RealGradient
CrossIC::gradient(const Point & p)
{
Point pxminus = p, pxplus = p, pyminus = p, pyplus = p;
pxminus(0) -= TOLERANCE;
pyminus(1) -= TOLERANCE;
pxplus(0) += TOLERANCE;
pyplus(1) += TOLERANCE;
Number uxminus = value(pxminus), uxplus = value(pxplus), uyminus = value(pyminus),
uyplus = value(pyplus);
return Gradient((uxplus - uxminus) / 2.0 / TOLERANCE, (uyplus - uyminus) / 2.0 / TOLERANCE);
}
Vector3D Terrain::norm(const Vector2D &p) const
{
Vector2D px(p.x()+epsilon,p.y());
Vector2D pxminus(p.x()-epsilon, p.y());
Vector2D py(p.x(),p.y()+epsilon);
Vector2D pyminus(p.x(),p.y()-epsilon);
double hpx=getHauteur(px);
double hpxminus = getHauteur(pxminus);
double hpy=getHauteur(py);
double hpyminus = getHauteur(pyminus);
Vector3D resu(-(hpx-hpxminus),2*epsilon,-(hpy-hpyminus));
resu.normalize();
return resu;
}
Vector3D Terrain::norm(const Vector2D &p)
{
/* Vector2D px(p.x()+epsilon,p.y());
Vector2D py(p.x(),p.y()+epsilon);
double hp=getHauteur(p);
double hpx=getHauteur(px);
double hpy=getHauteur(py);
Vector3D vp(p.x(),p.y(),(double)hp);
Vector3D vpx(px.x(),px.y(),(double)hpx);
Vector3D vpy(py.x(),py.y(),(double)hpy);
Vector3D u=vpx-vp;
Vector3D v=vpy-vp;
Vector3D n(-u.z()/u.x(),1.0f,-v.z()/v.y());
n.normalize();
return n;*/
//std::cout<<p.x()<<" "<<p.x()+epsilon<<std::endl;
Vector2D px(p.x()+epsilon,p.y());
Vector2D pxminus(p.x()-epsilon, p.y());
Vector2D py(p.x(),p.y()+epsilon);
Vector2D pyminus(p.x(),p.y()-epsilon);
double hpx=getHauteur(px);
double hpxminus = getHauteur(pxminus);
double hpy=getHauteur(py);
double hpyminus = getHauteur(pyminus);
//std::cout<<hpx<<" "<<hpxminus<<std::endl;
Vector3D resu(-(hpx-hpxminus),2*epsilon,-(hpy-hpyminus));
resu.normalize();
return resu;
}
