public-mirrors/3b1b-manim
1
0
Fork 0
mirror of https://github.com/3b1b/manim.git synced 2025-11-13 12:37:50 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Factor out Arc.create_quadratic_bezier_points to quadratic_bezier_points_for_arc

Browse source
This commit is contained in:
Grant Sanderson 2023-09-04 19:08:13 -04:00
parent 0a642133ad
commit 60a4f0e167
2 changed files with 20 additions and 26 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

36
manimlib/mobject/geometry.py
View file

@ -13,6 +13,7 @@ from manimlib.mobject.mobject import Mobject
from manimlib.mobject.types.vectorized_mobject import DashedVMobject
from manimlib.mobject.types.vectorized_mobject import VGroup
from manimlib.mobject.types.vectorized_mobject import VMobject
from manimlib.utils.bezier import quadratic_bezier_points_for_arc
from manimlib.utils.iterables import adjacent_n_tuples
from manimlib.utils.iterables import adjacent_pairs
from manimlib.utils.simple_functions import clip
@ -26,6 +27,7 @@ from manimlib.utils.space_ops import get_norm
from manimlib.utils.space_ops import normalize
from manimlib.utils.space_ops import rotate_vector
from manimlib.utils.space_ops import rotation_matrix_transpose
from manimlib.utils.space_ops import rotation_about_z
from typing import TYPE_CHECKING
@ -213,28 +215,11 @@ class Arc(TipableVMobject):
):
super().__init__(**kwargs)
self.set_points(Arc.create_quadratic_bezier_points(
angle=angle,
start_angle=start_angle,
n_components=n_components
))
self.set_points(quadratic_bezier_points_for_arc(angle, n_components))
self.rotate(start_angle, about_point=ORIGIN)
self.scale(radius, about_point=ORIGIN)
self.shift(arc_center)
@staticmethod
def create_quadratic_bezier_points(
angle: float,
start_angle: float = 0,
n_components: int = 8
) -> Vect3Array:
n_points = 2 * n_components + 1
angles = np.linspace(start_angle, start_angle + angle, n_points)
points = np.array([np.cos(angles), np.sin(angles), np.zeros(n_points)]).T
# Adjust handles
theta = angle / n_components
points[1::2] /= np.cos(theta / 2)
return points
def get_arc_center(self) -> Vect3:
"""
Looks at the normals to the first two
@ -448,8 +433,8 @@ class Annulus(VMobject):
)
self.radius = outer_radius
outer_path = outer_radius * Arc.create_quadratic_bezier_points(TAU, 0)
inner_path = inner_radius * Arc.create_quadratic_bezier_points(-TAU, 0)
outer_path = outer_radius * quadratic_bezier_points_for_arc(TAU)
inner_path = inner_radius * quadratic_bezier_points_for_arc(-TAU)
self.add_subpath(outer_path)
self.add_subpath(inner_path)
self.shift(center)
@ -490,10 +475,9 @@ class Line(TipableVMobject):
alpha = (PI - path_arc) / 2
center = start + radius * normalize(rotate_vector(end - start, alpha))
raw_arc_points = Arc.create_quadratic_bezier_points(
angle=path_arc - 2 * buff / radius,
start_angle=angle_of_vector(start - center) + buff / radius,
)
raw_arc_points = quadratic_bezier_points_for_arc(path_arc - 2 * buff / radius)
rot_matrix = rotation_about_z(angle_of_vector(start - center) + buff / radius)
raw_arc_points = raw_arc_points @ rot_matrix.T
if neg:
raw_arc_points = raw_arc_points[::-1]
self.set_points(center + radius * raw_arc_points)
@ -817,7 +801,7 @@ class FillArrow(Line):
R = (-b + np.sqrt(b**2 - 4 * a * c)) / (2 * a)
# Find arc points
points1 = Arc.create_quadratic_bezier_points(path_arc)
points1 = quadratic_bezier_points_for_arc(path_arc)
points2 = np.array(points1[::-1])
points1 *= (R + thickness / 2)
points2 *= (R - thickness / 2)

10
manimlib/utils/bezier.py
View file

@ -171,6 +171,16 @@ def match_interpolate(
)
def quadratic_bezier_points_for_arc(angle: float, n_components: int = 8):
n_points = 2 * n_components + 1
angles = np.linspace(0, angle, n_points)
points = np.array([np.cos(angles), np.sin(angles), np.zeros(n_points)]).T
# Adjust handles
theta = angle / n_components
points[1::2] /= np.cos(theta / 2)
return points
def approx_smooth_quadratic_bezier_handles(
points: FloatArray
) -> FloatArray: