+//=======================================================================
+//function : compensateError
+//purpose : adjust theParams so that the last segment length == an
+//=======================================================================
+
+static void compensateError(double a1, double an,
+ double U1, double Un,
+ double length,
+ GeomAdaptor_Curve& C3d,
+ list<double> & theParams)
+{
+ int i, nPar = theParams.size();
+ if ( a1 + an < length && nPar > 1 )
+ {
+ list<double>::reverse_iterator itU = theParams.rbegin();
+ double Ul = *itU++;
+ // dist from the last point to the edge end <Un>, it should be equal <an>
+ double Ln = GCPnts_AbscissaPoint::Length( C3d, Ul, Un );
+ double dLn = an - Ln; // error of <an>
+ if ( Abs( dLn ) <= Precision::Confusion() )
+ return;
+ double dU = Abs( Ul - *itU ); // parametric length of the last but one segment
+ double dUn = dLn * Abs( Un - U1 ) / length; // parametric error of <an>
+ if ( dUn < 0.5 * dU ) { // last segment is a bit shorter than it should
+ dUn = -dUn; // move the last parameter to the edge beginning
+ }
+ else { // last segment is much shorter than it should -> remove the last param and
+ theParams.pop_back(); nPar--; // move the rest points toward the edge end
+ Ln = GCPnts_AbscissaPoint::Length( C3d, theParams.back(), Un );
+ dUn = ( an - Ln ) * Abs( Un - U1 ) / length;
+ if ( dUn < 0.5 * dU )
+ dUn = -dUn;
+ }
+ if ( U1 > Un )
+ dUn = -dUn;
+ double q = dUn / ( nPar - 1 );
+ for ( itU = theParams.rbegin(), i = 1; i < nPar; itU++, i++ ) {
+ (*itU) += dUn;
+ dUn -= q;
+ }
+ }
+}
+
+static bool computeParamByFunc(Adaptor3d_Curve& C3d, double first, double last,
+ double length, bool theReverse,
+ int nbSeg, Function& func,
+ list<double>& theParams)
+{
+ OSD::SetSignal( true );
+
+ if( nbSeg<=0 )
+ return false;
+
+ MESSAGE( "computeParamByFunc" );
+
+ int nbPnt = 1 + nbSeg;
+ vector<double> x(nbPnt, 0.);
+
+ if( !buildDistribution( func, 0.0, 1.0, nbSeg, x, 1E-4 ) )
+ return false;
+
+ MESSAGE( "Points:\n" );
+ char buf[1024];
+ for( int i=0; i<=nbSeg; i++ )
+ {
+ sprintf( buf, "%f\n", float(x[i] ) );
+ MESSAGE( buf );
+ }
+
+
+
+ // apply parameters in range [0,1] to the space of the curve
+ double prevU = first;
+ double sign = 1.;
+ if (theReverse)
+ {
+ prevU = last;
+ sign = -1.;
+ }
+ for( int i = 1; i < nbSeg; i++ )
+ {
+ double curvLength = length * (x[i] - x[i-1]) * sign;
+ GCPnts_AbscissaPoint Discret( C3d, curvLength, prevU );
+ if ( !Discret.IsDone() )
+ return false;
+ double U = Discret.Parameter();
+ if ( U > first && U < last )
+ theParams.push_back( U );
+ else
+ return false;
+ prevU = U;
+ }
+ return true;
+}
+