void cDistorBilin::Diff(ElMatrix<REAL> & aM,Pt2dr aP) const
{
// InitEtatFromCorner(ToCoordGrid(aP));
Pt2dr aPds;
GetParamCorner(mCurCorner,aPds,ToCoordGrid(aP));
const Pt2dr & aP00 = Dist(mCurCorner+CamBilinCorn[0] ) ;
const Pt2dr & aP10 = Dist(mCurCorner+CamBilinCorn[1] ) ;
const Pt2dr & aP01 = Dist(mCurCorner+CamBilinCorn[2] ) ;
const Pt2dr & aP11 = Dist(mCurCorner+CamBilinCorn[3] ) ;
Pt2dr aGx = ((aP10-aP00)*aPds.y + (aP11-aP01)*(1-aPds.y)) / mStep.x;
Pt2dr aGy = ((aP01-aP00)*aPds.x + (aP11-aP10)*(1-aPds.x)) / mStep.y;
aM.ResizeInside(2,2);
SetCol(aM,0,aGx);
SetCol(aM,1,aGy);
// A conserver, verification par diff std
if (0)
{
ElMatrix<REAL> aM2(2,2);
DiffByDiffFinies(aM2,aP,euclid(mStep)/1e4);
static double aDMax = 0;
double aD = aM.L2(aM2);
if (aD>aDMax)
{
aDMax = aD;
std::cout << "DDDD " << aD << "\n";
}
}
// InitEtatFromCorner(ToCoordGrid(aP));
}
