static
bool ChangeTrimBdryToSing( ON_Brep& brep, ON_BrepTrim& trim,
ON_BrepTrim* prevtrim, ON_BrepTrim* nexttrim )
{
if ( trim.m_vi[0] == trim.m_vi[1] )
return false;
if ( trim.m_type == ON_BrepTrim::singular )
return false;
if ( trim.m_ei < 0 )
return false;
int vi0 = trim.m_vi[0];
int vi1 = trim.m_vi[1];
int sing_vi = vi0;
ON_BrepVertex* v0 = brep.Vertex(vi0);
if ( v0 )
v0->m_tolerance = ON_UNSET_VALUE;
ON_BrepVertex* v1 = brep.Vertex(vi1);
if ( v1 )
v1->m_tolerance = ON_UNSET_VALUE;
ON_BrepEdge* edge = brep.Edge(trim.m_ei);
if ( edge )
{
for ( int eti = 0; eti < edge->m_ti.Count(); eti++ )
{
if ( edge->m_ti[eti] == trim.m_trim_index )
{
edge->m_ti.Remove(eti);
break;
}
}
trim.m_ei = -1;
if ( 0 == edge->m_ti.Count() )
{
brep.DeleteEdge( *edge, true );
}
else if ( 1 == edge->m_ti.Count() && ON_BrepTrim::seam == trim.m_type )
{
// change neighbor trim type
ON_BrepTrim* other_trim = brep.Trim(edge->m_ti[0]);
if ( 0 != other_trim && ON_BrepTrim::seam == other_trim->m_type )
{
other_trim->m_type = ON_BrepTrim::boundary;
int j = (trim.m_bRev3d == other_trim->m_bRev3d) ? 0 : 1;
if ( trim.m_vi[0] == other_trim->m_vi[j]
&& trim.m_vi[1] == other_trim->m_vi[1-j] )
{
// we need a new singular vertex
sing_vi = brep.NewVertex(ON_UNSET_POINT).m_vertex_index;
}
}
}
}
trim.m_vi[0] = sing_vi;
trim.m_vi[1] = sing_vi;
trim.m_type = ON_BrepTrim::singular;
trim.m_bRev3d = false;
if ( nexttrim )
ChangeTrimVertex( brep,*nexttrim,0,vi1,sing_vi,true,true);
if ( prevtrim )
ChangeTrimVertex( brep,*prevtrim,1,vi0,sing_vi,true,true);
return true;
}
