// Copyright (c) 1995-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

Blend_Status Blend_Walking::TestArret(Blend_Function& Function,
				      const Blend_Status State,
				      const Standard_Boolean TestDefl,
				      const Standard_Boolean TestSolu,
				      const Standard_Boolean TestLengthStep)

// On regarde si le point donne est solution.
// Si c est le cas,
//  On verifie le critere de fleche sur surf1 et surf2
//   Si OK, on classifie les points sur surf1 et sur surf2.
//    Si les deux sont dedans : on retourne Blend_OK
//    sinon si un seul est dedans
//     on resout le pb inverse sur la restriction concernee
//    sinon on resout le pb inverse sur la surface pour laquelle
//     le point est le plus loin.
//   sinon (fleche non OK)
//    on renvoie Blend_StepTooLarge.
// sinon on renvoie Blend_StepTooLarge.
//

{
  gp_Pnt pt1,pt2;
  gp_Vec V1,V2;
  gp_Vec Tgp1,Tgp2,Nor1,Nor2;
  gp_Vec2d V12d,V22d;
  Blend_Status State1,State2;
  IntSurf_TypeTrans tras1,tras2;
  Blend_Point curpoint;
  Standard_Boolean loctwist1 = Standard_False, loctwist2 = Standard_False;
  Standard_Real tolsolu = tolesp;

  if ( !TestSolu) tolsolu *= 1000; //Ca doit toujours etre bon
  if (Function.IsSolution(sol,tolsolu)) {

#ifdef OCCT_DEBUG
    sectioncalculee = 1;
#endif
    Standard_Boolean curpointistangent = Function.IsTangencyPoint();
    pt1  = Function.PointOnS1();
    pt2  = Function.PointOnS2();
    if(curpointistangent){
      curpoint.SetValue(pt1,pt2,param,
			sol(1),sol(2),sol(3),sol(4));
    }
    else{
      V1   = Function.TangentOnS1();
      V2   = Function.TangentOnS2();
      V12d = Function.Tangent2dOnS1();
      V22d = Function.Tangent2dOnS2();
      curpoint.SetValue(pt1,pt2,param,
			sol(1),sol(2),sol(3),sol(4),
			V1,V2,V12d,V22d);
      if(Function.TwistOnS1()) loctwist1 = Standard_True;
      if(Function.TwistOnS2()) loctwist2 = Standard_True;
    }

    if (TestDefl && check) {

      // Verification du critere de fleche sur chaque surface
      //et sur la ligne guide
    
      State1 = CheckDeflection(Standard_True,curpoint);
      State2 = CheckDeflection(Standard_False,curpoint);
    }
    else {
       State1 = Blend_OK;
       State2 = Blend_OK;
       if (TestLengthStep) {
	 // On verifie juste que le pas n'est pas trop grand
	 // (Cas des prolongements foireux)
	 Standard_Real curparamu,curparamv, prevparamu,prevparamv;
	 math_Vector inf(1,4), sup(1,4);
	 Function.GetBounds(inf, sup);
	 sup -= inf;
	 sup *= 0.05; // Pas max : 5% du domaine
     
	 curpoint.ParametersOnS1(curparamu,curparamv);
	 previousP.ParametersOnS1(prevparamu,prevparamv);
	 if (Abs(curparamu-prevparamu) > sup(1)) State1 = Blend_StepTooLarge;
	 if (Abs(curparamv-prevparamv) > sup(2)) State1 = Blend_StepTooLarge;     
	 curpoint.ParametersOnS2(curparamu,curparamv);
	 previousP.ParametersOnS2(prevparamu,prevparamv);
	 if (Abs(curparamu-prevparamu) > sup(3)) State2 = Blend_StepTooLarge;
	 if (Abs(curparamv-prevparamv) > sup(4)) State2 = Blend_StepTooLarge;
       }
    }
      
    if (State1 == Blend_Backward) {
      State1 = Blend_StepTooLarge;
      rebrou= Standard_True;
    }

    if (State2 == Blend_Backward) {
      State2 = Blend_StepTooLarge;
      rebrou = Standard_True;
    }

    if (State1 == Blend_StepTooLarge ||
	State2 == Blend_StepTooLarge) {
      
      return Blend_StepTooLarge;
    }
    

    // Ici seulement on peut statuer sur le twist
    // Car les rejet ont ete effectue (BUC60322)
    if (loctwist1) twistflag1 = Standard_True;
    if (loctwist2) twistflag2 = Standard_True;

    if (!comptra && !curpointistangent) {
      Function.Tangent(sol(1),sol(2),sol(3),sol(4),Tgp1,Tgp2,Nor1,Nor2);
      Nor1.Normalize();
      Nor2.Normalize();
      Standard_Real testra = Tgp1.Dot(Nor1.Crossed(V1));
      if (Abs(testra) > Precision::Confusion()) {
	tras1 = IntSurf_In;
	if ((testra > 0. && !loctwist1) || (testra < 0. && loctwist1)) {
	  tras1 = IntSurf_Out;
	}
      
	testra = Tgp2.Dot(Nor2.Crossed(V2));
	if (Abs(testra) > Precision::Confusion()) {
	  tras2 = IntSurf_Out;
	  if ((testra > 0. && !loctwist2) || (testra < 0. && loctwist2)) {
	    tras2 = IntSurf_In;
	  }
	  comptra = Standard_True;
	  line->Set(tras1,tras2);
	}
      }
    }

    if (State1 == Blend_OK ||
	State2 == Blend_OK ) {
      previousP = curpoint;
      return State;
    }

    if (State1 == Blend_StepTooSmall &&
	State2 == Blend_StepTooSmall) {
      previousP = curpoint;
      if (State == Blend_OK) {
	return Blend_StepTooSmall;
      }
      else {
	return State;
      }
    }

    if (State == Blend_OK) {
      return Blend_SamePoints;
    }
    else {
      return State;
    }

  }
  else {
    return Blend_StepTooLarge;
  }
}


Blend_Status Blend_Walking::CheckDeflection
  (const Standard_Boolean OnFirst,
   const Blend_Point&     CurPoint)
{
  // regle par tests dans U4 correspond a 11.478 d
  const Standard_Real CosRef3D = 0.98;

  const Standard_Real CosRef2D = 0.88; // correspond a 25 d

  Standard_Real Norme, Cosi, Cosi2;
  Standard_Real prevNorme = 0.;
  Standard_Real FlecheCourante;
  Standard_Real Du,Dv,Duv;
  Standard_Real tolu,tolv;

  gp_Pnt Psurf;
  gp_Vec Tgsurf;
  gp_Vec2d Tgonsurf;
  Standard_Real curparamu, curparamv;
  Standard_Boolean curpointistangent = CurPoint.IsTangencyPoint();

  gp_Pnt prevP;
  gp_Vec prevTg;
  gp_Vec2d previousd2d;
  Standard_Real prevparamu, prevparamv;
  Standard_Boolean prevpointistangent = previousP.IsTangencyPoint();

  if (OnFirst) {
    Psurf = CurPoint.PointOnS1();
    if(!curpointistangent){
      Tgsurf = CurPoint.TangentOnS1();
    }
    prevP = previousP.PointOnS1();
    if(!prevpointistangent){
      prevTg = previousP.TangentOnS1();
    }
    tolu = TheSurfaceTool::UResolution(surf1,tolesp);
    tolv = TheSurfaceTool::VResolution(surf1,tolesp);
  }
  else {
    Psurf = CurPoint.PointOnS2();
    if(!curpointistangent){
      Tgsurf = CurPoint.TangentOnS2();
    }
    prevP = previousP.PointOnS2();
    if(!prevpointistangent){
      prevTg = previousP.TangentOnS2();
    }
    tolu = TheSurfaceTool::UResolution(surf2,tolesp);
    tolv = TheSurfaceTool::VResolution(surf2,tolesp);
  }

  gp_Vec Corde(prevP,Psurf);
  Norme = Corde.SquareMagnitude();
//  if(!curpointistangent) curNorme = Tgsurf.SquareMagnitude();
  if(!prevpointistangent) prevNorme = prevTg.SquareMagnitude();


  if (Norme <= tolesp*tolesp){
    // il faudra peut etre  forcer meme point
    return Blend_SamePoints;
  }
  if(!prevpointistangent){
    if(prevNorme <= tolesp*tolesp) {
      return Blend_SamePoints;
    }
    Cosi = sens*Corde*prevTg;
    if (Cosi <0.) { // angle 3d>pi/2. --> retour arriere
      return Blend_Backward;
    }
    
    Cosi2 = Cosi * Cosi / prevNorme / Norme;
    if (Cosi2 < CosRef3D) { 
      return Blend_StepTooLarge;
    }
  }

  if(!curpointistangent){
    // Voir s il faut faire le controle sur le signe de prevtg*Tgsurf
    Cosi = sens*Corde*Tgsurf;
    Cosi2 = Cosi * Cosi / Tgsurf.SquareMagnitude() / Norme;
    if (Cosi2 < CosRef3D || Cosi < 0.) { 
      return Blend_StepTooLarge;
    }
  }  
    
  if(check2d){
    if (OnFirst) {
      CurPoint.ParametersOnS1(curparamu,curparamv);
      if(!curpointistangent) Tgonsurf = CurPoint.Tangent2dOnS1();
      previousP.ParametersOnS1(prevparamu,prevparamv);
      if(!prevpointistangent) previousd2d = previousP.Tangent2dOnS1();
    }
    else {
      CurPoint.ParametersOnS2(curparamu,curparamv);
      if(!curpointistangent) Tgonsurf = CurPoint.Tangent2dOnS2();
      previousP.ParametersOnS2(prevparamu,prevparamv);
      if(!prevpointistangent) previousd2d = previousP.Tangent2dOnS2();
    }
    
    Du = curparamu - prevparamu;
    Dv = curparamv - prevparamv;
    Duv = Du * Du + Dv * Dv;
//    SqrtDuv = Sqrt(Duv);
    if (Abs(Du) < tolu && Abs(Dv) < tolv){
      // il faudra peut etre  forcer meme point
      return Blend_SamePoints; //point confondu 2d
    }
    if(!prevpointistangent){
      if(Abs(previousd2d.X()) < tolu && Abs(previousd2d.Y()) < tolv){
	// il faudra peut etre  forcer meme point
	return Blend_SamePoints; //point confondu 2d
      }
      Cosi = sens*(Du * previousd2d.X() + Dv * previousd2d.Y());
      if (Cosi < 0) {
	return Blend_Backward; 
      }
    }    
    if(!curpointistangent){
      // Voir s il faut faire le controle sur le signe de Cosi
      Cosi = sens*(Du * Tgonsurf.X() +  Dv * Tgonsurf.Y())/Tgonsurf.Magnitude();
      Cosi2 = Cosi * Cosi / Duv;
      if (Cosi2 < CosRef2D || Cosi <0.) { 
	return Blend_StepTooLarge;
      }
    }
  }
  if(!curpointistangent && !prevpointistangent){
    // Estimation de la fleche courante
    FlecheCourante = (prevTg.Normalized().XYZ()-Tgsurf.Normalized().XYZ()).SquareModulus()*Norme/64.;
    
    if (FlecheCourante <= 0.25*fleche*fleche) {
      return Blend_StepTooSmall;
    }
    if (FlecheCourante > fleche*fleche) {
      // pas trop grand : commentaire interessant
      return Blend_StepTooLarge;
    }
  }
  return Blend_OK;
}