pure function flux2d_LinearEuler2D_t(this,s,dsdx) result(flux)
class(LinearEuler2D_t),intent(in) :: this
real(prec),intent(in) :: s(1:this%nvar)
real(prec),intent(in) :: dsdx(1:this%nvar,1:2)
real(prec) :: flux(1:this%nvar,1:2)
flux(1,1) = this%rho0*s(2) ! density, x flux ; rho0*u
flux(1,2) = this%rho0*s(3) ! density, y flux ; rho0*v
flux(2,1) = s(4)/this%rho0 ! x-velocity, x flux; p/rho0
flux(2,2) = 0.0_prec ! x-velocity, y flux; 0
flux(3,1) = 0.0_prec ! y-velocity, x flux; 0
flux(3,2) = s(4)/this%rho0 ! y-velocity, y flux; p/rho0
flux(4,1) = this%c*this%c*this%rho0*s(2) ! pressure, x flux : rho0*c^2*u
flux(4,2) = this%c*this%c*this%rho0*s(3) ! pressure, y flux : rho0*c^2*v
endfunction flux2d_LinearEuler2D_t