//polychain2curve.ls
//
//february 12 2010
//clinton reese
//converter single 2 point polychain to a curve
//
//
//select the start point of the poly chain and run the script
//curve will be created in the same layer
//
@version 2.2
@warnings
@script modeler

//global var

pntindex = 0; //point index and curve point count
fgLayer = 0;  //forground layer
emptyLyr = 0; //empty layers

main
{
    //NEED SINGLE POINT TEST

    // note fg layer
    fgLayer = lyrfg();
    numfg = size(fgLayer);
    if(numfg>1) 
    {
        error("More than 1 foreground layer is active");
    }

    // note bg layer
    bgLayer = lyrbg();
    if(bgLayer==nil)
    {
        error("No background layer selected.");
    }
    numbg = size(bgLayer);
    if(numbg != 1) 
    {
        error("More than 1 background layer is active");
    }

    pntindex = 1;//initialize point index

    selmode(USER);

    //save first point and first polygon index list
    editbegin();
        pnts[pntindex] = points[1];//save first point
        mypolyindexlist = points[1].polygon();//polygon index list
    editend();
 
    
    selpoint(CLEAR);    // clear any existing selections

    //select all layers into the foreground then do it
    //need all layers so polgons array has all info needed
    alllayers = lyrdata();
    lyrsetfg(alllayers);

    selmode(GLOBAL);
    editbegin();
        //get points for the current polygon
        curpoly = polygons[mypolyindexlist[1]];
        prevpolyindex = mypolyindexlist[1];

        //make sure 2 point polygons only
        numpolypoints = polypointcount(curpoly);
        if(numpolypoints != 2) error("Not a 2 point poly chain.");

        //get new point
        if(curpoly.points[1] != pnts[pntindex])
        {
            newpoint = curpoly.points[1];
        }
 
        if(curpoly.points[2] != pnts[pntindex])
        {
            newpoint = curpoly.points[2];
        }
    editend();

    //add the new point to the list
    pntindex = pntindex + 1;
    pnts[pntindex] = newpoint;//add to list of points

    //now have first polygon and first 2 points

    //loop until new point only has 1 polygon == end of the chain
    mypolycount=2;
    editbegin();
    while(mypolycount==2)
    {
        //editbegin();
        //get next polygon
        mypolyindexlist = pnts[pntindex].polygon();//list of polygons indexes for point

        if(mypolyindexlist[1] != prevpolyindex)
        {
            newpolyindex = mypolyindexlist[1];
        }
        if(mypolyindexlist[2] != prevpolyindex)
        {
            newpolyindex = mypolyindexlist[2];
        }
        prevpolyindex = newpolyindex;

        //get next vertex using the polygon 
        newpoly = polygons[newpolyindex];

        //make sure 2 point polygons only
        numpolypoints = polypointcount(newpoly);
        if(numpolypoints != 2) error("Not a 2 point poly chain.");

        if(pnts[pntindex] != newpoly.points[1])
        {
            newpoint = newpoly.points[1];
        }
        if(pnts[pntindex] != newpoly.points[2])
        {
            newpoint = newpoly.points[2];
        }
        pntindex = pntindex + 1;
        pnts[pntindex] = newpoint;// add new vertex to the list

        //get polygon count value for this vertex
        mypolycount = pnts[pntindex].polygon;
    //editend();
    }
    editend();

    lyrsetfg(fgLayer);//back to 2 point poly chain layer

    //clear selection and select points in order
    selmode(USER);
    curvepointcount = pntindex;
    selpoint(CLEAR);
    for(j=1;j<=curvepointcount;j++)
    {
        selpoint(SET, POINTID, pnts[j]);
    }

    //create a curve
    editbegin();
        curveid = addcurve(points);
    editend();

    //selpoint(CLEAR);//must deselect points before select curve
    selpolygon(SET, CURVE);
    //selpolygon(SET, POLYID, curveid);//this does not work for some reason
    cut();
    lyrsetfg(bgLayer);
    paste();
    lyrsetfg(fgLayer);//back to 2 point poly chain layer
    lyrsetbg(bgLayer);//restore background

    //selpoint(CLEAR);

}


mainOLD
{
 // note fg layer
 fgLayer = lyrfg();
 numfg = size(fgLayer);
 if(numfg>1) 
 {
  error("More than 1 foreground layer is active");
 }

 // note free layers
 emptyLyr = lyrempty(); // first and second in [1] and [2]

 alllayers = lyrdata();

 selmode(DIRECT);
 //save list of all selected end points
 count = editbegin();
 mypoints = points;
 editend();

 selmode(USER);

//check for point selection
 if(count==0) error("Must select points first");

 selpoint(CLEAR);    // clear any existing selections

 //for each 2 point poly chain create a curve
 for(i=1;i<=count;i++)
 {
  //build list for current curve
  selList = buildSelectionList(mypoints[i]);
  
  //clear selection and select points in order
  selmode(USER);
  curvepointcount = pntindex;
  selpoint(CLEAR);
  for(j=1;j<=curvepointcount;j++)
  {
    selpoint(SET, POINTID, selList[j]);
  }

  //create a curve and move it to a new layer
  editbegin();
   addcurve(points);
  editend();
  selpolygon(SET, CURVE);
  cut();
  lyrsetfg(emptyLyr[1]);
  paste();
  lyrsetfg(fgLayer);//back to 2 point poly chain layer
  selpoint(CLEAR);
 }
 //name the new layer
 lyrsetfg(emptyLyr[1]);
 setlayername("curveFromPoly");
 lyrsetfg(fgLayer);
}

buildSelectionList: firstPoint
{
 pntindex = 1;//initialize point index

 //select the first point
 selmode(USER);
 selpoint(SET,POINTID,firstPoint);

 //save first point and first polygon index list
 editbegin();
  pnts[pntindex] = points[1];//save first point
  mypolyindexlist = points[1].polygon();//polygon index list
 editend();
 
 selpoint(CLEAR);    // clear any existing selections

 //get polygon count of layers above the foreground layer
 polyOffset = 0;
 //if(fgLayer[1] != 1)
 //{
 //  k=1;
 //  while(k<fgLayer[1])
 //  {
 //    lyrsetfg(k);
 //    pc = polycount();
 //    //info(pc);
 //    polyOffset = polyOffset + pc[1];
 //    k = k + 1;
 //  }
 //}
 //lyrsetfg(fgLayer);//back to 2 point poly chain layer


 //select all layers into the foreground then do it
 //need all layers so polgons array has all info needed
 //alllayers = lyrdata();
 lyrsetfg(alllayers);


 selmode(GLOBAL);
 editbegin();
  //get points for the current polygon
  curpoly = polygons[mypolyindexlist[1]];
  prevpolyindex = mypolyindexlist[1];

  //make sure 2 point polygons only
  numpolypoints = polypointcount(curpoly);
  if(numpolypoints != 2) error("Not a 2 point poly chain.");

  //get new point
  if(curpoly.points[1] != pnts[pntindex])
  {
   newpoint = curpoly.points[1];
  }
 
  if(curpoly.points[2] != pnts[pntindex])
  {
   newpoint = curpoly.points[2];
  }
 editend();

 //add the new point to the list
 pntindex = pntindex + 1;
 pnts[pntindex] = newpoint;//add to list of points

 //now have first polygon and first 2 points

 //loop until new point only has 1 polygon == end of the chain
 mypolycount=2;
 while(mypolycount==2)
 {
  editbegin();
   //get next polygon
   mypolyindexlist = pnts[pntindex].polygon();//list of polygons indexes for point

   if(mypolyindexlist[1] != prevpolyindex)
   {
    newpolyindex = mypolyindexlist[1];
   }
   if(mypolyindexlist[2] != prevpolyindex)
   {
    newpolyindex = mypolyindexlist[2];
   }
   prevpolyindex = newpolyindex;

   //get next vertex using the polygon 
   newpoly = polygons[newpolyindex];

   //make sure 2 point polygons only
   numpolypoints = polypointcount(newpoly);
   if(numpolypoints != 2) error("Not a 2 point poly chain.");

   if(pnts[pntindex] != newpoly.points[1])
   {
    newpoint = newpoly.points[1];
   }
   if(pnts[pntindex] != newpoly.points[2])
   {
    newpoint = newpoly.points[2];
   }
   pntindex = pntindex + 1;
   pnts[pntindex] = newpoint;// add new vertex to the list

   //get polygon count value for this vertex
   mypolycount = pnts[pntindex].polygon;
  editend();
 }

 lyrsetfg(fgLayer);//back to 2 point poly chain layer

 return(pnts);
}