//------------------------------------------------------------------------------
private bool JoinPoints(JoinRec j, out OutPt p1, out OutPt p2)
{
p1 = null; p2 = null;
OutRec outRec1 = m_PolyOuts[j.poly1Idx];
OutRec outRec2 = m_PolyOuts[j.poly2Idx];
if (outRec1 == null || outRec2 == null) return false;
OutPt pp1a = outRec1.pts;
OutPt pp2a = outRec2.pts;
IntPoint pt1 = j.pt2a, pt2 = j.pt2b;
IntPoint pt3 = j.pt1a, pt4 = j.pt1b;
if (!FindSegment(ref pp1a, m_UseFullRange, ref pt1, ref pt2)) return false;
if (outRec1 == outRec2)
{
//we're searching the same polygon for overlapping segments so
//segment 2 mustn't be the same as segment 1 ...
pp2a = pp1a.next;
if (!FindSegment(ref pp2a, m_UseFullRange, ref pt3, ref pt4) || (pp2a == pp1a))
return false;
}
else if (!FindSegment(ref pp2a, m_UseFullRange, ref pt3, ref pt4)) return false;
if (!GetOverlapSegment(pt1, pt2, pt3, pt4, ref pt1, ref pt2)) return false;
OutPt p3, p4, prev = pp1a.prev;
//get p1 & p2 polypts - the overlap start & endpoints on poly1
if (PointsEqual(pp1a.pt, pt1)) p1 = pp1a;
else if (PointsEqual(prev.pt, pt1)) p1 = prev;
else p1 = InsertPolyPtBetween(pp1a, prev, pt1);
if (PointsEqual(pp1a.pt, pt2)) p2 = pp1a;
else if (PointsEqual(prev.pt, pt2)) p2 = prev;
else if ((p1 == pp1a) || (p1 == prev))
p2 = InsertPolyPtBetween(pp1a, prev, pt2);
else if (Pt3IsBetweenPt1AndPt2(pp1a.pt, p1.pt, pt2))
p2 = InsertPolyPtBetween(pp1a, p1, pt2);
else
p2 = InsertPolyPtBetween(p1, prev, pt2);
//get p3 & p4 polypts - the overlap start & endpoints on poly2
prev = pp2a.prev;
if (PointsEqual(pp2a.pt, pt1)) p3 = pp2a;
else if (PointsEqual(prev.pt, pt1)) p3 = prev;
else p3 = InsertPolyPtBetween(pp2a, prev, pt1);
if (PointsEqual(pp2a.pt, pt2)) p4 = pp2a;
else if (PointsEqual(prev.pt, pt2)) p4 = prev;
else if ((p3 == pp2a) || (p3 == prev))
p4 = InsertPolyPtBetween(pp2a, prev, pt2);
else if (Pt3IsBetweenPt1AndPt2(pp2a.pt, p3.pt, pt2))
p4 = InsertPolyPtBetween(pp2a, p3, pt2);
else
p4 = InsertPolyPtBetween(p3, prev, pt2);
//p1.pt == p3.pt and p2.pt == p4.pt so join p1 to p3 and p2 to p4 ...
if (p1.next == p2 && p3.prev == p4)
{
p1.next = p3;
p3.prev = p1;
p2.prev = p4;
p4.next = p2;
return true;
}
else if (p1.prev == p2 && p3.next == p4)
{
p1.prev = p3;
p3.next = p1;
p2.next = p4;
p4.prev = p2;
return true;
}
else
return false; //an orientation is probably wrong
}
//----------------------------------------------------------------------
private void FixupJoinRecs(JoinRec j, OutPt pt, int startIdx)
{
for (int k = startIdx; k < m_Joins.Count; k++)
{
JoinRec j2 = m_Joins[k];
if (j2.poly1Idx == j.poly1Idx && PointIsVertex(j2.pt1a, pt))
j2.poly1Idx = j.poly2Idx;
if (j2.poly2Idx == j.poly1Idx && PointIsVertex(j2.pt2a, pt))
j2.poly2Idx = j.poly2Idx;
}
}
//------------------------------------------------------------------------------
private void AddJoin(TEdge e1, TEdge e2, int e1OutIdx, int e2OutIdx)
{
JoinRec jr = new JoinRec();
if (e1OutIdx >= 0)
jr.poly1Idx = e1OutIdx;
else
jr.poly1Idx = e1.outIdx;
jr.pt1a = new IntPoint(e1.xcurr, e1.ycurr);
jr.pt1b = new IntPoint(e1.xtop, e1.ytop);
if (e2OutIdx >= 0)
jr.poly2Idx = e2OutIdx;
else
jr.poly2Idx = e2.outIdx;
jr.pt2a = new IntPoint(e2.xcurr, e2.ycurr);
jr.pt2b = new IntPoint(e2.xtop, e2.ytop);
m_Joins.Add(jr);
}