Source code for manim.mobject.geometry.line

r"""Mobjects that are lines or variations of them."""

from __future__ import annotations

__all__ = [

from typing import Any, Sequence

import numpy as np
from colour import Color

from manim import config
from manim.constants import *
from manim.mobject.geometry.arc import Arc, ArcBetweenPoints, Dot, TipableVMobject
from import ArrowTriangleFilledTip
from manim.mobject.mobject import Mobject
from manim.mobject.opengl.opengl_compatibility import ConvertToOpenGL
from manim.mobject.opengl.opengl_mobject import OpenGLMobject
from manim.mobject.types.vectorized_mobject import DashedVMobject, VGroup, VMobject
from manim.utils.color import *
from manim.utils.color import Colors
from manim.utils.space_ops import angle_of_vector, line_intersection, normalize

[docs]class Line(TipableVMobject): def __init__(self, start=LEFT, end=RIGHT, buff=0, path_arc=None, **kwargs): self.dim = 3 self.buff = buff self.path_arc = path_arc self._set_start_and_end_attrs(start, end) super().__init__(**kwargs)
[docs] def generate_points(self): self.set_points_by_ends( start=self.start, end=self.end, buff=self.buff, path_arc=self.path_arc, )
def set_points_by_ends(self, start, end, buff=0, path_arc=0): if path_arc: arc = ArcBetweenPoints(self.start, self.end, angle=self.path_arc) self.set_points(arc.points) else: self.set_points_as_corners([start, end]) self._account_for_buff(buff) init_points = generate_points def _account_for_buff(self, buff): if buff == 0: return # if self.path_arc == 0: length = self.get_length() else: length = self.get_arc_length() # if length < 2 * buff: return buff_proportion = buff / length self.pointwise_become_partial(self, buff_proportion, 1 - buff_proportion) return self def _set_start_and_end_attrs(self, start, end): # If either start or end are Mobjects, this # gives their centers rough_start = self._pointify(start) rough_end = self._pointify(end) vect = normalize(rough_end - rough_start) # Now that we know the direction between them, # we can find the appropriate boundary point from # start and end, if they're mobjects self.start = self._pointify(start, vect) self.end = self._pointify(end, -vect) def _pointify( self, mob_or_point: Mobject | Sequence[float], direction: Sequence[float] | None = None, ) -> np.ndarray: """Transforms a mobject into its corresponding point. Does nothing if a point is passed. ``direction`` determines the location of the point along its bounding box in that direction. Parameters ---------- mob_or_point The mobject or point. direction The direction. """ if isinstance(mob_or_point, (Mobject, OpenGLMobject)): mob = mob_or_point if direction is None: return mob.get_center() else: return mob.get_boundary_point(direction) return np.array(mob_or_point) def set_path_arc(self, new_value): self.path_arc = new_value self.init_points()
[docs] def put_start_and_end_on(self, start: Sequence[float], end: Sequence[float]): """Sets starts and end coordinates of a line. Examples -------- .. manim:: LineExample class LineExample(Scene): def construct(self): d = VGroup() for i in range(0,10): d.add(Dot()) d.arrange_in_grid(buff=1) self.add(d) l= Line(d[0], d[1]) self.add(l) self.wait() l.put_start_and_end_on(d[1].get_center(), d[2].get_center()) self.wait() l.put_start_and_end_on(d[4].get_center(), d[7].get_center()) self.wait() """ curr_start, curr_end = self.get_start_and_end() if np.all(curr_start == curr_end): # TODO, any problems with resetting # these attrs? self.start = start self.end = end self.generate_points() return super().put_start_and_end_on(start, end)
def get_vector(self): return self.get_end() - self.get_start() def get_unit_vector(self): return normalize(self.get_vector()) def get_angle(self): return angle_of_vector(self.get_vector())
[docs] def get_projection(self, point: Sequence[float]) -> Sequence[float]: """Returns the projection of a point onto a line. Parameters ---------- point The point to which the line is projected. """ start = self.get_start() end = self.get_end() unit_vect = normalize(end - start) return start + - start, unit_vect) * unit_vect
def get_slope(self): return np.tan(self.get_angle()) def set_angle(self, angle, about_point=None): if about_point is None: about_point = self.get_start() self.rotate( angle - self.get_angle(), about_point=about_point, ) return self def set_length(self, length): return self.scale(length / self.get_length())
[docs]class DashedLine(Line): """A dashed :class:`Line`. Parameters ---------- args Arguments to be passed to :class:`Line` dash_length The length of each individual dash of the line. dashed_ratio The ratio of dash space to empty space. Range of 0-1. kwargs Additional arguments to be passed to :class:`Line` .. seealso:: :class:`~.DashedVMobject` Examples -------- .. manim:: DashedLineExample :save_last_frame: class DashedLineExample(Scene): def construct(self): # dash_length increased dashed_1 = DashedLine(config.left_side, config.right_side, dash_length=2.0).shift(UP*2) # normal dashed_2 = DashedLine(config.left_side, config.right_side) # dashed_ratio decreased dashed_3 = DashedLine(config.left_side, config.right_side, dashed_ratio=0.1).shift(DOWN*2) self.add(dashed_1, dashed_2, dashed_3) """ def __init__( self, *args: Any, dash_length: float = DEFAULT_DASH_LENGTH, dashed_ratio: float = 0.5, **kwargs, ): self.dash_length = dash_length self.dashed_ratio = dashed_ratio super().__init__(*args, **kwargs) dashes = DashedVMobject( self, num_dashes=self._calculate_num_dashes(), dashed_ratio=dashed_ratio, ) self.clear_points() self.add(*dashes) def _calculate_num_dashes(self) -> int: """Returns the number of dashes in the dashed line. Examples -------- :: >>> DashedLine()._calculate_num_dashes() 20 """ # Minimum number of dashes has to be 2 return max( 2, int(np.ceil((self.get_length() / self.dash_length) * self.dashed_ratio)), )
[docs] def get_start(self) -> np.ndarray: """Returns the start point of the line. Examples -------- :: >>> DashedLine().get_start() array([-1., 0., 0.]) """ if len(self.submobjects) > 0: return self.submobjects[0].get_start() else: return super().get_start()
[docs] def get_end(self) -> np.ndarray: """Returns the end point of the line. Examples -------- :: >>> DashedLine().get_end() array([1., 0., 0.]) """ if len(self.submobjects) > 0: return self.submobjects[-1].get_end() else: return super().get_end()
[docs] def get_first_handle(self) -> np.ndarray: """Returns the point of the first handle. Examples -------- :: >>> DashedLine().get_first_handle() array([-0.98333333, 0. , 0. ]) """ return self.submobjects[0].points[1]
[docs] def get_last_handle(self) -> np.ndarray: """Returns the point of the last handle. Examples -------- :: >>> DashedLine().get_last_handle() array([0.98333333, 0. , 0. ]) """ return self.submobjects[-1].points[-2]
[docs]class TangentLine(Line): """Constructs a line tangent to a :class:`~.VMobject` at a specific point. Parameters ---------- vmob The VMobject on which the tangent line is drawn. alpha How far along the shape that the line will be constructed. range: 0-1. length Length of the tangent line. d_alpha The ``dx`` value kwargs Additional arguments to be passed to :class:`Line` .. seealso:: :meth:`~.VMobject.point_from_proportion` Examples -------- .. manim:: TangentLineExample :save_last_frame: class TangentLineExample(Scene): def construct(self): circle = Circle(radius=2) line_1 = TangentLine(circle, alpha=0.0, length=4, color=BLUE_D) # right line_2 = TangentLine(circle, alpha=0.4, length=4, color=GREEN) # top left self.add(circle, line_1, line_2) """ def __init__( self, vmob: VMobject, alpha: float, length: float = 1, d_alpha: float = 1e-6, **kwargs, ): self.length = length self.d_alpha = d_alpha da = self.d_alpha a1 = np.clip(alpha - da, 0, 1) a2 = np.clip(alpha + da, 0, 1) super().__init__( vmob.point_from_proportion(a1), vmob.point_from_proportion(a2), **kwargs ) self.scale(self.length / self.get_length())
[docs]class Elbow(VMobject, metaclass=ConvertToOpenGL): """Two lines that create a right angle about each other: L-shape. Parameters ---------- width The length of the elbow's sides. angle The rotation of the elbow. kwargs Additional arguments to be passed to :class:`~.VMobject` .. seealso:: :class:`RightAngle` Examples -------- .. manim:: ElbowExample :save_last_frame: class ElbowExample(Scene): def construct(self): elbow_1 = Elbow() elbow_2 = Elbow(width=2.0) elbow_3 = Elbow(width=2.0, angle=5*PI/4) elbow_group = Group(elbow_1, elbow_2, elbow_3).arrange(buff=1) self.add(elbow_group) """ def __init__(self, width: float = 0.2, angle: float = 0, **kwargs): self.angle = angle super().__init__(**kwargs) self.set_points_as_corners([UP, UP + RIGHT, RIGHT]) self.scale_to_fit_width(width, about_point=ORIGIN) self.rotate(self.angle, about_point=ORIGIN)
[docs]class Arrow(Line): """An arrow. Parameters ---------- args Arguments to be passed to :class:`Line`. stroke_width The thickness of the arrow. Influenced by :attr:`max_stroke_width_to_length_ratio`. buff The distance of the arrow from its start and end points. max_tip_length_to_length_ratio :attr:`tip_length` scales with the length of the arrow. Increasing this ratio raises the max value of :attr:`tip_length`. max_stroke_width_to_length_ratio :attr:`stroke_width` scales with the length of the arrow. Increasing this ratio ratios the max value of :attr:`stroke_width`. kwargs Additional arguments to be passed to :class:`Line`. .. seealso:: :class:`ArrowTip` :class:`CurvedArrow` Examples -------- .. manim:: ArrowExample :save_last_frame: from import ArrowSquareTip class ArrowExample(Scene): def construct(self): arrow_1 = Arrow(start=RIGHT, end=LEFT, color=GOLD) arrow_2 = Arrow(start=RIGHT, end=LEFT, color=GOLD, tip_shape=ArrowSquareTip).shift(DOWN) g1 = Group(arrow_1, arrow_2) # the effect of buff square = Square(color=MAROON_A) arrow_3 = Arrow(start=LEFT, end=RIGHT) arrow_4 = Arrow(start=LEFT, end=RIGHT, buff=0).next_to(arrow_1, UP) g2 = Group(arrow_3, arrow_4, square) # a shorter arrow has a shorter tip and smaller stroke width arrow_5 = Arrow(start=ORIGIN, * 4) arrow_6 = Arrow( + DOWN, * 3) g3 = Group(arrow_5, arrow_6) self.add(Group(g1, g2, g3).arrange(buff=2)) .. manim:: ArrowExample :save_last_frame: class ArrowExample(Scene): def construct(self): left_group = VGroup() # As buff increases, the size of the arrow decreases. for buff in np.arange(0, 2.2, 0.45): left_group += Arrow(buff=buff, start=2 * LEFT, end=2 * RIGHT) # Required to arrange arrows. left_group.arrange(DOWN) left_group.move_to(4 * LEFT) middle_group = VGroup() # As max_stroke_width_to_length_ratio gets bigger, # the width of stroke increases. for i in np.arange(0, 5, 0.5): middle_group += Arrow(max_stroke_width_to_length_ratio=i) middle_group.arrange(DOWN) UR_group = VGroup() # As max_tip_length_to_length_ratio increases, # the length of the tip increases. for i in np.arange(0, 0.3, 0.1): UR_group += Arrow(max_tip_length_to_length_ratio=i) UR_group.arrange(DOWN) UR_group.move_to(4 * RIGHT + 2 * UP) DR_group = VGroup() DR_group += Arrow(start=LEFT, end=RIGHT, color=BLUE, tip_shape=ArrowSquareTip) DR_group += Arrow(start=LEFT, end=RIGHT, color=BLUE, tip_shape=ArrowSquareFilledTip) DR_group += Arrow(start=LEFT, end=RIGHT, color=YELLOW, tip_shape=ArrowCircleTip) DR_group += Arrow(start=LEFT, end=RIGHT, color=YELLOW, tip_shape=ArrowCircleFilledTip) DR_group.arrange(DOWN) DR_group.move_to(4 * RIGHT + 2 * DOWN) self.add(left_group, middle_group, UR_group, DR_group) """ def __init__( self, *args: Any, stroke_width: float = 6, buff: float = MED_SMALL_BUFF, max_tip_length_to_length_ratio: float = 0.25, max_stroke_width_to_length_ratio: float = 5, **kwargs, ): self.max_tip_length_to_length_ratio = max_tip_length_to_length_ratio self.max_stroke_width_to_length_ratio = max_stroke_width_to_length_ratio tip_shape = kwargs.pop("tip_shape", ArrowTriangleFilledTip) super().__init__(*args, buff=buff, stroke_width=stroke_width, **kwargs) # TODO, should this be affected when # Arrow.set_stroke is called? self.initial_stroke_width = self.stroke_width self.add_tip(tip_shape=tip_shape) self._set_stroke_width_from_length()
[docs] def scale(self, factor, scale_tips=False, **kwargs): r"""Scale an arrow, but keep stroke width and arrow tip size fixed. .. seealso:: :meth:`~.Mobject.scale` Examples -------- :: >>> arrow = Arrow(np.array([-1, -1, 0]), np.array([1, 1, 0]), buff=0) >>> scaled_arrow = arrow.scale(2) >>> np.round(scaled_arrow.get_start_and_end(), 8) + 0 array([[-2., -2., 0.], [ 2., 2., 0.]]) >>> arrow.tip.length == scaled_arrow.tip.length True Manually scaling the object using the default method :meth:`~.Mobject.scale` does not have the same properties:: >>> new_arrow = Arrow(np.array([-1, -1, 0]), np.array([1, 1, 0]), buff=0) >>> another_scaled_arrow = VMobject.scale(new_arrow, 2) >>> another_scaled_arrow.tip.length == arrow.tip.length False """ if self.get_length() == 0: return self if scale_tips: super().scale(factor, **kwargs) self._set_stroke_width_from_length() return self has_tip = self.has_tip() has_start_tip = self.has_start_tip() if has_tip or has_start_tip: old_tips = self.pop_tips() super().scale(factor, **kwargs) self._set_stroke_width_from_length() if has_tip: self.add_tip(tip=old_tips[0]) if has_start_tip: self.add_tip(tip=old_tips[1], at_start=True) return self
[docs] def get_normal_vector(self) -> np.ndarray: """Returns the normal of a vector. Examples -------- :: >>> np.round(Arrow().get_normal_vector()) + 0. # add 0. to avoid negative 0 in output array([ 0., 0., -1.]) """ p0, p1, p2 = self.tip.get_start_anchors()[:3] return normalize(np.cross(p2 - p1, p1 - p0))
[docs] def reset_normal_vector(self): """Resets the normal of a vector""" self.normal_vector = self.get_normal_vector() return self
[docs] def get_default_tip_length(self) -> float: """Returns the default tip_length of the arrow. Examples -------- :: >>> Arrow().get_default_tip_length() 0.35 """ max_ratio = self.max_tip_length_to_length_ratio return min(self.tip_length, max_ratio * self.get_length())
def _set_stroke_width_from_length(self): """Sets stroke width based on length.""" max_ratio = self.max_stroke_width_to_length_ratio if config.renderer == RendererType.OPENGL: self.set_stroke( width=min(self.initial_stroke_width, max_ratio * self.get_length()), recurse=False, ) else: self.set_stroke( width=min(self.initial_stroke_width, max_ratio * self.get_length()), family=False, ) return self
[docs]class Vector(Arrow): """A vector specialized for use in graphs. Parameters ---------- direction The direction of the arrow. buff The distance of the vector from its endpoints. kwargs Additional arguments to be passed to :class:`Arrow` Examples -------- .. manim:: VectorExample :save_last_frame: class VectorExample(Scene): def construct(self): plane = NumberPlane() vector_1 = Vector([1,2]) vector_2 = Vector([-5,-2]) self.add(plane, vector_1, vector_2) """ def __init__(self, direction: list | np.ndarray = RIGHT, buff: float = 0, **kwargs): self.buff = buff if len(direction) == 2: direction = np.hstack([direction, 0]) super().__init__(ORIGIN, direction, buff=buff, **kwargs)
[docs] def coordinate_label( self, integer_labels: bool = True, n_dim: int = 2, color: Color | None = None, **kwargs, ): """Creates a label based on the coordinates of the vector. Parameters ---------- integer_labels Whether or not to round the coordinates to integers. n_dim The number of dimensions of the vector. color Sets the color of label, optional. kwargs Additional arguments to be passed to :class:`~.Matrix`. Returns ------- :class:`~.Matrix` The label. Examples -------- .. manim:: VectorCoordinateLabel :save_last_frame: class VectorCoordinateLabel(Scene): def construct(self): plane = NumberPlane() vec_1 = Vector([1, 2]) vec_2 = Vector([-3, -2]) label_1 = vec_1.coordinate_label() label_2 = vec_2.coordinate_label(color=YELLOW) self.add(plane, vec_1, vec_2, label_1, label_2) """ # avoiding circular imports from ..matrix import Matrix vect = np.array(self.get_end()) if integer_labels: vect = np.round(vect).astype(int) vect = vect[:n_dim] vect = vect.reshape((n_dim, 1)) label = Matrix(vect, **kwargs) label.scale(LARGE_BUFF - 0.2) shift_dir = np.array(self.get_end()) if shift_dir[0] >= 0: # Pointing right shift_dir -= label.get_left() + DEFAULT_MOBJECT_TO_MOBJECT_BUFFER * LEFT else: # Pointing left shift_dir -= label.get_right() + DEFAULT_MOBJECT_TO_MOBJECT_BUFFER * RIGHT label.shift(shift_dir) if color is not None: label.set_color(color) return label
[docs]class DoubleArrow(Arrow): """An arrow with tips on both ends. Parameters ---------- args Arguments to be passed to :class:`Arrow` kwargs Additional arguments to be passed to :class:`Arrow` .. seealso:: :class:`.~ArrowTip` :class:`.~CurvedDoubleArrow` Examples -------- .. manim:: DoubleArrowExample :save_last_frame: from import ArrowCircleFilledTip class DoubleArrowExample(Scene): def construct(self): circle = Circle(radius=2.0) d_arrow = DoubleArrow(start=circle.get_left(), end=circle.get_right()) d_arrow_2 = DoubleArrow(tip_shape_end=ArrowCircleFilledTip, tip_shape_start=ArrowCircleFilledTip) group = Group(Group(circle, d_arrow), d_arrow_2).arrange(UP, buff=1) self.add(group) .. manim:: DoubleArrowExample2 :save_last_frame: class DoubleArrowExample2(Scene): def construct(self): box = Square() p1 = box.get_left() p2 = box.get_right() d1 = DoubleArrow(p1, p2, buff=0) d2 = DoubleArrow(p1, p2, buff=0, tip_length=0.2, color=YELLOW) d3 = DoubleArrow(p1, p2, buff=0, tip_length=0.4, color=BLUE) Group(d1, d2, d3).arrange(DOWN) self.add(box, d1, d2, d3) """ def __init__(self, *args: Any, **kwargs): if "tip_shape_end" in kwargs: kwargs["tip_shape"] = kwargs.pop("tip_shape_end") tip_shape_start = kwargs.pop("tip_shape_start", ArrowTriangleFilledTip) super().__init__(*args, **kwargs) self.add_tip(at_start=True, tip_shape=tip_shape_start)
[docs]class Angle(VMobject, metaclass=ConvertToOpenGL): """A circular arc or elbow-type mobject representing an angle of two lines. Parameters ---------- line1 : The first line. line2 : The second line. radius : The radius of the :class:`Arc`. quadrant A sequence of two :class:`int` numbers determining which of the 4 quadrants should be used. The first value indicates whether to anchor the arc on the first line closer to the end point (1) or start point (-1), and the second value functions similarly for the end (1) or start (-1) of the second line. Possibilities: (1,1), (-1,1), (1,-1), (-1,-1). other_angle : Toggles between the two possible angles defined by two points and an arc center. If set to False (default), the arc will always go counterclockwise from the point on line1 until the point on line2 is reached. If set to True, the angle will go clockwise from line1 to line2. dot Allows for a :class:`Dot` in the arc. Mainly used as an convention to indicate a right angle. The dot can be customized in the next three parameters. dot_radius The radius of the :class:`Dot`. If not specified otherwise, this radius will be 1/10 of the arc radius. dot_distance Relative distance from the center to the arc: 0 puts the dot in the center and 1 on the arc itself. dot_color The color of the :class:`Dot`. elbow Produces an elbow-type mobject indicating a right angle, see :class:`RightAngle` for more information and a shorthand. **kwargs Further keyword arguments that are passed to the constructor of :class:`Arc` or :class:`Elbow`. Examples -------- The first example shows some right angles with a dot in the middle while the second example shows all 8 possible angles defined by two lines. .. manim:: RightArcAngleExample :save_last_frame: class RightArcAngleExample(Scene): def construct(self): line1 = Line( LEFT, RIGHT ) line2 = Line( DOWN, UP ) rightarcangles = [ Angle(line1, line2, dot=True), Angle(line1, line2, radius=0.4, quadrant=(1,-1), dot=True, other_angle=True), Angle(line1, line2, radius=0.5, quadrant=(-1,1), stroke_width=8, dot=True, dot_color=YELLOW, dot_radius=0.04, other_angle=True), Angle(line1, line2, radius=0.7, quadrant=(-1,-1), color=RED, dot=True, dot_color=GREEN, dot_radius=0.08), ] plots = VGroup() for angle in rightarcangles: plot=VGroup(line1.copy(),line2.copy(), angle) plots.add(plot) plots.arrange(buff=1.5) self.add(plots) .. manim:: AngleExample :save_last_frame: class AngleExample(Scene): def construct(self): line1 = Line( LEFT + (1/3) * UP, RIGHT + (1/3) * DOWN ) line2 = Line( DOWN + (1/3) * RIGHT, UP + (1/3) * LEFT ) angles = [ Angle(line1, line2), Angle(line1, line2, radius=0.4, quadrant=(1,-1), other_angle=True), Angle(line1, line2, radius=0.5, quadrant=(-1,1), stroke_width=8, other_angle=True), Angle(line1, line2, radius=0.7, quadrant=(-1,-1), color=RED), Angle(line1, line2, other_angle=True), Angle(line1, line2, radius=0.4, quadrant=(1,-1)), Angle(line1, line2, radius=0.5, quadrant=(-1,1), stroke_width=8), Angle(line1, line2, radius=0.7, quadrant=(-1,-1), color=RED, other_angle=True), ] plots = VGroup() for angle in angles: plot=VGroup(line1.copy(),line2.copy(), angle) plots.add(VGroup(plot,SurroundingRectangle(plot, buff=0.3))) plots.arrange_in_grid(rows=2,buff=1) self.add(plots) .. manim:: FilledAngle :save_last_frame: class FilledAngle(Scene): def construct(self): l1 = Line(ORIGIN, 2 * UP + RIGHT).set_color(GREEN) l2 = ( Line(ORIGIN, 2 * UP + RIGHT) .set_color(GREEN) .rotate(-20 * DEGREES, about_point=ORIGIN) ) norm = l1.get_length() a1 = Angle(l1, l2, other_angle=True, radius=norm - 0.5).set_color(GREEN) a2 = Angle(l1, l2, other_angle=True, radius=norm).set_color(GREEN) q1 = a1.points # save all coordinates of points of angle a1 q2 = a2.reverse_direction().points # save all coordinates of points of angle a1 (in reversed direction) pnts = np.concatenate([q1, q2, q1[0].reshape(1, 3)]) # adds points and ensures that path starts and ends at same point mfill = VMobject().set_color(ORANGE) mfill.set_points_as_corners(pnts).set_fill(GREEN, opacity=1) self.add(l1, l2) self.add(mfill) """ def __init__( self, line1: Line, line2: Line, radius: float = None, quadrant: Sequence[int] = (1, 1), other_angle: bool = False, dot: bool = False, dot_radius: float | None = None, dot_distance: float = 0.55, dot_color: Colors = WHITE, elbow: bool = False, **kwargs, ): super().__init__(**kwargs) self.lines = (line1, line2) self.quadrant = quadrant self.dot_distance = dot_distance self.elbow = elbow inter = line_intersection( [line1.get_start(), line1.get_end()], [line2.get_start(), line2.get_end()], ) if radius is None: if quadrant[0] == 1: dist_1 = np.linalg.norm(line1.get_end() - inter) else: dist_1 = np.linalg.norm(line1.get_start() - inter) if quadrant[1] == 1: dist_2 = np.linalg.norm(line2.get_end() - inter) else: dist_2 = np.linalg.norm(line2.get_start() - inter) if np.minimum(dist_1, dist_2) < 0.6: radius = (2 / 3) * np.minimum(dist_1, dist_2) else: radius = 0.4 else: self.radius = radius anchor_angle_1 = inter + quadrant[0] * radius * line1.get_unit_vector() anchor_angle_2 = inter + quadrant[1] * radius * line2.get_unit_vector() if elbow: anchor_middle = ( inter + quadrant[0] * radius * line1.get_unit_vector() + quadrant[1] * radius * line2.get_unit_vector() ) angle_mobject = Elbow(**kwargs) angle_mobject.set_points_as_corners( [anchor_angle_1, anchor_middle, anchor_angle_2], ) else: angle_1 = angle_of_vector(anchor_angle_1 - inter) angle_2 = angle_of_vector(anchor_angle_2 - inter) if not other_angle: start_angle = angle_1 if angle_2 > angle_1: angle_fin = angle_2 - angle_1 else: angle_fin = 2 * np.pi - (angle_1 - angle_2) else: start_angle = angle_1 if angle_2 < angle_1: angle_fin = -angle_1 + angle_2 else: angle_fin = -2 * np.pi + (angle_2 - angle_1) self.angle_value = angle_fin angle_mobject = Arc( radius=radius, angle=self.angle_value, start_angle=start_angle, arc_center=inter, **kwargs, ) if dot: if dot_radius is None: dot_radius = radius / 10 else: self.dot_radius = dot_radius right_dot = Dot(ORIGIN, radius=dot_radius, color=dot_color) dot_anchor = ( inter + (angle_mobject.get_center() - inter) / np.linalg.norm(angle_mobject.get_center() - inter) * radius * dot_distance ) right_dot.move_to(dot_anchor) self.add(right_dot) self.set_points(angle_mobject.points)
[docs] def get_lines(self) -> VGroup: """Get the lines forming an angle of the :class:`Angle` class. Returns ------- :class:`~.VGroup` A :class:`~.VGroup` containing the lines that form the angle of the :class:`Angle` class. Examples -------- :: >>> line_1, line_2 = Line(ORIGIN, RIGHT), Line(ORIGIN, UR) >>> angle = Angle(line_1, line_2) >>> angle.get_lines() VGroup(Line, Line) """ return VGroup(*self.lines)
[docs] def get_value(self, degrees: bool = False) -> float: """Get the value of an angle of the :class:`Angle` class. Parameters ---------- degrees A boolean to decide the unit (deg/rad) in which the value of the angle is returned. Returns ------- :class:`float` The value in degrees/radians of an angle of the :class:`Angle` class. Examples -------- .. manim:: GetValueExample :save_last_frame: class GetValueExample(Scene): def construct(self): line1 = Line(LEFT+(1/3)*UP, RIGHT+(1/3)*DOWN) line2 = Line(DOWN+(1/3)*RIGHT, UP+(1/3)*LEFT) angle = Angle(line1, line2, radius=0.4) value = DecimalNumber(angle.get_value(degrees=True), unit="^{\\circ}") value.next_to(angle, UR) self.add(line1, line2, angle, value) """ if degrees: return self.angle_value / DEGREES return self.angle_value
[docs] @staticmethod def from_three_points( A: np.ndarray, B: np.ndarray, C: np.ndarray, **kwargs ) -> Angle: """The angle between the lines AB and BC. This constructs the angle :math:`\\angle ABC`. Parameters ---------- A The endpoint of the first angle leg B The vertex of the angle C The endpoint of the second angle leg **kwargs Further keyword arguments are passed to :class:`.Angle` Returns ------- The Angle calculated from the three points Angle(line1, line2, radius=0.5, quadrant=(-1,1), stroke_width=8), Angle(line1, line2, radius=0.7, quadrant=(-1,-1), color=RED, other_angle=True), Examples -------- .. manim:: AngleFromThreePointsExample :save_last_frame: class AngleFromThreePointsExample(Scene): def construct(self): sample_angle = Angle.from_three_points(UP, ORIGIN, LEFT) red_angle = Angle.from_three_points(LEFT + UP, ORIGIN, RIGHT, radius=.8, quadrant=(-1,-1), color=RED, stroke_width=8, other_angle=True) self.add(red_angle, sample_angle) """ return Angle(Line(B, A), Line(B, C), **kwargs)
[docs]class RightAngle(Angle): """An elbow-type mobject representing a right angle between two lines. Parameters ---------- line1 The first line. line2 The second line. length The length of the arms. **kwargs Further keyword arguments that are passed to the constructor of :class:`Angle`. Examples -------- .. manim:: RightAngleExample :save_last_frame: class RightAngleExample(Scene): def construct(self): line1 = Line( LEFT, RIGHT ) line2 = Line( DOWN, UP ) rightangles = [ RightAngle(line1, line2), RightAngle(line1, line2, length=0.4, quadrant=(1,-1)), RightAngle(line1, line2, length=0.5, quadrant=(-1,1), stroke_width=8), RightAngle(line1, line2, length=0.7, quadrant=(-1,-1), color=RED), ] plots = VGroup() for rightangle in rightangles: plot=VGroup(line1.copy(),line2.copy(), rightangle) plots.add(plot) plots.arrange(buff=1.5) self.add(plots) """ def __init__(self, line1: Line, line2: Line, length: float | None = None, **kwargs): super().__init__(line1, line2, radius=length, elbow=True, **kwargs)