Replace the Rounded<S> type by a non-generic RoundCylinder type.

src/geometry/collider.rs

@@ -4,7 +4,7 @@ use crate::geometry::{
     Segment, Shape, ShapeType, Triangle, Trimesh,
 };
 #[cfg(feature = "dim3")]
-use crate::geometry::{Cone, Cylinder, Rounded};
+use crate::geometry::{Cone, Cylinder, RoundCylinder};
 use crate::math::{AngVector, Isometry, Point, Rotation, Vector};
 use na::Point3;
 use ncollide::bounding_volume::AABB;
@@ -39,10 +39,11 @@ impl ColliderShape {
     /// (along along the y axis), its radius, and its roundedness (the
     /// radius of the sphere used for dilating the cylinder).
     #[cfg(feature = "dim3")]
-    pub fn round_cylinder(half_height: f32, radius: f32, round_radius: f32) -> Self {
-        ColliderShape(Arc::new(Rounded::new(
-            Cylinder::new(half_height, radius),
-            round_radius,
+    pub fn round_cylinder(half_height: f32, radius: f32, border_radius: f32) -> Self {
+        ColliderShape(Arc::new(RoundCylinder::new(
+            half_height,
+            radius,
+            border_radius,
         )))
     }
 
@@ -170,7 +171,7 @@ impl<'de> serde::Deserialize<'de> for ColliderShape {
                     #[cfg(feature = "dim3")]
                     Some(ShapeType::Cone) => deser::<A, Cone>(&mut seq)?,
                     #[cfg(feature = "dim3")]
-                    Some(ShapeType::RoundCylinder) => deser::<A, Rounded<Cylinder>>(&mut seq)?,
+                    Some(ShapeType::RoundCylinder) => deser::<A, RoundCylinder>(&mut seq)?,
                     None => {
                         return Err(serde::de::Error::custom(
                             "found invalid shape type to deserialize",
@@ -332,11 +333,11 @@ impl ColliderBuilder {
     /// (along along the y axis), its radius, and its roundedness (the
     /// radius of the sphere used for dilating the cylinder).
     #[cfg(feature = "dim3")]
-    pub fn round_cylinder(half_height: f32, radius: f32, round_radius: f32) -> Self {
+    pub fn round_cylinder(half_height: f32, radius: f32, border_radius: f32) -> Self {
         Self::new(ColliderShape::round_cylinder(
             half_height,
             radius,
-            round_radius,
+            border_radius,
         ))
     }
 

src/geometry/contact_generator/pfm_pfm_contact_generator.rs

@@ -24,11 +24,11 @@ impl Default for PfmPfmContactManifoldGeneratorWorkspace {
 }
 
 pub fn generate_contacts_pfm_pfm(ctxt: &mut PrimitiveContactGenerationContext) {
-    if let (Some((pfm1, round_radius1)), Some((pfm2, round_radius2))) = (
+    if let (Some((pfm1, border_radius1)), Some((pfm2, border_radius2))) = (
         ctxt.shape1.as_polygonal_feature_map(),
         ctxt.shape2.as_polygonal_feature_map(),
     ) {
-        do_generate_contacts(pfm1, round_radius1, pfm2, round_radius2, ctxt);
+        do_generate_contacts(pfm1, border_radius1, pfm2, border_radius2, ctxt);
         ctxt.manifold.update_warmstart_multiplier();
         ctxt.manifold.sort_contacts(ctxt.prediction_distance);
     }
@@ -36,9 +36,9 @@ pub fn generate_contacts_pfm_pfm(ctxt: &mut PrimitiveContactGenerationContext) {
 
 fn do_generate_contacts(
     pfm1: &dyn PolygonalFeatureMap,
-    round_radius1: f32,
+    border_radius1: f32,
     pfm2: &dyn PolygonalFeatureMap,
-    round_radius2: f32,
+    border_radius2: f32,
     ctxt: &mut PrimitiveContactGenerationContext,
 ) {
     let pos12 = ctxt.position1.inverse() * ctxt.position2;
@@ -61,7 +61,7 @@ fn do_generate_contacts(
         .downcast_mut()
         .expect("Invalid workspace type, expected a PfmPfmContactManifoldGeneratorWorkspace.");
 
-    let total_prediction = ctxt.prediction_distance + round_radius1 + round_radius2;
+    let total_prediction = ctxt.prediction_distance + border_radius1 + border_radius2;
     let contact = query::contact_support_map_support_map_with_params(
         &Isometry::identity(),
         pfm1,
@@ -93,11 +93,11 @@ fn do_generate_contacts(
                 ctxt.manifold,
             );
 
-            if round_radius1 != 0.0 || round_radius2 != 0.0 {
+            if border_radius1 != 0.0 || border_radius2 != 0.0 {
                 for contact in &mut ctxt.manifold.points {
-                    contact.local_p1 += *normal1 * round_radius1;
-                    contact.local_p2 += *normal2 * round_radius2;
-                    contact.dist -= round_radius1 + round_radius2;
+                    contact.local_p1 += *normal1 * border_radius1;
+                    contact.local_p2 += *normal2 * border_radius2;
+                    contact.dist -= border_radius1 + border_radius2;
                 }
             }
 

src/geometry/mod.rs

@@ -19,7 +19,7 @@ pub use self::narrow_phase::NarrowPhase;
 pub use self::polygon::Polygon;
 pub use self::proximity::ProximityPair;
 pub use self::proximity_detector::{DefaultProximityDispatcher, ProximityDispatcher};
-pub use self::rounded::{Roundable, Rounded};
+pub use self::round_cylinder::RoundCylinder;
 pub use self::trimesh::Trimesh;
 pub use ncollide::query::Proximity;
 
@@ -98,5 +98,5 @@ mod wquadtree;
 mod capsule;
 #[cfg(feature = "dim3")]
 mod polygonal_feature_map;
-mod rounded;
+mod round_cylinder;
 mod shape;

src/geometry/round_cylinder.rs

@@ -1,6 +1,5 @@
 #[cfg(feature = "dim3")]
 use crate::geometry::Cylinder;
-use crate::geometry::ShapeType;
 use crate::math::{Isometry, Point, Vector};
 use na::Unit;
 use ncollide::query::{
@@ -8,44 +7,35 @@ use ncollide::query::{
 };
 use ncollide::shape::{FeatureId, SupportMap};
 
-/// A shape which corner can be rounded.
-pub trait Roundable {
-    /// The ShapeType fo this shape after rounding its corners.
-    fn rounded_shape_type() -> ShapeType;
-}
-
-#[cfg(feature = "dim3")]
-impl Roundable for Cylinder {
-    fn rounded_shape_type() -> ShapeType {
-        ShapeType::RoundCylinder
-    }
-}
-
-/// A rounded shape.
+/// A rounded cylinder.
 #[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
-pub struct Rounded<S: Roundable> {
-    /// The shape being rounded.
-    pub shape: S,
+#[derive(Copy, Clone, Debug)]
+pub struct RoundCylinder {
+    /// The cylinder being rounded.
+    pub cylinder: Cylinder,
     /// The rounding radius.
-    pub radius: f32,
+    pub border_radius: f32,
 }
 
-impl<S: Roundable> Rounded<S> {
-    /// Create sa new shape where all its edges and vertices are rounded by a radius of `radius`.
+impl RoundCylinder {
+    /// Create sa new cylinder where all its edges and vertices are rounded by a radius of `radius`.
     ///
-    /// This is done by applying a dilation of the given radius to the shape.
-    pub fn new(shape: S, radius: f32) -> Self {
-        Self { shape, radius }
+    /// This is done by applying a dilation of the given radius to the cylinder.
+    pub fn new(half_height: f32, radius: f32, border_radius: f32) -> Self {
+        Self {
+            cylinder: Cylinder::new(half_height, radius),
+            border_radius,
+        }
     }
 }
 
-impl<S: Roundable + SupportMap<f32>> SupportMap<f32> for Rounded<S> {
+impl SupportMap<f32> for RoundCylinder {
     fn local_support_point(&self, dir: &Vector<f32>) -> Point<f32> {
         self.local_support_point_toward(&Unit::new_normalize(*dir))
     }
 
     fn local_support_point_toward(&self, dir: &Unit<Vector<f32>>) -> Point<f32> {
-        self.shape.local_support_point_toward(dir) + **dir * self.radius
+        self.cylinder.local_support_point_toward(dir) + **dir * self.border_radius
     }
 
     fn support_point(&self, transform: &Isometry<f32>, dir: &Vector<f32>) -> Point<f32> {
@@ -63,7 +53,7 @@ impl<S: Roundable + SupportMap<f32>> SupportMap<f32> for Rounded<S> {
     }
 }
 
-impl<S: Roundable + SupportMap<f32>> RayCast<f32> for Rounded<S> {
+impl RayCast<f32> for RoundCylinder {
     fn toi_and_normal_with_ray(
         &self,
         m: &Isometry<f32>,
@@ -90,7 +80,7 @@ impl<S: Roundable + SupportMap<f32>> RayCast<f32> for Rounded<S> {
 
 // TODO: if PointQuery had a `project_point_with_normal` method, we could just
 // call this and adjust the projected point accordingly.
-impl<S: Roundable + SupportMap<f32>> PointQuery<f32> for Rounded<S> {
+impl PointQuery<f32> for RoundCylinder {
     #[inline]
     fn project_point(
         &self,

src/geometry/shape.rs

@@ -1,6 +1,6 @@
 use crate::dynamics::MassProperties;
 use crate::geometry::{
-    Ball, Capsule, Cuboid, HeightField, Roundable, Rounded, Segment, Triangle, Trimesh,
+    Ball, Capsule, Cuboid, HeightField, RoundCylinder, Segment, Triangle, Trimesh,
 };
 use crate::math::Isometry;
 use downcast_rs::{impl_downcast, DowncastSync};
@@ -132,11 +132,8 @@ impl dyn Shape {
     }
 
     /// Converts this abstract shape to a cone, if it is one.
-    pub fn as_rounded<S>(&self) -> Option<&Rounded<S>>
-    where
-        S: Roundable,
-        Rounded<S>: Shape,
-    {
+    #[cfg(feature = "dim3")]
+    pub fn as_round_cylinder(&self) -> Option<&RoundCylinder> {
         self.downcast_ref()
     }
 }
@@ -364,19 +361,21 @@ impl Shape for Cone {
 }
 
 #[cfg(feature = "dim3")]
-impl Shape for Rounded<Cylinder> {
+impl Shape for RoundCylinder {
     #[cfg(feature = "serde-serialize")]
     fn as_serialize(&self) -> Option<&dyn Serialize> {
         Some(self as &dyn Serialize)
     }
 
     fn compute_aabb(&self, position: &Isometry<f32>) -> AABB<f32> {
-        self.shape.compute_aabb(position).loosened(self.radius)
+        self.cylinder
+            .compute_aabb(position)
+            .loosened(self.border_radius)
     }
 
     fn mass_properties(&self, density: f32) -> MassProperties {
         // We ignore the margin here.
-        self.shape.mass_properties(density)
+        self.cylinder.mass_properties(density)
     }
 
     fn shape_type(&self) -> ShapeType {
@@ -385,6 +384,9 @@ impl Shape for Rounded<Cylinder> {
 
     #[cfg(feature = "dim3")]
     fn as_polygonal_feature_map(&self) -> Option<(&dyn PolygonalFeatureMap, f32)> {
-        Some((&self.shape as &dyn PolygonalFeatureMap, self.radius))
+        Some((
+            &self.cylinder as &dyn PolygonalFeatureMap,
+            self.border_radius,
+        ))
     }
 }

src_testbed/engine.rs

@@ -412,7 +412,10 @@ impl GraphicsManager {
         }
 
         #[cfg(feature = "dim3")]
-        if let Some(cylinder) = shape.as_cylinder().or(shape.as_rounded().map(|r| &r.shape)) {
+        if let Some(cylinder) = shape
+            .as_cylinder()
+            .or(shape.as_round_cylinder().map(|r| &r.cylinder))
+        {
             out.push(Node::Cylinder(Cylinder::new(
                 handle,
                 cylinder.half_height,