Method AppendPolygon

TheForceEngine/TFE_Polygon/clipper.cpp:2367–2460

//------------------------------------------------------------------------------

void Clipper::AppendPolygon(TEdge *e1, TEdge *e2)
{
  //get the start and ends of both output polygons ...
  OutRec *outRec1 = m_PolyOuts[e1->OutIdx];
  OutRec *outRec2 = m_PolyOuts[e2->OutIdx];

  OutRec *holeStateRec;
  if (OutRec1RightOfOutRec2(outRec1, outRec2))
    holeStateRec = outRec2;
  else if (OutRec1RightOfOutRec2(outRec2, outRec1))
    holeStateRec = outRec1;
  else 
    holeStateRec = GetLowermostRec(outRec1, outRec2);

  //get the start and ends of both output polygons and
  //join e2 poly onto e1 poly and delete pointers to e2 ...

  OutPt* p1_lft = outRec1->Pts;
  OutPt* p1_rt = p1_lft->Prev;
  OutPt* p2_lft = outRec2->Pts;
  OutPt* p2_rt = p2_lft->Prev;

  //join e2 poly onto e1 poly and delete pointers to e2 ...
  if(  e1->Side == esLeft )
  {
    if(  e2->Side == esLeft )
    {
      //z y x a b c
      ReversePolyPtLinks(p2_lft);
      p2_lft->Next = p1_lft;
      p1_lft->Prev = p2_lft;
      p1_rt->Next = p2_rt;
      p2_rt->Prev = p1_rt;
      outRec1->Pts = p2_rt;
    } else
    {
      //x y z a b c
      p2_rt->Next = p1_lft;
      p1_lft->Prev = p2_rt;
      p2_lft->Prev = p1_rt;
      p1_rt->Next = p2_lft;
      outRec1->Pts = p2_lft;
    }
  } else
  {
    if(  e2->Side == esRight )
    {
      //a b c z y x
      ReversePolyPtLinks(p2_lft);
      p1_rt->Next = p2_rt;
      p2_rt->Prev = p1_rt;
      p2_lft->Next = p1_lft;
      p1_lft->Prev = p2_lft;
    } else
    {
      //a b c x y z
      p1_rt->Next = p2_lft;
      p2_lft->Prev = p1_rt;