Midpoint circle and circle intersection

This commit is contained in:
NichiHachi
2024-05-27 23:00:16 +02:00
parent 93ea5d6f18
commit 2244dd7b85
2 changed files with 136 additions and 16 deletions

View File

@@ -1,5 +1,5 @@
from Metro_Line import *
from math import pi, cos, sin
from math import pi, cos, sin, sqrt, atan2, inf
from pygame import Surface
import pygame
@@ -83,7 +83,7 @@ def bezier_curve(control_points, num_points) -> tuple[list[Position], list[Posit
def osculating_circle(points: list[Position], derivative: list[Position], second_derivative: list[Position]) \
-> list[tuple[float, Position]]:
-> list[tuple[int, Position]]:
"""
Calculate the osculating circle at each point of a curve
An osculating circle is the circle that best approximates the curve at a given point
@@ -107,12 +107,12 @@ def osculating_circle(points: list[Position], derivative: list[Position], second
center = points[i] + Position(-derivative[i].y * radius / normal, derivative[i].x * radius / normal)
else:
center = points[i] + Position(derivative[i].y * radius / normal, -derivative[i].x * radius / normal)
circle.append((radius, center))
circle.append((int(radius), center))
return circle
def merge_similar_circles(circles: list[tuple[float, Position]], radius_threshold: float, center_threshold: float) \
-> list[tuple[float, Position]]:
def merge_similar_circles(circles: list[tuple[int, Position]], radius_threshold: float, center_threshold: float) \
-> list[tuple[int, Position]]:
"""
Merge similar osculating circles
@@ -127,7 +127,7 @@ def merge_similar_circles(circles: list[tuple[float, Position]], radius_threshol
radius1, center1 = circles[i]
radius2, center2 = circles[i + 1]
if abs(radius1 - radius2) <= radius_threshold and center1.distance_to(center2) <= center_threshold:
merged_radius = (radius1 + radius2) / 2
merged_radius = (radius1 + radius2) // 2
merged_center = Position((center1.x + center2.x) // 2, (center1.y + center2.y) // 2)
merged_circles.append((merged_radius, merged_center))
i += 2
@@ -143,6 +143,81 @@ def merge_similar_circles(circles: list[tuple[float, Position]], radius_threshol
return merge_similar_circles(merged_circles, radius_threshold, center_threshold)
def circle_intersection(circle1: tuple[int, Position], circle2: tuple[int, Position]) -> list[Position]:
distance = circle1[1].distance_to(circle2[1])
if (distance > circle1[0] + circle2[0] or distance < abs(circle1[0] - circle2[0])
or (distance == 0 and circle1[0] == circle2[0])):
return []
distance_line_circle = (circle1[0] ** 2 - circle2[0] ** 2 + distance ** 2) / (2 * distance)
distance_line_intersec_point = sqrt(circle1[0] ** 2 - distance_line_circle ** 2)
p = circle1[1] + (circle2[1] - circle1[1]) * distance_line_circle / distance
return [Position(int(p.x + distance_line_intersec_point * (circle2[1].y - circle1[1].y) / distance),
int(p.y - distance_line_intersec_point * (circle2[1].x - circle1[1].x) / distance)),
Position(int(p.x - distance_line_intersec_point * (circle2[1].y - circle1[1].y) / distance),
int(p.y + distance_line_intersec_point * (circle2[1].x - circle1[1].x) / distance))]
def closest_to_curve(points: list[Position], curve_points: list[Position]) -> Position:
closest_point = Position()
distance = inf
for point in points:
for curve_point in curve_points:
distance_point_curve = point.distance_to(curve_point)
if distance_point_curve < distance:
distance = distance_point_curve
closest_point = point
return closest_point
def midpoint_circle_segment(circle: tuple[int, Position], start_point: Position, end_point: Position, curve_points: list[Position]) -> list[
Position]:
points = []
start_angle = circle[1].angle_to(start_point)
end_angle = circle[1].angle_to(end_point)
if start_angle < 0:
start_angle += 2 * pi
if end_angle < 0:
end_angle += 2 * pi
if start_angle > end_angle:
start_angle, end_angle = end_angle, start_angle
middle_angle = (start_angle+end_angle)/2
middle_point = circle[1] + Position(int(circle[0]*cos(middle_angle)), -int(circle[0]*sin(middle_angle)))
is_outside_point = closest_to_curve([middle_point, circle[1]], curve_points) == middle_point
x0, y0 = circle[1].x, circle[1].y
x = circle[0]
y = 0
err = 0
while x >= y:
for (x1, y1) in [(x0 + x, y0 + y), (x0 + y, y0 + x), (x0 - y, y0 + x), (x0 - x, y0 + y),
(x0 - x, y0 - y), (x0 - y, y0 - x), (x0 + y, y0 - x), (x0 + x, y0 - y)]:
angle = atan2(y0 - y1, x1 - x0)
if angle < 0:
angle += 2*pi
if is_outside_point:
if start_angle <= angle <= end_angle:
points.append(Position(int(x1), int(y1)))
else:
if angle <= start_angle or end_angle <= angle:
points.append(Position(int(x1), int(y1)))
if err <= 0:
y += 1
err += 2 * y + 1
if err > 0:
x -= 1
err -= 2 * x + 1
return points
def calculate_control_points(station, next_station, curve_factor) -> tuple[Position, Position]:
"""
Calculate the control points for a Bézier curve between two stations
@@ -164,8 +239,8 @@ def calculate_control_points(station, next_station, curve_factor) -> tuple[Posit
return control_point_pos, control_point_next_pos
def metro_line_osculating_circles(metro: Metro_Line, curve_factor: float = 0.5, num_points_factor: float = 1/20) -> (
tuple)[list[tuple[float, Position]], list[list[Position]]]:
def metro_line_osculating_circles(metro: Metro_Line, curve_factor: float = 0.5, num_points_factor: float = 1 / 20) -> (
tuple)[list[tuple[int, Position]], list[Position]]:
"""
Calculate the osculating circles of a metro line
@@ -191,17 +266,18 @@ def metro_line_osculating_circles(metro: Metro_Line, curve_factor: float = 0.5,
int(distance * num_points_factor))
osculating_circles = osculating_circle(points, derivatives, second_derivatives)
merged_circles = merge_similar_circles(osculating_circles, 100, 100)
print(f"[METRO LINE] {len(osculating_circles) - len(merged_circles)} out of {len(osculating_circles)} circles deleted !")
merged_circles = merge_similar_circles(osculating_circles, 50, 50)
print(
f"[METRO LINE] {len(osculating_circles) - len(merged_circles)} out of {len(osculating_circles)} circles deleted !")
circles.extend(merged_circles)
points_list.append(points)
points_list.extend(points)
print(f"[METRO LINE] Osculating circles done")
return circles, points_list
# --- DRAW PART ---
def draw_osculating_circle(circle: list[tuple[float, Position]], surface: Surface):
def draw_osculating_circle(circle: list[tuple[int, Position]], surface: Surface):
"""
:param circle: The osculating circles to draw
:param surface: The surface on which to draw the circles
@@ -228,6 +304,15 @@ def draw_points(points: list[Position], surface):
pygame.draw.circle(surface, (40, 255, 40), (point.x, point.y), 5)
def draw_point(point: Position, surface):
pygame.draw.circle(surface, (40, 255, 40), (point.x, point.y), 5)
def draw_pixels(points: list[Position], surface):
for point in points:
surface.set_at((point.x, point.y), (0, 255, 255))
def draw_metro_line(metro: Metro_Line, surface: Surface, show_points: bool = True):
"""
:param metro: The metro line to draw
@@ -241,9 +326,37 @@ def draw_metro_line(metro: Metro_Line, surface: Surface, show_points: bool = Tru
circles, points = metro_line_osculating_circles(metro)
draw_osculating_circle(circles, surface)
if show_points:
for points in points:
draw_points(points, surface)
for i in range(1, len(circles) - 1):
intersect_point_circle_before = closest_to_curve(circle_intersection(circles[i - 1], circles[i]), points)
intersect_point_circle_after = closest_to_curve(circle_intersection(circles[i], circles[i + 1]), points)
if intersect_point_circle_before == Position():
continue
intersect_point_circle_before = circles[i - 1][1]
else:
draw_point(intersect_point_circle_before, surface)
if intersect_point_circle_after == Position():
continue
intersect_point_circle_after = circles[i + 1][1]
else:
draw_point(intersect_point_circle_after, surface)
points_midpoint = midpoint_circle_segment(circles[i], intersect_point_circle_before,
intersect_point_circle_after, points)
draw_pixels(points_midpoint, surface)
if len(points) != 0:
intersect_point_circle_before = points[0]
intersect_point_circle_after = closest_to_curve(circle_intersection(circles[0], circles[1]), points)
points_midpoint = midpoint_circle_segment(circles[0], intersect_point_circle_before,
intersect_point_circle_after, points)
draw_pixels(points_midpoint, surface)
intersect_point_circle_before = points[-1]
intersect_point_circle_after = closest_to_curve(circle_intersection(circles[-1], circles[-2]), points)
points_midpoint = midpoint_circle_segment(circles[-1], intersect_point_circle_before,
intersect_point_circle_after, points)
draw_pixels(points_midpoint, surface)
def interface():