#!/usr/bin/env python
# coding: utf-8
"""
Modelling a Coherently Polarised Aperture
======================================================

This example uses the frequency domain :func:`lyceanem.models.frequency_domain.calculate_farfield` function to predict
the farfield pattern for a linearly polarised aperture. This could represent an antenna array without any beamforming
weights.


"""
import numpy as np
import open3d as o3d
import copy

# %%
# Setting Farfield Resolution and Wavelength
# -------------------------------------------
# LyceanEM uses Elevation and Azimuth to record spherical coordinates, ranging from -180 to 180 degrees in azimuth,
# and from -90 to 90 degrees in elevation. In order to launch the aperture projection function, the resolution in
# both azimuth and elevation is requried.
# In order to ensure a fast example, 37 points have been used here for both, giving a total of 1369 farfield points.
#
# The wavelength of interest is also an important variable for antenna array analysis, so we set it now for 10GHz,
# an X band aperture.

az_res = 181
elev_res = 181
wavelength = 3e8 / 10e9

# %%
# Geometries
# ------------------------
# In order to make things easy to start, an example geometry has been included within LyceanEM for a UAV, and the
# :class:`open3d.geometry.TriangleMesh` structures can be accessed by importing the data subpackage
import lyceanem.tests.reflectordata as data

body, array, source_coords = data.exampleUAV(10e9)

# %%
# Visualise the Resultant UAV and Array
# ---------------------------------------
# :func:`open3d.visualization.draw_geometries` can be used to visualise the open3d data
# structures :class:`open3d.geometry.PointCloud` and :class:`open3d.geometry.PointCloud`

mesh_frame = o3d.geometry.TriangleMesh.create_coordinate_frame(
    size=0.5, origin=[0, 0, 0]
)
o3d.visualization.draw_geometries([body, array, source_coords, mesh_frame])

# %%
# .. image:: ../_static/UAVArraywithPoints.png

# crop the inner surface of the array trianglemesh (not strictly required, as the UAV main body provides blocking to
# the hidden surfaces, but correctly an aperture will only have an outer face.
surface_array = copy.deepcopy(array)
surface_array.triangles = o3d.utility.Vector3iVector(
    np.asarray(array.triangles)[: len(array.triangles) // 2, :]
)
surface_array.triangle_normals = o3d.utility.Vector3dVector(
    np.asarray(array.triangle_normals)[: len(array.triangle_normals) // 2, :]
)

from lyceanem.base_classes import structures

blockers = structures([body, array])

from lyceanem.models.frequency_domain import calculate_farfield

from lyceanem.geometry.targets import source_cloud_from_shape

source_points, _ = source_cloud_from_shape(surface_array, wavelength * 0.5)

o3d.visualization.draw_geometries([body, array, source_points])

# %%
# .. image:: ../_static/sourcecloudfromshapeuav.png

# %%
# Drawbacks of :func:`lyceanem.geometry.geometryfunctions.sourcecloudfromshape`
# ------------------------------------------------------------------------------
# As can be seen by comparing the two source point sets, :func:`lyceanem.geometry.geometryfunctions.sourcecloudfromshape`
# has a significant drawback when used for complex sharply curved antenna arrays, as the poisson disk sampling method
# does not produce consistently spaced results.

desired_E_axis = np.zeros((1, 3), dtype=np.float32)
desired_E_axis[0, 2] = 1.0

Etheta, Ephi = calculate_farfield(
    source_coords,
    blockers,
    desired_E_axis,
    az_range=np.linspace(-180, 180, az_res),
    el_range=np.linspace(-90, 90, elev_res),
    wavelength=wavelength,
    farfield_distance=20,
    project_vectors=True,
)

# %%
# Storing and Manipulating Antenna Patterns
# ---------------------------------------------
# The resultant antenna pattern can be stored in :class:`lyceanem.base.antenna_pattern` as it has been modelled as one
# distributed aperture, the advantage of this class is the integrated display, conversion and export functions. It is
# very simple to define, and save the pattern, and then display with a call
# to :func:`lyceanem.base.antenna_pattern.display_pattern`. This produces 3D polar plots which can be manipulated to
# give a better view of the whole pattern, but if contour plots are required, then this can also be produced by passing
# plottype='Contour' to the function.

from lyceanem.base_classes import antenna_pattern

UAV_Static_Pattern = antenna_pattern(
    azimuth_resolution=az_res, elevation_resolution=elev_res
)
UAV_Static_Pattern.pattern[:, :, 0] = Etheta
UAV_Static_Pattern.pattern[:, :, 0] = Ephi

UAV_Static_Pattern.display_pattern()

# %%
# .. image:: ../_static/sphx_glr_02_coherently_polarised_array_001.png
# .. image:: ../_static/sphx_glr_02_coherently_polarised_array_002.png

UAV_Static_Pattern.display_pattern(plottype="Contour")

# %%
# .. image:: ../_static/sphx_glr_02_coherently_polarised_array_003.png
# .. image:: ../_static/sphx_glr_02_coherently_polarised_array_004.png