C++ Portal::getSideRelativeToPortalPlane方法代码示例

void Portal::_traverseConnectedZoneSpaces( SceneTraversalState* state )
{
   PROFILE_SCOPE( Portal_traverseConnectedZoneSpaces );

   // Don't traverse out from the portal if it is invalid.

   if( mClassification == InvalidPortal )
      return;

   AssertFatal( !mIsGeometryDirty, "Portal::_traverseConnectedZoneSpaces - Geometry not up-to-date!" );

   // When starting traversal within a portal zone, we cannot really use the portal
   // plane itself to direct our visibility queries.  For example, the camera might
   // actually be located in front of the portal plane and thus cannot actually look
   // through the portal, though it will still see what lies on front of where the
   // portal leads.
   //
   // So if we're the start of the traversal chain, i.e. the traversal has started
   // out in the portal zone, then just put the traversal through to SceneZoneSpace
   // so it can hand it over to all connected zone managers.
   //
   // Otherwise, just do a normal traversal by stepping through the portal.

   if( state->getTraversalDepth() == 1 )
   {
      Parent::_traverseConnectedZoneSpaces( state );
      return;
   }
   
   SceneCullingState* cullingState = state->getCullingState();
   const SceneCameraState& cameraState = cullingState->getCameraState();

   // Get the data of the zone we're coming from.  Note that at this point
   // the portal zone itself is already on top of the traversal stack, so
   // we skip over the bottom-most entry.

   const U32 sourceZoneId = state->getZoneIdFromStack( 1 );
   const SceneZoneSpace* sourceZoneSpace = state->getZoneFromStack( 1 );

   // Find out which side of the portal we are on given the
   // source zone.

   const Portal::Side currentZoneSide =
      sourceZoneId == SceneZoneSpaceManager::RootZoneId
      ? ( getInteriorSideOfExteriorPortal() == FrontSide ? BackSide : FrontSide )
      : getSideRelativeToPortalPlane( sourceZoneSpace->getPosition() );

   // Don't step through portal if the side we're interested in isn't passable.

   if( !isSidePassable( currentZoneSide ) )
      return;

   // If the viewpoint isn't on the same side of the portal as the source zone,
   // then stepping through the portal would mean we are stepping back towards
   // the viewpoint which doesn't make sense; so, skip the portal.

   const Point3F& viewPos = cameraState.getViewPosition();
   const F32 viewPosDistToPortal = mFabs( getPortalPlane().distToPlane( viewPos ) );
   if( !mIsZero( viewPosDistToPortal ) && getSideRelativeToPortalPlane( viewPos ) != currentZoneSide )
      return;

   // Before we go ahead and do the real work, try to find out whether
   // the portal is at a perpendicular or near-perpendicular angle to the view
   // direction.  If so, there's no point in going further since we can't really
   // see much through the portal anyway.  It also prevents us from stepping
   // over front/back side ambiguities.

   Point3F viewDirection = cameraState.getViewDirection();
   const F32 dotProduct = mDot( viewDirection, getPortalPlane() );
   if( mIsZero( dotProduct ) )
      return;

   // Finally, if we have come through a portal to the current zone, check if the target
   // portal we are trying to step through now completely lies on the "backside"--i.e.
   // the side of portal on which our current zone lies--of the source portal.  If so,
   // we can be sure this portal leads us in the wrong direction.  This prevents the
   // outdoor zone from having just arrived through a window on one side of a house just
   // to go round the house and re-enter it from the other side.

   Portal* sourcePortal = state->getTraversalDepth() > 2 ? dynamic_cast< Portal* >( state->getZoneFromStack( 2 ) ) : NULL;
   if( sourcePortal != NULL )
   {
      const Side sourcePortalFrontSide =
         sourceZoneId == SceneZoneSpaceManager::RootZoneId
         ? sourcePortal->getInteriorSideOfExteriorPortal()
         : sourcePortal->getSideRelativeToPortalPlane( sourceZoneSpace->getPosition() );
      const PlaneF::Side sourcePortalPlaneFrontSide =
         sourcePortalFrontSide == FrontSide ? PlaneF::Front : PlaneF::Back;

      bool allPortalVerticesOnBackside = true;
      const U32 numVertices = mPortalPolygonWS.size();
      for( U32 i = 0; i < numVertices; ++ i )
      {
         // Not using getSideRelativeToPortalPlane here since we want PlaneF::On to be
         // counted as backside here.
         if( sourcePortal->mPortalPlane.whichSide( mPortalPolygonWS[ i ] ) == sourcePortalPlaneFrontSide )
         {
            allPortalVerticesOnBackside = false;
            break;
         }
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