void OffsetHandlePosition(const POS* pPos, float HandleLen, POS* pResult)
{
pResult->x = pPos->x + HandleLen * SinDeg(pPos->Rot) * CosDeg(pPos->Elev);
pResult->y = pPos->y + HandleLen * SinDeg(pPos->Elev);
pResult->z = pPos->z + HandleLen * CosDeg(pPos->Rot) * CosDeg(pPos->Elev);
pResult->Elev = pPos->Elev;
pResult->Rot = pPos->Rot;
}
bool Bridge:: FinalRadius(const double height,
const double theta,
const double alpha,
const bool save)
{
//__________________________________________________________________________
//
// do we save ?
//__________________________________________________________________________
if(save)
{
static vfs & fs = local_fs::instance();
fs.try_remove_file("profile.dat");
}
//__________________________________________________________________________
//
// check possibility
//__________________________________________________________________________
const double omega = lens->omega(alpha);
const double angle = omega+theta;
if(angle>=180)
{
return false;
}
//__________________________________________________________________________
//
// prepare initial conditions
//__________________________________________________________________________
const double Rc = lens->rho(0.0)+height;
const double R0 = lens->rho(alpha);
const double r0 = R0*SinDeg(alpha);
const double z0 = Rc - R0*CosDeg(alpha);
const double drdz = CosDeg(angle)/SinDeg(angle);
Y[1] = r0;
Y[2] = drdz;
//__________________________________________________________________________
//
// do we save ?
//__________________________________________________________________________
auto_ptr<ios::ostream> fp;
if(save)
{
fp.reset(new ios::ocstream("profile.dat",false) );
(*fp)("%g %g\n", r0, z0 );
}
//__________________________________________________________________________
//
// Try to integrate
//__________________________________________________________________________
double reg[3] = { Y[1],0,0 }; // curvature detector
size_t num = 1;
bool success = true;
for(size_t i=NUM_STEPS;i>0;--i)
{
const double z_ini = (i*z0)/NUM_STEPS;
const double z = ((i-1)*z0)/NUM_STEPS;
RK4(z_ini, z);
//______________________________________________________________________
//
// analyze
//______________________________________________________________________
const double r = Y[1];
//______________________________________________________________________
//
// absolute position
//______________________________________________________________________
if( isnan(r) || isinf(r) || r <= 0.0 )
{
success = false;
break;
}
//______________________________________________________________________
//
// Relative position: inside lens ?
//______________________________________________________________________
const double dr = r;
const double dz = Rc-z;
const double dist = Hypotenuse(dr, dz);
const double aa = Rad2Deg(2.0 * Atan( dr / (dz+dist)));
const double ra = lens->rho(aa);
if(dist<ra)
{
success = false;
break;
}
//__________________________________________________________________
//
// test valid curvature
//__________________________________________________________________
if(num<3)
{
reg[num++] = r;
}
else
{
reg[0] = reg[1];
reg[1] = reg[2];
reg[2] = r;
if((reg[1]+reg[1])>= (reg[0]+reg[2]) )
{
success = false;
break;
}
}
if(save && (r<=4*Rc))
{
(*fp)("%g %g\n", r, z );
}
}
return success;
}
