c generate screen data from Tom's surfcae points
c NOTE: for left screen, flip sign of points to right side
c
      real*8, dimension(3,3) :: p1, p2, p3, plaser1,plaser2, xnorm
      real*8, dimension(3) ::  c,a ,b
c
      do iscreen=1,3
      read(*,*)
      read(*,*) plaser1(:,iscreen)
      read(*,*) plaser2(:,iscreen)
      read(*,*) p1(:,iscreen)
      read(*,*) p2(:,iscreen)
      read(*,*) p3(:,iscreen)
c
!c image for left side
!c
!      plaser1(2:3,iscreen)=-plaser1(2:3,iscreen)
!      plaser2(2:3,iscreen)=-plaser2(2:3,iscreen)
!      p1(2:3,iscreen)=-p1(2:3,iscreen)
!      p2(2:3,iscreen)=-p2(2:3,iscreen)
!      p3(2:3,iscreen)=-p3(2:3,iscreen)
c
c get screen normal
c
      a=p2(:,iscreen)-p1(:,iscreen)
      b=p3(:,iscreen)-p2(:,iscreen)
      call axb(a,b,c)
      xnorm(:,iscreen)=c
      enddo
c
c write out data for doall script
      do iscreen=1,3
      write(*,"(3f12.6)") plaser1(:,iscreen)
      write(*,"(3f12.6)") plaser2(:,iscreen)
      enddo
c
      do iscreen=1,3
      write(*,"(6f12.6)") xnorm(:,iscreen), p1(:,iscreen)
      enddo
c
      stop
      end
c*********************************
      subroutine axb(a,b,c)
      real*8, dimension(3) :: a, b, c
      real*8 c2
c
      c(1)=a(2)*b(3)-b(2)*a(3)
      c(2)=a(3)*b(1)-b(3)*a(1)
      c(3)=a(1)*b(2)-b(1)*a(2)
      c2=dot_product(c,c)
      if(c2.eq.0.d0)return
      c=c/sqrt(c2)
      return
      end