source 2002 Billet--Joye "The Jacobi model of an elliptic curve and side-channel analysis", formula (11), plus specialization to doubling
compute X3 = X1 Z1 Y1+Y1 X1 Z1
compute Y3 = ((Z1 Z1)^2+(X1 X1)^2) (Y1 Y1+2 a X1 X1 Z1 Z1)+2 X1 X1 Z1 Z1 (X1^2 Z1^2+Z1^2 X1^2)
compute Z3 = (Z1 Z1)^2-(X1 X1)^2