Beispiel #1
0
ZZn8 line(ECn& A,ECn& C,ZZn& slope,ZZn4& Qx,ZZn4& Qy)
{ 
    ZZn8 w;
    ZZn4 m=Qx;
    ZZn x,y,z,t;
#ifdef AFFINE
    extract(A,x,y);
    m-=x; m*=slope;  
    w.set((ZZn4)-y,Qy); w-=m;
#endif
#ifdef PROJECTIVE
    extract(A,x,y,z);
    x*=z; t=z; z*=z; z*=t;      
      
    x*=slope; t=slope*z;
    m*=t; m-=x; t=z;
    extract(C,x,x,z);
    m+=(z*y); t*=z;
    w.set(m,-Qy*t);

#endif
    return w;
}