From 9b87f06a856c4d673642e210f8b0986cfdbac3af Mon Sep 17 00:00:00 2001
From: Sébastien Crozet <sebcrozet@dimforge.com>
Date: Sun, 21 Jan 2024 21:02:23 +0100
Subject: feat: implement new "small-steps" solver + joint improvements

---
 src/dynamics/joint/generic_joint.rs | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

(limited to 'src/dynamics/joint/generic_joint.rs')

diff --git a/src/dynamics/joint/generic_joint.rs b/src/dynamics/joint/generic_joint.rs
index 5096e15..83e27be 100644
--- a/src/dynamics/joint/generic_joint.rs
+++ b/src/dynamics/joint/generic_joint.rs
@@ -1,7 +1,7 @@
 use crate::dynamics::solver::MotorParameters;
 use crate::dynamics::{FixedJoint, MotorModel, PrismaticJoint, RevoluteJoint, RopeJoint};
 use crate::math::{Isometry, Point, Real, Rotation, UnitVector, Vector, SPATIAL_DIM};
-use crate::utils::{WBasis, WReal};
+use crate::utils::{SimdBasis, SimdRealCopy};
 
 #[cfg(feature = "dim3")]
 use crate::dynamics::SphericalJoint;
@@ -121,7 +121,7 @@ pub struct JointLimits<N> {
     pub impulse: N,
 }
 
-impl<N: WReal> Default for JointLimits<N> {
+impl<N: SimdRealCopy> Default for JointLimits<N> {
     fn default() -> Self {
         Self {
             min: -N::splat(Real::MAX),
@@ -131,6 +131,16 @@ impl<N: WReal> Default for JointLimits<N> {
     }
 }
 
+impl<N: SimdRealCopy> From<[N; 2]> for JointLimits<N> {
+    fn from(value: [N; 2]) -> Self {
+        Self {
+            min: value[0],
+            max: value[1],
+            impulse: N::splat(0.0),
+        }
+    }
+}
+
 /// A joint’s motor along one of its degrees of freedom.
 #[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
 #[derive(Copy, Clone, Debug, PartialEq)]
@@ -210,14 +220,23 @@ pub struct GenericJoint {
     /// The degrees-of-freedoms motorised by this joint.
     pub motor_axes: JointAxesMask,
     /// The coupled degrees of freedom of this joint.
+    ///
+    /// Note that coupling degrees of freedoms (DoF) changes the interpretation of the coupled joint’s limits and motors.
+    /// If multiple linear DoF are limited/motorized, only the limits/motor configuration for the first
+    /// coupled linear DoF is applied to all coupled linear DoF. Similarly, if multiple angular DoF are limited/motorized
+    /// only the limits/motor configuration for the first coupled angular DoF is applied to all coupled angular DoF.
     pub coupled_axes: JointAxesMask,
     /// The limits, along each degrees of freedoms of this joint.
     ///
     /// Note that the limit must also be explicitly enabled by the `limit_axes` bitmask.
+    /// For coupled degrees of freedoms (DoF), only the first linear (resp. angular) coupled DoF limit and `limit_axis`
+    /// bitmask is applied to the coupled linear (resp. angular) axes.
     pub limits: [JointLimits<Real>; SPATIAL_DIM],
     /// The motors, along each degrees of freedoms of this joint.
     ///
-    /// Note that the mostor must also be explicitly enabled by the `motors` bitmask.
+    /// Note that the motor must also be explicitly enabled by the `motor_axes` bitmask.
+    /// For coupled degrees of freedoms (DoF), only the first linear (resp. angular) coupled DoF motor and `motor_axes`
+    /// bitmask is applied to the coupled linear (resp. angular) axes.
     pub motors: [JointMotor; SPATIAL_DIM],
     /// Are contacts between the attached rigid-bodies enabled?
     pub contacts_enabled: bool,
-- 
cgit