Allow using polylines as a collider shape.

examples2d/polyline2.rs

@@ -0,0 +1,74 @@
+use na::{ComplexField, 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 = 50.0;
+    let nsubdivs = 2000;
+    let step_size = ground_size / (nsubdivs as f32);
+    let mut points = Vec::new();
+
+    points.push(Point2::new(-ground_size / 2.0, 40.0));
+    for i in 1..nsubdivs - 1 {
+        let x = -ground_size / 2.0 + i as f32 * step_size;
+        let y = ComplexField::cos(i as f32 * step_size) * 2.0;
+        points.push(Point2::new(x, y));
+    }
+    points.push(Point2::new(ground_size / 2.0, 40.0));
+
+    let rigid_body = RigidBodyBuilder::new_static().build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::polyline(points, None).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let num = 20;
+    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 {
+            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).build();
+                colliders.insert(collider, handle, &mut bodies);
+            } else {
+                let collider = ColliderBuilder::ball(rad).build();
+                colliders.insert(collider, handle, &mut bodies);
+            }
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point2::new(0.0, 0.0), 10.0);
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Heightfield", init_world)]);
+    testbed.run()
+}