Method buildBoxData

Engine/source/math/mPolyhedron.impl.h:447–518

template< typename Polyhedron >
void PolyhedronData::buildBoxData( Polyhedron& poly, const MatrixF& mat, const Box3F& box, bool invertNormals )
{
   AssertFatal( poly.getNumPoints() == 8, "PolyhedronData::buildBox - Incorrect point count!" );
   AssertFatal( poly.getNumEdges() == 12, "PolyhedronData::buildBox - Incorrect edge count!" );
   AssertFatal( poly.getNumPlanes() == 6, "PolyhedronData::buildBox - Incorrect plane count!" );

   // Box is assumed to be axis aligned in the source space.
   // Transform into geometry space.

   Point3F xvec = mat.getRightVector() * box.len_x();
   Point3F yvec = mat.getForwardVector() * box.len_y();
   Point3F zvec = mat.getUpVector() * box.len_z();

   Point3F min;
   mat.mulP( box.minExtents, &min );

   // Corner points.

   typename Polyhedron::PointListType& pointList = poly.mPointList;

   pointList[ 0 ] = min; // near left bottom
   pointList[ 1 ] = min + yvec; // far left bottom
   pointList[ 2 ] = min + xvec + yvec; // far right bottom
   pointList[ 3 ] = min + xvec; // near right bottom
   pointList[ 4 ] = pointList[ 0 ] + zvec; // near left top
   pointList[ 5 ] = pointList[ 1 ] + zvec; // far left top
   pointList[ 6 ] = pointList[ 2 ] + zvec; // far right top
   pointList[ 7 ] = pointList[ 3 ] + zvec; // near right top

   // Side planes.

   typename Polyhedron::PlaneListType& planeList = poly.mPlaneList;

   const F32 pos = invertNormals ? -1.f : 1.f;
   const F32 neg = - pos;

   planeList[ 0 ].set( pointList[ 0 ], xvec * pos ); // left
   planeList[ 1 ].set( pointList[ 2 ], yvec * neg ); // far
   planeList[ 2 ].set( pointList[ 2 ], xvec * neg ); // right
   planeList[ 3 ].set( pointList[ 0 ], yvec * pos ); // front
   planeList[ 4 ].set( pointList[ 0 ], zvec * pos ); // bottom
   planeList[ 5 ].set( pointList[ 4 ], zvec * neg ); // top

   // The edges are constructed so that the vertices
   // are oriented clockwise for face[0].

   typename Polyhedron::EdgeType* edge = &poly.mEdgeList[ 0 ];

   for( U32 i = 0; i < 4; ++ i )
   {
      S32 n = ( i == 3 ) ? 0: i + 1;
      S32 p = ( i == 0 ) ? 3: i - 1;

      edge->vertex[ 0 ] = !invertNormals ? n : i;
      edge->vertex[ 1 ] = !invertNormals ? i : n;
      edge->face[ 0 ] = i;
      edge->face[ 1 ] = 4;
      edge ++;