-- CalcPaths.lua by Egaltech s.r.l. 2022/06/28
-- Calcolo percorsi di lavoro per Stampa 3d

-- Tabella per definizione modulo
local CalcPaths = {}

-- Intestazioni
require( 'EgtBase')

EgtOutLog( ' CalcPaths started', 1)

-- Dati
local AMD = require( 'AddManData')

---------------------------------------------------------------------
local s_nPartId
local s_dOffsCorr = 10 * GEO.EPS_SMALL

---------------------------------------------------------------------
local function GetLayerParamsForPathCalc()   
   local LayerParams = {}   
   LayerParams.nShellsNbr = EgtGetInfo( s_nPartId, KEY_SHELLS_NBR, 'i')
   LayerParams.dStrand = EgtGetInfo( s_nPartId, KEY_STRAND, 'd') 
   LayerParams.nStrandOverlap = EgtGetInfo( s_nPartId, KEY_STRAND_OVERLAP, 'i') or 0
   LayerParams.dOffs = EgtGetInfo( s_nPartId, KEY_OFFSET_SLICE, 'd')
   LayerParams.nFloorNbr = EgtGetInfo( s_nPartId, KEY_FLOOR_NBR, 'i') or 0
   LayerParams.nFloorType = EgtGetInfo( s_nPartId, KEY_FLOOR_TYPE, 'i') or INFILL_TYPE.ZIGZAG
   LayerParams.nCeilNbr = EgtGetInfo( s_nPartId, KEY_CEIL_NBR, 'i') or 0
   LayerParams.nCeilType = EgtGetInfo( s_nPartId, KEY_CEIL_TYPE, 'i') or INFILL_TYPE.ZIGZAG
   LayerParams.vtSlicing = EgtGetInfo( s_nPartId, KEY_SLICING_DIR, 'v')
   LayerParams.bPrintInvert = ( EgtGetInfo( s_nPartId, KEY_PRINT_DIRECTION, 'i') == PRINT_DIRECTION.CW)
   -- parametri costolature
   LayerParams.bRibsInvertOrder = EgtGetInfo( s_nPartId, KEY_RIBS_INVERT_ORDER, 'b')
   return LayerParams
end

----------------------------------------------------------------------
local function ComputeSurfOffset( nSrf, nGrpId, dOffs)
   
   local nCopySrf = EgtCopy( nSrf, nGrpId)
   local bOk = EgtSurfFrOffset( nCopySrf, dOffs)
   local bExists = EgtSurfFrChunkCount( nCopySrf) > 0
   if not bOk or not bExists then
      EgtErase( nCopySrf)
      nCopySrf = EgtCopyGlob( nSrf, nGrpId)
      bOk = EgtSurfFrOffset( nCopySrf, dOffs + 0.05)
      bExists = EgtSurfFrChunkCount( nCopySrf) > 0
   end
   return bOk, bExists, nCopySrf
end

---------------------------------------------------------------------
local function GetLayerStartPoint( nLayId, vtSlicing)
   
   -- recupero quota layer
   local dZ = EgtGetInfo( nLayId, KEY_SLICE_REAL_Z, 'd')
   local dDeltaZ = EgtGetInfo( nLayId, KEY_SLICE_DELTAZ, 'd')
   local frSlicing = Frame3d( ORIG(), vtSlicing)
   local ptOn = Point3d( 0, 0, dZ + dDeltaZ)
   ptOn:toGlob( frSlicing)
   
   -- gruppo temporaneo dove salvo i risultati
   local nGrpTmp = EgtGroup( nLayId)
   
   local vPtStart = {}
   local nMachStartGrp = EgtGetFirstNameInGroup( s_nPartId, LAY_MACH_START)
   local nStartId = EgtGetFirstInGroup( nMachStartGrp)
   while nStartId do
      local nType = EgtGetType( nStartId)
      -- se punto
      if nType == GDB_TY.GEO_POINT then
         table.insert( vPtStart, EgtSP( nStartId))
      else
         -- se curva interseco con il piano
         local nId, nCnt = EgtPlaneCurveInters( ptOn, vtSlicing, nStartId, nGrpTmp, GDB_RT.GLOB)
         if nId then
            for i = nId, nId + nCnt - 1 do
               table.insert( vPtStart, EgtSP( i))
            end
         end
      end
      nStartId = EgtGetNext( nStartId)
   end
   
   EgtErase( nGrpTmp)
   return vPtStart
end

---------------------------------------------------------------------
local function ModifyStartPoint( nCrvId, vPtStart)
   
   -- cerco lo start point più vicino tra quelli possibili
   if vPtStart and #vPtStart > 0 then
      local nMinIdx = -1
      local dMinDist = GEO.INFINITO
      for i = 1, #vPtStart do
         local dDist = EgtPointCurveDist( vPtStart[i], nCrvId)
         if dDist < dMinDist - 10 * GEO.EPS_SMALL then
            dMinDist = dDist
            nMinIdx = i
         end
      end
      EgtChangeClosedCurveStartPoint( nCrvId, vPtStart[nMinIdx])
   end
end

---------------------------------------------------------------------
local function GetPathsFromSurf( nSrfId, sName, nType, nGrpId, vPtStart)
   
   local vIds = {}
   local nChunks = EgtSurfFrChunkCount( nSrfId) 
   for nC = 0, nChunks - 1 do 
      -- estraggo i contorni 
      local nCrvId, nCrvCnt = EgtExtractSurfFrChunkLoops( nSrfId, nC, nGrpId)
      for nInd = 0, nCrvCnt - 1 do
         EgtSetName( nCrvId + nInd, sName)
         EgtSetInfo( nCrvId + nInd, KEY_TYPE, nType)
         
         -- se è loop interno lo inverto per averlo orientato in senso antiorario 
         if nInd > 0 then
            EgtInvertCurve( nCrvId + nInd)
         end
         
         -- verifico soddisfi i requisiti (lunghezza e area)
         local dLen = EgtCurveLength( nCrvId + nInd)
         local _ , _ , dArea = EgtCurveArea( nCrvId + nInd)
         if dLen < MIN_LEN or dArea < MIN_AREA then
            EgtErase( nCrvId + nInd)
            return
         end
         
         table.insert( vIds, nCrvId + nInd)
         ModifyStartPoint( nCrvId + nInd, vPtStart)
      end
   end
   
   return vIds
end

----------------------------------------------------------------------
local function VerifyPath( nCrvId, dStrand, vtSlicing, nGrp)
   
   local _, _, dArea = EgtCurveArea( nCrvId)
   
   -- verifico se esiste l'offset (permetto una piccola sovrapposizione)
   local dAllowedOverlap = 1
   local nRes, nCnt = EgtOffsetCurveAdv( nCrvId, - dStrand / 2 + dAllowedOverlap)
   -- se errore ritento con valore leggermente modificato
   if not nRes then
      nRes, nCnt = EgtOffsetCurveAdv( nCrvId, - dStrand / 2 + 0.05)
      if not nRes then return false end
   end  
   for j = nRes, nRes + nCnt - 1 do
      EgtErase( j)
   end
   
   if nRes == GDB_ID.NULL or not dArea or dArea < GEO.EPS_SMALL then
      -- verifico se fattibile con una sola passata
      -- TODO da sistemare con medial axis per curva generica
      local bSingleStrand = false
      if EgtCurveIsClosed( nCrvId) then
         local nGrpTmp = EgtGroup( nGrp, Frame3d( ORIG(), vtSlicing))
         EgtRelocateGlob( nCrvId, nGrpTmp)
         local frLoc, dDimX, dDimY = EgtCurveMinAreaRectangleXY( nCrvId)
         if dDimY < 0.5 then
            -- TODO  curva generica
            local dZ = EgtSP( nCrvId):getZ()
            -- creo la curva che corrisponde alla sigola passata
            local ptS = frLoc:getOrigin() - dDimX / 2 * frLoc:getVersX() + dZ * Z_AX()
            local ptE = frLoc:getOrigin() + dDimX / 2 * frLoc:getVersX() + dZ * Z_AX()
            if dist( ptS, ptE) > 5 then
               local nId = EgtCurveCompoFromPoints( nGrpTmp, { ptS, ptE})
               local sName = EgtGetName( nCrvId)
               if sName then EgtSetName( nId, sName) end
               local nType = EgtGetInfo( nCrvId, KEY_TYPE, 'i')
               if nType then EgtSetInfo( nId, KEY_TYPE, nType) end
               EgtErase( nCrvId)
               EgtChangeId( nId, nCrvId)
               bSingleStrand = true
            end
         end
         EgtRelocateGlob( nCrvId, nGrp, GDB_IN.LAST_SON)
         EgtErase( nGrpTmp)
      end
      -- se non è fattibile con unica passata lo cancello      
      if not bSingleStrand then
         EgtErase( nCrvId)
         return false
      end
   end
   
   return true
end

-------------------------------------------------------------------
local function ComputeTrimSurfWithOverlaps( vIds, nSrfBase, sKeyOverlap, dStrand, nGrp)
   
   -- per ogni overlap creo le superfici con cui fare i trim
   local vSurfOffs = {}
   for i = 1, #vIds do
      local nOverlap = EgtGetInfo( vIds[i], sKeyOverlap, 'i')
      if not vSurfOffs[nOverlap] then
         local dNewOffs = nOverlap / 100 * dStrand
         local bOk, bExists, nSrfOffs = ComputeSurfOffset( nSrfBase, nGrp, dNewOffs)
         if bOk then
            vSurfOffs[nOverlap] = nSrfOffs
         end
      end
   end
   return vSurfOffs
end

--------------------------------------------------------------------
--------------------- RIEMPIMENTI PIENI ----------------------------
--------------------------------------------------------------------
local function AdjustSurfForFloorCeil( nStrandDiff, nSrfTrim, nShellNbrSurfGrp)
   
   if EgtSurfFrChunkCount( nSrfTrim) == 0 then return end

   local nSurf = EgtCopyGlob( nSrfTrim, EgtGetParent( nSrfTrim))
   
   if nShellNbrSurfGrp then
      local nIdx = nStrandDiff
      local nShellSurf = EgtGetFirstNameInGroup( nShellNbrSurfGrp, SHELL_NBR_SURF .. tostring( nIdx))
      while nShellSurf do
         EgtSurfFrSubtract( nSurf, nShellSurf)
         nIdx = nIdx + 1
         nShellSurf = EgtGetFirstNameInGroup( nShellNbrSurfGrp, SHELL_NBR_SURF .. tostring( nIdx))
      end
   end
   
   return nSurf
end

--------------------------------------------------------------------
local function ReorderPath( vOldIds, vNewIds)
   
   if not vNewIds then return end 
   if #vOldIds == 1 and #vNewIds == 1 then
      EgtRelocateGlob( vNewIds[1], vOldIds[1], GDB_IN.AFTER)
      return
   end
   
   -- associo ad ogni elemento di vOldIds gli elementi di vNewIds che contiene
   local vOrdered = {}
   if #vOldIds == 1 then
      vOrdered[vOldIds[1]] = vNewIds
   else      
      local nGrp = EgtGetParent( vOldIds[1])
      -- creo le superifici a partire dalle curve in vOldIds
      local vOldSurf = {}
      for i = 1, #vOldIds do         
         local nSrf = EgtSurfFlatRegion( nGrp, {vOldIds[i]})
         table.insert( vOldSurf, EgtIf( nSrf, nSrf, GDB_ID.NULL))
      end
      
      for i = 1, #vNewIds do
         for j = 1, #vOldSurf do
            if vOldSurf[j] ~= GDB_ID.NULL then
               if not EgtSurfFrTestExternal( vOldSurf[j], vNewIds[i]) then
                  if vOrdered[vOldIds[j]] then
                     table.insert( vOrdered[vOldIds[j]], vNewIds[i])
                  else
                     vOrdered[vOldIds[j]] = {vNewIds[i]}
                  end
                  break
               end
            end
         end
      end
      
      for i = 1, #vOldSurf do
         EgtErase( vOldSurf[i])
      end
   end
   
   -- riordino
   for nParentIdx, vChildren in pairs( vOrdered) do      
      if #vChildren == 1 then
         -- se racchiude solo una curva
         EgtRelocateGlob( vChildren[1], nParentIdx, GDB_IN.AFTER)
      else
         EgtSpInit() 
         -- se racchiude più curve uso shortest path per ordinarle
         for j = 1, #vChildren do
            local pt = EgtGP( vChildren[j])
            EgtSpAddPoint( pt:getX(), pt:getY(), pt:getZ(), 0, 0, pt:getX(), pt:getY(), pt:getZ(), 0, 0)
         end
         local ptS = EgtSP( nParentIdx)
         EgtSpSetOpenBound( true, SHP_OB.NEAR_PNT, ptS:getX(), ptS:getY(), ptS:getZ(), 0, 0)
         local vOrd, _ = EgtSpCalculate( SHP_TY.OPEN)
         EgtSpTerminate()
         
         for j = #vOrd, 1, -1 do
            EgtRelocateGlob( vChildren[vOrd[j]], nParentIdx, GDB_IN.AFTER)
         end
      end
   end
end

---------------------------------------------------------------------------
local function ComputeOffsetInfill( nSrf, dStrand, vtSlicing, sName, nType, vPtStart, nGrp)
   
   local nChunk = EgtSurfFrChunkCount( nSrf)
   if nChunk == 0 then return end
   
   -- estraggo i contorni della superficie  
   local vOldIds = GetPathsFromSurf( nSrf, sName, nType, nGrp, vPtStart)
   local dOffs = - dStrand
   local bOk, bExists, nSrfOffs = ComputeSurfOffset( nSrf, nGrp, dOffs)
   while bOk and bExists do
      -- estraggo i contorni
      local vNewIds = GetPathsFromSurf( nSrfOffs, sName, nType, nGrp, vPtStart)
      if vNewIds then
         -- riordino
         ReorderPath( vOldIds, vNewIds)         
         -- verifico fattibilità
         local k = 1
         while k <= #vNewIds do
            if VerifyPath( vNewIds[k], dStrand, vtSlicing, nGrp) then
               k = k + 1
            else
               -- se non è fattibile lo rimuovo dalla table per non ritrovarlo nello step successivo
               table.remove( vNewIds, k)
            end
         end
         vOldIds = vNewIds
      end
      
      EgtErase( nSrfOffs)
      -- offset successivo
      dOffs = dOffs - dStrand
      bOk, bExists, nSrfOffs = ComputeSurfOffset( nSrf, nGrp, dOffs)      
   end

end

--------------------------------------------------------------------------------
local function ComputeZigZagInfill( nSrf, dStrand, vtSlicing, sName, nType, vPtStart, nGrp)

   local nChunk = EgtSurfFrChunkCount( nSrf)
   if nChunk == 0 then return end
   
   local nCopySrf = EgtCopyGlob( nSrf, nGrp)
   if  EgtSurfFrChunkCount( nSrf) == 0 then return end 
   
   local nFirst, nCnt = EgtExplodeSurf( nCopySrf)
   local frLoc = Frame3d( ORIG(), vtSlicing)
   local vIds = {}
   for nId = nFirst, nFirst + nCnt - 1 do
      local nGrpTmp = EgtGroup( nGrp, frLoc)
         
      -- recupero outer curve
      local nCrvGrpId = EgtGetParent( nGrp)
      local nOuterCrv = EgtGetFirstNameInGroup( nCrvGrpId, OUTER_CRV)
      local nCopyOuterCrv = EgtCopyGlob( nOuterCrv, nGrpTmp)
      
      -- cerco il lato più lungo
      local vCrvIds = GetPathsFromSurf( nId, 'Tmp', nType, nGrpTmp)
      local dMaxLen = - GEO.INFINITO
      local dDist = GEO.INFINITO
      local vtDir
      
      for j = 1, #vCrvIds do
         local nId, nCnt = EgtExplodeCurveCompo( vCrvIds[j])
         
         -- cerco il lato più lungo
         for k = nId, nId + nCnt - 1 do
            local dCurrLen = EgtCurveLength( k)
            if dCurrLen > dMaxLen + GEO.EPS_SMALL then
               dMaxLen = dCurrLen
            end
         end
         -- tra i lati più lunghi scelgo quello più vicino al bordo
         for k = nId, nId + nCnt - 1 do
            local dCurrLen = EgtCurveLength( k)
            if abs( dMaxLen - dCurrLen) < 10 then
               local dCurrDist = EgtPointCurveDist( EgtMP( k), nCopyOuterCrv)
               if dCurrDist < dDist + 10 * GEO.EPS_SMALL then
                  vtDir = EgtSV( k)
                  dDist = dCurrDist
               end
            end
         end
      end
      EgtErase( nGrpTmp)
      
      local _, _, dAng = SphericalFromVector( vtDir)
      vtDir:toGlob( frLoc)
      
      local nInd, nCnt = EgtGetSurfFrZigZagInfill( nId, nGrp, dStrand, dAng, false, false)
      if not nInd then return end
      for j = nInd, nInd + nCnt - 1 do
         EgtSetName( j, sName)
         EgtSetInfo( j, KEY_TYPE, nType)
         EgtSetInfo( j, KEY_ZIG_ZAG_DIR, vtDir)
         EgtSetInfo( j, KEY_ZIG_ZAG_INFILL, 1)
         EgtModifyCurveExtrusion( j, vtSlicing)
         table.insert( vIds, j)
      end
      local vtS = EgtSV( nInd)
      EgtErase( nId)
   end
   
end

-------------------------------------------------------------------
--------------------------- RIBS -----------------------------------
--------------------------------------------------------------------
-- Funzione che sistema le intersezioni fra costolature nel caso generico
local function AdjustRibsOffsetForIntersection( nCrv1, nCrv2, LayerParams, nOffsGrp)
  
   -- calcolo gli offset della curva principale ( nCrv1) da usare per trim
   local nShells = EgtGetInfo( nCrv1, KEY_RIBS_SHELLS_NBR, 'i')
   local nOverlap1 = EgtGetInfo( nCrv1, KEY_RIBS_OVERLAP, 'i')
   local nOverlap2 = EgtGetInfo( nCrv2, KEY_RIBS_OVERLAP, 'i')
   local nOverlap = min( nOverlap1, nOverlap2)
   local dOffs = ( nShells - 1) * LayerParams.dStrand / 2
   local nSrf = EgtSurfFrFatCurve( nOffsGrp, nCrv1, dOffs + ( 1 - nOverlap / 100) * LayerParams.dStrand, false) 
   
   -- recupero gli offset della curva secondaria ( nCrv2)
   local vOffs2 = EgtGetNameInGroup( nOffsGrp, EgtGetName( nCrv2))
   -- trim degli offset della curva secondaria
   for i = 1, #vOffs2 do
      local nId, nCnt = EgtTrimCurveWithRegion( vOffs2[i], nSrf, false, true)
      EgtChangeId( nId, vOffs2[i])
      if nCnt > 1 then
         EgtSetInfo( nId + 1, KEY_SPLIT_RIB, vOffs2[i])
         EgtRelocateGlob( nId + 1, nOffsGrp, GDB_IN.LAST_SON)
      end
   end 
   EgtErase( nSrf)
   
end

--------------------------------------------------------------------
-- Funzione che sistema le intersezioni fra costolature nel caso di 2 passate 
local function AdjustRibsOffsetForIntersection2Shells( nCrv1, nCrv2, LayerParams, nOffsGrp, nOrigGrp) 

   -- recupero gli offset originali delle due curve
   local vOffsOrig1 = EgtGetNameInGroup( nOrigGrp, EgtGetName( nCrv1))
   local vOffsOrig2 = EgtGetNameInGroup( nOrigGrp, EgtGetName( nCrv2))
   
   -- costruisco le superfici da usare per trim
   local nOverlap = EgtGetInfo( nCrv1, KEY_RIBS_OVERLAP, 'i')
   local dOffs = LayerParams.dStrand / 2 + ( 1 - nOverlap / 100) * LayerParams.dStrand
   
   local nRect1 = EgtRectangle3P( nOffsGrp, EgtSP( vOffsOrig1[1]), EgtEP( vOffsOrig1[2]), EgtEP( vOffsOrig1[1]))
   local nSrf1 = EgtSurfFlatRegion( nOffsGrp, {nRect1})
   local vtN1 = EgtSurfFrNormVersor( nSrf1, GDB_ID.ROOT)   
   if LayerParams.vtSlicing * vtN1 < 0 then
      EgtInvertSurf( nSrf1)
   end
   
   local nRect2 = EgtRectangle3P( nOffsGrp, EgtSP( vOffsOrig2[1]), EgtEP( vOffsOrig2[2]), EgtEP( vOffsOrig2[1]))
   local nSrf2 = EgtSurfFlatRegion( nOffsGrp, {nRect2})
   local vtN2 = EgtSurfFrNormVersor( nSrf2, GDB_ID.ROOT)   
   if LayerParams.vtSlicing * vtN2 < 0 then
      EgtInvertSurf( nSrf2)
   end
   
   -- trim degli offset di nCrv1
   local vOffs1 = EgtGetNameInGroup( nOffsGrp, EgtGetName( nCrv1))
   for i = 1, #vOffs1 do
      local nId, nCnt = EgtTrimCurveWithRegion( vOffs1[i], nSrf2, false, true)
   end 

   -- trim degli offset di nCrv2
   local vOffs2 = EgtGetNameInGroup( nOffsGrp, EgtGetName( nCrv2))  
   for i = 1, #vOffs2 do 
      local nId, nCnt = EgtTrimCurveWithRegion( vOffs2[i], nSrf1, false, true)
   end
   
   EgtErase( nSrf1)
   EgtErase( nRect1)
   EgtErase( nSrf2)
   EgtErase( nRect2)
   
end

--------------------------------------------------------------------
local function HandleRibsIntersections( nRibsGrp, LayerParams, nOffsGrp, nRibsPathGrp, bAllTwoStrands)
  
   local nCrvGrp = EgtGetParent( nRibsPathGrp)
   -- copio gli offset delle costolature nel RibsPathGrp
   local vOffsRib = EgtGetAllInGroup( nOffsGrp)
   for i = 1, #vOffsRib do
      EgtCopyGlob( vOffsRib[i], nRibsPathGrp)
   end
   
   -- calcolo la regione nella quale ha senso considerare l'intersezione
   local nSrf = EgtGetFirstNameInGroup( nCrvGrp, TOT_SHELL_TRIM_SURF)
   local bOk, bExists, nSrfOffs = ComputeSurfOffset( nSrf, nCrvGrp, 2 * LayerParams.dStrand) 
   if not bOk or not bExists then
      nSrfOffs = EgtCopyGlob( nSrf, nCrvGrp)
   end
     
   local vRibsIds = EgtGetNameInGroup( nRibsGrp, RIBS_CRV .. '*')   
   local bInters = false
   local vSplit = {}
   for i = 1, #vRibsIds do
      -- verifico se interseca uno dei setti successivi
      for j = i + 1, #vRibsIds do
         local ptInt = EgtIP( vRibsIds[i], vRibsIds[j], ORIG())
         if ptInt then
            
            -- verifico se l'interserzione si trova nella regione dello slice  
            local nPtId = EgtPoint( nRibsPathGrp, ptInt)
            if not EgtSurfFrTestExternal( nSrfOffs, nPtId) then
               bInters = true
               
               local dPar1 = EgtCurveParamAtPoint( vRibsIds[i], ptInt)
               local dPar2 = EgtCurveParamAtPoint( vRibsIds[j], ptInt)
               local _, dParE1 =  EgtCurveDomain( vRibsIds[i])
               local _, dParE2 =  EgtCurveDomain( vRibsIds[j])
               
               local nCrv1 = vRibsIds[i]   -- curva principale che non viene tagliata
               local nCrv2 = vRibsIds[j]   -- curve secondaria da modificare
               if dPar1 < 10 * GEO.EPS_SMALL or abs( dPar1 - dParE1) < 10 * GEO.EPS_SMALL then
                  nCrv1, nCrv2 = nCrv2, nCrv1
               end
               
               if bAllTwoStrands then
                  -- nel caso di 2 passate gestione speciale
                  AdjustRibsOffsetForIntersection2Shells( nCrv1, nCrv2, LayerParams, nRibsPathGrp, nOffsGrp)
               else
                  AdjustRibsOffsetForIntersection( nCrv1, nCrv2, LayerParams, nRibsPathGrp)
               end
            end
            EgtErase( nPtId)
         end
      end
   end
   
   EgtErase( nSrfOffs)
 
   return bInters
end

--------------------------------------------------------------------
-- Funzione che riordina le costolature nel caso generico
local function ReorderRibs( nGrp, bInvertOrder, dStrand, nMaxNbr)
   
   EgtSpInit()
   local vIds = EgtGetNameInGroup( nGrp, RIBS_CRV .. '*')
   if not vIds or #vIds == 0 then return end
   
   local vSplitRibs = {}
   local vSPRibs = {}
   for i = 1, #vIds do
      local nInfo = EgtGetInfo( vIds[i], KEY_SPLIT_RIB, 'i')
      local nShells = EgtGetInfo( vIds[i], KEY_RIBS_SHELLS_NBR, 'i')
      -- se è ottenuto dalla divisione di una costolatura non va considerato per il TSP ( viene aggiunto in seguito)
      if nInfo and nShells == 1 then
         table.insert( vSplitRibs, vIds[i])
      else
         local pt = EgtMP( vIds[i], GDB_RT.GLOB)
         EgtSpAddPoint( pt:getX(), pt:getY(), pt:getZ(), 0, 0, pt:getX(), pt:getY(), pt:getZ(), 0, 0)
         table.insert( vSPRibs, vIds[i])
      end
   end
   local vOrd, dLen = EgtSpCalculate( SHP_TY.OPEN)
   EgtSpTerminate()
   
   EgtRelocateGlob( vSPRibs[vOrd[1]], nGrp, EgtIf( bInvertOrder, GDB_IN.LAST, GDB_IN.FIRST))
   for i = 2, #vOrd do
      EgtRelocateGlob( vSPRibs[vOrd[i]], vSPRibs[vOrd[i-1]], EgtIf( bInvertOrder, GDB_IN.BEFORE, GDB_IN.AFTER))
   end
   
   -- sistemo nomi
   local kMax = nMaxNbr + 1   
   local dTol = 500 * GEO.EPS_SMALL
   for i = 1, nMaxNbr do
      local vIds = EgtGetNameInGroup( nGrp, RIBS_CRV .. tostring(i)) or {}
      for j = 2, #vIds do
         local dDistS = EgtPointCurveDist( EgtSP( vIds[j]), vIds[j-1])
         local dDistM = EgtPointCurveDist( EgtMP( vIds[j]), vIds[j-1])
         local dDistE = EgtPointCurveDist( EgtEP( vIds[j]), vIds[j-1])
         if abs( dDistS - dStrand) < dTol or abs( dDistM - dStrand) < dTol or abs( dDistE - dStrand) < dTol then
            -- se le costolatura è vicina alla precedente avrà lo stesso nome
            EgtSetName( vIds[j], EgtGetName( vIds[j-1]))
            EgtRelocateGlob( vIds[j], vIds[j-1], GDB_IN.AFTER)
         else
            -- se la costolatura dista troppo dalla precedente le cambio il nome
            EgtSetName( vIds[j], RIBS_CRV .. tostring( kMax))
            kMax = kMax + 1
         end
      end
   end 
   
   -- aggiusto tutte le costolature divise
   local tabSplitted = {}
   for i = 1, #vSplitRibs do
      local nPrevId = EgtGetInfo( vSplitRibs[i], KEY_SPLIT_RIB, 'i')
      local bInverted = EgtGetInfo( vSplitRibs[i], KEY_INVERTED_CRV, 'b') or false
      -- aggiungo come successiva alla costolatura da cui si è generata
      EgtRelocateGlob( vSplitRibs[i], nPrevId, EgtIf( bInverted, GDB_IN.BEFORE, GDB_IN.AFTER))
      -- correggo le info per gestire correttamente nel calcolo toolpath
      if bInverted and not tabSplitted[nPrevId] then
         EgtRemoveInfo( vSplitRibs[i], KEY_SPLIT_RIB)
         EgtSetInfo( nPrevId, KEY_SPLIT_RIB, vSplitRibs[i])
         tabSplitted[nPrevId] = 1
      end
   end
   
end

--------------------------------------------------------------------------------------------
local function CopyInfo( nSouId, nDestId, sInfo, sType)
   local info = EgtGetInfo( nSouId, sInfo, sType)
   EgtSetInfo( nDestId, sInfo, info)
end

--------------------------------------------------------------------------------------------
local function ReassignInfo( nCrv, nCnt, vOrig)
   
   for nId = nCrv, nCrv + nCnt - 1 do      
      local ptS = EgtSP( nId)
      local ptE = EgtEP( nId)
      
      -- info overlap
      local nOverlap = EgtGetInfo( s_nPartId, KEY_RIBS_OVERLAP, 'i')
      EgtSetInfo( nId, KEY_RIBS_OVERLAP, nOverlap)
      
      local bStart = false
      local bEnd = false
      while not bStart and not bEnd do
         -- scorro le curve originarie per capire da quali deriva
         for i = 1, #vOrig do
            local ptSOrig = EgtSP( vOrig[i])
            local ptEOrig = EgtEP( vOrig[i])
            
            -- verifico se corrisponde al suo start
            if AreSamePointApprox( ptS, ptSOrig) or AreSamePointApprox( ptS, ptEOrig) then
               CopyInfo( vOrig[i], nId, KEY_RIBS_LEAD_IN_INVERT, 'b')
               CopyInfo( vOrig[i], nId, KEY_RIBS_LEAD_IN_LEN, 'd')
               CopyInfo( vOrig[i], nId, KEY_ASSOCIATED_SURF, 'i')
               bStart = true
            end
            -- verifico se corrisponde al suo end
            if AreSamePointApprox( ptE, ptSOrig) or AreSamePointApprox( ptE, ptEOrig) then
               CopyInfo( vOrig[i], nId, KEY_RIBS_LEAD_OUT_INVERT, 'b')
               CopyInfo( vOrig[i], nId, KEY_RIBS_LEAD_OUT_LEN, 'd')
               CopyInfo( vOrig[i], nId, KEY_RIBS_LEAD_OUT_COASTING, 'd')
               CopyInfo( vOrig[i], nId, KEY_RIBS_LEAD_OUT_WIPE, 'd')
               CopyInfo( vOrig[i], nId, KEY_RIBS_LEAD_OUT_WIPE_DIR, 'd')
               bEnd = true
            end
         end
      end
   end
   
   -- dopo aver salvato le info è inutile conservare le curve originali
   for i = 1, #vOrig do
      EgtErase( vOrig[i])
   end
end

---------------------------------------------------------------------------------------------
-- Funzione che riordina le costolature nel caso di intersezioni e 2 passate
local function ReorderRibsInters2Shells( nOffsGrp, dStrand)
   
   local vOffs = EgtGetNameInGroup( nOffsGrp, RIBS_CRV .. '*')
   -- copio le curve originali ( per recuperarne le info)
   local vCopy = {}
   for i = 1, #vOffs do
      local nNewId = EgtCopy( vOffs[i], nOffsGrp)
      table.insert( vCopy, nNewId)
   end
   
   -- concateno le curve
   local nCrv, nCnt = EgtCurveCompoByChain( nOffsGrp, vOffs, ORIG())
   
   local vIds = {}
   for i = nCrv, nCrv + nCnt - 1 do
      EgtSetInfo( i, KEY_TYPE, TYPE.RIB)
      table.insert( vIds, i)
   end

   local k = 0   -- indice da utilizzare per i nomi
   while #vIds > 0 do
      k = k + 1
      -- prendo la prima tra le curve a disposizione
      nCurrCrv = vIds[1]
      table.remove( vIds, 1)
      EgtSetName( nCurrCrv, RIBS_CRV .. tostring(k))
      local pt = EgtEP( nCurrCrv)
      local _, dParE = EgtCurveDomain( nCurrCrv)
      local nCnt = 0
      -- scorro alla ricerca di una curva che posso collegare alla corrente
      while nCurrCrv do
         local bFound = false
         for j = 1, #vIds do
            if vIds[j] ~= nCrv and not EgtCurveIsClosed(vIds[j]) then
               
               -- verifico se il collegamento è possibile
               local bAdd = false
               local bInvert = false
               local dDist, _, dParMinDist = EgtPointCurveDist( pt, vIds[j])
               if dDist < dStrand + 10 * GEO.EPS_SMALL then
                  -- controllo che sia vicino ad uno degli estremi
                  local dParS, dParE = EgtCurveDomain( vIds[j])
                  if abs( dParMinDist - dParS) < 500 * GEO.EPS_SMALL then
                     bAdd = true
                  elseif abs( dParMinDist - dParE) < 500 * GEO.EPS_SMALL then
                     bAdd = true
                     -- è se necessaria inversione di vIds[j]
                     bInvert = true
                  end
               end

               if not bAdd then
                  -- check sullo start point di vIds[j]
                  local dDist, _, dParMinDist = EgtPointCurveDist( EgtSP( vIds[j]), nCurrCrv)
                  if dDist < dStrand + 10 * GEO.EPS_SMALL then
                     bInvert = false
                     -- controllo sia vicino all'end point della curva corrente
                     if dParE - dParMinDist < 500 * GEO.EPS_SMALL then
                        bAdd = true
                     -- altrimenti può essere vicino allo start
                     elseif dParMinDist < 500 * GEO.EPS_SMALL and nCnt == 0 then                        
                        bAdd = true
                        EgtInvertCurve( nCurrCrv)
                     end
                  end
                  -- se non è aggiunto check con end point di vIds[j]
                  if not bAdd then
                     local dDist, _, dParMinDist = EgtPointCurveDist( EgtEP( vIds[j]), nCurrCrv)
                     if dDist < dStrand + 10 * GEO.EPS_SMALL then
                        bInvert = true
                        if dParE - dParMinDist < 500 * GEO.EPS_SMALL then
                           bAdd = true
                        elseif dParMinDist < 500 * GEO.EPS_SMALL and nCnt == 0 then
                           bAdd = true
                           EgtInvertCurve( nCurrCrv)
                        end
                     end
                  end
               end
              
               if bAdd then 
                  bFound = true
                  nCnt = nCnt + 1
                  EgtRelocateGlob( vIds[j], nCurrCrv, GDB_IN.AFTER)
                  EgtSetName( vIds[j], RIBS_CRV .. tostring( k))
                  -- eventuale inversione della curva
                  if bInvert then EgtInvertCurve( vIds[j]) end
                  
                  -- aggiorno per collegamento successivo
                  pt = EgtEP( vIds[j])
                  _, dParE = EgtCurveDomain( vIds[j])
                  nCurrCrv = vIds[j]
                  -- elimino la curva dal vettore di curve da considerare
                  table.remove( vIds, j)
                  break
               end
            end
         end
         -- se non ho più curve da collegare
         if not bFound and nCnt == 0 then
            -- se era la prima curva faccio un tentativo invertendola
            nCnt = 1
            EgtInvertCurve( nCurrCrv)
            pt = EgtEP( nCurrCrv)
         elseif not bFound then
            nCurrCrv = nil
         end
      end
   end
   
   -- Recupero le info dalle curve originali
   ReassignInfo( nCrv, nCnt, vCopy)
end

--------------------------------------------------------------------
local function CalcRibsPaths( nSliceGrp, nRibsGrp, LayerParams, nIdx, nMaxStrandDiff)

   local vRibs = EgtGetNameInGroup( nRibsGrp, RIBS_CRV .. '*')
   -- verifico se tutte le costolature vengono fatte con 2 passate
   local bAllTwoStrands = true
   for i = 1, #vRibs do
      local nStrand = EgtGetInfo( vRibs[i], KEY_RIBS_SHELLS_NBR, 'i')
      if nStrand ~= 2 then
         bAllTwoStrands = false
         break
      end
   end
   
   local nLast = EgtGetLastNameInGroup( nRibsGrp, RIBS_CRV .. '*')
   local sLastName = EgtGetName( nLast)
   local nMaxNbr = tonumber( string.sub( sLastName, 4))
   
   -- calcolo gli offset
   local nOffsGrp = EgtGroup( nRibsGrp)
   for i = 1, #vRibs do
      local nShellsNbr = EgtGetInfo( vRibs[i], KEY_RIBS_SHELLS_NBR, 'i')
      local dOffs = ( nShellsNbr - 1) * LayerParams.dStrand / 2
      for k = 0, nShellsNbr - 1 do
         local nNewId = EgtOffsetCurveAdv( vRibs[i], - dOffs + k * LayerParams.dStrand)
         EgtSetName( nNewId, EgtGetName( vRibs[i]))
         EgtSetInfo( nNewId, KEY_TYPE, TYPE.RIB)
         EgtRelocateGlob( nNewId, nOffsGrp)
      end
   end

   -- scorro i gruppi di curve
   local dOffs = 0.5 * LayerParams.dStrand - LayerParams.dOffs + ( LayerParams.nShellsNbr - 1) * LayerParams.dStrand
   local nCrvGrp = EgtGetFirstNameInGroup( nSliceGrp, CONTOUR_GRP .. '*')
   while nCrvGrp do
      
      -- creo o svuoto il gruppo
      local nRibsPathGrp = EgtGetFirstNameInGroup( nCrvGrp, RIBS_GRP)
      if not nRibsPathGrp then
         nRibsPathGrp = EgtGroup( nCrvGrp)
         EgtSetName( nRibsPathGrp, RIBS_GRP)
         EgtSetStatus( nRibsPathGrp, GDB_ST.OFF)
      else
         EgtEmptyGroup( nRibsPathGrp)
      end
      
      -- creo le superfici con cui fare i trim
      local nSrfBase = EgtGetFirstNameInGroup( nCrvGrp, TOT_SHELL_TRIM_SURF)
      if not nSrfBase then
         EgtOutLog( 'Warning : Ribs not possible (layer '..tostring( nIdx)..') - CalcPaths')
      else
         local vSurfOffs = ComputeTrimSurfWithOverlaps( vRibs, nSrfBase, KEY_RIBS_OVERLAP, LayerParams.dStrand, nRibsPathGrp)

         -- gestisco eventuali intersezioni fra costolature
         local bInters = HandleRibsIntersections( nRibsGrp, LayerParams, nOffsGrp, nRibsPathGrp, bAllTwoStrands)
         EgtSetInfo( nRibsPathGrp or GDB_ID.NULL, KEY_RIBS_INTERS, bInters)
         EgtSetInfo( nRibsPathGrp or GDB_ID.NULL, KEY_RIBS_TWO_STRANDS, bAllTwoStrands)         

         -- eseguo il trim delle costole con la regione offsettata
         local tOldNewIds = {}
         local vOrderedRibs = EgtGetNameInGroup( nRibsPathGrp, RIBS_CRV ..'*')
         for i = 1, #vOrderedRibs do
            -- trim con superficie opportuna
            local nOverlap = EgtGetInfo( vOrderedRibs[i], KEY_RIBS_OVERLAP, 'i')
            if not vSurfOffs[ nOverlap] then
               -- la costolatura non è fattibile
               EgtOutLog( 'Warning: Ribs not possibile (layer '..tostring( nIdx)..') - CalcPaths')
               EgtErase( vOrderedRibs[i])
            else
                local nCrv, nCnt = EgtTrimCurveWithRegion( vOrderedRibs[i], vSurfOffs[nOverlap], true, false)
                tOldNewIds[ vOrderedRibs[i]] = {}
                
                -- elimino tratti troppo corti
                for nInd = 0, nCnt - 1 do
                  local dLen = EgtCurveLength( nCrv + nInd)
                  if dLen < MIN_RIBS_LEN then
                     EgtErase( nCrv + nInd)
                  else
                     table.insert( tOldNewIds[ vOrderedRibs[i]], nCrv + nInd)
                     
                     -- controllo la direzione (consideriamo inclinazione solo lungo X)
                     local vtDir = EgtMV( nCrv + nInd)
                     local dXl = sqrt( sqr( vtDir:getX()) + sqr( vtDir:getZ()))
                     local dYl = abs( vtDir:getY())
                     local dVal = EgtIf( dXl > dYl - GEO.EPS_SMALL, vtDir:getX(), vtDir:getY())
                     local bInvert = dVal < - GEO.EPS_SMALL
                     -- inversione della curva
                     local bInvertInfo = EgtGetInfo( nCrv + nInd, KEY_RIBS_INVERT_DIR, 'b') or false
                     if bInvert ~= bInvertInfo then      
                        EgtInvertCurve( nCrv + nInd)
                        EgtSetInfo( nCrv + nInd, KEY_INVERTED_CRV, 1)
                     end
                     
                     -- salvo info della superficie di trim associata
                     EgtSetInfo( nCrv + nInd, KEY_ASSOCIATED_SURF, vSurfOffs[nOverlap])
         
                     if nInd == 0 then
                        -- aggiorno la info
                        local nInfo = EgtGetInfo( nCrv + nInd, KEY_SPLIT_RIB, 'i')
                        if nInfo then
                           -- aggiorno info
                           if #tOldNewIds[nInfo] > 0 then
                              local nLast = #tOldNewIds[nInfo]
                              EgtSetInfo( nCrv + nInd, KEY_SPLIT_RIB, tOldNewIds[nInfo][nLast])
                           else
                              -- se la costolatura da cui deriva è stata eliminata, tolgo l'info che le associava
                              EgtRemoveInfo( nCrv + nInd, KEY_SPLIT_RIB)
                           end
                        end
                     end
                  end
                end
            end
         end

         -- riordino le costolature
         if bAllTwoStrands and bInters then
            -- gestione caso speciale di intersezione e 2 passate
            ReorderRibsInters2Shells( nRibsPathGrp, LayerParams.dStrand)
         else
            ReorderRibs( nRibsPathGrp, LayerParams.bRibsInvertOrder, LayerParams.dStrand, nMaxNbr)
         end
      end
      
      if not EgtGetFirstNameInGroup( nRibsPathGrp, RIBS_CRV .. '*') then
         EgtErase( nRibsPathGrp) 
      end
      nCrvGrp = EgtGetNextName( nCrvGrp, CONTOUR_GRP .. '*')
   end
end

--------------------------------------------------------------------
----------------- REGIONI CON DIVERSE PASSATE ----------------------
--------------------------------------------------------------------
local function CreateShellNbrSurfaces( nGrp, nShellsNbr)
   
   if not nGrp then return end
   
   local tDiffCrvs = {}
   local nMaxShellNbrDiff = 0
   local nCrvId = EgtGetFirstNameInGroup( nGrp, SHELL_NBR_CRV .. '*')
   while nCrvId do
      if EgtCurveIsClosed( nCrvId) then
         -- recupero info sul gap
         local nShellNbrDiff = EgtGetInfo( nCrvId, KEY_SHELL_NBR_DIFF, 'i')
         -- aggiorno eventuale massimo
         if nMaxShellNbrDiff < nShellNbrDiff then nMaxShellNbrDiff = nShellNbrDiff end
         -- salvo gli id delle curve
         if not tDiffCrvs[nShellNbrDiff] then
            tDiffCrvs[nShellNbrDiff]  = { nCrvId}
         else
            table.insert( tDiffCrvs[nShellNbrDiff], nCrvId)
         end
      end
      
      nCrvId = EgtGetNextName( nCrvId, SHELL_NBR_CRV .. '*')
   end
   
   -- eventuale correzione del numero massimo in base al numero di passate
   nMaxShellNbrDiff = min( nMaxShellNbrDiff, nShellsNbr)
   
   -- costruisco per ogni valore la superficie complessiva
   local nSrfGrp = EgtGroup( nGrp)
   for nDiff = 1, nMaxShellNbrDiff do
      -- recupero gli id delle curve coinvolte
      local vCrvIds = {}
      for nG, vIds in pairs( tDiffCrvs) do
         if nG >= nDiff then
            for k = 1, #vIds do
               table.insert( vCrvIds, vIds[k])
            end
         end
      end
      -- costruisco la surf
      local nSrfId, nCnt = EgtSurfFlatRegion( nSrfGrp, vCrvIds)
      for nIdSrf = nSrfId + 1, nSrfId + nCnt - 1 do
         EgtSurfFrAdd( nSrfId, nIdSrf)
         EgtErase( nIdSrf)
      end
      EgtSetName( nSrfId, SHELL_NBR_SURF .. tostring( nDiff))
   end
end

--------------------------------------------------------------------
local function ComputeMaxShellNbrDiff( nSrf, nShellNbrSurfGrp)
   
   local nMaxShellNbrDiff = 0
   if nShellNbrSurfGrp then
      local nId = 1
      local nShellNbrSrf = EgtGetFirstNameInGroup( nShellNbrSurfGrp, SHELL_NBR_SURF .. tostring( nId))
      while nShellNbrSrf do
         -- se interessa la regione considerata aggiorno il nMaxShellNbrDiff
         if not  EgtSurfFrTestExternal( nSrf, nShellNbrSrf) then            
            nMaxShellNbrDiff = nId
         end
         
         -- passo al successivo
         nId = nId + 1
         nShellNbrSrf = EgtGetFirstNameInGroup( nShellNbrSurfGrp, SHELL_NBR_SURF .. tostring( nId))
      end
   end
   
   return nMaxShellNbrDiff
end

--------------------------------------------------------------------
local function UpdateTotalShellSurf( nSrf, nCrv, dStrand, nGrpId)

   local nSrfExtraShell = EgtSurfFrFatCurve( nGrpId, nCrv, dStrand - s_dOffsCorr, false)  
   if nSrfExtraShell then
      local vtSrfN = EgtSurfFrNormVersor( nSrf, GDB_ID.ROOT)
      local vtSrfExShN = EgtSurfFrNormVersor( nSrfExtraShell, GDB_ID.ROOT)
      if vtSrfExShN * vtSrfN < 0 then
         EgtInvertSurf( nSrfExtraShell)
      end
      EgtSurfFrSubtract( nSrf, nSrfExtraShell)
      EgtErase( nSrfExtraShell)
   end

end

---------------------------------------------------------------------
local function ReorderExtraShells( nPathGrp, dStrand, vPtStart, bPrintInvert)
  
  -- verifico se posso unire due tratti consecutivi della stessa shell
   local nFirst = EgtGetFirstNameInGroup( nPathGrp, EXTRA_SHELL_CRV .. '*')
   while nFirst do
      -- recupero tratti appartenenti alla stessa shell
      local vShells = EgtGetNameInGroup( nPathGrp, EgtGetName( nFirst))     
      local nCurr = vShells[1]
      for i = 2, #vShells do
         if dist( EgtEP( nCurr), EgtSP( vShells[i])) < dStrand + GEO.EPS_SMALL then
            -- unisco le curve
            EgtAddCurveCompoLine( nCurr, EgtSP( vShells[i]))
            EgtAddCurveCompoCurve( nCurr, vShells[i])
         else
            nCurr = vShells[i]
         end
      end
      -- check su prima e ultima curva
      if nCurr ~= nFirst and dist( EgtEP( nCurr), EgtSP( nFirst)) < dStrand + GEO.EPS_SMALL then
         -- unisco le curve
         EgtAddCurveCompoLine( nCurr, EgtSP( nFirst))
         EgtAddCurveCompoCurve( nCurr, nFirst)
      end
      
      nFirst = EgtGetNextName( nCurr, EXTRA_SHELL_CRV .. '*')
   end
   
   local vIds = EgtGetNameInGroup( nPathGrp, EXTRA_SHELL_CRV .. '*')
   if not vIds then return end
   
   -- eventuale inversione di tutte le curve
   if bPrintInvert then
      for i = 1, #vIds do
         EgtInvertCurve( vIds[i])
         EgtSetInfo( vIds[i], KEY_INVERTED_CRV, 1)
      end
   end

   -- cerco di creare percorsi
   local k = 0   -- indice da utilizzare per i nomi
   while #vIds > 0 do
      k = k + 1
      -- prendo la prima tra le curve a disposizione
      nCurrCrv = vIds[1]
      table.remove( vIds, 1)
      EgtSetName( nCurrCrv, EXTRA_SHELL_CRV .. tostring(k))
      
      local ptSCurr = EgtSP( nCurrCrv)
      local ptECurr = EgtEP( nCurrCrv)
      local nCnt = 0
      -- se curva è chiusa
      if EgtCurveIsClosed( nCurrCrv) then
         ModifyStartPoint( nCurrCrv, vPtStart)
         -- setto a nil per ripartire subito con curva successiva
         nCurrCrv = nil
      end
      
      -- scorro alla ricerca di una curva che posso collegare alla corrente
      while nCurrCrv do
         local bFound = false
         for j = 1, #vIds do
 
            if not EgtCurveIsClosed( vIds[j]) then 
               local ptS = EgtSP( vIds[j])
               local ptE = EgtEP( vIds[j])
   
               local bLink = dist( ptS, ptECurr) < 1.5 * dStrand
   
               if dist( ptE, ptECurr) < 1.5 * dStrand then
                  -- congiungo end-end
                  EgtInvertCurve( vIds[j])
                  EgtSetInfo( vIds[j], KEY_INVERTED_CRV, EgtIf( bPrintInvert, 0, 1))
                  bLink = true
               elseif nCnt == 0 and dist( ptS, ptSCurr) < 1.5 * dStrand then
                  -- congiungo start-start
                  EgtInvertCurve( nCurrCrv)
                  EgtSetInfo( nCurrCrv, KEY_INVERTED_CRV, EgtIf( bPrintInvert, 0, 1))
                  bLink = true
               end
               
               if bLink then
                  nCnt = nCnt + 1
                  EgtRelocateGlob( vIds[j], nCurrCrv, GDB_IN.AFTER)
                  EgtSetName( vIds[j], EXTRA_SHELL_CRV .. tostring( k))
                  
                  -- aggiorno per collegamento successivo
                  bFound = true
                  nCurrCrv = vIds[j]
                  ptSCurr = EgtSP( vIds[j])
                  ptECurr = EgtEP( vIds[j])
                  table.remove( vIds, j)
                  break
               end
            end
         end
         -- se non ho più curve da collegare
         if not bFound then
            nCurrCrv = nil
         end
      end
   end
end

--------------------------------------------------------------------
local function CalcExtraShellsPath( nMaxShellNbrDiff, nShellNbrGrp, nCrvGrpId, dOffs, LayerParams, nIdx, vPtStart)
   
   local nGrpId = EgtGetFirstNameInGroup( nCrvGrpId, PATH_GRP)
   
   -- recupero la superficie occupata dalle shell per trim
   local nSrfTrim = EgtGetFirstNameInGroup( nCrvGrpId, TOT_SHELL_TRIM_SURF)  
   if not nSrfTrim then
      EgtOutLog( 'Warning : ExtraInnerShells not possible (layer '..tostring( nIdx)..') - CalcPaths')
      return
   end

   for nInd = nMaxShellNbrDiff, 1, -1 do
      dOffs = dOffs + LayerParams.dStrand * ( 1 - LayerParams.nStrandOverlap / 100)
      
      local nSrfDiff = EgtGetFirstNameInGroup( nShellNbrGrp, SHELL_NBR_SURF .. tostring( nInd))
      local nOuterCrv = EgtGetFirstNameInGroup( nCrvGrpId, OUTER_CRV)
      while nOuterCrv do
         local nCopy = EgtCopyGlob( nOuterCrv, nGrpId)
         ModifyStartPoint( nCopy, vPtStart)
         
         -- trim della curva con la regione con diverso numero di passate
         local nTrimCrv, nTrimCnt = EgtTrimCurveWithRegion( nCopy, nSrfDiff, false, false)
         if nTrimCnt ~= 0 then
            -- verifico se prima e ultima curva possono essere unite
            if nTrimCnt > 1 and AreSamePointApprox( EgtEP( nTrimCrv + nTrimCnt - 1), EgtSP( nTrimCrv)) then
               local nNewId = EgtCurveCompo( nGrpId, { nTrimCrv + nTrimCnt - 1, nTrimCrv})
                EgtChangeId( nNewId, nTrimCrv) 
               nTrimCnt = nTrimCnt - 1
            end
            
            for nCrvT = nTrimCrv, nTrimCrv + nTrimCnt - 1 do
               -- calcolo offset della curva ( è il percorso della shell) 
               EgtModifyCurveExtrusion( nCrvT, LayerParams.vtSlicing)
               local nOffs, nOffsCnt = EgtOffsetCurveAdv( nCrvT, - dOffs)
               EgtErase( nCrvT)              
               for nCrvOffs = nOffs, nOffs + nOffsCnt - 1 do
                  -- trim con la regione già occupata dal altre shell
                  local nCrv, nCnt = EgtTrimCurveWithRegion( nCrvOffs, nSrfTrim, true, true)
                  if nCrv and nCnt ~= 0 then
                     for nId = nCrv, nCrv + nCnt - 1 do
                        local dLen = EgtCurveLength( nId)
                        local bValid = true
                        if EgtCurveIsClosed( nId) then
                           bValid = VerifyPath( nId, LayerParams.dStrand, LayerParams.vtSlicing, nGrpId)
                        end
                        -- verifico se soddisfa vincolo sulla lunghezza
                        if dLen > MIN_LEN and bValid then
                           EgtModifyCurveExtrusion( nId, LayerParams.vtSlicing)
                           EgtSetName( nId, EXTRA_SHELL_CRV .. tostring( nMaxShellNbrDiff - nInd + 1))
                           if nInd == LayerParams.nShellsNbr then
                              EgtSetInfo( nId, KEY_TYPE, TYPE.EXTRA_OUTER_SHELL)
                           else
                              EgtSetInfo( nId, KEY_TYPE, TYPE.EXTRA_SHELL)
                           end
                           
                           -- aggiorno la superficie occupata dalle shell con quella appena calcolata (tenendo conto dell'overlap)
                           UpdateTotalShellSurf( nSrfTrim, nId, ( 1 - LayerParams.nStrandOverlap / 100) * LayerParams.dStrand, nGrpId)
                           -- se la superficie si annulla non è possibile realizzare altro, quindi cancello tutte le curve rimaste
                           if EgtSurfFrChunkCount( nSrfTrim) == 0 then
                              for j = nId + 1, nCrv + nCnt - 1 do
                                 EgtErase( j)
                              end
                              for j = nCrvT + 1, nTrimCrv + nTrimCnt - 1 do
                                 EgtErase( j)
                              end
                              -- aggiorno superficie
                              EgtSurfFrOffset( nSrfTrim, - LayerParams.nStrandOverlap / 100 * LayerParams.dStrand)
                              -- riordino le curve appena create e se possibile creo percorsi chiusi
                              ReorderExtraShells( nGrpId, LayerParams.dStrand, vPtStart, LayerParams.bPrintInvert)
                              return
                           end
                        else
                           EgtErase( nId)
                        end
                     end
                  end
               end
            end
         end
         nOuterCrv = EgtGetNextName( nOuterCrv, OUTER_CRV)
      end
   end
   
   -- aggiorno superificie
   EgtSurfFrOffset( nSrfTrim, - LayerParams.nStrandOverlap / 100 * LayerParams.dStrand) 
   -- riordino le curve appena create e se possibile creo percorsi chiusi
   ReorderExtraShells( nGrpId, LayerParams.dStrand, vPtStart, LayerParams.bPrintInvert)

end

--------------------------------------------------------------------
------------------  AUX SOLIDS -------------------------------------
--------------------------------------------------------------------
local function UpdateTrimSurfWithAuxSolidsOffset( nSrfSolid, nSrfBase, dStrand, nCrvGrp)
   
   -- offset della superifice del solido
   local bOk, bExists, nSrfOffs = ComputeSurfOffset( nSrfSolid, nCrvGrp, dStrand)
   if nSrfOffs then
      EgtSurfFrSubtract( nSrfBase, nSrfOffs)
      EgtErase( nSrfOffs)
   end   
end

--------------------------------------------------------------------
local function UpdateTrimSurfWithAuxSolidsZigZag( nAuxSolidsGrp, sName, nSrfBase, dStrand, nSrf)
   
   local nGrpTmp = EgtGroup( nAuxSolidsGrp)   -- gruppo temporaneo per conti
   
   -- recupero le curve associate
   local vCrvs = EgtGetNameInGroup( nAuxSolidsGrp, sName)
   for i = 1, #vCrvs do
      
      local vtDir = EgtSV( vCrvs[i])
      -- costruisco percorso associato
      local nCopyCrv = EgtCopyGlob( vCrvs[i], nGrpTmp)
      local nCopy2 = EgtCopyGlob( vCrvs[i], nGrpTmp)
      EgtInvertCurve( nCopy2)
      EgtAddCurveCompoCurve( nCopyCrv, nCopy2)
      local nOffsP = EgtOffsetCurveAdv( nCopyCrv, dStrand, GDB_OT.FILLET)
      local nFirst, nCnt =  EgtExplodeCurveCompo( nOffsP, nGrpTmp)
      
      -- cerco tratti lineari orientati ortogonalmente alla direzione di svuotatura
      local nRes = EgtCurveCompo( nGrpTmp, {nFirst})
      local nInd = nFirst + 1
      while nInd < nFirst + nCnt do
         local vtCurrDir = EgtSV( nInd)
         local nType = EgtGetType( nInd)
         
         -- se è linea ortognale alla direzione della svuotatura la approssimo
         if nType == GDB_TY.CRV_LINE and abs( vtDir * vtCurrDir) < 10 * GEO.EPS_SMALL then                     
            -- cerco ultima curva con lo stesso orientamento
            local nLastValidId = nInd
            local nInd2 = nInd + 1
            while nInd2 < nFirst + nCnt do
               nType = EgtGetType( nInd2)
               if nType == GDB_TY.CRV_LINE then
                  if AreSameVectorApprox( EgtSV( nInd2), vtCurrDir) then
                     nLastValidId = nInd2
                  else
                     break
                  end
               end
               nInd2 = nInd2 + 1
            end
            
            -- aggiungo l'approssimazione lineare
            EgtAddCurveCompoLine( nRes, EgtEP( nLastValidId))
            -- setto l'indice per ripartire correttamente dopo l'approssimazione
            nInd = nLastValidId
            
         else
            -- se arco o linea inclinata, aggiungo direttamente al percorso
            EgtAddCurveCompoCurve( nRes, nInd)
         end
         
         nInd = nInd + 1
      end
      
      -- utilizzo la curva per creare superficie
      local nSrfZigZag = EgtSurfFlatRegion( nGrpTmp, {nRes})
      if nSrfZigZag then
         EgtSurfFrSubtract( nSrfBase, nSrfZigZag)
      else
         EgtSurfFrSubtract( nSrfBase, nSrf)
      end
      
   end
   EgtErase( nGrpTmp)

end

-------------------------------------------------------------------
local function AddExtraZigZag( nSrf, sName, dStrand, vtSlicing, nGrp, nSrfTrim)
   
   local vIds = EgtGetNameInGroup( nGrp, sName)
   local vtDir = EgtSV( vIds[1])
   local vtYLoc = vtSlicing ^ vtDir
   
   local nOuterLoop = EgtExtractSurfFrChunkLoops( nSrf, 0, nGrp)

   for i = 1, #vIds do
      local _, dParE = EgtCurveDomain( vIds[i])
      local ptS = EgtUP( vIds[i], dParE - 1) + dStrand * vtYLoc
      local ptE = EgtEP( vIds[i]) + dStrand * vtYLoc
      local nExtraCrv = EgtLine( nGrp, ptS, ptE)
      -- verifico se la linea aggiuntiva serve
      local dDist = EgtPointCurveDist( EgtMP( nExtraCrv), nOuterLoop)
      if dDist < dStrand - 1 then
         -- verifico se si trova nella regione ammissibile
         if EgtCurveWithRegionClassify( nExtraCrv, nSrfTrim) == GDB_CRC.IN then
            EgtInvertCurve( nExtraCrv)
            EgtAddCurveCompoLine( vIds[i], ptE)
            EgtAddCurveCompoCurve( vIds[i], nExtraCrv)
         end
      end
      EgtErase( nExtraCrv)
   end
   
   EgtErase( nOuterLoop)
end

--------------------------------------------------------------------
local function CalcAuxSolidsPaths( nSliceGrp, nSolidGrp, LayerParams, vPtStart)
   
   -- recupero i solidi ausiliari
   local vSolidIds = EgtGetAllInGroup( nSolidGrp)
   
   -- scorro i gruppi di curve
   local nCrvGrp = EgtGetFirstNameInGroup( nSliceGrp, CONTOUR_GRP .. '*')
   while nCrvGrp do
      
      -- creo o svuoto il gruppo per i solidi ausiliari
      local nSolidPathGrp = EgtGetFirstNameInGroup( nCrvGrp, AUX_SOLIDS_GRP)
      if not nSolidPathGrp then
         nSolidPathGrp = EgtGroup( nCrvGrp)
         EgtSetName( nSolidPathGrp, AUX_SOLIDS_GRP)
         EgtSetStatus( nSolidPathGrp, GDB_ST.OFF)
      else
         EgtEmptyGroup( nSolidPathGrp)
      end

      -- creo le superfici con cui fare i trim
      local nSrfBase = EgtGetFirstNameInGroup( nCrvGrp, TOT_SHELL_TRIM_SURF)
      if not nSrfBase then
         EgtOutLog( 'Warning : AuxSolids not possible (layer '..tostring( nIdx)..') - CalcPaths')
      else
         local vSurfOffs = ComputeTrimSurfWithOverlaps( vSolidIds, nSrfBase, KEY_AUX_SOLIDS_OVERLAP, LayerParams.dStrand, nSolidPathGrp)
         
         for i = 1, #vSolidIds do
            -- creo la flat region corrispondente al solido ausiliario
            local sName = EgtGetName( vSolidIds[i])
            local nOverlap = EgtGetInfo( vSolidIds[i], KEY_AUX_SOLIDS_OVERLAP, 'i')
            local nSrfId = EgtSurfFlatRegion( nSolidPathGrp, vSolidIds[i])
            EgtSetName( nSrfId, AUX_SOLIDS_SRF)
            -- trim con la superficie di offset
            EgtSurfFrIntersect( nSrfId, vSurfOffs[nOverlap])
             
            local nFirst, nCnt = EgtExplodeSurf( nSrfId)
            for j = 0, nCnt - 1 do
               local sNewName = sName .. EgtIf( j == 0, '', '_' .. tostring( j))
               local nInfillType = EgtGetInfo( vSolidIds[i], KEY_AUX_SOLIDS_INFILL, 'i')
               if nInfillType == INFILL_TYPE.OFFSET then
                  ComputeOffsetInfill( nFirst + j, LayerParams.dStrand, LayerParams.vtSlicing, sNewName, TYPE.AUX_SOLID, vPtStart, nSolidPathGrp)
                  -- aggiorno la trim surf
                  UpdateTrimSurfWithAuxSolidsOffset( nFirst + j, nSrfBase, LayerParams.dStrand, nSolidPathGrp)
               else
                  ComputeZigZagInfill( nFirst + j, LayerParams.dStrand, LayerParams.vtSlicing, sNewName, TYPE.AUX_SOLID, vPtStart, nSolidPathGrp)
                  -- aggiungo eventuale passata extra
                  AddExtraZigZag( nFirst + j, sNewName, LayerParams.dStrand, LayerParams.vtSlicing, nSolidPathGrp, vSurfOffs[nOverlap])
                  -- aggiorno la trim surf
                  UpdateTrimSurfWithAuxSolidsZigZag( nSolidPathGrp, sNewName, nSrfBase, LayerParams.dStrand, nFirst + j)
               end
            end
         end
      
         -- elimino le superfici utilizzate per il trim
         for k, v in pairs( vSurfOffs) do
            EgtErase( v)
         end
      end
      
      -- verifico se il gruppo contine qualcosa
      if not EgtGetFirstNameInGroup( nSolidPathGrp, AUX_SOLIDS_CRV .. '*') then
         EgtErase( nSolidPathGrp) 
      end
         
      -- passo al gruppo di contorni successivo
      nCrvGrp = EgtGetNextName( nCrvGrp, CONTOUR_GRP .. '*')
   end
end

---------------------------------------------------------------------
function CalcPaths.Exec( nPartId)
   
   s_nPartId = nPartId

   local vLayIds = EgtGetNameInGroup( s_nPartId, SLICE_LAYER.."*") 
   if not vLayIds then
      EgtOutBox( 'Error no slice', 'PathCalc')
     return 
   end

   -- recupero i parametri per calcolo dei path
   local LayerParams = GetLayerParamsForPathCalc()
   -- scorro tutti i suoi layer
   for nIdx = 1, #vLayIds do
      
      local nRibsGrp = EgtGetFirstNameInGroup( vLayIds[nIdx], RIBS_GRP)
      local nAuxSolidsGrp = EgtGetFirstNameInGroup( vLayIds[nIdx], AUX_SOLIDS_GRP)
     
      -- regioni con diverso numero di passate
      local nShellNbrGrp = EgtGetFirstNameInGroup( vLayIds[nIdx], SHELL_NBR_GRP)
      local nMaxShell = max( LayerParams.nShellsNbr, LayerParams.nFloorNbr, LayerParams.nCeilNbr)
      CreateShellNbrSurfaces( nShellNbrGrp, nMaxShell)
      local nShellNbrSurfGrp = EgtGetFirstGroupInGroup( nShellNbrGrp or GDB_ID.NULL)
      
      -- recupero gli start point per il layer
      local vPtStart = GetLayerStartPoint( vLayIds[nIdx], LayerParams.vtSlicing)
      
      -- scorro tutti i gruppi di contorni
      local nCrvGrpId = EgtGetFirstNameInGroup( vLayIds[nIdx], CONTOUR_GRP.."*") or GDB_ID.NULL
      while nCrvGrpId ~= GDB_ID.NULL do
         
         -- verifico se il path e il solido sono già stati calcolati
         local nGrpId = EgtGetFirstNameInGroup( nCrvGrpId, PATH_GRP) or GDB_ID.NULL
         if nGrpId == GDB_ID.NULL then
            nGrpId = EgtGroup( nCrvGrpId)
            EgtSetName( nGrpId, PATH_GRP)
         else
            EgtEmptyGroup( nGrpId)
            EgtSetStatus( nGrpId, GDB_ST.ON)
         end
         local nSolidGrpId = EgtGetFirstNameInGroup( nCrvGrpId, SOLID_GRP) or GDB_ID.NULL
         if nSolidGrpId ~= GDB_ID.NULL then
            EgtErase( nSolidGrpId)
         end
         
         -- recupero la superficie ottenuta dallo slicing
         local nSrf = EgtGetFirstNameInGroup( nCrvGrpId, LAYER_SRF)
         if nSrf then
            
            local nMaxShellNbrDiff = ComputeMaxShellNbrDiff( nSrf, nShellNbrSurfGrp)
            nMaxShellNbrDiff = min( nMaxShellNbrDiff, LayerParams.nShellsNbr)
            
            -- parete esterna
            local dOffs = - LayerParams.dOffs - 0.5 * LayerParams.dStrand
            if nMaxShellNbrDiff < LayerParams.nShellsNbr then
               dOffs = dOffs + LayerParams.dStrand
               local bOk, bExists, nSrfId = ComputeSurfOffset( nSrf, nCrvGrpId, - dOffs)
               if not bOk then
                  EgtOutLog( 'Error on ExtOffset (layer '..tostring( nIdx)..') - CalcPaths')
               elseif not bExists then
                  EgtOutLog( 'Warning : ExtOffset not possible (layer '..tostring( nIdx)..') - CalcPaths')
               else
                  -- se offset riuscito, estraggo i contorni (pareti esterne)
                  GetPathsFromSurf( nSrfId, SHELL_CRV ..'0', TYPE.OUTER_SHELL, nGrpId, vPtStart)
               end
               EgtErase( nSrfId)
            end
            
            local vPtInnerStart = {}
            local vOuterShell = EgtGetNameInGroup( nGrpId, SHELL_CRV .. '0') or {}
            for i = 1, #vOuterShell do
               table.insert( vPtInnerStart, EgtSP( vOuterShell[i]))
            end
            if #vPtInnerStart == 0 then vPtInnerStart = vPtStart end 
            
            -- pareti interne complete
            for nInd = 1, LayerParams.nShellsNbr - 1 - nMaxShellNbrDiff do
               -- offset della superficie originale
               dOffs = dOffs + LayerParams.dStrand * ( 1 - LayerParams.nStrandOverlap / 100)
               local bOk, bExists, nSrfId = ComputeSurfOffset( nSrf, nCrvGrpId, - dOffs)
               if not bOk then
                  EgtOutLog( 'Error on IntOffset (layer '..tostring( nIdx)..') - CalcPaths')
               elseif not bExists then
                  EgtOutLog( 'Warning : IntOffset not possible (layer '..tostring( nIdx)..') - CalcPaths')
               else
                  -- se offset riuscito, estraggo i contorni ( pareti interne)
                  GetPathsFromSurf( nSrfId, SHELL_CRV..tostring( nInd), TYPE.INNER_SHELL, nGrpId, vPtInnerStart)
               end
               EgtErase( nSrfId)
            end
            
            -- preparo superficie occupata dalle shell da usare per trim
            local dSurfTrimOffs = dOffs + LayerParams.dStrand
            if nMaxShellNbrDiff > 0 then
               -- se hai extra shell tieni conto anche dell'overlap ammesso
               dSurfTrimOffs = dOffs + ( 1 - LayerParams.nStrandOverlap / 100) * LayerParams.dStrand - s_dOffsCorr
            end
            local bOkTrim, bExistsTrim, nSrfTrim = ComputeSurfOffset( nSrf, nCrvGrpId, - dSurfTrimOffs)
            if not bOkTrim then
               EgtOutLog( 'Error on IntOffset (layer '..tostring( nIdx)..') - CalcPaths')
            elseif bExistsTrim then
               EgtSetName( nSrfTrim, TOT_SHELL_TRIM_SURF)
               EgtSetStatus( nSrfTrim, GDB_ST.OFF)
            end
  
            -- eventuali pareti interne coinvolte dal diverso numero di passate
            if nMaxShellNbrDiff > 0 then
               CalcExtraShellsPath( nMaxShellNbrDiff, nShellNbrSurfGrp, nCrvGrpId, dOffs, LayerParams, nIdx, vPtInnerStart)
            end
            
            -- gestione eventuale floor/ceil
            if nIdx <= LayerParams.nFloorNbr then
               local nSurfInfill = AdjustSurfForFloorCeil( LayerParams.nFloorNbr - nIdx + 1, nSrfTrim, nShellNbrSurfGrp) or nSrfTrim
               if LayerParams.nFloorType == INFILL_TYPE.OFFSET then
                  ComputeOffsetInfill( nSurfInfill, LayerParams.dStrand, LayerParams.vtSlicing, INFILL_CRV, TYPE.INFILL, vPtStart, nGrpId)
               elseif LayerParams.nFloorType == INFILL_TYPE.ZIGZAG then
                  ComputeZigZagInfill( nSurfInfill, LayerParams.dStrand, LayerParams.vtSlicing, INFILL_CRV, TYPE.INFILL, vPtStart, nGrpId)
               end
               EgtErase( nSurfInfill)
            elseif nIdx > #vLayIds - LayerParams.nCeilNbr then
               local nSurfInfill = AdjustSurfForFloorCeil( LayerParams.nCeilNbr - ( #vLayIds - nIdx), nSrfTrim, nShellNbrSurfGrp) or nSrfTrim
               if LayerParams.nCeilType == INFILL_TYPE.OFFSET then
                  ComputeOffsetInfill( nSurfInfill, LayerParams.dStrand, LayerParams.vtSlicing, INFILL_CRV, TYPE.INFILL, vPtStart, nGrpId)
               elseif LayerParams.nCeilType == INFILL_TYPE.ZIGZAG then
                  ComputeZigZagInfill( nSurfInfill, LayerParams.dStrand, LayerParams.vtSlicing, INFILL_CRV, TYPE.INFILL, vPtStart, nGrpId)
               end
               EgtErase( nSurfInfill)
            end
         end
         
         -- passo al gruppo di contorni successivo
         nCrvGrpId = EgtGetNextName( nCrvGrpId, CONTOUR_GRP.."*") or GDB_ID.NULL
      end
      
      if nIdx > LayerParams.nFloorNbr and nIdx <= #vLayIds - LayerParams.nCeilNbr then
         
         -- sistemo eventuali solidi ausiliari
         if nAuxSolidsGrp then
            CalcAuxSolidsPaths( vLayIds[nIdx], nAuxSolidsGrp, LayerParams, vPtStart)
         end

         -- sistemo eventuali costolature
         if nRibsGrp then
            CalcRibsPaths( vLayIds[nIdx], nRibsGrp, LayerParams, nIdx, nMaxStrandDiff)
         end
      end
      
      if EgtProcessEvents( EgtIf( PRINT, 100, 0) + nIdx / #vLayIds * 100, 0) == 1 then
         EgtDraw()
         return 
      end
   end
end

---------------------------------------------------------------------
return CalcPaths