def segment_squared_distance(
box: Box, segment: Segment,
dot_producer: QuaternaryPointFunction[Scalar],
segments_collision_detector: QuaternaryPointFunction[bool],
point_cls: Type[Point]) -> Scalar:
segment_start, segment_end = segment.start, segment.end
min_x, min_y, max_x, max_y = (rationalize(box.min_x), rationalize(
box.min_y), rationalize(box.max_x), rationalize(box.max_y))
return (
0 if
((min_x <= segment_start.x <= max_x
and min_y <= segment_start.y <= max_y) or
(min_x <= segment_end.x <= max_x and min_y <= segment_end.y <= max_y))
else
((segment_point_squared_distance(segment_start, segment_end,
point_cls(min_x, min_y), dot_producer)
if min_y == max_y else segment_segment_squared_distance(
segment_start, segment_end, point_cls(min_x, min_y),
point_cls(min_x, max_y), dot_producer,
segments_collision_detector)) if min_x == max_x else
(segment_segment_squared_distance(
segment_start, segment_end, point_cls(min_x, min_y),
point_cls(max_x, min_y), dot_producer, segments_collision_detector
) if min_y == max_y else _non_degenerate_segment_squared_distance(
max_x, max_y, min_x, min_y, segment_start, segment_end,
dot_producer, segments_collision_detector, point_cls))))
def centroid(multipoint: Multipoint,
point_cls: Type[Point],
inverse: Callable[[int], Fraction] = Fraction(1).__truediv__
) -> Point:
result_x = result_y = 0
for point in multipoint.points:
result_x += rationalize(point.x)
result_y += rationalize(point.y)
inverted_points_count = inverse(len(multipoint.points))
return point_cls(result_x * inverted_points_count,
result_y * inverted_points_count)
def signed_area(contour: Contour[Scalar],
*,
_half: Fraction = Fraction(1, 2)) -> Scalar:
vertices = contour.vertices
result, vertex = 0, vertices[-1]
vertex_x, vertex_y = rationalize(vertex.x), rationalize(vertex.y)
for next_vertex in vertices:
next_vertex_x, next_vertex_y = (rationalize(next_vertex.x),
rationalize(next_vertex.y))
result += vertex_x * next_vertex_y - next_vertex_x * vertex_y
vertex_x, vertex_y = next_vertex_x, next_vertex_y
return _half * result
def centroid_components(
vertices: Sequence[Point]) -> Tuple[Scalar, Scalar, Scalar]:
double_area = x_numerator = y_numerator = 0
prev_vertex = vertices[-1]
prev_x, prev_y = rationalize(prev_vertex.x), rationalize(prev_vertex.y)
for vertex in vertices:
x, y = rationalize(vertex.x), rationalize(vertex.y)
area_component = prev_x * y - prev_y * x
double_area += area_component
x_numerator += (prev_x + x) * area_component
y_numerator += (prev_y + y) * area_component
prev_x, prev_y = x, y
return x_numerator, y_numerator, double_area
def centroid(multisegment: Multisegment, point_cls: Type[Point],
sqrt: Callable[[Scalar], Scalar]) -> Point:
accumulated_x = accumulated_y = accumulated_length = 0
for segment in multisegment.segments:
start, end = segment.start, segment.end
start_x, start_y = rationalize(start.x), rationalize(start.y)
end_x, end_y = rationalize(end.x), rationalize(end.y)
length = sqrt((end_x - start_x)**2 + (end_y - start_y)**2)
accumulated_x += (start_x + end_x) * length
accumulated_y += (start_y + end_y) * length
accumulated_length += length
inverted_divisor = 1 / (2 * accumulated_length)
return point_cls(accumulated_x * inverted_divisor,
accumulated_y * inverted_divisor)
def multiply(first_start: Point,
first_end: Point,
second_start: Point,
second_end: Point) -> Scalar:
return ((rationalize(first_end.x) - rationalize(first_start.x))
* (rationalize(second_end.x) - rationalize(second_start.x))
+ (rationalize(first_end.y) - rationalize(first_start.y))
* (rationalize(second_end.y) - rationalize(second_start.y)))
def centroid(contour: Contour, point_cls: Type[Point],
sqrt: Callable[[Scalar], Scalar]) -> Point:
vertices = contour.vertices
accumulated_x = accumulated_y = accumulated_length = 0
vertex = vertices[-1]
start_x, start_y = rationalize(vertex.x), rationalize(vertex.y)
for vertex in vertices:
end_x, end_y = rationalize(vertex.x), rationalize(vertex.y)
length = sqrt((end_x - start_x)**2 + (end_y - start_y)**2)
accumulated_x += (start_x + end_x) * length
accumulated_y += (start_y + end_y) * length
accumulated_length += length
start_x, start_y = end_x, end_y
inverted_divisor = 1 / (2 * accumulated_length)
return point_cls(accumulated_x * inverted_divisor,
accumulated_y * inverted_divisor)
def rotate_translate_point(point: Point, cosine: Scalar, sine: Scalar,
step_x: Scalar, step_y: Scalar,
point_cls: Type[Point]) -> Point:
x, y = rationalize(point.x), rationalize(point.y)
cosine, sine = rationalize(cosine), rationalize(sine)
return point_cls(cosine * x - sine * y + rationalize(step_x),
sine * x + cosine * y + rationalize(step_y))
def test(point: Point, first: Point, second: Point, third: Point) -> Scalar:
point_x, point_y = rationalize(point.x), rationalize(point.y)
first_dx, first_dy = (rationalize(first.x) - point_x,
rationalize(first.y) - point_y)
second_dx, second_dy = (rationalize(second.x) - point_x,
rationalize(second.y) - point_y)
third_dx, third_dy = (rationalize(third.x) - point_x,
rationalize(third.y) - point_y)
return Location(1 +
to_sign((first_dx * first_dx + first_dy * first_dy) *
(second_dx * third_dy - second_dy * third_dx) -
(second_dx * second_dx + second_dy * second_dy) *
(first_dx * third_dy - first_dy * third_dx) +
(third_dx * third_dx + third_dy * third_dy) *
(first_dx * second_dy - first_dy * second_dx)))
def point_squared_distance(segment_start: Point,
segment_end: Point,
point: Point,
dot_producer: QuaternaryPointFunction[Scalar]
) -> Scalar:
end_factor = max(0, min(1,
dot_producer(segment_start, point, segment_start,
segment_end)
/ point_point_squared_distance(segment_start,
segment_end)))
start_factor = 1 - end_factor
return ((start_factor * rationalize(segment_start.x)
+ end_factor * rationalize(segment_end.x)
- rationalize(point.x)) ** 2
+ (start_factor * rationalize(segment_start.y)
+ end_factor * rationalize(segment_end.y)
- rationalize(point.y)) ** 2)
def translate_point(point: Point, step_x: Scalar, step_y: Scalar,
point_cls: Type[Point]) -> Point:
return point_cls(
rationalize(point.x) + rationalize(step_x),
rationalize(point.y) + rationalize(step_y))
def point_squared_distance(box: Box, point: Point) -> Scalar:
return (_linear_interval_distance(rationalize(
box.min_x), rationalize(box.max_x), rationalize(point.x))**2 +
_linear_interval_distance(rationalize(
box.min_y), rationalize(box.max_y), rationalize(point.y))**2)
def scale_point(point: Point, factor_x: Scalar, factor_y: Scalar,
point_cls: Type[Point]) -> Point:
return point_cls(
rationalize(point.x) * rationalize(factor_x),
rationalize(point.y) * rationalize(factor_y))
def centroid(segment: Segment, point_cls: Type[Point]) -> Point:
return point_cls(
(rationalize(segment.start.x) + rationalize(segment.end.x)) / 2,
(rationalize(segment.start.y) + rationalize(segment.end.y)) / 2)
def rotate_point_around_origin(point: Point, cosine: Scalar, sine: Scalar,
point_cls: Type[Point]) -> Point:
cosine, sine = rationalize(cosine), rationalize(sine)
x, y = rationalize(point.x), rationalize(point.y)
return point_cls(cosine * x - sine * y, sine * x + cosine * y)
def point_to_step(point: Point, cosine: Scalar,
sine: Scalar) -> Tuple[Scalar, Scalar]:
x, y = rationalize(point.x), rationalize(point.y)
cosine, sine = rationalize(cosine), rationalize(sine)
return x - (cosine * x - sine * y), y - (sine * x + cosine * y)
