def wave_abr_pre_calc(fod, fld, wvl, foc, ray_pkg, chief_ray_pkg):
"""Pre-calculate the part of the OPD calc independent of focus."""
cr, cr_exp_seg = chief_ray_pkg
chief_ray, chief_ray_op, wvl = cr
cr_exp_pt, cr_exp_dir, cr_exp_dist, ifc, cr_b4_pt, cr_b4_dir = cr_exp_seg
ray, ray_op, wvl = ray_pkg
k = -2 # last interface in sequence
# eq 3.12
e1 = eic_distance((ray[1][mc.p], ray[0][mc.d]),
(chief_ray[1][mc.p], chief_ray[0][mc.d]))
# eq 3.13
ekp = eic_distance((ray[k][mc.p], ray[k][mc.d]),
(chief_ray[k][mc.p], chief_ray[k][mc.d]))
pre_opd = -abs(fod.n_obj) * e1 - ray_op + abs(
fod.n_img) * ekp + chief_ray_op
b4_pt, b4_dir = transform_after_surface(ifc, (ray[k][mc.p], ray[k][mc.d]))
dst = ekp - cr_exp_dist
eic_exp_pt = b4_pt - dst * b4_dir
p_coord = eic_exp_pt - cr_exp_pt
return pre_opd, p_coord, b4_pt, b4_dir
def wave_abr_full_calc(fod, fld, wvl, foc, ray_pkg, chief_ray_pkg, ref_sphere):
"""Given a ray, a chief ray and an image pt, evaluate the OPD.
The main references for the calculations are in the H. H. Hopkins paper
`Calculation of the Aberrations and Image Assessment for a General Optical
System <https://doi.org/10.1080/713820605>`_
Args:
fod: :class:`~.FirstOrderData` for object and image space refractive
indices
fld: :class:`~.Field` point for wave aberration calculation
wvl: wavelength of ray (nm)
foc: defocus amount
ray_pkg: input tuple of ray, ray_op, wvl
chief_ray_pkg: input tuple of chief_ray, cr_exp_seg
ref_sphere: input tuple of image_pt, ref_dir, ref_sphere_radius
Returns:
opd: OPD of ray wrt chief ray at **fld**
"""
image_pt, ref_dir, ref_sphere_radius = ref_sphere
cr, cr_exp_seg = chief_ray_pkg
chief_ray, chief_ray_op, wvl = cr
cr_exp_pt, cr_exp_dir, cr_exp_dist, ifc, cr_b4_pt, cr_b4_dir = cr_exp_seg
ray, ray_op, wvl = ray_pkg
k = -2 # last interface in sequence
# eq 3.12
e1 = eic_distance((ray[1][mc.p], ray[0][mc.d]),
(chief_ray[1][mc.p], chief_ray[0][mc.d]))
# eq 3.13
ekp = eic_distance((ray[k][mc.p], ray[k][mc.d]),
(chief_ray[k][mc.p], chief_ray[k][mc.d]))
b4_pt, b4_dir = transform_after_surface(ifc, (ray[k][mc.p], ray[k][mc.d]))
dst = ekp - cr_exp_dist
eic_exp_pt = b4_pt - dst * b4_dir
p_coord = eic_exp_pt - cr_exp_pt
F = ref_dir.dot(b4_dir) - b4_dir.dot(p_coord) / ref_sphere_radius
J = p_coord.dot(p_coord) / ref_sphere_radius - 2.0 * ref_dir.dot(p_coord)
sign_soln = -1 if ref_dir[2] * cr.ray[-1][mc.d][2] < 0 else 1
denom = F + sign_soln * sqrt(F**2 + J / ref_sphere_radius)
ep = 0 if denom == 0 else J / denom
n_obj = abs(fod.n_obj)
n_img = abs(fod.n_img)
opd = -n_obj * e1 - ray_op + n_img * ekp + chief_ray_op - n_img * ep
return opd