// File:	TopOpeBRepBuild_BlockBuilder.cxx
// Created:	Thu Mar 11 12:56:30 1993
// Author:	Jean Yves LEBEY
//		<jyl@sdsun2>
// Copyright:    Matra Datavision	

#include <BOP_BlockBuilder.ixx>

#include <Standard_Failure.hxx>

//=======================================================================
//function : BOP_BlockBuilder::BOP_BlockBuilder
//purpose  : 
//=======================================================================
  BOP_BlockBuilder::BOP_BlockBuilder()
:
  myIsDone(Standard_False)
{
}

//=======================================================================
//function : BOP_BlockBuilder::BOP_BlockBuilder
//purpose  : 
//=======================================================================
  BOP_BlockBuilder::BOP_BlockBuilder (BOP_ShapeSet& SS)
  :myIsDone(Standard_False)
{
  MakeBlock(SS);
}

//=======================================================================
//function : MakeBlock
//purpose  : 
//=======================================================================
  void BOP_BlockBuilder::MakeBlock(BOP_ShapeSet& SS)
{
  // Compute the set of connexity blocks of elements of element set SS
  //
  // Logic : 
  // - A block is a set of connex elements of SS
  // - We assume that any element of SS appears in only 1 connexity block.
  //
  // Implementation :
  // - All the elements of all the blocks are stored in map myOrientedShapeMap(M).
  // - A connexity block is a segment [f,l] of element indices of M.
  // - myBlocks is a sequence of integer; each integer is the index of the 
  //   first element (in M) of a connexity block.
  // - Bounds [f,l] of a connexity block are : 
  //    f = myBlocks(i)
  //    l = myBlocks(i+1) - 1

  myOrientedShapeMap.Clear();
  myOrientedShapeMapIsValid.Clear();
  myBlocks.Clear();
  myBlocksIsRegular.Clear();
  //
  Standard_Boolean IsRegular, CurNei, Mextent, Eindex,
                   EnewinM, searchneighbours, condregu;
  Standard_Integer iiregu;
  //
  //
  SS.InitStartElements();
  for (; SS.MoreStartElements(); SS.NextStartElement()) {
    const TopoDS_Shape& E = SS.StartElement(); 
    Mextent = myOrientedShapeMap.Extent();
    Eindex = AddElement(E); 

    // E = current element of the element set SS
    // Mextent = index of last element stored in map M, before E is added. 
    // Eindex  = index of E added to M : Eindex > Mextent => E is new in M

    EnewinM = (Eindex > Mextent);
    if (EnewinM) {
      //
      // make a new block starting at element Eindex
      myBlocks.Append(Eindex);
      IsRegular = Standard_True; CurNei = 0;
      // put in current block all the elements connex to E :
      // while an element E has been added to M
      //    - compute neighbours of E : N(E)
      //    - add each element N of N(E) to M

      Mextent = myOrientedShapeMap.Extent();
      searchneighbours = (Eindex <= Mextent);
      while (searchneighbours) {

	// E = element of M on which neighbours must be searched
	// first step : Eindex = index of starting element of SS
	// next steps : Eindex = index of neighbours of starting element of SS 
	const TopoDS_Shape& anE = myOrientedShapeMap(Eindex);
	CurNei = SS.MaxNumberSubShape(anE);
	
	condregu = (CurNei > 2) ? Standard_False : Standard_True;
	
	IsRegular = IsRegular && condregu;
	//
	// compute neighbours of E : add them to M to increase M.Extent().
	SS.InitNeighbours(anE);

	for (; SS.MoreNeighbours(); SS.NextNeighbour()) {
	  const TopoDS_Shape& N = SS.Neighbour();
	  AddElement(N);
	}
	
	Eindex++;
	Mextent = myOrientedShapeMap.Extent();
	searchneighbours = (Eindex <= Mextent);
	
      } // while (searchneighbours)

      iiregu = IsRegular ? 1 : 0;
      myBlocksIsRegular.Append(iiregu);      
    } // if (EnewinM)
  } // for ()
  //
  // To value the l bound of the last connexity block created above,
  // we create an artificial block of value = myOrientedShapeMap.Extent() + 1
  // The real number of connexity blocks is myBlocks.Length() - 1
  Mextent = myOrientedShapeMap.Extent();
  myBlocks.Append(Mextent + 1);

  myIsDone = Standard_True;
}

//=======================================================================
//function : InitBlock
//purpose  : 
//=======================================================================
  void BOP_BlockBuilder::InitBlock()
{
  myBlockIndex = 1;
}

//=======================================================================
//function : MoreBlock
//purpose  : 
//=======================================================================
  Standard_Boolean BOP_BlockBuilder::MoreBlock() const
{
  // the length of myBlocks is 1 + number of connexity blocks
  Standard_Integer l =  myBlocks.Length();
  Standard_Boolean b = (myBlockIndex < l);
  return b;
}

//=======================================================================
//function : NextBlock
//purpose  : 
//=======================================================================
  void BOP_BlockBuilder::NextBlock()
{
  myBlockIndex++;
}

//=======================================================================
//function : BlockIterator
//purpose  : 
//=======================================================================
  BOP_BlockIterator BOP_BlockBuilder::BlockIterator() const
{
  Standard_Integer lower, upper;

  lower = myBlocks(myBlockIndex);
  upper = myBlocks(myBlockIndex+1)-1;

  return BOP_BlockIterator(lower,upper);
}

//=======================================================================
//function : Element
//purpose  : 
//=======================================================================
  const TopoDS_Shape& BOP_BlockBuilder::Element (const BOP_BlockIterator& BI) const
{
  Standard_Boolean isbound = BI.More();
  if (!isbound) {
    Standard_Failure::Raise("OutOfRange");
  }
  
  Standard_Integer index = BI.Value();
  const TopoDS_Shape& E = myOrientedShapeMap(index);
  return E;
} 
//=======================================================================
//function : Element
//purpose  : 
//=======================================================================
  const TopoDS_Shape& BOP_BlockBuilder::Element (const Standard_Integer index) const
{
  Standard_Boolean isbound = myOrientedShapeMapIsValid.IsBound(index);
  if (!isbound) {
    Standard_Failure::Raise("OutOfRange");
  }
  const TopoDS_Shape& E = myOrientedShapeMap(index);
  return E;
} 
//=======================================================================
//function : Element
//purpose  : 
//=======================================================================
  Standard_Integer BOP_BlockBuilder::Element (const TopoDS_Shape& E) const
{
  Standard_Boolean isbound = myOrientedShapeMap.Contains(E);
  if (!isbound) {
    Standard_Failure::Raise("OutOfRange");
  }
  
  Standard_Integer I = myOrientedShapeMap.FindIndex(E);
  return I;
}

//=======================================================================
//function : ElementIsValid
//purpose  : 
//=======================================================================
  Standard_Boolean BOP_BlockBuilder::ElementIsValid (const BOP_BlockIterator& BI) const 
{  
  Standard_Boolean isvalid, isbound = BI.More();
  if (!isbound) {
    return Standard_False;
  }
  Standard_Integer Sindex, isb;
  
  Sindex = BI.Value();
  isb = myOrientedShapeMapIsValid.Find(Sindex);
  isvalid = (isb == 1)? Standard_True: Standard_False;
  
  return isvalid;
}
//=======================================================================
//function : ElementIsValid
//purpose  : 
//=======================================================================
  Standard_Boolean BOP_BlockBuilder::ElementIsValid (const Standard_Integer Sindex) const
{  
  Standard_Boolean isvalid, isbound = myOrientedShapeMapIsValid.IsBound(Sindex);
  if (!isbound) return Standard_False;

  Standard_Integer isb = myOrientedShapeMapIsValid.Find(Sindex);
  isvalid = (isb == 1)? Standard_True: Standard_False;
  
  return isvalid;
}

//=======================================================================
//function : AddElement
//purpose  : 
//=======================================================================
  Standard_Integer BOP_BlockBuilder::AddElement(const TopoDS_Shape& S) 
{
  Standard_Integer Sindex = myOrientedShapeMap.Add(S);
  myOrientedShapeMapIsValid.Bind(Sindex, 1);

  return Sindex;
}

//=======================================================================
//function : SetValid
//purpose  : 
//=======================================================================
  void BOP_BlockBuilder::SetValid(const BOP_BlockIterator& BI,
				  const Standard_Boolean isvalid)
{
  Standard_Boolean isbound = BI.More();
  if (!isbound) {
    return;
  }
  Standard_Integer Sindex, i;
  Sindex = BI.Value();
  i = (isvalid) ? 1 : 0;
  myOrientedShapeMapIsValid.Bind(Sindex,i);
}
//=======================================================================
//function : SetValid
//purpose  : 
//=======================================================================
  void BOP_BlockBuilder::SetValid(const Standard_Integer Sindex,
				  const Standard_Boolean isvalid)
{
  Standard_Boolean isbound = myOrientedShapeMapIsValid.IsBound(Sindex);
  if (!isbound) {
    return;
  }

  Standard_Integer i = (isvalid) ? 1 : 0;
  myOrientedShapeMapIsValid.Bind(Sindex,i);
}

//=======================================================================
//function : CurrentBlockIsRegular
//purpose  : 
//=======================================================================
  Standard_Boolean BOP_BlockBuilder::CurrentBlockIsRegular()
{
  Standard_Boolean b = Standard_False;
  Standard_Integer i = myBlocksIsRegular.Value(myBlockIndex);
  
  if(i == 1) {
    b = Standard_True;
  }
  return b;
}