def is_on_line(seg_start, seg_end, point, precision=PRECISION):
if is_same(seg_start, point, precision=precision) or is_same(seg_end, point, precision=precision):
return True
if is_same(seg_start, seg_end, precision=precision):
return False
vector_from_start_to_end = points_diff(seg_start, seg_end)
vector_from_start_to_point = points_diff(seg_start, point)
angle = math.degrees(
math.acos(
min(
1.0,
max(
-1.0,
dot_product(vector_from_start_to_end, vector_from_start_to_point)
/ (magnitude(vector_from_start_to_end) * magnitude(vector_from_start_to_point)),
),
)
)
)
# ==
return (
is_same(angle, 0, precision=precision)
or is_same(angle, 360.0, precision=precision)
or is_same(angle, -360.0, precision=precision)
)
def actual_intersection(segments, i, j):
segment = segments[i]
other_segment = segments[j]
if is_same(dot_product(points_diff(*segment), points_diff(*other_segment)), 0.0):
return False
for index1, p1 in enumerate(segment):
for index2, p2 in enumerate(other_segment):
if is_same(p1, p2):
segment1 = segments[i - 1][index1], segments[(i + 1) % len(segments)][index1]
segment2 = segments[j - 1][index2], segments[(j + 1) % len(segments)][index2]
if have_common_point(segment1, segment2):
return False
if not segments_are_intersecting(segment1, segment2):
return False
# ==
if index1 == 0:
connected_segment1 = segments[i - 1]
else:
connected_segment1 = segments[(i + 1) % len(segments)]
if index2 == 0:
connected_segment2 = segments[j - 1]
else:
connected_segment2 = segments[(j + 1) % len(segments)]
if is_same(
cross_product(points_diff(*connected_segment1), points_diff(*other_segment)), 0.0
) or is_same(cross_product(points_diff(*connected_segment2), points_diff(*segment)), 0.0):
return False
center = p1
if _is_in_angle(segment1[0], center, segment1[1], segment2[0]) == _is_in_angle(
segment1[0], center, segment1[1], segment2[1]
):
return False
for index1, p1 in enumerate(segment):
if is_on_segment(other_segment[0], other_segment[1], p1):
full_segment = (segments[i - 1][index1], segments[(i + 1) % len(segments)][index1])
if have_common_point(other_segment, full_segment):
return False
if not segments_are_intersecting(full_segment, other_segment):
return False
for index2, p2 in enumerate(other_segment):
if is_on_segment(segment[0], segment[1], p2):
full_segment = (segments[j - 1][index2], segments[(j + 1) % len(segments)][index2])
if have_common_point(segment, full_segment):
return False
if not segments_are_intersecting(full_segment, segment):
return False
return True
