//---------------------------------------------------------
size_t CSG_PRQuadTree::_Select_Nearest_Points(CSG_Array &Selection, double x, double y, size_t maxPoints, double Radius, int iQuadrant) const
{
if( Selection.Get_Value_Size() != sizeof(TLeaf) )
{
Selection.Create(sizeof(TLeaf), 0, SG_ARRAY_GROWTH_3);
}
else
{
Selection.Set_Array(0, false);
}
if( m_pRoot )
{
double Distance;
if( maxPoints < 1 )
{
maxPoints = m_nPoints;
}
if( iQuadrant != 4 )
{
_Select_Nearest_Points(Selection, m_pRoot, x, y, Distance = 0.0, Radius, maxPoints, iQuadrant);
}
else // if( iQuadrant == 4 ) // quadrant-wise search
{
for(iQuadrant=0; iQuadrant<4; iQuadrant++)
{
_Select_Nearest_Points(Selection, m_pRoot, x, y, Distance = 0.0, Radius, maxPoints, iQuadrant);
}
}
}
return( Selection.Get_Size() );
}
//---------------------------------------------------------
inline bool CSG_PRQuadTree::_Add_Selected(CSG_Array &Selection, CSG_PRQuadTree_Leaf *pLeaf, double Distance) const
{
if( Selection.Inc_Array() )
{
TLeaf *pL = (TLeaf *)Selection.Get_Entry(Selection.Get_Size() - 1);
pL->pLeaf = pLeaf;
pL->Distance = Distance;
return( true );
}
return( false );
}
//---------------------------------------------------------
size_t CSG_PRQuadTree::Get_Nearest_Points(CSG_Points_Z &Points, double x, double y, size_t maxPoints, double Radius, int iQuadrant) const
{
CSG_Array Selection;
_Select_Nearest_Points(Selection, x, y, maxPoints, Radius, iQuadrant);
Points.Clear();
for(size_t i=0; i<Selection.Get_Size(); i++)
{
CSG_PRQuadTree_Leaf *pLeaf = _Get_Selected(Selection, i)->pLeaf;
Points.Add(pLeaf->Get_X(), pLeaf->Get_Y(), pLeaf->Get_Z());
}
return( Points.Get_Count() );
}
//---------------------------------------------------------
void CSG_PRQuadTree::_Select_Nearest_Points(CSG_Array &Selection, CSG_PRQuadTree_Item *pItem, double x, double y, double &Distance, double Radius, size_t maxPoints, int iQuadrant) const
{
//-----------------------------------------------------
if( pItem->is_Leaf() )
{
CSG_PRQuadTree_Leaf *pLeaf = (CSG_PRQuadTree_Leaf *)pItem;
if( _Quadrant_Contains(x, y, iQuadrant, pLeaf->Get_Point()) == false )
{
return;
}
double d = SG_Get_Distance(x, y, pLeaf->Get_X(), pLeaf->Get_Y(), m_bPolar);
if( Radius > 0.0 && Radius < d )
{
return;
}
//-------------------------------------------------
if( Selection.Get_Size() < maxPoints )
{
if( Distance < d )
{
Distance = d;
}
_Add_Selected(Selection, pLeaf, d);
}
else if( d < Distance )
{
size_t i;
for(i=0; i<Selection.Get_Size(); i++)
{
if( Distance <= _Get_Selected(Selection, i)->Distance )
{
_Set_Selected(Selection, i, pLeaf, d);
break;
}
}
for(i=0, Distance=d; i<maxPoints; i++)
{
if( Distance < _Get_Selected(Selection, i)->Distance )
{
Distance = _Get_Selected(Selection, i)->Distance;
}
}
}
}
//-----------------------------------------------------
else // if( pItem->is_Node() )
{
int i;
CSG_PRQuadTree_Item *pChild;
for(i=0; i<4; i++)
{
if( (pChild = ((CSG_PRQuadTree_Node *)pItem)->Get_Child(i)) != NULL && pChild->Contains(x, y) == true )
{
_Select_Nearest_Points(Selection, pChild, x, y, Distance, Radius, maxPoints, iQuadrant);
}
}
for(i=0; i<4; i++)
{
if( (pChild = ((CSG_PRQuadTree_Node *)pItem)->Get_Child(i)) != NULL && pChild->Contains(x, y) == false )
{
if( _Radius_Intersects(x, y, Radius, iQuadrant, pChild) )
{
if( Get_Selected_Count() < maxPoints
|| ( Distance > (x < pChild->Get_xCenter() ? pChild->Get_xMin() - x : x - pChild->Get_xMax())
&& Distance > (y < pChild->Get_yCenter() ? pChild->Get_yMin() - y : y - pChild->Get_yMax()) ) )
{
_Select_Nearest_Points(Selection, pChild, x, y, Distance, Radius, maxPoints, iQuadrant);
}
}
}
}
}
}