occt/src/IntCurveSurface/IntCurveSurface_HCurveTool.gxx

// Created on: 1995-07-17
// Created by: Modelistation
// Copyright (c) 1995-1999 Matra Datavision
// Copyright (c) 1999-2012 OPEN CASCADE SAS
//
// The content of this file is subject to the Open CASCADE Technology Public
// License Version 6.5 (the "License"). You may not use the content of this file
// except in compliance with the License. Please obtain a copy of the License
// at http://www.opencascade.org and read it completely before using this file.
//
// The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
// main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
//
// The Original Code and all software distributed under the License is
// distributed on an "AS IS" basis, without warranty of any kind, and the
// Initial Developer hereby disclaims all such warranties, including without
// limitation, any warranties of merchantability, fitness for a particular
// purpose or non-infringement. Please see the License for the specific terms
// and conditions governing the rights and limitations under the License.


#include CurveGen_hxx
#include <GeomAbs_CurveType.hxx>
#include <GeomAbs_Shape.hxx>
#include <Handle_Geom_BezierCurve.hxx>
#include <Handle_Geom_BSplineCurve.hxx>

#include <TColStd_Array1OfReal.hxx>
#include <TColStd_Array1OfBoolean.hxx>
#include <gce_MakeLin.hxx>
#include <gp_Pnt.hxx>
#include <gp_Lin.hxx>

#define myMinPnts 5
//============================================================
Standard_Integer IntCurveSurface_HCurveTool::NbSamples (const CurveGen& C,
						       const Standard_Real U0,
						       const Standard_Real U1) {
  GeomAbs_CurveType typC = C->GetType();
  const Standard_Real nbsOther = 10.0;
  Standard_Real nbs = nbsOther;
  
  if(typC == GeomAbs_Line) 
    nbs = 2;
  else if(typC == GeomAbs_BezierCurve) 
    nbs = 3 + C->NbPoles();
  else if(typC == GeomAbs_BSplineCurve) { 
    nbs = C->NbKnots();
    nbs*= C->Degree();
    nbs*= C->LastParameter()- C->FirstParameter();
    nbs/= U1-U0;
    if(nbs < 2.0) nbs=2;
  }
  if(nbs>50)
    nbs = 50;
  return((Standard_Integer)nbs);
}
//============================================================
void IntCurveSurface_HCurveTool::SamplePars (const CurveGen& C,
					     const Standard_Real U0,
					     const Standard_Real U1,
					     const Standard_Real Defl,
					     const Standard_Integer NbMin,
					     Handle(TColStd_HArray1OfReal)& Pars) {
  GeomAbs_CurveType typC = C->GetType();
  const Standard_Real nbsOther = 10.0;
  Standard_Real nbs = nbsOther;
  
  if(typC == GeomAbs_Line) 
    nbs = 2;
  else if(typC == GeomAbs_BezierCurve) {
    nbs = 3 + C->NbPoles();
  }
  
  if(typC != GeomAbs_BSplineCurve) {
    if(nbs>50)
      nbs = 50;
    Standard_Integer nnbs = (Standard_Integer)nbs;

    Pars = new TColStd_HArray1OfReal(1, nnbs);
    Standard_Real du = (U1-U0)/(nnbs - 1);

    Pars->SetValue(1, U0);
    Pars->SetValue(nnbs, U1);
    Standard_Integer i;
    Standard_Real u;
    for(i = 2, u = U0+du; i < nnbs; ++i, u += du) {
      Pars->SetValue(i, u);
    }
    return;
  }

  const Handle(Geom_BSplineCurve)& aBC = C->BSpline();

  Standard_Integer i, j, k, nbi;
  Standard_Real t1, t2, dt;
  Standard_Integer ui1 = aBC->FirstUKnotIndex();
  Standard_Integer ui2 = aBC->LastUKnotIndex();
 
  for(i = ui1; i < ui2; ++i) {
    if(U0 >= aBC->Knot(i) && U0 < aBC->Knot(i+1)) {
      ui1 = i;
      break;
    }
  }

  for(i = ui2; i > ui1; --i) {
    if(U1 <= aBC->Knot(i) && U1 > aBC->Knot(i-1)) {
      ui2 = i;
      break;
    }
  }

  Standard_Integer nbsu = ui2-ui1+1; nbsu += (nbsu - 1) * (aBC->Degree()-1);
  Standard_Boolean bUniform = Standard_False;
  if(nbsu < NbMin) {
    nbsu = NbMin;
    bUniform = Standard_True;
  }

  TColStd_Array1OfReal aPars(1, nbsu);
  TColStd_Array1OfBoolean aFlg(1, nbsu);
  //Filling of sample parameters
  if(bUniform) {
    t1 = U0;
    t2 = U1;
    dt = (t2 - t1)/(nbsu - 1);
    aPars(1) = t1;
    aFlg(1) = Standard_False;
    aPars(nbsu) = t2;
    aFlg(nbsu) = Standard_False;
    for(i = 2, t1 += dt; i < nbsu; ++i, t1 += dt) {
      aPars(i) = t1;
      aFlg(i) = Standard_False;
    }
  }
  else {  
    nbi = aBC->Degree();
    k = 0;
    t1 = U0;
    for(i = ui1+1; i <= ui2; ++i) {
      if(i == ui2) t2 = U1;
      else t2 = aBC->Knot(i);
      dt = (t2 - t1)/nbi;
      j = 1;
      do { 
	++k;
	aPars(k) = t1;
	aFlg(k) = Standard_False;
	t1 += dt;	
      }
      while (++j <= nbi);
      t1 = t2;
    }
    ++k;
    aPars(k) = t1;
  }
 //Analysis of deflection


  Standard_Real aDefl2 = Max(Defl*Defl, 1.e-9);
  Standard_Real tol = Max(0.01*aDefl2, 1.e-9);
  Standard_Integer l;

  Standard_Integer NbSamples = 2;
  aFlg(1) = Standard_True;
  aFlg(nbsu) = Standard_True;
  j = 1;
  Standard_Boolean bCont = Standard_True;
  while (j < nbsu-1 && bCont) {
    
    if(aFlg(j+1)) {
      ++j;
      continue;
    }
    
    t2 = aPars(j);
    gp_Pnt p1 = aBC->Value(t2);
    for(k = j+2; k <= nbsu; ++k) {
      t2 = aPars(k);
      gp_Pnt p2 = aBC->Value(t2);

      if(p1.SquareDistance(p2) <= tol) continue;

      gce_MakeLin MkLin(p1, p2);
      const gp_Lin& lin = MkLin.Value();
      Standard_Boolean ok = Standard_True;
      for(l = j+1; l < k; ++l) {
	
	if(aFlg(l)) {
	  ok = Standard_False;
	  break;
	}
	
	gp_Pnt pp =  aBC->Value(aPars(l));
	Standard_Real d = lin.SquareDistance(pp);
	
	if(d <= aDefl2) continue;
	
	ok = Standard_False;
	break;
      }
      
      if(!ok) {
	j = k - 1;
	aFlg(j) = Standard_True;
	++NbSamples;
	break;
      }
      
      if(aFlg(k)) {
	j = k;
	break;
      }
      
      
    }
    
    if(k >= nbsu) bCont = Standard_False;
    
  }

  if(NbSamples < myMinPnts) {
    //uniform distribution 
    NbSamples = myMinPnts;
    Pars = new TColStd_HArray1OfReal(1, NbSamples);
    t1 = U0;
    t2 = U1;
    dt = (t2 - t1)/(NbSamples - 1);
    Pars->SetValue(1, t1);
    Pars->SetValue(NbSamples, t2);
    for(i = 2, t1 += dt; i < NbSamples; ++i, t1 += dt) {
      Pars->SetValue(i, t1);
    }
    return;
  }

  Pars = new TColStd_HArray1OfReal(1, NbSamples);
  j = 0;
  for(i = 1; i <= nbsu; ++i) {
    if(aFlg(i)) {
      ++j;
      Pars->SetValue(j,aPars(i));
    }
  }

  

}