Fix warnings and add comments.

src/dynamics/joint/fixed_joint.rs

@@ -4,6 +4,7 @@ use crate::math::{Isometry, Point, Real};
 #[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
 #[derive(Copy, Clone, Debug, PartialEq)]
 #[repr(transparent)]
+/// A fixed joint, locks all relative motion between two bodies.
 pub struct FixedJoint {
     data: GenericJoint,
 }
@@ -15,47 +16,56 @@ impl Default for FixedJoint {
 }
 
 impl FixedJoint {
+    /// Creates a new fixed joint.
     #[must_use]
     pub fn new() -> Self {
         let data = GenericJointBuilder::new(JointAxesMask::LOCKED_FIXED_AXES).build();
         Self { data }
     }
 
+    /// The joint’s frame, expressed in the first rigid-body’s local-space.
     #[must_use]
     pub fn local_frame1(&self) -> &Isometry<Real> {
         &self.data.local_frame1
     }
 
+    /// Sets the joint’s frame, expressed in the first rigid-body’s local-space.
     pub fn set_local_frame1(&mut self, local_frame: Isometry<Real>) -> &mut Self {
         self.data.set_local_frame1(local_frame);
         self
     }
 
+    /// The joint’s frame, expressed in the second rigid-body’s local-space.
     #[must_use]
     pub fn local_frame2(&self) -> &Isometry<Real> {
         &self.data.local_frame2
     }
 
+    /// Sets joint’s frame, expressed in the second rigid-body’s local-space.
     pub fn set_local_frame2(&mut self, local_frame: Isometry<Real>) -> &mut Self {
         self.data.set_local_frame2(local_frame);
         self
     }
 
+    /// The joint’s anchor, expressed in the local-space of the first rigid-body.
     #[must_use]
     pub fn local_anchor1(&self) -> Point<Real> {
         self.data.local_anchor1()
     }
 
+    /// Sets the joint’s anchor, expressed in the local-space of the first rigid-body.
     pub fn set_local_anchor1(&mut self, anchor1: Point<Real>) -> &mut Self {
         self.data.set_local_anchor1(anchor1);
         self
     }
 
+    /// The joint’s anchor, expressed in the local-space of the second rigid-body.
     #[must_use]
     pub fn local_anchor2(&self) -> Point<Real> {
         self.data.local_anchor2()
     }
 
+    /// Sets the joint’s anchor, expressed in the local-space of the second rigid-body.
     pub fn set_local_anchor2(&mut self, anchor2: Point<Real>) -> &mut Self {
         self.data.set_local_anchor2(anchor2);
         self
@@ -68,39 +78,46 @@ impl Into<GenericJoint> for FixedJoint {
     }
 }
 
+/// Create fixed joints using the builder pattern.
 #[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
 #[derive(Copy, Clone, Debug, PartialEq, Default)]
 pub struct FixedJointBuilder(FixedJoint);
 
 impl FixedJointBuilder {
+    /// Creates a new builder for fixed joints.
     pub fn new() -> Self {
         Self(FixedJoint::new())
     }
 
+    /// Sets the joint’s frame, expressed in the first rigid-body’s local-space.
     #[must_use]
     pub fn local_frame1(mut self, local_frame: Isometry<Real>) -> Self {
         self.0.set_local_frame1(local_frame);
         self
     }
 
+    /// Sets joint’s frame, expressed in the second rigid-body’s local-space.
     #[must_use]
     pub fn local_frame2(mut self, local_frame: Isometry<Real>) -> Self {
         self.0.set_local_frame2(local_frame);
         self
     }
 
+    /// Sets the joint’s anchor, expressed in the local-space of the first rigid-body.
     #[must_use]
     pub fn local_anchor1(mut self, anchor1: Point<Real>) -> Self {
         self.0.set_local_anchor1(anchor1);
         self
     }
 
+    /// Sets the joint’s anchor, expressed in the local-space of the second rigid-body.
     #[must_use]
     pub fn local_anchor2(mut self, anchor2: Point<Real>) -> Self {
         self.0.set_local_anchor2(anchor2);
         self
     }
 
+    /// Build the fixed joint.
     #[must_use]
     pub fn build(self) -> FixedJoint {
         self.0