordering::Less,
+    });
+
+    let i = builders
+        .iter()
+        .position(|builder| builder.0.to_camel_case().as_str() == demo.as_str())
+        .unwrap_or(0);
+    let testbed = Testbed::from_builders(i, builders);
+
+    testbed.run()
+}
diff --git a/examples2d/balls2.rs b/examples2d/balls2.rs
new file mode 100644
index 0000000..4c85d86
--- /dev/null
+++ b/examples2d/balls2.rs
@@ -0,0 +1,68 @@
+use na::Point2;
+use rapier2d::dynamics::{BodyStatus, JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+    /*
+     * Ground
+     */
+    let _ground_size = 25.0;
+
+    /*
+    let ground_shape = ShapeHandle::new(Cuboid::new(Vector2::new(ground_size, 1.0)));
+
+    let ground_handle = bodies.insert(Ground::new());
+    let co = ColliderDesc::new(ground_shape)
+        .translation(-Vector2::y())
+        .build(BodyPartHandle(ground_handle, 0));
+    colliders.insert(co);
+    */
+
+    /*
+     * Create the balls
+     */
+    let num = 50;
+    let rad = 1.0;
+
+    let shiftx = rad * 2.5;
+    let shifty = rad * 2.0;
+    let centerx = shiftx * (num as f32) / 2.0;
+    let centery = shifty / 2.0;
+
+    for i in 0..num {
+        for j in 0usize..num * 5 {
+            let x = i as f32 * shiftx - centerx;
+            let y = j as f32 * shifty + centery;
+
+            let status = if j == 0 {
+                BodyStatus::Static
+            } else {
+                BodyStatus::Dynamic
+            };
+
+            // Build the rigid body.
+            let rigid_body = RigidBodyBuilder::new(status).translation(x, y).build();
+            let handle = bodies.insert(rigid_body);
+            let collider = ColliderBuilder::ball(rad).density(1.0).build();
+            colliders.insert(collider, handle, &mut bodies);
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(0.0, 2.5), 5.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Balls", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/boxes2.rs b/examples2d/boxes2.rs
new file mode 100644
index 0000000..8b09def
--- /dev/null
+++ b/examples2d/boxes2.rs
@@ -0,0 +1,73 @@
+use na::Point2;
+use rapier2d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = 25.0;
+
+    let rigid_body = RigidBodyBuilder::new_static().build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, 1.2).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    let rigid_body = RigidBodyBuilder::new_static()
+        .rotation(std::f32::consts::FRAC_PI_2)
+        .translation(ground_size, ground_size * 2.0)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size * 2.0, 1.2).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    let rigid_body = RigidBodyBuilder::new_static()
+        .rotation(std::f32::consts::FRAC_PI_2)
+        .translation(-ground_size, ground_size * 2.0)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size * 2.0, 1.2).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let num = 26;
+    let rad = 0.5;
+
+    let shift = rad * 2.0;
+    let centerx = shift * (num as f32) / 2.0;
+    let centery = shift / 2.0;
+
+    for i in 0..num {
+        for j in 0usize..num * 5 {
+            let x = i as f32 * shift - centerx;
+            let y = j as f32 * shift + centery + 2.0;
+
+            // Build the rigid body.
+            let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
+            let handle = bodies.insert(rigid_body);
+            let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+            colliders.insert(collider, handle, &mut bodies);
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(0.0, 50.0), 10.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Balls", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/capsules2.rs b/examples2d/capsules2.rs
new file mode 100644
index 0000000..041edf5
--- /dev/null
+++ b/examples2d/capsules2.rs
@@ -0,0 +1,76 @@
+use na::Point2;
+use rapier2d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = 25.0;
+
+    let rigid_body = RigidBodyBuilder::new_static().build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, 1.2).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    let rigid_body = RigidBodyBuilder::new_static()
+        .rotation(std::f32::consts::FRAC_PI_2)
+        .translation(ground_size, ground_size * 4.0)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size * 4.0, 1.2).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    let rigid_body = RigidBodyBuilder::new_static()
+        .rotation(std::f32::consts::FRAC_PI_2)
+        .translation(-ground_size, ground_size * 4.0)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size * 4.0, 1.2).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let num = 26;
+    let rad = 0.5;
+
+    let shift = rad * 2.0;
+    let shifty = rad * 5.0;
+    let centerx = shift * (num as f32) / 2.0;
+    let centery = shift / 2.0;
+
+    for i in 0..num {
+        for j in 0usize..num * 5 {
+            let x = i as f32 * shift - centerx;
+            let y = j as f32 * shifty + centery + 3.0;
+
+            // Build the rigid body.
+            let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
+            let handle = bodies.insert(rigid_body);
+            let collider = ColliderBuilder::capsule_y(rad * 1.5, rad)
+                .density(1.0)
+                .build();
+            colliders.insert(collider, handle, &mut bodies);
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(0.0, 50.0), 10.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Balls", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/debug_box_ball2.rs b/examples2d/debug_box_ball2.rs
new file mode 100644
index 0000000..2cc5e45
--- /dev/null
+++ b/examples2d/debug_box_ball2.rs
@@ -0,0 +1,44 @@
+use rapier2d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let rad = 1.0;
+    let rigid_body = RigidBodyBuilder::new_static()
+        .translation(0.0, -rad)
+        .rotation(std::f32::consts::PI / 4.0)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(rad, rad).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    // Build the dynamic box rigid body.
+    let rigid_body = RigidBodyBuilder::new_dynamic()
+        .translation(0.0, 3.0 * rad)
+        .can_sleep(false)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::ball(rad).density(1.0).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    //    testbed.look_at(Point2::new(10.0, 10.0, 10.0), Point2::origin());
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Boxes", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/heightfield2.rs b/examples2d/heightfield2.rs
new file mode 100644
index 0000000..b03afe3
--- /dev/null
+++ b/examples2d/heightfield2.rs
@@ -0,0 +1,72 @@
+use na::{DVector, Point2, Vector2};
+use rapier2d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = Vector2::new(50.0, 1.0);
+    let nsubdivs = 2000;
+
+    let heights = DVector::from_fn(nsubdivs + 1, |i, _| {
+        if i == 0 || i == nsubdivs {
+            80.0
+        } else {
+            (i as f32 * ground_size.x / (nsubdivs as f32)).cos() * 2.0
+        }
+    });
+
+    let rigid_body = RigidBodyBuilder::new_static().build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::heightfield(heights, ground_size).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let num = 26;
+    let rad = 0.5;
+
+    let shift = rad * 2.0;
+    let centerx = shift * (num / 2) as f32;
+    let centery = shift / 2.0;
+
+    for i in 0..num {
+        for j in 0usize..num * 5 {
+            let x = i as f32 * shift - centerx;
+            let y = j as f32 * shift + centery + 3.0;
+
+            // Build the rigid body.
+            let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
+            let handle = bodies.insert(rigid_body);
+
+            if j % 2 == 0 {
+                let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+                colliders.insert(collider, handle, &mut bodies);
+            } else {
+                let collider = ColliderBuilder::ball(rad).density(1.0).build();
+                colliders.insert(collider, handle, &mut bodies);
+            }
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(0.0, 50.0), 10.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Heightfield", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/joints2.rs b/examples2d/joints2.rs
new file mode 100644
index 0000000..c3df921
--- /dev/null
+++ b/examples2d/joints2.rs
@@ -0,0 +1,75 @@
+use na::Point2;
+use rapier2d::dynamics::{BallJoint, BodyStatus, JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let mut joints = JointSet::new();
+
+    /*
+     * Create the balls
+     */
+    // Build the rigid body.
+    // NOTE: a smaller radius (e.g. 0.1) breaks Box2D so
+    // in order to be able to compare rapier with Box2D,
+    // we set it to 0.4.
+    let rad = 0.4;
+    let numi = 100; // Num vertical nodes.
+    let numk = 100; // Num horizontal nodes.
+    let shift = 1.0;
+
+    let mut body_handles = Vec::new();
+
+    for k in 0..numk {
+        for i in 0..numi {
+            let fk = k as f32;
+            let fi = i as f32;
+
+            let status = if i == 0 && (k % 4 == 0 || k == numk - 1) {
+                BodyStatus::Static
+            } else {
+                BodyStatus::Dynamic
+            };
+
+            let rigid_body = RigidBodyBuilder::new(status)
+                .translation(fk * shift, -fi * shift)
+                .build();
+            let child_handle = bodies.insert(rigid_body);
+            let collider = ColliderBuilder::ball(rad).density(1.0).build();
+            colliders.insert(collider, child_handle, &mut bodies);
+
+            // Vertical joint.
+            if i > 0 {
+                let parent_handle = *body_handles.last().unwrap();
+                let joint = BallJoint::new(Point2::origin(), Point2::new(0.0, shift));
+                joints.insert(&mut bodies, parent_handle, child_handle, joint);
+            }
+
+            // Horizontal joint.
+            if k > 0 {
+                let parent_index = body_handles.len() - numi;
+                let parent_handle = body_handles[parent_index];
+                let joint = BallJoint::new(Point2::origin(), Point2::new(-shift, 0.0));
+                joints.insert(&mut bodies, parent_handle, child_handle, joint);
+            }
+
+            body_handles.push(child_handle);
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(numk as f32 * rad, numi as f32 * -rad), 5.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Joints", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/kinematic2.rs b/examples2d/kinematic2.rs
new file mode 100644
index 0000000..d979cd0
--- /dev/null
+++ b/examples2d/kinematic2.rs
@@ -0,0 +1,93 @@
+use na::Point2;
+use rapier2d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground.
+     */
+    let ground_size = 10.0;
+    let ground_height = 0.1;
+
+    let rigid_body = RigidBodyBuilder::new_static()
+        .translation(0.0, -ground_height)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, ground_height).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the boxes
+     */
+    let num = 6;
+    let rad = 0.2;
+
+    let shift = rad * 2.0;
+    let centerx = shift * num as f32 / 2.0;
+    let centery = shift / 2.0 + 3.04;
+
+    for i in 0usize..num {
+        for j in 0usize..num * 50 {
+            let x = i as f32 * shift - centerx;
+            let y = j as f32 * shift + centery;
+
+            // Build the rigid body.
+            let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
+            let handle = bodies.insert(rigid_body);
+            let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+            colliders.insert(collider, handle, &mut bodies);
+        }
+    }
+
+    /*
+     * Setup a kinematic rigid body.
+     */
+    let platform_body = RigidBodyBuilder::new_kinematic()
+        .translation(-10.0 * rad, 1.5 + 0.8)
+        .build();
+    let platform_handle = bodies.insert(platform_body);
+    let collider = ColliderBuilder::cuboid(rad * 10.0, rad)
+        .density(1.0)
+        .build();
+    colliders.insert(collider, platform_handle, &mut bodies);
+
+    /*
+     * Setup a callback to control the platform.
+     */
+    testbed.add_callback(move |bodies, _, _, _, time| {
+        let mut platform = bodies.get_mut(platform_handle).unwrap();
+        let mut next_pos = platform.position;
+
+        let dt = 0.016;
+        next_pos.translation.vector.y += (time * 5.0).sin() * dt;
+        next_pos.translation.vector.x += time.sin() * 5.0 * dt;
+
+        if next_pos.translation.vector.x >= rad * 10.0 {
+            next_pos.translation.vector.x -= dt;
+        }
+        if next_pos.translation.vector.x <= -rad * 10.0 {
+            next_pos.translation.vector.x += dt;
+        }
+
+        platform.set_next_kinematic_position(next_pos);
+    });
+
+    /*
+     * Run the simulation.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(0.0, 1.0), 40.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Kinematic body", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/pyramid2.rs b/examples2d/pyramid2.rs
new file mode 100644
index 0000000..4d6fe07
--- /dev/null
+++ b/examples2d/pyramid2.rs
@@ -0,0 +1,60 @@
+use na::Point2;
+use rapier2d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = 100.0;
+    let ground_thickness = 1.0;
+
+    let rigid_body = RigidBodyBuilder::new_static().build();
+    let ground_handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, ground_thickness).build();
+    colliders.insert(collider, ground_handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let num = 100;
+    let rad = 0.5;
+
+    let shift = rad * 2.0;
+    let centerx = shift * (num as f32) / 2.0;
+    let centery = shift / 2.0 + ground_thickness + rad * 1.5;
+
+    for i in 0usize..num {
+        for j in i..num {
+            let fj = j as f32;
+            let fi = i as f32;
+            let x = (fi * shift / 2.0) + (fj - fi) * shift - centerx;
+            let y = fi * shift + centery;
+
+            // Build the rigid body.
+            let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
+            let handle = bodies.insert(rigid_body);
+            let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+            colliders.insert(collider, handle, &mut bodies);
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(0.0, 2.5), 5.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Balls", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/sensor2.rs b/examples2d/sensor2.rs
new file mode 100644
index 0000000..75634a8
--- /dev/null
+++ b/examples2d/sensor2.rs
@@ -0,0 +1,101 @@
+use na::{Point2, Point3};
+use rapier2d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet, Proximity};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground.
+     */
+    let ground_size = 200.1;
+    let ground_height = 0.1;
+
+    let rigid_body = RigidBodyBuilder::new_static()
+        .translation(0.0, -ground_height)
+        .build();
+    let ground_handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, ground_height).build();
+    colliders.insert(collider, ground_handle, &mut bodies);
+
+    /*
+     * Create some boxes.
+     */
+    let num = 10;
+    let rad = 0.2;
+
+    let shift = rad * 2.0;
+    let centerx = shift * num as f32 / 2.0;
+
+    for i in 0usize..num {
+        let x = i as f32 * shift - centerx;
+        let y = 3.0;
+
+        // Build the rigid body.
+        let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
+        let handle = bodies.insert(rigid_body);
+        let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+        colliders.insert(collider, handle, &mut bodies);
+
+        testbed.set_body_color(handle, Point3::new(0.5, 0.5, 1.0));
+    }
+
+    /*
+     * Create a cube that will have a ball-shaped sensor attached.
+     */
+
+    // Rigid body so that the sensor can move.
+    let sensor = RigidBodyBuilder::new_dynamic()
+        .translation(0.0, 10.0)
+        .build();
+    let sensor_handle = bodies.insert(sensor);
+
+    // Solid cube attached to the sensor which
+    // other colliders can touch.
+    let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+    colliders.insert(collider, sensor_handle, &mut bodies);
+
+    // We create a collider desc without density because we don't
+    // want it to contribute to the rigid body mass.
+    let sensor_collider = ColliderBuilder::ball(rad * 5.0).sensor(true).build();
+    colliders.insert(sensor_collider, sensor_handle, &mut bodies);
+
+    testbed.set_body_color(sensor_handle, Point3::new(0.5, 1.0, 1.0));
+
+    // Callback that will be executed on the main loop to handle proximities.
+    testbed.add_callback(move |_, colliders, events, graphics, _| {
+        while let Ok(prox) = events.proximity_events.try_recv() {
+            let color = match prox.new_status {
+                Proximity::WithinMargin | Proximity::Intersecting => Point3::new(1.0, 1.0, 0.0),
+                Proximity::Disjoint => Point3::new(0.5, 0.5, 1.0),
+            };
+
+            let parent_handle1 = colliders.get(prox.collider1).unwrap().parent();
+            let parent_handle2 = colliders.get(prox.collider2).unwrap().parent();
+
+            if parent_handle1 != ground_handle && parent_handle1 != sensor_handle {
+                graphics.set_body_color(parent_handle1, color);
+            }
+            if parent_handle2 != ground_handle && parent_handle2 != sensor_handle {
+                graphics.set_body_color(parent_handle2, color);
+            }
+        }
+    });
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(0.0, 1.0), 100.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Sensor", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/stress_joint_ball2.rs b/examples2d/stress_joint_ball2.rs
new file mode 100644
index 0000000..55db1b7
--- /dev/null
+++ b/examples2d/stress_joint_ball2.rs
@@ -0,0 +1,72 @@
+use na::Point2;
+use rapier2d::dynamics::{BallJoint, BodyStatus, JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let mut joints = JointSet::new();
+
+    /*
+     * Create the balls
+     */
+    // Build the rigid body.
+    let rad = 0.4;
+    let numi = 100; // Num vertical nodes.
+    let numk = 100; // Num horizontal nodes.
+    let shift = 1.0;
+
+    let mut body_handles = Vec::new();
+
+    for k in 0..numk {
+        for i in 0..numi {
+            let fk = k as f32;
+            let fi = i as f32;
+
+            let status = if k >= numk / 2 - 3 && k <= numk / 2 + 3 && i == 0 {
+                BodyStatus::Static
+            } else {
+                BodyStatus::Dynamic
+            };
+
+            let rigid_body = RigidBodyBuilder::new(status)
+                .translation(fk * shift, -fi * shift)
+                .build();
+            let child_handle = bodies.insert(rigid_body);
+            let collider = ColliderBuilder::ball(rad).density(1.0).build();
+            colliders.insert(collider, child_handle, &mut bodies);
+
+            // Vertical joint.
+            if i > 0 {
+                let parent_handle = *body_handles.last().unwrap();
+                let joint = BallJoint::new(Point2::origin(), Point2::new(0.0, shift));
+                joints.insert(&mut bodies, parent_handle, child_handle, joint);
+            }
+
+            // Horizontal joint.
+            if k > 0 {
+                let parent_index = body_handles.len() - numi;
+                let parent_handle = body_handles[parent_index];
+                let joint = BallJoint::new(Point2::origin(), Point2::new(-shift, 0.0));
+                joints.insert(&mut bodies, parent_handle, child_handle, joint);
+            }
+
+            body_handles.push(child_handle);
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(numk as f32 * rad, numi as f32 * -rad), 5.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Joints", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/stress_joint_fixed2.rs b/examples2d/stress_joint_fixed2.rs
new file mode 100644
index 0000000..31b3e4f
--- /dev/null
+++ b/examples2d/stress_joint_fixed2.rs
@@ -0,0 +1,85 @@
+use na::{Isometry2, Point2};
+use rapier2d::dynamics::{BodyStatus, FixedJoint, JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed2d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let mut joints = JointSet::new();
+
+    /*
+     * Create the balls
+     */
+    // Build the rigid body.
+    let rad = 0.4;
+    let num = 30; // Num vertical nodes.
+    let shift = 1.0;
+
+    let mut body_handles = Vec::new();
+
+    for xx in 0..4 {
+        let x = xx as f32 * shift * (num as f32 + 2.0);
+
+        for yy in 0..4 {
+            let y = yy as f32 * shift * (num as f32 + 4.0);
+
+            for k in 0..num {
+                for i in 0..num {
+                    let fk = k as f32;
+                    let fi = i as f32;
+
+                    let status = if k == 0 {
+                        BodyStatus::Static
+                    } else {
+                        BodyStatus::Dynamic
+                    };
+
+                    let rigid_body = RigidBodyBuilder::new(status)
+                        .translation(x + fk * shift, y - fi * shift)
+                        .build();
+                    let child_handle = bodies.insert(rigid_body);
+                    let collider = ColliderBuilder::ball(rad).density(1.0).build();
+                    colliders.insert(collider, child_handle, &mut bodies);
+
+                    // Vertical joint.
+                    if i > 0 {
+                        let parent_handle = *body_handles.last().unwrap();
+                        let joint = FixedJoint::new(
+                            Isometry2::identity(),
+                            Isometry2::translation(0.0, shift),
+                        );
+                        joints.insert(&mut bodies, parent_handle, child_handle, joint);
+                    }
+
+                    // Horizontal joint.
+                    if k > 0 {
+                        let parent_index = body_handles.len() - num;
+                        let parent_handle = body_handles[parent_index];
+                        let joint = FixedJoint::new(
+                            Isometry2::identity(),
+                            Isometry2::translation(-shift, 0.0),
+                        );
+                        joints.insert(&mut bodies, parent_handle, child_handle, joint);
+                    }
+
+                    body_handles.push(child_handle);
+                }
+            }
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(50.0, 50.0), 5.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Joints", init_world)]);
+    testbed.run()
+}
diff --git a/examples2d/stress_joint_prismatic2.rs b/examples2d/stress_joint_prismatic2.rs
new file mode 100644
index 0000000..91ef48e
--- /dev/null
+++ b/examples2d/stress_joint_prismatic2.rs
@@ -0,0 +1,69 @@
+use na::{Point2, Unit, Vector2};
+use rapier2d::dynamics::{JointSet, PrismaticJoint, RigidBodyBuilder, RigidBodySet};
+use rapier2d::geometry::{ColliderBuild