Fix issue with display of contact points in testbed application

testbed/src/Scene.cpp

@@ -189,9 +189,6 @@ void Scene::rotate(int xMouse, int yMouse) {
 // Called when some contacts occur
 void Scene::onContact(const rp3d::CollisionCallback::CallbackData& callbackData) {
 
-    // Clear contacts points
-    mContactPoints.clear();
-
     // For each contact pair
     for (uint p=0; p < callbackData.getNbContactPairs(); p++) {
 

testbed/src/SceneDemo.cpp

@@ -124,6 +124,9 @@ void SceneDemo::update() {
 // Can be called several times per frame
 void SceneDemo::updatePhysics() {
 
+    // Clear contacts points
+    mContactPoints.clear();
+
     if (getDynamicsWorld() != nullptr) {
 
         // Take a simulation step