Add and clean proper objects for Polyline, Point2D, Circle

This commit is contained in:
2024-06-11 01:29:07 +02:00
parent 23fa587292
commit 0c18414176
4 changed files with 160 additions and 70 deletions

View File

@@ -0,0 +1,68 @@
from typing import Type
import Point2D
class Circle:
def __init__(center: Type[Point2D], inner: int, outer: int):
self.center = center
self.inner = inner
self.outer = outer
self.coordinates = []
circle(self.center, self.inner, self.outer)
def circle(center: Type[Point2D], inner: int, outer: int):
"""Compute discrete value of a 2d-circle with thickness.
https://stackoverflow.com/questions/27755514/circle-with-thickness-drawing-algorithm
Args:
center (Type[Point2D]): Center of the circle. Circles always have an odd diameter due to the central coordinate.
inner (int): The minimum radius at which the disc is filled (included).
outer (int): The maximum radius where disc filling stops (included).
"""
xo = outer
xi = inner
y = 0
erro = 1 - xo
erri = 1 - xi
while xo >= y:
_x_line(center.x + xi, center.x + xo, center.y + y)
_y_line(center.x + y, center.y + xi, center.y + xo)
_x_line(center.x - xo, center.x - xi, center.y + y)
_y_line(center.x - y, center.y + xi, center.y + xo)
_x_line(center.x - xo, center.x - xi, center.y - y)
_y_line(center.x - y, center.y - xo, center.y - xi)
_x_line(center.x + xi, center.x + xo, center.y - y)
_y_line(center.x + y, center.y - xo, center.y - xi)
y += 1
if erro < 0:
erro += 2 * y + 1
else:
xo -= 1
erro += 2 * (y - xo + 1)
if y > inner:
xi = y
else:
if erri < 0:
erri += 2 * y + 1
else:
xi -= 1
erri += 2 * (y - xi + 1)
def _x_line(x1, x2, y):
while x1 <= x2:
self.coordinates.append(Point2D(x1, y))
x1 += 1
def _y_line(x, y1, y2):
while y1 <= y2:
self.coordinate.append(Point2D(x, y1))
y1 += 1
def __repr__(self):
return f"Circle(center: {self.center}, inner: {self.inner}, outer: {self.outer})"

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@@ -0,0 +1,16 @@
from typing import Type
class Point2D:
def __init__(self, x: int, y: int):
self.x = x
self.y = y
def copy(self):
return Point2D(self.x, self.y)
def coordinates(self):
return (self.x, self.y)
def __repr__(self):
return f"Point2D(x: {self.x}, y: {self.y})"

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@@ -1,38 +1,28 @@
from typing import Type
import Point2D
from math import sqrt, inf
import numpy as np
class Point2D:
def __init__(self, x, y):
self.x = x
self.y = y
def __repr__(self):
return f"({self.x} {self.y})"
def copy(self):
return Point2D(self.x, self.y)
def get_coordinates(self):
return (self.x, self.y)
def coordinates_to_vectors(coordinates):
vectors = []
for coordinate in coordinates:
vectors.append(np.array(coordinate.get_coordinates()))
if (len(vectors) == 1):
return vectors[0]
else:
return vectors
class Polyline:
def __init__(self, points):
def __init__(self, points: List[Point2D]):
"""A polyline with smooth corners, only composed of segments and circle arc.
Mathematics and algorithms behind this can be found here: https://cdr.lib.unc.edu/concern/dissertations/pz50gw814?locale=en, E2 Construction of arc roads from polylines, page 210.
Args:
points (List[Point2D]): List of 2d-points in order describing the polyline.
Raises:
ValueError: At least 4 points required.
"""
self.points = coordinates_to_vectors(points)
self.length_polyline = len(points)
if self.length_polyline < 4:
raise ValueError("The list must contain at least 4 elements.")
self.vectors = [None] * self.length_polyline
self.lengths = [None] * self.length_polyline
self.unit_vectors = [None] * self.length_polyline
@@ -40,46 +30,14 @@ class Polyline:
self.alpha_radii = [None] * self.length_polyline
self.compute_requirements()
self.compute_alpha_radii()
self._compute_requirements()
self._compute_alpha_radii()
def compute_requirements(self):
_alpha_assign(0, self.length_polyline-1)
# Between two points, there is only one segment
for j in range(self.length_polyline-1):
self.vectors[j] = self.points[j+1] - self.points[j]
self.lengths[j] = np.linalg.norm(self.vectors[j])
self.unit_vectors[j] = self.vectors[j]/self.lengths[j]
# print("\n\n", vectors, "\n\n", lengths, "\n\n", unit_vectors, "\n\n")
# Between two segments, there is only one angle
for k in range(1, self.length_polyline-1):
cross = np.dot(self.unit_vectors[k], self.unit_vectors[k-1])
self.tangente[k] = sqrt((1+cross)/(1-cross))
def compute_alpha_radii(self):
self.alpha_radii[0] = 0
self.alpha_radii[self.length_polyline-1] = 0
for i in range(1, self.length_polyline-2):
self.alpha_radii[i] = min(self.lengths[i-1] - self.alpha_radii[i-1], (self.lengths[i]
* self.tangente[i+1])/(self.tangente[i]+self.tangente[i+1]))
def radius_balance(self, i):
def _alpha_assign(self, start_index, end_index):
"""
Returns the radius that balances the radii on either end segement i.
"""
alpha_a = min(self.lengths[i-1], (self.lengths[i]*self.tangente[i+1]) /
(self.tangente[i] + self.tangente[i+1]))
alpha_b = min(self.lengths[i+1], self.lengths[i]-alpha_a)
return alpha_a, alpha_b, max(self.tangente[i]*alpha_a, self.tangente[i+1]*alpha_b)
def alpha_assign(self, start_index, end_index):
"""
The Alpha-assign procedure assigning radii based on a polyline.
The alpha-assign procedure assigning radii based on a polyline.
"""
minimum_radius, minimum_index = inf, end_index
@@ -96,7 +54,7 @@ class Polyline:
alpha_low, alpha_high = self.alpha_radii[start_index], alpha_b
for i in range(start_index + 1, end_index - 2): # Radii for internal segments
alpha_a, alpha_b, current_radius = self.radius_balance(i)
alpha_a, alpha_b, current_radius = self._radius_balance(i)
if current_radius < minimum_radius:
alpha_low, alpha_high = alpha_a, self.alpha_radii[end_index]
@@ -106,15 +64,52 @@ class Polyline:
print(alpha_low, alpha_high)
# Recur on lower segments
self.alpha_assign(start_index, minimum_index)
self._alpha_assign(start_index, minimum_index)
# Recur on higher segments
self.alpha_assign(minimum_index + 1, end_index)
self._alpha_assign(minimum_index + 1, end_index)
def _radius_balance(self, i: int):
"""
Returns the radius that balances the radii on either end segement i.
"""
alpha_a = min(self.lengths[i-1], (self.lengths[i]*self.tangente[i+1]) /
(self.tangente[i] + self.tangente[i+1]))
alpha_b = min(self.lengths[i+1], self.lengths[i]-alpha_a)
return alpha_a, alpha_b, max(self.tangente[i]*alpha_a, self.tangente[i+1]*alpha_b)
def _compute_requirements(self):
# Between two points, there is only one segment
for j in range(self.length_polyline-1):
self.vectors[j] = self.points[j+1] - self.points[j]
self.lengths[j] = np.linalg.norm(self.vectors[j])
self.unit_vectors[j] = self.vectors[j]/self.lengths[j]
# print("\n\n", vectors, "\n\n", lengths, "\n\n", unit_vectors, "\n\n")
# Between two segments, there is only one angle
for k in range(1, self.length_polyline-1):
cross = np.dot(self.unit_vectors[k], self.unit_vectors[k-1])
self.tangente[k] = sqrt((1+cross)/(1-cross))
def _compute_alpha_radii(self):
self.alpha_radii[0] = 0
self.alpha_radii[self.length_polyline-1] = 0
for i in range(1, self.length_polyline-2):
self.alpha_radii[i] = min(self.lengths[i-1] - self.alpha_radii[i-1], (self.lengths[i]
* self.tangente[i+1])/(self.tangente[i]+self.tangente[i+1]))
polyline = Polyline((Point2D(0, 0), Point2D(0, 10), Point2D(
10, 10), Point2D(10, 20), Point2D(20, 20), Point2D(20, 30), Point2D(60, 60), Point2D(60, 0)))
# polyline = Polyline((Point2D(0, 9), Point2D(0, 10), Point2D(
# 10, 10), Point2D(10, 20), Point2D(20, 20), Point2D(20, 30), Point2D(60, 60), Point2D(-60, -60)))
polyline = Polyline((Point2D(0, 10), Point2D(-10, -10),
Point2D(20, 0), Point2D(20, 20)))
# print(polyline.radius_balance(2))
polyline.alpha_assign(1, polyline.length_polyline-1)
polyline._alpha_assign(1, polyline.length_polyline-1)
print(polyline.alpha_radii)

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@@ -511,3 +511,14 @@ def curved_corner_by_curvature(
distance_from_intersection = round(distance(start_curve_point, center))
return curve_corner_points, center, distance_from_intersection, parallel(
(xyz0, intersection), -curvature_radius), parallel((xyz1, intersection), curvature_radius)
def coordinates_to_vectors(coordinates):
vectors = []
for coordinate in coordinates:
vectors.append(np.array(coordinate.get_coordinates()))
if (len(vectors) == 1):
return vectors[0]
else:
return vectors