From e63fa60d06f57b1f33c71ee7c09caffc7ef7597d Mon Sep 17 00:00:00 2001
From: Sébastien Crozet <developer@crozet.re>
Date: Mon, 2 May 2022 13:13:01 +0200
Subject: Backport fix for bug where changing collision groups would not be
 taken into account for pre-existing contacts.

---
 src/geometry/contact_pair.rs |  7 +++++++
 src/geometry/narrow_phase.rs | 11 +++++++++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/geometry/contact_pair.rs b/src/geometry/contact_pair.rs
index f4e7834..f57f0fa 100644
--- a/src/geometry/contact_pair.rs
+++ b/src/geometry/contact_pair.rs
@@ -77,6 +77,13 @@ impl ContactPair {
         }
     }
 
+    /// Clears all the contacts of this contact pair.
+    pub fn clear(&mut self) {
+        self.manifolds.clear();
+        self.has_any_active_contact = false;
+        self.workspace = None;
+    }
+
     /// Finds the contact with the smallest signed distance.
     ///
     /// If the colliders involved in this contact pair are penetrating, then
diff --git a/src/geometry/narrow_phase.rs b/src/geometry/narrow_phase.rs
index 18900b9..e4ee955 100644
--- a/src/geometry/narrow_phase.rs
+++ b/src/geometry/narrow_phase.rs
@@ -377,9 +377,9 @@ impl NarrowPhase {
             let co_changes: Option<&ColliderChanges> = colliders.get(handle.0);
 
             if let Some(co_changes) = co_changes {
-                if co_changes.needs_narrow_phase_update() {
+                if !co_changes.needs_narrow_phase_update() {
                     // No flag relevant to the narrow-phase is enabled for this collider.
-                    return;
+                    continue;
                 }
 
                 if let Some(gid) = self.graph_indices.get(handle.0) {
@@ -745,11 +745,13 @@ impl NarrowPhase {
             if !co_flags1.active_collision_types.test(rb_type1, rb_type2)
                 && !co_flags2.active_collision_types.test(rb_type1, rb_type2)
             {
+                edge.weight = false;
                 return;
             }
 
             // Filter based on collision groups.
             if !co_flags1.collision_groups.test(co_flags2.collision_groups) {
+                edge.weight = false;
                 return;
             }
 
@@ -760,6 +762,7 @@ impl NarrowPhase {
             if !co_flags1.active_collision_types.test(rb_type1, rb_type2)
                 && !co_flags2.active_collision_types.test(rb_type1, rb_type2)
             {
+                edge.weight = false;
                 return;
             }
 
@@ -775,6 +778,7 @@ impl NarrowPhase {
 
                 if !hooks.filter_intersection_pair(&context) {
                     // No intersection allowed.
+                    edge.weight = false;
                     return;
                 }
             }
@@ -867,11 +871,13 @@ impl NarrowPhase {
             if !co_flags1.active_collision_types.test(rb_type1, rb_type2)
                 && !co_flags2.active_collision_types.test(rb_type1, rb_type2)
             {
+                pair.clear();
                 return;
             }
 
             // Filter based on collision groups.
             if !co_flags1.collision_groups.test(co_flags2.collision_groups) {
+                pair.clear();
                 return;
             }
 
@@ -892,6 +898,7 @@ impl NarrowPhase {
                     solver_flags
                 } else {
                     // No contact allowed.
+                    pair.clear();
                     return;
                 }
             } else {
-- 
cgit