/*******************************************************************************

* *

* Author : Angus Johnson *

* Version : 5.1.6 *

* Date : 23 May 2013 *

* Website : http://www.angusj.com *

* Copyright : Angus Johnson 2010-2013 *

* *

* License: *

* Use, modification & distribution is subject to Boost Software License Ver 1.*

* http://www.boost.org/LICENSE_1_0.txt *

* *

* Attributions: *

* The code in this library is an extension of Bala Vatti's clipping algorithm:*

* "A generic solution to polygon clipping" *

* Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63. *

* http://portal.acm.org/citation.cfm?id=129906 *

* *

* Computer graphics and geometric modeling: implementation and algorithms *

* By Max K. Agoston *

* Springer; 1 edition (January 4, 2005) *

* http://books.google.com/books?q=vatti+clipping+agoston *

* *

* See also: *

* "Polygon Offsetting by Computing Winding Numbers" *

* Paper no. DETC2005-85513 pp. 565-575 *

* ASME 2005 International Design Engineering Technical Conferences *

* and Computers and Information in Engineering Conference (IDETC/CIE2005) *

* September 24-28, 2005 , Long Beach, California, USA *

* http://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf *

* *

******************************************************************************/

#include "PolyNode.h"

using namespace ClipperLib;

void PolyNode::AddChild(PolyNode &child) {

unsigned cnt = Childs.size();

Childs.push_back(&child);

child.Parent = this;

child.Index = cnt;

}

PolyNode *PolyNode::GetNext() const {

return Childs.empty() ? GetNextSiblingUp() : Childs[0];

}

PolyNode *PolyNode::GetNextSiblingUp() const {

if (!Parent) return 0; // protects against PolyTree.GetNextSiblingUp()

if (Index == Parent->Childs.size() - 1)

return Parent->GetNextSiblingUp();

return Parent->Childs[Index + 1];

}

bool PolyNode::IsHole() const {

bool result = true;

PolyNode *node = Parent;

while (node) {

result = !result;

node = node->Parent;

}

return result;

}

void PolyNode::AddToPolygons(Polygons &polygons) const {

if (!Contour.empty()) polygons.push_back(Contour);

for (int i = 0; i < ChildCount(); i++)

Childs[i]->AddToPolygons(polygons);

}