Physics: better rest collision filter based on ball travel distance i…

…nstead of time

src/physics/collide.cpp

@@ -15,21 +15,17 @@ void HitObject::FireHitEvent(Ball * const pball)
 {
    if (m_obj && m_fe && m_enabled)
    {
-      // is this the same place as last event and elapsed time is short enough, then ignores it
-      if ((g_pplayer->m_time_msec - pball->m_lastEventTime) <= 2 * PHYSICS_STEPTIME / 1000)
+      // is this the same place as last event and ball did not travel in between, then ignores it
+      if (pball->m_lastEventSqrDist < 0.5f) // 0.5 VPU is a magic value to filter out rest collision
       {
          const float dist_ls = (pball->m_lastEventPos - pball->m_d.m_pos).LengthSquared();
          const float normalDist = (m_ObjType == eHitTarget) ? 0.0f // hit targets when used with a captured ball have always a too small distance
                                                             : 0.25f; //!! magic distance
          if (dist_ls <= normalDist) // must be a new place if only by a little
-         {
-            pball->m_lastEventTime = g_pplayer->m_time_msec;
             return;
-         }
       }
-
+      pball->m_lastEventSqrDist = 0.f;
       pball->m_lastEventPos = pball->m_d.m_pos; // remember last collision position
-      pball->m_lastEventTime = g_pplayer->m_time_msec;
       ((IFireEvents*)m_obj)->FireGroupEvent(DISPID_HitEvents_Hit);
    }
 }

src/physics/hitball.cpp

@@ -498,6 +498,8 @@ void Ball::UpdateDisplacements(const float dtime)
       const Vertex3Ds ds = dtime * m_d.m_vel;
       m_d.m_pos += ds;
 
+      m_lastEventSqrDist += ds.LengthSquared();
+
 #ifdef C_DYNAMIC
       m_drsq = ds.LengthSquared(); // used to determine if static ball
 #endif

src/physics/hitball.h

@@ -64,8 +64,8 @@ class Ball : public HitObject
 
    Vertex3Ds m_oldVel;       // hack for kicker hole handling only
 
-   U32 m_lastEventTime; // last hit event time (to filter hit 'equal' hit events)
    Vertex3Ds m_lastEventPos; // last hit event position (to filter hit 'equal' hit events)
+   float m_lastEventSqrDist; // distance travelled since last event
 
    Vertex3Ds m_angularmomentum;