# polygon
INTEGRAL_FLUX
  ! 1 x - x 1 
  ! 1 m^2 \perp Y
  ! @ 1 mm/s for 2 s = 2 kg total, 1 kg/s
  NAME Y
  POLYGON
    0. 1. 0.
    1. 1. 1.
  /
END

# coordinates and directions
INTEGRAL_FLUX
  ! 1 m^2 \perp X, Y, Z = 3 m^2 total
  ! @ 1 mm/s for 2 s = 2 kg total, 1 kg/s
  NAME top_north_east_corner_y
  COORDINATES_AND_DIRECTIONS
    1.5 2. 1.5 0. 1. 0.  ! north face of cell 8
  /
END

# =============================== Y plane at 0 ================================
INTEGRAL_FLUX
  ! @ 1 mm/s for 2 s = -8 kg total, -4 kg/s
  INVERT_DIRECTION
  NAME Y_at_0
  PLANE
    0. 0. 0.
    1. 0. 0.
    0. 0. 1.
  /
END

! the four below should sum to the above
INTEGRAL_FLUX Y_at_0_1
  POLYGON
    0. 0. 0.
    1. 0. 1.
  /
END

INTEGRAL_FLUX Y_at_0_2
  POLYGON
    1. 0. 0.
    2. 0. 1.
  /
END

INTEGRAL_FLUX Y_at_0_5
  POLYGON
    0. 0. 1.
    1. 0. 2.
  /
END

INTEGRAL_FLUX Y_at_0_6
  POLYGON
    1. 0. 1.
    2. 0. 2.
  /
END

# =============================== Y plane at 2 ================================
INTEGRAL_FLUX
  ! @ 1 mm/s for 2 s = 8 kg total, 4 kg/s
  NAME Y_at_0
  PLANE
    0. 2. 0.
    1. 2. 0.
    0. 2. 1.
  /
END

! the four below should sum to the above
INTEGRAL_FLUX Y_at_2_3
  POLYGON
    0. 2. 0.
    1. 2. 1.
  /
END

INTEGRAL_FLUX Y_at_2_4
  POLYGON
    1. 2. 0.
    2. 2. 1.
  /
END

INTEGRAL_FLUX Y_at_2_7
  POLYGON
    0. 2. 1.
    1. 2. 2.
  /
END

INTEGRAL_FLUX Y_at_2_8
  POLYGON
    1. 2. 1.
    2. 2. 2.
  /
END

