// File:	IntCurve_ExactIntersectionPoint.gxx
// Created:	Wed Dec 15 16:18:55 1999
// Author:	Atelier CAS2000
//		<cas@cageox.paris1.matra-dtv.fr>


#include <math_Vector.hxx>
#include <math_FunctionSetRoot.hxx>
#include <math_NewtonFunctionSetRoot.hxx>
#include <gp_Vec2d.hxx>



//======================================================================
//===   
//======================================================================
IntCurve_ExactIntersectionPoint::IntCurve_ExactIntersectionPoint(const TheCurve& C1,const TheCurve& C2,const Standard_Real Tol)
    : done(Standard_False),
      nbroots(0),
      myTol(Tol*Tol),
      FctDist(C1,C2),
      ToleranceVector(1,2),
      BInfVector(1,2),
      BSupVector(1,2),
      StartingPoint(1,2),
      Root(1,2),
      anErrorOccurred(Standard_False)
    {
      ToleranceVector.Value(1) = TheCurveTool::EpsX(C1);
      ToleranceVector.Value(2) = TheCurveTool::EpsX(C2);
    }
  //----------------------------------------------------------------------
void IntCurve_ExactIntersectionPoint::Perform( const IntCurve_ThePolygon2d& Poly1
					      ,const IntCurve_ThePolygon2d& Poly2
					      ,Standard_Integer&            NumSegOn1
					      ,Standard_Integer&            NumSegOn2
					      ,Standard_Real&               ParamOnSeg1
					      ,Standard_Real&               ParamOnSeg2) {
    //----------------------------------------------------------------------
    //-- On prend comme bornes de recherches  : 
    //--
    //--   Segment      :      i-1        i           i+1        i+2      
    //--
    //--                  |---------|-----X-------|---------|----------|
    //--                Inf                                Sup
    //--                  
    if(NumSegOn1 >= Poly1.NbSegments() && ParamOnSeg1==0.0) { 
      NumSegOn1--; ParamOnSeg1 = 1.0;
    }
    if(NumSegOn2 >= Poly2.NbSegments() && ParamOnSeg2==0.0) { 
      NumSegOn2--; ParamOnSeg2 = 1.0;
    }
    if(NumSegOn1 <=0) { 
      NumSegOn1=1; ParamOnSeg1 = 0.0;
    }
    if(NumSegOn2 <=0) { 
      NumSegOn2=1; ParamOnSeg2 = 0.0;
    }
    
    StartingPoint.Value(1) = Poly1.ApproxParamOnCurve(NumSegOn1,ParamOnSeg1);
    if(NumSegOn1<=2) BInfVector.Value(1)= Poly1.InfParameter(); 
    else  BInfVector.Value(1)= Poly1.ApproxParamOnCurve(NumSegOn1-1,(Standard_Real)0.0); 
    if(NumSegOn1 >= (Poly1.NbSegments() -2)) BSupVector.Value(1)= Poly1.SupParameter();
    else BSupVector.Value(1)= Poly1.ApproxParamOnCurve(NumSegOn1+2,(Standard_Real)0.0);
    
    StartingPoint.Value(2) = Poly2.ApproxParamOnCurve(NumSegOn2,ParamOnSeg2);
    if(NumSegOn2<=2) BInfVector.Value(2)= Poly2.InfParameter();
    else BInfVector.Value(2)= Poly2.ApproxParamOnCurve(NumSegOn2-1,(Standard_Real)0.0);
    if(NumSegOn2 >= (Poly2.NbSegments() -2)) BSupVector.Value(2)= Poly2.SupParameter();
    else BSupVector.Value(2)= Poly2.ApproxParamOnCurve(NumSegOn2+2,(Standard_Real)0.0);
    

    IntCurve_ExactIntersectionPoint::MathPerform();
    if(nbroots == 0) { 
//      Standard_Real DeflectionOn1 = Poly1.DeflectionOverEstimation();
      Poly1.DeflectionOverEstimation();
//      Standard_Real DeflectionOn2 = Poly2.DeflectionOverEstimation();
      Poly2.DeflectionOverEstimation();
      // if(DeflectionOn2 > Poly1.BeginOfSeg(NumSegOn1).Distance(Poly1.EndOfSeg(NumSegOn1))) {
	{
	//-- On risque de donner des bornes sur la courbe 1 trop etroites. 
	Standard_Integer diff=1;
	Standard_Real AnBinfVector = BInfVector.Value(1);
	Standard_Real AnBsupVector = BSupVector.Value(1);
	//---------------- On elargit les bornes par la gauche --------------------
	do { 
	  diff++;
	  if((NumSegOn1-diff)<=1) { 
	    BInfVector.Value(1)= Poly1.InfParameter(); 
	    diff=0;
	  }
	  else BInfVector.Value(1)= Poly1.ApproxParamOnCurve(NumSegOn1-diff,(Standard_Real)0.0); 
	  IntCurve_ExactIntersectionPoint::MathPerform();
	  //-- le 18 nov 97 
	  if(diff>3) diff+=NumSegOn1/2;	  
	}
	while( nbroots==0 && diff!=0);
	//---------------- On elargit les bornes par la droite --------------------	
	if(nbroots==0) { 
	  BInfVector.Value(1) = AnBinfVector;
	  diff=1;
	  do { 
	    diff++;
	    if((NumSegOn1+diff) >= (Poly1.NbSegments() -1)) { 
	      BSupVector.Value(1)= Poly1.SupParameter();
	      diff=0;
	    }
	    else BSupVector.Value(1)= Poly1.ApproxParamOnCurve(NumSegOn1+1+diff,(Standard_Real)0.0);
	    IntCurve_ExactIntersectionPoint::MathPerform();
	    //-- le 18 nov 97 
	    if(diff>3) diff+=1+(Poly1.NbSegments()-NumSegOn1)/2;
	  }
	  while( nbroots==0 && diff!=0);
	}
	BSupVector.Value(1) = AnBsupVector;
      }
    
      if(nbroots==0) { 
	//-- On risque de donner des bornes sur la courbe 1 trop etroites. 
	Standard_Integer diff=1;
	Standard_Real AnBinfVector = BInfVector.Value(2);
	Standard_Real AnBsupVector = BSupVector.Value(2);
	//---------------- On elargit les bornes par la gauche --------------------
	do { 
	  diff++;
	  if((NumSegOn2-diff)<=1) { 
	    BInfVector.Value(2)= Poly2.InfParameter(); 
	    diff=0;
	  }
	  else BInfVector.Value(2)= Poly2.ApproxParamOnCurve(NumSegOn2-diff,(Standard_Real)0.0); 
	  IntCurve_ExactIntersectionPoint::MathPerform();
	  //-- le 18 nov 97 
	  if(diff>3) diff+=NumSegOn2/2;
	}
	while( nbroots==0 && diff!=0);
	//---------------- On elargit les bornes par la droite --------------------	
	if(nbroots==0) { 
	  BInfVector.Value(2) = AnBinfVector;
	  diff=1;
	  do { 
	    diff++;
	    if((NumSegOn2+diff) >= (Poly2.NbSegments() -1)) { 
	      BSupVector.Value(2)= Poly2.SupParameter();
	      diff=0;
	    }
	    else BSupVector.Value(2)= Poly2.ApproxParamOnCurve(NumSegOn2+1+diff,(Standard_Real)0.0);
	    IntCurve_ExactIntersectionPoint::MathPerform();
	    //-- le 18 nov 97 
	    if(diff>3) diff+=1+(Poly2.NbSegments()-NumSegOn2)/2;
	  }
	  while( nbroots==0 && diff!=0);
	}
	BSupVector.Value(2) = AnBsupVector;
      }
    }
  }
  //----------------------------------------------------------------------
void IntCurve_ExactIntersectionPoint::Perform( const Standard_Real Uo
	       ,const Standard_Real Vo
	       ,const Standard_Real UInf
	       ,const Standard_Real VInf
	       ,const Standard_Real USup
	       ,const Standard_Real VSup) { 
    
    done = Standard_True;
    
    BInfVector.Value(1) = UInf;
    BInfVector.Value(2) = VInf;
    BSupVector.Value(1) = USup;
    BSupVector.Value(2) = VSup;
    StartingPoint.Value(1) = Uo;
    StartingPoint.Value(2) = Vo;
    
    IntCurve_ExactIntersectionPoint::MathPerform();
    
  }
  //----------------------------------------------------------------------
Standard_Integer IntCurve_ExactIntersectionPoint::NbRoots() const { return(nbroots); } 
  //----------------------------------------------------------------------

void IntCurve_ExactIntersectionPoint::Roots(Standard_Real& U,Standard_Real& V) {
    U=Root.Value(1);
    V=Root.Value(2); 
  }
  //----------------------------------------------------------------------

void IntCurve_ExactIntersectionPoint::MathPerform(void) {
    math_FunctionSetRoot Fct( FctDist
			     ,StartingPoint
			     ,ToleranceVector
			     ,BInfVector
			     ,BSupVector
			     ,50);
    
    if(Fct.IsDone()) { 
      Fct.Root(Root); nbroots = 1; 
      math_Vector XY(1,2);
      FctDist.Value(Root,XY);
      Standard_Real dist2 = ((XY(1)*XY(1)+XY(2)*XY(2)));
      if(dist2 > myTol) nbroots = 0;
    }
    else { 
      anErrorOccurred = Standard_True;
      nbroots = 0; 
    }
  }
    
//======================================================================

Standard_Boolean IntCurve_ExactIntersectionPoint::AnErrorOccurred() const
{
  return anErrorOccurred;
}