Method _updateGeometry

Engine/source/T3D/portal.cpp:583–647

//-----------------------------------------------------------------------------

void Portal::_updateGeometry()
{
   const F32 boxHalfWidth = getScale().x * 0.5f;
   const F32 boxHalfHeight = getScale().z * 0.5f;

   const Point3F center = getTransform().getPosition();
   const Point3F up = getTransform().getUpVector() * boxHalfHeight;
   const Point3F right = getTransform().getRightVector() * boxHalfWidth;

   // Update the portal polygon and plane.

   if( mIsBox )
   {
      // It's a box so the portal polygon is a rectangle.
      // Simply compute the corner points by stepping from the
      // center to the corners using the up and right vector.

      mPortalPolygonWS.setSize( 4 );

      mPortalPolygonWS[ 0 ] = center + right - up; // bottom right
      mPortalPolygonWS[ 1 ] = center - right - up; // bottom left
      mPortalPolygonWS[ 2 ] = center - right + up; // top left
      mPortalPolygonWS[ 3 ] = center + right + up; // top right

      // Update the plane by going through three of the points.

      mPortalPlane = PlaneF(
         mPortalPolygonWS[ 0 ],
         mPortalPolygonWS[ 1 ],
         mPortalPolygonWS[ 2 ]
      );
   }
   else
   {
      // It's not necessarily a box so we must use the general
      // routine.

      // Update the portal plane by building a plane that cuts the
      // OBB in half vertically along its Y axis.

      mPortalPlane = PlaneF(
         center + right - up,
         center - right - up,
         center - right + up
      );

      // Slice the polyhedron along the same plane in object space.

      const PlaneF slicePlane = PlaneF( Point3F::Zero, Point3F( 0.f, 1.f, 0.f ) );

      mPortalPolygonWS.setSize( mPolyhedron.getNumEdges() );
      U32 numPoints = mPolyhedron.constructIntersection( slicePlane, mPortalPolygonWS.address(), mPortalPolygonWS.size() );
      mPortalPolygonWS.setSize( numPoints );

      // Transform the polygon to world space.

      for( U32 i = 0; i < numPoints; ++ i )
      {