Fix some solver issues

- Fix the wrong codepath taken  by the solver for contacts involving a collider without parent.
- Properly adress the non-linear treatment of the friction direction
- Simplify the sleeping strategy
- Add an impulse resolution multiplier

1 files changed, 12 insertions, 1 deletions

diff --git a/src/dynamics/solver/delta_vel.rs b/src/dynamics/solver/delta_vel.rs
index 9160f2e..697fd24 100644
--- a/src/dynamics/solver/delta_vel.rs
+++ b/src/dynamics/solver/delta_vel.rs
@@ -1,7 +1,7 @@
 use crate::math::{AngVector, Vector, SPATIAL_DIM};
 use na::{DVectorSlice, DVectorSliceMut};
 use na::{Scalar, SimdRealField};
-use std::ops::AddAssign;
+use std::ops::{AddAssign, Sub};
 
 #[derive(Copy, Clone, Debug)]
 #[repr(C)]
@@ -44,3 +44,14 @@ impl<N: SimdRealField + Copy> AddAssign for DeltaVel<N> {
         self.angular += rhs.angular;
     }
 }
+
+impl<N: SimdRealField + Copy> Sub for DeltaVel<N> {
+    type Output = Self;
+
+    fn sub(self, rhs: Self) -> Self {
+        DeltaVel {
+            linear: self.linear - rhs.linear,
+            angular: self.angular - rhs.angular,
+        }
+    }
+}