/*------------------------------------------------------------------------------*/
void GW_Mesh::ReOrientMesh( GW_Face& start_face )
{
/* march on the voronoi diagram */
T_FaceList FaceToProceed;
FaceToProceed.push_back( &start_face );
T_FaceMap FaceDone;
FaceDone[ start_face.GetID() ] = &start_face;
while( !FaceToProceed.empty() )
{
GW_Face* pFace = FaceToProceed.front();
GW_ASSERT( pFace!=NULL );
FaceToProceed.pop_front();
/* add neighbors */
for( GW_U32 i=0; i<3; ++i )
{
GW_Vertex* pVertDir = pFace->GetVertex(i); GW_ASSERT( pVertDir!=NULL );
GW_Face* pNewFace = pFace->GetFaceNeighbor(*pVertDir);
if( pNewFace!=NULL && FaceDone.find(pNewFace->GetID())==FaceDone.end() )
{
/* find the two other vertices */
GW_U32 i1 = (i+1)%3;
GW_U32 i2 = (i+2)%3;
GW_Vertex* pNewVert[3];
pNewVert[0] = pFace->GetVertex(i2); GW_ASSERT( pNewVert[0]!=NULL );
pNewVert[1] = pFace->GetVertex(i1); GW_ASSERT( pNewVert[1]!=NULL );
pNewVert[2] = pNewFace->GetVertex(*pNewVert[0], *pNewVert[1]); GW_ASSERT( pNewVert[2]!=NULL );
GW_Face* pNeigh[3];
pNeigh[0] = pNewFace->GetFaceNeighbor( *pNewVert[0] );
pNeigh[1] = pNewFace->GetFaceNeighbor( *pNewVert[1] );
pNeigh[2] = pNewFace->GetFaceNeighbor( *pNewVert[2] );
/* reorient the face */
pNewFace->SetVertex( *pNewVert[0], *pNewVert[1], *pNewVert[2] );
pNewFace->SetFaceNeighbor( pNeigh[0], pNeigh[1], pNeigh[2] );
FaceToProceed.push_back( pNewFace );
FaceDone[ pNewFace->GetID() ] = pNewFace; // so that it won't be added anymore
}
}
}
/* check for global orientation (just an heuristic) */
GW_Face* pFace = this->GetFace(0); GW_ASSERT( pFace!=NULL );
GW_Vector3D v = pFace->GetVertex(0)->GetPosition() +
pFace->GetVertex(1)->GetPosition() +
pFace->GetVertex(2)->GetPosition();
GW_Vector3D n = pFace->ComputeNormal();
if( n*v<0 )
this->FlipOrientation();
}
/*------------------------------------------------------------------------------*/
void GW_Mesh::ReOrientNormals()
{
for( GW_U32 i=0; i<this->GetNbrFace(); ++i )
{
GW_Face* pFace = this->GetFace(i); GW_ASSERT( pFace!=NULL );
GW_Vector3D n = pFace->ComputeNormal();
for( GW_U32 k=0; k<3; ++k )
{
GW_Vector3D& nv = pFace->GetVertex(k)->GetNormal();
if( nv*n < 0 )
nv = -nv;
}
}
}
