def calculate_local_north_and_up_in_celestial_coords(self, force_update):
current_time = self.get_time_in_millis()
diff = math.fabs(current_time - self.celestial_coords_last_updated)
if (not force_update) and diff < self.MINIMUM_TIME_BETWEEN_CELESTIAL_COORD_UPDATES_MILLIS:
return
self.celestial_coords_last_updated = current_time
self.update_magnetic_correction()
up_ra, up_dec = Geometry.calculate_RADec_of_zenith(self.get_time(), self.location)
self.up_celestial = get_instance(up_ra, up_dec)
z = self.AXIS_OF_EARTHS_ROTATION
z_dotu = Geometry.scalar_product(self.up_celestial, z)
self.true_north_celestial = \
Geometry.add_vectors(z, Geometry.scale_vector(self.up_celestial, -z_dotu))
self.true_north_celestial.normalize()
self.true_east_celestial = Geometry.vector_product(self.true_north_celestial, \
self.up_celestial)
# Apply magnetic correction. Rather than correct the phone's axes for
# the magnetic declination, it's more efficient to rotate the
# celestial axes by the same amount in the opposite direction.
declination = self.magnetic_declination_calc.get_declination()
rotation_matrix = Geometry.calculate_rotation_matrix(declination, self.up_celestial)
magnetic_north_celestial = Geometry.matrix_vector_multiply(rotation_matrix, \
self.true_north_celestial)
magnetic_east_celestial = Geometry.vector_product(magnetic_north_celestial, \
self.up_celestial)
self.axes_magnetic_celestial_matrix = get_colmatrix_from_vectors(magnetic_north_celestial, \
self.up_celestial, \
magnetic_east_celestial)
def calculate_pointing(self):
'''
update the direction that the phone is pointing and the up vector
perpendicular to the phone (in celestial coords).
'''
if not (self.auto_update_pointing):
return
transform = Geometry.matrix_multiply(self.axes_magnetic_celestial_matrix, \
self.axes_phone_inverse_matrix)
view_in_space_space = \
Geometry.matrix_vector_multiply(transform, self.POINTING_DIR_IN_PHONE_COORDS)
screen_up_in_space_space = \
Geometry.matrix_vector_multiply(transform, self.SCREEN_UP_IN_PHONE_COORDS)
self.pointing.update_line_of_sight(view_in_space_space)
self.pointing.update_perpendicular(screen_up_in_space_space)
def rotate(self, degrees):
'''
rotate astronomers view (clockwise/anti-clockwise)
'''
if not self.enabled: return
pointing = self.model.pointing
pointing_xyz = pointing.get_line_of_sight()
top_xyz = pointing.get_perpendicular()
rotation = Geometry.calculate_rotation_matrix(degrees, pointing_xyz)
new_up_xyz = Geometry.matrix_vector_multiply(rotation, top_xyz)
new_up_xyz.normalize()
self.model.set_pointing(pointing_xyz, new_up_xyz)
