Method ProcessHorizontal

TheForceEngine/TFE_Polygon/clipper.cpp:2636–2824

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

void Clipper::ProcessHorizontal(TEdge *horzEdge)
{
  Direction dir;
  cInt horzLeft, horzRight;
  bool IsOpen = (horzEdge->WindDelta == 0);

  GetHorzDirection(*horzEdge, dir, horzLeft, horzRight);

  TEdge* eLastHorz = horzEdge, *eMaxPair = 0;
  while (eLastHorz->NextInLML && IsHorizontal(*eLastHorz->NextInLML)) 
    eLastHorz = eLastHorz->NextInLML;
  if (!eLastHorz->NextInLML)
    eMaxPair = GetMaximaPair(eLastHorz);

  MaximaList::const_iterator maxIt;
  MaximaList::const_reverse_iterator maxRit;
  if (m_Maxima.size() > 0)
  {
      //get the first maxima in range (X) ...
      if (dir == dLeftToRight)
      {
          maxIt = m_Maxima.begin();
          while (maxIt != m_Maxima.end() && *maxIt <= horzEdge->Bot.X) maxIt++;
          if (maxIt != m_Maxima.end() && *maxIt >= eLastHorz->Top.X)
              maxIt = m_Maxima.end();
      }
      else
      {
          maxRit = m_Maxima.rbegin();
          while (maxRit != m_Maxima.rend() && *maxRit > horzEdge->Bot.X) maxRit++;
          if (maxRit != m_Maxima.rend() && *maxRit <= eLastHorz->Top.X)
              maxRit = m_Maxima.rend();
      }
  }

  OutPt* op1 = 0;

  for (;;) //loop through consec. horizontal edges
  {
		  
    bool IsLastHorz = (horzEdge == eLastHorz);
    TEdge* e = GetNextInAEL(horzEdge, dir);
    while(e)
    {

        //this code block inserts extra coords into horizontal edges (in output
        //polygons) whereever maxima touch these horizontal edges. This helps
        //'simplifying' polygons (ie if the Simplify property is set).
        if (m_Maxima.size() > 0)
        {
            if (dir == dLeftToRight)
            {
                while (maxIt != m_Maxima.end() && *maxIt < e->Curr.X) 
                {
                  if (horzEdge->OutIdx >= 0 && !IsOpen)
                    AddOutPt(horzEdge, IntPoint(*maxIt, horzEdge->Bot.Y));
                  maxIt++;
                }