Source code for manim.mobject.geometry

r"""Mobjects that are simple geometric shapes.


.. manim:: UsefulAnnotations

    class UsefulAnnotations(Scene):
        def construct(self):
            m0 = Dot()
            m1 = AnnotationDot()
            m2 = LabeledDot("ii")
            m3 = LabeledDot(MathTex(r"\alpha").set_color(ORANGE))
            m4 = CurvedArrow(2*LEFT, 2*RIGHT, radius= -5)
            m5 = CurvedArrow(2*LEFT, 2*RIGHT, radius= 8)
            m6 = CurvedDoubleArrow(ORIGIN, 2*RIGHT)

            self.add(m0, m1, m2, m3, m4, m5, m6)
            for i, mobj in enumerate(self.mobjects):
                mobj.shift(DOWN * (i-3))


__all__ = [

import itertools
import math
import warnings
from typing import Iterable, Optional, Sequence

import numpy as np
from colour import Color

from manim.mobject.opengl_mobject import OpenGLMobject

from .. import config, logger
from ..constants import *
from ..mobject.mobject import Mobject
from ..mobject.types.vectorized_mobject import DashedVMobject, VGroup, VMobject
from ..utils.color import *
from ..utils.iterables import adjacent_n_tuples, adjacent_pairs
from ..utils.space_ops import (
from .opengl_compatibility import ConvertToOpenGL

[docs]class TipableVMobject(VMobject, metaclass=ConvertToOpenGL): """ Meant for shared functionality between Arc and Line. Functionality can be classified broadly into these groups: * Adding, Creating, Modifying tips - add_tip calls create_tip, before pushing the new tip into the TipableVMobject's list of submobjects - stylistic and positional configuration * Checking for tips - Boolean checks for whether the TipableVMobject has a tip and a starting tip * Getters - Straightforward accessors, returning information pertaining to the TipableVMobject instance's tip(s), its length etc """ def __init__( self, tip_length=DEFAULT_ARROW_TIP_LENGTH, normal_vector=OUT, tip_style={}, **kwargs, ): self.tip_length = tip_length self.normal_vector = normal_vector self.tip_style = tip_style super().__init__(**kwargs) # Adding, Creating, Modifying tips
[docs] def add_tip(self, tip=None, tip_shape=None, tip_length=None, at_start=False): """ Adds a tip to the TipableVMobject instance, recognising that the endpoints might need to be switched if it's a 'starting tip' or not. """ if tip is None: tip = self.create_tip(tip_shape, tip_length, at_start) else: self.position_tip(tip, at_start) self.reset_endpoints_based_on_tip(tip, at_start) self.asign_tip_attr(tip, at_start) self.add(tip) return self
[docs] def create_tip(self, tip_shape=None, tip_length=None, at_start=False): """ Stylises the tip, positions it spatially, and returns the newly instantiated tip to the caller. """ tip = self.get_unpositioned_tip(tip_shape, tip_length) self.position_tip(tip, at_start) return tip
[docs] def get_unpositioned_tip(self, tip_shape=None, tip_length=None): """ Returns a tip that has been stylistically configured, but has not yet been given a position in space. """ if tip_shape is None: tip_shape = ArrowTriangleFilledTip if tip_length is None: tip_length = self.get_default_tip_length() color = self.get_color() style = {"fill_color": color, "stroke_color": color} style.update(self.tip_style) tip = tip_shape(length=tip_length, **style) return tip
def position_tip(self, tip, at_start=False): # Last two control points, defining both # the end, and the tangency direction if at_start: anchor = self.get_start() handle = self.get_first_handle() else: handle = self.get_last_handle() anchor = self.get_end() angles = cartesian_to_spherical(handle - anchor) tip.rotate( angles[1] - PI - tip.tip_angle, ) # Rotates the tip along the azimuthal if not hasattr(self, "_init_positioning_axis"): axis = [ np.sin(angles[1]), -np.cos(angles[1]), 0, ] # Obtains the perpendicular of the tip tip.rotate( -angles[2] + PI / 2, axis=axis, ) # Rotates the tip along the vertical wrt the axis self._init_positioning_axis = axis tip.shift(anchor - tip.tip_point) return tip def reset_endpoints_based_on_tip(self, tip, at_start): if self.get_length() == 0: # Zero length, put_start_and_end_on wouldn't work return self if at_start: self.put_start_and_end_on(tip.base, self.get_end()) else: self.put_start_and_end_on(self.get_start(), tip.base) return self def asign_tip_attr(self, tip, at_start): if at_start: self.start_tip = tip else: self.tip = tip return self # Checking for tips def has_tip(self): return hasattr(self, "tip") and self.tip in self def has_start_tip(self): return hasattr(self, "start_tip") and self.start_tip in self # Getters def pop_tips(self): start, end = self.get_start_and_end() result = self.get_group_class()() if self.has_tip(): result.add(self.tip) self.remove(self.tip) if self.has_start_tip(): result.add(self.start_tip) self.remove(self.start_tip) self.put_start_and_end_on(start, end) return result
[docs] def get_tips(self): """ Returns a VGroup (collection of VMobjects) containing the TipableVMObject instance's tips. """ result = self.get_group_class()() if hasattr(self, "tip"): result.add(self.tip) if hasattr(self, "start_tip"): result.add(self.start_tip) return result
[docs] def get_tip(self): """Returns the TipableVMobject instance's (first) tip, otherwise throws an exception.""" tips = self.get_tips() if len(tips) == 0: raise Exception("tip not found") else: return tips[0]
def get_default_tip_length(self): return self.tip_length def get_first_handle(self): return self.points[1] def get_last_handle(self): return self.points[-2]
[docs] def get_end(self): if self.has_tip(): return self.tip.get_start() else: return super().get_end()
[docs] def get_start(self): if self.has_start_tip(): return self.start_tip.get_start() else: return super().get_start()
def get_length(self): start, end = self.get_start_and_end() return np.linalg.norm(start - end)
[docs]class Arc(TipableVMobject): """A circular arc. Examples -------- A simple arc of angle Pi. .. manim:: ArcExample :save_last_frame: class ArcExample(Scene): def construct(self): self.add(Arc(angle=PI)) """ def __init__( self, radius: float = 1.0, start_angle=0, angle=TAU / 4, num_components=9, arc_center=ORIGIN, **kwargs, ): if radius is None: # apparently None is passed by ArcBetweenPoints radius = 1.0 self.radius = radius self.num_components = num_components self.arc_center = arc_center self.start_angle = start_angle self.angle = angle self._failed_to_get_center = False super().__init__(**kwargs)
[docs] def generate_points(self): self.set_pre_positioned_points() self.scale(self.radius, about_point=ORIGIN) self.shift(self.arc_center)
# Points are set a bit differently when rendering via OpenGL. # TODO: refactor Arc so that only one strategy for setting points # has to be used. def init_points(self): self.set_points( Arc.create_quadratic_bezier_points( angle=self.angle, start_angle=self.start_angle, n_components=self.num_components, ), ) self.scale(self.radius, about_point=ORIGIN) self.shift(self.arc_center) @staticmethod def create_quadratic_bezier_points(angle, start_angle=0, n_components=8): samples = np.array( [ [np.cos(a), np.sin(a), 0] for a in np.linspace( start_angle, start_angle + angle, 2 * n_components + 1, ) ], ) theta = angle / n_components samples[1::2] /= np.cos(theta / 2) points = np.zeros((3 * n_components, 3)) points[0::3] = samples[0:-1:2] points[1::3] = samples[1::2] points[2::3] = samples[2::2] return points def set_pre_positioned_points(self): anchors = np.array( [ np.cos(a) * RIGHT + np.sin(a) * UP for a in np.linspace( self.start_angle, self.start_angle + self.angle, self.num_components, ) ], ) # Figure out which control points will give the # Appropriate tangent lines to the circle d_theta = self.angle / (self.num_components - 1.0) tangent_vectors = np.zeros(anchors.shape) # Rotate all 90 degrees, via (x, y) -> (-y, x) tangent_vectors[:, 1] = anchors[:, 0] tangent_vectors[:, 0] = -anchors[:, 1] # Use tangent vectors to deduce anchors handles1 = anchors[:-1] + (d_theta / 3) * tangent_vectors[:-1] handles2 = anchors[1:] - (d_theta / 3) * tangent_vectors[1:] self.set_anchors_and_handles(anchors[:-1], handles1, handles2, anchors[1:])
[docs] def get_arc_center(self, warning=True): """ Looks at the normals to the first two anchors, and finds their intersection points """ # First two anchors and handles a1, h1, h2, a2 = self.points[:4] if np.all(a1 == a2): # For a1 and a2 to lie at the same point arc radius # must be zero. Thus arc_center will also lie at # that point. return a1 # Tangent vectors t1 = h1 - a1 t2 = h2 - a2 # Normals n1 = rotate_vector(t1, TAU / 4) n2 = rotate_vector(t2, TAU / 4) try: return line_intersection(line1=(a1, a1 + n1), line2=(a2, a2 + n2)) except Exception: if warning: warnings.warn("Can't find Arc center, using ORIGIN instead") self._failed_to_get_center = True return np.array(ORIGIN)
def move_arc_center_to(self, point): self.shift(point - self.get_arc_center()) return self def stop_angle(self): return angle_of_vector(self.points[-1] - self.get_arc_center()) % TAU
[docs]class ArcBetweenPoints(Arc): """ Inherits from Arc and additionally takes 2 points between which the arc is spanned. Example -------------------- .. manim:: ArcBetweenPointsExample class ArcBetweenPointsExample(Scene): def construct(self): circle = Circle(radius=2, stroke_color=GREY) dot_1 = Dot(color=GREEN).move_to([2, 0, 0]).scale(0.5) dot_1_text = Tex("(2,0)").scale(0.5).next_to(dot_1, RIGHT).set_color(BLUE) dot_2 = Dot(color=GREEN).move_to([0, 2, 0]).scale(0.5) dot_2_text = Tex("(0,2)").scale(0.5).next_to(dot_2, UP).set_color(BLUE) arc= ArcBetweenPoints(start=2 * RIGHT, end=2 * UP, stroke_color=YELLOW) self.add(circle, dot_1, dot_2, dot_1_text, dot_2_text) """ def __init__(self, start, end, angle=TAU / 4, radius=None, **kwargs): if radius is not None: self.radius = radius if radius < 0: sign = -2 radius *= -1 else: sign = 2 halfdist = np.linalg.norm(np.array(start) - np.array(end)) / 2 if radius < halfdist: raise ValueError( """ArcBetweenPoints called with a radius that is smaller than half the distance between the points.""", ) arc_height = radius - math.sqrt(radius ** 2 - halfdist ** 2) angle = math.acos((radius - arc_height) / radius) * sign super().__init__(radius=radius, angle=angle, **kwargs) if angle == 0: self.set_points_as_corners([LEFT, RIGHT]) self.put_start_and_end_on(start, end) if radius is None: center = self.get_arc_center(warning=False) if not self._failed_to_get_center: self.radius = np.linalg.norm(np.array(start) - np.array(center)) else: self.radius = math.inf
[docs]class CurvedArrow(ArcBetweenPoints): def __init__(self, start_point, end_point, **kwargs): tip_shape = kwargs.pop("tip_shape", ArrowTriangleFilledTip) super().__init__(start_point, end_point, **kwargs) self.add_tip(tip_shape=tip_shape)
[docs]class CurvedDoubleArrow(CurvedArrow): def __init__(self, start_point, end_point, **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__(start_point, end_point, **kwargs) self.add_tip(at_start=True, tip_shape=tip_shape_start)
[docs]class Circle(Arc): """A circle. Parameters ---------- color : :class:`~.Colors`, optional The color of the shape. kwargs : Any Additional arguments to be passed to :class:`Arc` Examples -------- .. manim:: CircleExample :save_last_frame: class CircleExample(Scene): def construct(self): circle_1 = Circle(radius=1.0) circle_2 = Circle(radius=1.5, color=GREEN) circle_3 = Circle(radius=1.0, color=BLUE_B, fill_opacity=1) circle_group = Group(circle_1, circle_2, circle_3).arrange(buff=1) self.add(circle_group) """ def __init__( self, radius: float = None, color=RED, **kwargs, ): super().__init__( radius=radius, start_angle=0, angle=TAU, color=color, **kwargs, )
[docs] def surround(self, mobject, dim_to_match=0, stretch=False, buffer_factor=1.2): """Modifies a circle so that it surrounds a given mobject. Parameters ---------- mobject : :class:`~.Mobject` The mobject that the circle will be surrounding. dim_to_match : :class:`int`, optional buffer_factor : :class:`float`, optional Scales the circle with respect to the mobject. A `buffer_factor` < 1 makes the circle smaller than the mobject. stretch : :class:`bool`, optional Stretches the circle to fit more tightly around the mobject. Note: Does not work with :class:`Line` Examples -------- .. manim:: CircleSurround :save_last_frame: class CircleSurround(Scene): def construct(self): triangle1 = Triangle() circle1 = Circle().surround(triangle1) group1 = Group(triangle1,circle1) # treat the two mobjects as one line2 = Line() circle2 = Circle().surround(line2, buffer_factor=2.0) group2 = Group(line2,circle2) # buffer_factor < 1, so the circle is smaller than the square square3 = Square() circle3 = Circle().surround(square3, buffer_factor=0.5) group3 = Group(square3, circle3) group = Group(group1, group2, group3).arrange(buff=1) self.add(group) """ # Ignores dim_to_match and stretch; result will always be a circle # TODO: Perhaps create an ellipse class to handle single-dimension stretching # Something goes wrong here when surrounding lines? # TODO: Figure out and fix self.replace(mobject, dim_to_match, stretch) self.width = np.sqrt(mobject.width ** 2 + mobject.height ** 2) return self.scale(buffer_factor)
[docs] def point_at_angle(self, angle): """Returns the position of a point on the circle. Parameters ---------- angle : class: `float` The angle of the point along the circle in radians. Examples -------- .. manim:: PointAtAngleExample :save_last_frame: class PointAtAngleExample(Scene): def construct(self): circle = Circle(radius=2.0) p1 = circle.point_at_angle(PI/2) p2 = circle.point_at_angle(270*DEGREES) s1 = Square(side_length=0.25).move_to(p1) s2 = Square(side_length=0.25).move_to(p2) self.add(circle, s1, s2) Returns ------- :class:`numpy.ndarray` The location of the point along the circle's circumference. """ start_angle = angle_of_vector(self.points[0] - self.get_center()) return self.point_from_proportion((angle - start_angle) / TAU)
[docs] @staticmethod def from_three_points( p1: Sequence[float], p2: Sequence[float], p3: Sequence[float], **kwargs ): """Returns a circle passing through the specified three points. Example ------- .. manim:: CircleFromPointsExample :save_last_frame: class CircleFromPointsExample(Scene): def construct(self): circle = Circle.from_three_points(LEFT, LEFT + UP, UP * 2, color=RED) dots = VGroup( Dot(LEFT), Dot(LEFT + UP), Dot(UP * 2), ) self.add(NumberPlane(), circle, dots) """ center = line_intersection( perpendicular_bisector([p1, p2]), perpendicular_bisector([p2, p3]), ) radius = np.linalg.norm(p1 - center) return Circle(radius=radius, **kwargs).shift(center)
[docs]class Dot(Circle): """A circle with a very small radius. Parameters ---------- point : Union[:class:`list`, :class:`numpy.ndarray`], optional The location of the dot. radius : Optional[:class:`float`] The radius of the dot. stroke_width : :class:`float`, optional The thickness of the outline of the dot. fill_opacity : :class:`float`, optional The opacity of the dot's fill_colour color : :class:`~.Colors`, optional The color of the dot. kwargs : Any Additional arguments to be passed to :class:`Circle` Examples -------- .. manim:: DotExample :save_last_frame: class DotExample(Scene): def construct(self): dot1 = Dot(point=LEFT, radius=0.08) dot2 = Dot(point=ORIGIN) dot3 = Dot(point=RIGHT) self.add(dot1,dot2,dot3) """ def __init__( self, point=ORIGIN, radius: float = DEFAULT_DOT_RADIUS, stroke_width=0, fill_opacity=1.0, color=WHITE, **kwargs, ): super().__init__( arc_center=point, radius=radius, stroke_width=stroke_width, fill_opacity=fill_opacity, color=color, **kwargs, )
[docs]class AnnotationDot(Dot): """ A dot with bigger radius and bold stroke to annotate scenes. """ def __init__( self, radius: float = DEFAULT_DOT_RADIUS * 1.3, stroke_width=5, stroke_color=WHITE, fill_color=BLUE, **kwargs, ): super().__init__( radius=radius, stroke_width=stroke_width, stroke_color=stroke_color, fill_color=fill_color, **kwargs, )
[docs]class LabeledDot(Dot): """A :class:`Dot` containing a label in its center. Parameters ---------- label : Union[:class:`str`, :class:`~.SingleStringMathTex`, :class:`~.Text`, :class:`~.Tex`] The label of the :class:`Dot`. This is rendered as :class:`~.MathTex` by default (i.e., when passing a :class:`str`), but other classes representing rendered strings like :class:`~.Text` or :class:`~.Tex` can be passed as well. radius : :class:`float` The radius of the :class:`Dot`. If ``None`` (the default), the radius is calculated based on the size of the ``label``. Examples -------- .. manim:: SeveralLabeledDots :save_last_frame: class SeveralLabeledDots(Scene): def construct(self): sq = Square(fill_color=RED, fill_opacity=1) self.add(sq) dot1 = LabeledDot(Tex("42", color=RED)) dot2 = LabeledDot(MathTex("a", color=GREEN)) dot3 = LabeledDot(Text("ii", color=BLUE)) dot4 = LabeledDot("3") dot1.next_to(sq, UL) dot2.next_to(sq, UR) dot3.next_to(sq, DL) dot4.next_to(sq, DR) self.add(dot1, dot2, dot3, dot4) """ def __init__(self, label, radius=None, **kwargs) -> None: if isinstance(label, str): from manim import MathTex rendered_label = MathTex(label, color=BLACK) else: rendered_label = label if radius is None: radius = 0.1 + max(rendered_label.width, rendered_label.height) / 2 super().__init__(radius=radius, **kwargs) rendered_label.move_to(self.get_center()) self.add(rendered_label)
[docs]class Ellipse(Circle): """A circular shape; oval, circle. Parameters ---------- width : :class:`float`, optional The horizontal width of the ellipse. height : :class:`float`, optional The vertical height of the ellipse. kwargs : Any Additional arguments to be passed to :class:`Circle` Examples -------- .. manim:: EllipseExample :save_last_frame: class EllipseExample(Scene): def construct(self): ellipse_1 = Ellipse(width=2.0, height=4.0, color=BLUE_B) ellipse_2 = Ellipse(width=4.0, height=1.0, color=BLUE_D) ellipse_group = Group(ellipse_1,ellipse_2).arrange(buff=1) self.add(ellipse_group) """ def __init__(self, width=2, height=1, **kwargs): super().__init__(**kwargs) self.stretch_to_fit_width(width) self.stretch_to_fit_height(height)
[docs]class AnnularSector(Arc): """ Parameters ---------- inner_radius The inside radius of the Annular Sector. outer_radius The outside radius of the Annular Sector. angle The clockwise angle of the Annular Sector. start_angle The starting clockwise angle of the Annular Sector. fill_opacity The opacity of the color filled in the Annular Sector. stroke_width The stroke width of the Annular Sector. color The color filled into the Annular Sector. Examples -------- .. manim:: AnnularSectorExample :save_last_frame: class AnnularSectorExample(Scene): def construct(self): # Changes background color to clearly visualize changes in fill_opacity. = WHITE # The default parameter start_angle is 0, so the AnnularSector starts from the +x-axis. s1 = AnnularSector(color=YELLOW).move_to(2 * UL) # Different inner_radius and outer_radius than the default. s2 = AnnularSector(inner_radius=1.5, outer_radius=2, angle=45 * DEGREES, color=RED).move_to(2 * UR) # fill_opacity is typically a number > 0 and <= 1. If fill_opacity=0, the AnnularSector is transparent. s3 = AnnularSector(inner_radius=1, outer_radius=1.5, angle=PI, fill_opacity=0.25, color=BLUE).move_to(2 * DL) # With a negative value for the angle, the AnnularSector is drawn clockwise from the start value. s4 = AnnularSector(inner_radius=1, outer_radius=1.5, angle=-3 * PI / 2, color=GREEN).move_to(2 * DR) self.add(s1, s2, s3, s4) """ def __init__( self, inner_radius=1, outer_radius=2, angle=TAU / 4, start_angle=0, fill_opacity=1, stroke_width=0, color=WHITE, **kwargs, ): self.inner_radius = inner_radius self.outer_radius = outer_radius super().__init__( start_angle=start_angle, angle=angle, fill_opacity=fill_opacity, stroke_width=stroke_width, color=color, **kwargs, )
[docs] def generate_points(self): inner_arc, outer_arc = ( Arc( start_angle=self.start_angle, angle=self.angle, radius=radius, arc_center=self.arc_center, ) for radius in (self.inner_radius, self.outer_radius) ) outer_arc.reverse_points() self.append_points(inner_arc.points) self.add_line_to(outer_arc.points[0]) self.append_points(outer_arc.points) self.add_line_to(inner_arc.points[0])
init_points = generate_points
[docs]class Sector(AnnularSector): """ Examples -------- .. manim:: ExampleSector :save_last_frame: class ExampleSector(Scene): def construct(self): sector = Sector(outer_radius=2, inner_radius=1) sector2 = Sector(outer_radius=2.5, inner_radius=0.8).move_to([-3, 0, 0]) sector.set_color(RED) sector2.set_color(PINK) self.add(sector, sector2) """ def __init__(self, outer_radius=1, inner_radius=0, **kwargs): super().__init__(inner_radius=inner_radius, outer_radius=outer_radius, **kwargs)
[docs]class Annulus(Circle): """Region between two concentric :class:`Circles <.Circle>`. Parameters ---------- inner_radius The radius of the inner :class:`Circle`. outer_radius The radius of the outer :class:`Circle`. kwargs : Any Additional arguments to be passed to :class:`Annulus` Examples -------- .. manim:: AnnulusExample :save_last_frame: class AnnulusExample(Scene): def construct(self): annulus_1 = Annulus(inner_radius=0.5, outer_radius=1).shift(UP) annulus_2 = Annulus(inner_radius=0.3, outer_radius=0.6, color=RED).next_to(annulus_1, DOWN) self.add(annulus_1, annulus_2) """ def __init__( self, inner_radius: Optional[float] = 1, outer_radius: Optional[float] = 2, fill_opacity=1, stroke_width=0, color=WHITE, mark_paths_closed=False, **kwargs, ): self.mark_paths_closed = mark_paths_closed # is this even used? self.inner_radius = inner_radius self.outer_radius = outer_radius super().__init__( fill_opacity=fill_opacity, stroke_width=stroke_width, color=color, **kwargs )
[docs] def generate_points(self): self.radius = self.outer_radius outer_circle = Circle(radius=self.outer_radius) inner_circle = Circle(radius=self.inner_radius) inner_circle.reverse_points() self.append_points(outer_circle.points) self.append_points(inner_circle.points) self.shift(self.arc_center)
init_points = generate_points
[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 set_path_arc(self, new_value): self.path_arc = new_value self.init_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, direction=None): 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)
[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 : Any Arguments to be passed to :class:`Line` dash_length : :class:`float`, optional The length of each individual dash of the line. dashed_ratio : :class:`float`, optional The ratio of dash space to empty space. Range of 0-1. kwargs : Any Additional arguments to be passed to :class:`Line` 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) See Also -------- :class:`~.DashedVMobject` """ def __init__( self, *args, dash_length=DEFAULT_DASH_LENGTH, dashed_ratio=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)
[docs] 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 : :class:`~.VMobject` The VMobject on which the tangent line is drawn. alpha : :class:`float` How far along the shape that the line will be constructed. range: 0-1. length : :class:`float`, optional Length of the tangent line. d_alpha: :class:`float`, optional The ``dx`` value kwargs : Any Additional arguments to be passed to :class:`Line` 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) See Also -------- :meth:`~.VMobject.point_from_proportion` """ def __init__(self, vmob, alpha, length=1, d_alpha=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 : :class:`float`, optional The length of the elbow's sides. angle : :class:`float`, optional The rotation of the elbow. kwargs : Any Additional arguments to be passed to :class:`~.VMobject` 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) See Also -------- :class:`RightAngle` """ def __init__(self, width=0.2, angle=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 : Any Arguments to be passed to :class:`Line`. stroke_width : :class:`float`, optional The thickness of the arrow. Influenced by :attr:`max_stroke_width_to_length_ratio`. buff : :class:`float`, optional The distance of the arrow from its start and end points. max_tip_length_to_length_ratio : :class:`float`, optional :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 : :class:`float`, optional :attr:`stroke_width` scales with the length of the arrow. Increasing this ratio ratios the max value of :attr:`stroke_width`. kwargs : Any Additional arguments to be passed to :class:`Line`. Examples -------- .. manim:: ArrowExample :save_last_frame: from manim.mobject.geometry 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) See Also -------- :class:`ArrowTip` :class:`CurvedArrow` """ def __init__( self, *args, stroke_width=6, buff=MED_SMALL_BUFF, max_tip_length_to_length_ratio=0.25, max_stroke_width_to_length_ratio=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. See Also -------- :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())
[docs] def set_stroke_width_from_length(self): """Used internally. Sets stroke width based on length.""" max_ratio = self.max_stroke_width_to_length_ratio if config.renderer == "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 : Union[:class:`list`, :class:`numpy.ndarray`] The direction of the arrow. buff : :class:`float` The distance of the vector from its endpoints. kwargs : Any 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=RIGHT, buff=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: Optional[Color] = 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`. 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) Returns ------- :class:`~.Matrix` The label. """ # 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 : Any Arguments to be passed to :class:`Arrow` kwargs : Any Additional arguments to be passed to :class:`Arrow` Examples -------- .. manim:: DoubleArrowExample :save_last_frame: from manim.mobject.geometry 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) See Also -------- :class:`ArrowTip` :class:`CurvedDoubleArrow` """ def __init__(self, *args, **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 CubicBezier(VMobject, metaclass=ConvertToOpenGL): """ Example ------- .. manim:: BezierSplineExample :save_last_frame: class BezierSplineExample(Scene): def construct(self): p1 = np.array([-3, 1, 0]) p1b = p1 + [1, 0, 0] d1 = Dot(point=p1).set_color(BLUE) l1 = Line(p1, p1b) p2 = np.array([3, -1, 0]) p2b = p2 - [1, 0, 0] d2 = Dot(point=p2).set_color(RED) l2 = Line(p2, p2b) bezier = CubicBezier(p1b, p1b + 3 * RIGHT, p2b - 3 * RIGHT, p2b) self.add(l1, d1, l2, d2, bezier) """ def __init__(self, start_anchor, start_handle, end_handle, end_anchor, **kwargs): super().__init__(**kwargs) self.add_cubic_bezier_curve(start_anchor, start_handle, end_handle, end_anchor)
[docs]class Polygram(VMobject, metaclass=ConvertToOpenGL): """A generalized :class:`Polygon`, allowing for disconnected sets of edges. Parameters ---------- vertex_groups The groups of vertices making up the :class:`Polygram`. The first vertex in each group is repeated to close the shape. Each point must be 3-dimensional: ``[x,y,z]`` color The color of the :class:`Polygram`. kwargs Forwarded to the parent constructor. Examples -------- .. manim:: PolygramExample import numpy as np class PolygramExample(Scene): def construct(self): hexagram = Polygram( [[0, 2, 0], [-np.sqrt(3), -1, 0], [np.sqrt(3), -1, 0]], [[-np.sqrt(3), 1, 0], [0, -2, 0], [np.sqrt(3), 1, 0]], ) self.add(hexagram) dot = Dot(), hexagram), run_time=5, rate_func=linear) self.remove(dot) self.wait() """ def __init__(self, *vertex_groups: Iterable[Sequence[float]], color=BLUE, **kwargs): super().__init__(color=color, **kwargs) for vertices in vertex_groups: first_vertex, *vertices = vertices first_vertex = np.array(first_vertex) self.start_new_path(first_vertex) self.add_points_as_corners( [*(np.array(vertex) for vertex in vertices), first_vertex], )
[docs] def get_vertices(self) -> np.ndarray: """Gets the vertices of the :class:`Polygram`. Returns ------- :class:`numpy.ndarray` The vertices of the :class:`Polygram`. Examples -------- :: >>> sq = Square() >>> sq.get_vertices() array([[ 1., 1., 0.], [-1., 1., 0.], [-1., -1., 0.], [ 1., -1., 0.]]) """ return self.get_start_anchors()
[docs] def get_vertex_groups(self) -> np.ndarray: """Gets the vertex groups of the :class:`Polygram`. Returns ------- :class:`numpy.ndarray` The vertex groups of the :class:`Polygram`. Examples -------- :: >>> poly = Polygram([ORIGIN, RIGHT, UP], [LEFT, LEFT + UP, 2 * LEFT]) >>> poly.get_vertex_groups() array([[[ 0., 0., 0.], [ 1., 0., 0.], [ 0., 1., 0.]], <BLANKLINE> [[-1., 0., 0.], [-1., 1., 0.], [-2., 0., 0.]]]) """ vertex_groups = [] group = [] for start, end in zip(self.get_start_anchors(), self.get_end_anchors()): group.append(start) if self.consider_points_equals(end, group[0]): vertex_groups.append(group) group = [] return np.array(vertex_groups)
[docs] def round_corners(self, radius: float = 0.5): """Rounds off the corners of the :class:`Polygram`. Parameters ---------- radius The curvature of the corners of the :class:`Polygram`. Examples -------- .. manim:: PolygramRoundCorners :save_last_frame: class PolygramRoundCorners(Scene): def construct(self): star = Star(outer_radius=2) shapes = VGroup(star) shapes.add(star.copy().round_corners(radius=0.1)) shapes.add(star.copy().round_corners(radius=0.25)) shapes.arrange(RIGHT) self.add(shapes) See Also -------- :class:`RoundedRectangle` """ if radius == 0: return self new_points = [] for vertices in self.get_vertex_groups(): arcs = [] for v1, v2, v3 in adjacent_n_tuples(vertices, 3): vect1 = v2 - v1 vect2 = v3 - v2 unit_vect1 = normalize(vect1) unit_vect2 = normalize(vect2) angle = angle_between_vectors(vect1, vect2) # Negative radius gives concave curves angle *= np.sign(radius) # Distance between vertex and start of the arc cut_off_length = radius * np.tan(angle / 2) # Determines counterclockwise vs. clockwise sign = np.sign(np.cross(vect1, vect2)[2]) arc = ArcBetweenPoints( v2 - unit_vect1 * cut_off_length, v2 + unit_vect2 * cut_off_length, angle=sign * angle, ) arcs.append(arc) # To ensure that we loop through starting with last arcs = [arcs[-1], *arcs[:-1]] for arc1, arc2 in adjacent_pairs(arcs): new_points.extend(arc1.points) line = Line(arc1.get_end(), arc2.get_start()) # Make sure anchors are evenly distributed len_ratio = line.get_length() / arc1.get_arc_length() line.insert_n_curves(int(arc1.get_num_curves() * len_ratio)) new_points.extend(line.points) self.set_points(new_points) return self
[docs]class Polygon(Polygram): """A shape consisting of one closed loop of vertices. Parameters ---------- vertices The vertices of the :class:`Polygon`. kwargs Forwarded to the parent constructor. Examples -------- .. manim:: PolygonExample :save_last_frame: class PolygonExample(Scene): def construct(self): isosceles = Polygon([-5, 1.5, 0], [-2, 1.5, 0], [-3.5, -2, 0]) position_list = [ [4, 1, 0], # middle right [4, -2.5, 0], # bottom right [0, -2.5, 0], # bottom left [0, 3, 0], # top left [2, 1, 0], # middle [4, 3, 0], # top right ] square_and_triangles = Polygon(*position_list, color=PURPLE_B) self.add(isosceles, square_and_triangles) """ def __init__(self, *vertices: Sequence[float], **kwargs): super().__init__(vertices, **kwargs)
[docs]class RegularPolygram(Polygram): """A :class:`Polygram` with regularly spaced vertices. Parameters ---------- num_vertices The number of vertices. density The density of the :class:`RegularPolygram`. Can be thought of as how many vertices to hop to draw a line between them. Every ``density``-th vertex is connected. radius The radius of the circle that the vertices are placed on. start_angle The angle the vertices start at; the rotation of the :class:`RegularPolygram`. kwargs Forwarded to the parent constructor. Examples -------- .. manim:: RegularPolygramExample :save_last_frame: class RegularPolygramExample(Scene): def construct(self): pentagram = RegularPolygram(5, radius=2) self.add(pentagram) """ def __init__( self, num_vertices: int, *, density: int = 2, radius: float = 1, start_angle: Optional[float] = None, **kwargs, ): # Regular polygrams can be expressed by the number of their vertices # and their density. This relation can be expressed as its Schläfli # symbol: {num_vertices/density}. # # For instance, a pentagon can be expressed as {5/1} or just {5}. # A pentagram, however, can be expressed as {5/2}. # A hexagram *would* be expressed as {6/2}, except that 6 and 2 # are not coprime, and it can be simplified to 2{3}, which corresponds # to the fact that a hexagram is actually made up of 2 triangles. # # See # for more information. num_gons = np.gcd(num_vertices, density) num_vertices //= num_gons density //= num_gons # Utility function for generating the individual # polygon vertices. def gen_polygon_vertices(start_angle): reg_vertices, start_angle = regular_vertices( num_vertices, radius=radius, start_angle=start_angle, ) vertices = [] i = 0 while True: vertices.append(reg_vertices[i]) i += density i %= num_vertices if i == 0: break return vertices, start_angle first_group, self.start_angle = gen_polygon_vertices(start_angle) vertex_groups = [first_group] for i in range(1, num_gons): start_angle = self.start_angle + (i / num_gons) * TAU / num_vertices group, _ = gen_polygon_vertices(start_angle) vertex_groups.append(group) super().__init__(*vertex_groups, **kwargs)
[docs]class RegularPolygon(RegularPolygram): """An n-sided regular :class:`Polygon`. Parameters ---------- n The number of sides of the :class:`RegularPolygon`. kwargs Forwarded to the parent constructor. Examples -------- .. manim:: RegularPolygonExample :save_last_frame: class RegularPolygonExample(Scene): def construct(self): poly_1 = RegularPolygon(n=6) poly_2 = RegularPolygon(n=6, start_angle=30*DEGREES, color=GREEN) poly_3 = RegularPolygon(n=10, color=RED) poly_group = Group(poly_1, poly_2, poly_3).scale(1.5).arrange(buff=1) self.add(poly_group) """ def __init__(self, n: int = 6, **kwargs): super().__init__(n, density=1, **kwargs)
[docs]class Star(Polygon): """A regular polygram without the intersecting lines. Parameters ---------- n How many points on the :class:`Star`. outer_radius The radius of the circle that the outer vertices are placed on. inner_radius The radius of the circle that the inner vertices are placed on. If unspecified, the inner radius will be calculated such that the edges of the :class:`Star` perfectly follow the edges of its :class:`RegularPolygram` counterpart. density The density of the :class:`Star`. Only used if ``inner_radius`` is unspecified. See :class:`RegularPolygram` for more information. start_angle The angle the vertices start at; the rotation of the :class:`Star`. kwargs Forwardeds to the parent constructor. Raises ------ :exc:`ValueError` If ``inner_radius`` is unspecified and ``density`` is not in the range ``[1, n/2)``. Examples -------- .. manim:: StarExample :save_as_gif: class StarExample(Scene): def construct(self): pentagram = RegularPolygram(5, radius=2) star = Star(outer_radius=2, color=RED) self.add(pentagram), run_time=3), run_time=2) .. manim:: DifferentDensitiesExample :save_last_frame: class DifferentDensitiesExample(Scene): def construct(self): density_2 = Star(7, outer_radius=2, density=2, color=RED) density_3 = Star(7, outer_radius=2, density=3, color=PURPLE) self.add(VGroup(density_2, density_3).arrange(RIGHT)) """ def __init__( self, n: int = 5, *, outer_radius: float = 1, inner_radius: Optional[float] = None, density: int = 2, start_angle: Optional[float] = TAU / 4, **kwargs, ): inner_angle = TAU / (2 * n) if inner_radius is None: # See for an # overview of how to calculate the inner radius of a # perfect star. if density <= 0 or density >= n / 2: raise ValueError( f"Incompatible density {density} for number of points {n}", ) outer_angle = TAU * density / n inverse_x = 1 - np.tan(inner_angle) * ( (np.cos(outer_angle) - 1) / np.sin(outer_angle) ) inner_radius = outer_radius / (np.cos(inner_angle) * inverse_x) outer_vertices, self.start_angle = regular_vertices( n, radius=outer_radius, start_angle=start_angle, ) inner_vertices, _ = regular_vertices( n, radius=inner_radius, start_angle=self.start_angle + inner_angle, ) vertices = [] for pair in zip(outer_vertices, inner_vertices): vertices.extend(pair) super().__init__(*vertices, **kwargs)
[docs]class ArcPolygon(VMobject, metaclass=ConvertToOpenGL): """A generalized polygon allowing for points to be connected with arcs. This version tries to stick close to the way :class:`Polygon` is used. Points can be passed to it directly which are used to generate the according arcs (using :class:`ArcBetweenPoints`). An angle or radius can be passed to it to use across all arcs, but to configure arcs individually an ``arc_config`` list has to be passed with the syntax explained below. .. tip:: Two instances of :class:`ArcPolygon` can be transformed properly into one another as well. Be advised that any arc initialized with ``angle=0`` will actually be a straight line, so if a straight section should seamlessly transform into an arced section or vice versa, initialize the straight section with a negligible angle instead (such as ``angle=0.0001``). There is an alternative version (:class:`ArcPolygonFromArcs`) that is instantiated with pre-defined arcs. See Also -------- :class:`ArcPolygonFromArcs` Parameters ---------- vertices : Union[:class:`list`, :class:`np.array`] A list of vertices, start and end points for the arc segments. angle : :class:`float` The angle used for constructing the arcs. If no other parameters are set, this angle is used to construct all arcs. radius : Optional[:class:`float`] The circle radius used to construct the arcs. If specified, overrides the specified ``angle``. arc_config : Optional[Union[List[:class:`dict`]], :class:`dict`] When passing a ``dict``, its content will be passed as keyword arguments to :class:`~.ArcBetweenPoints`. Otherwise, a list of dictionaries containing values that are passed as keyword arguments for every individual arc can be passed. kwargs Further keyword arguments that are passed to the constructor of :class:`~.VMobject`. Attributes ---------- arcs : :class:`list` The arcs created from the input parameters:: >>> from manim import ArcPolygon >>> ap = ArcPolygon([0, 0, 0], [2, 0, 0], [0, 2, 0]) >>> ap.arcs [ArcBetweenPoints, ArcBetweenPoints, ArcBetweenPoints] Examples -------- .. manim:: SeveralArcPolygons class SeveralArcPolygons(Scene): def construct(self): a = [0, 0, 0] b = [2, 0, 0] c = [0, 2, 0] ap1 = ArcPolygon(a, b, c, radius=2) ap2 = ArcPolygon(a, b, c, angle=45*DEGREES) ap3 = ArcPolygon(a, b, c, arc_config={'radius': 1.7, 'color': RED}) ap4 = ArcPolygon(a, b, c, color=RED, fill_opacity=1, arc_config=[{'radius': 1.7, 'color': RED}, {'angle': 20*DEGREES, 'color': BLUE}, {'radius': 1}]) ap_group = VGroup(ap1, ap2, ap3, ap4).arrange()*[Create(ap) for ap in [ap1, ap2, ap3, ap4]]) self.wait() For further examples see :class:`ArcPolygonFromArcs`. """ def __init__(self, *vertices, angle=PI / 4, radius=None, arc_config=None, **kwargs): n = len(vertices) point_pairs = [(vertices[k], vertices[(k + 1) % n]) for k in range(n)] if not arc_config: if radius: all_arc_configs = itertools.repeat({"radius": radius}, len(point_pairs)) else: all_arc_configs = itertools.repeat({"angle": angle}, len(point_pairs)) elif isinstance(arc_config, dict): all_arc_configs = itertools.repeat(arc_config, len(point_pairs)) else: assert len(arc_config) == n all_arc_configs = arc_config arcs = [ ArcBetweenPoints(*pair, **conf) for (pair, conf) in zip(point_pairs, all_arc_configs) ] super().__init__(**kwargs) # Adding the arcs like this makes ArcPolygon double as a VGroup. # Also makes changes to the ArcPolygon, such as scaling, affect # the arcs, so that their new values are usable. self.add(*arcs) for arc in arcs: self.append_points(arc.points) # This enables the use of ArcPolygon.arcs as a convenience # because ArcPolygon[0] returns itself, not the first Arc. self.arcs = arcs
[docs]class ArcPolygonFromArcs(VMobject, metaclass=ConvertToOpenGL): """A generalized polygon allowing for points to be connected with arcs. This version takes in pre-defined arcs to generate the arcpolygon and introduces little new syntax. However unlike :class:`Polygon` it can't be created with points directly. For proper appearance the passed arcs should connect seamlessly: ``[a,b][b,c][c,a]`` If there are any gaps between the arcs, those will be filled in with straight lines, which can be used deliberately for any straight sections. Arcs can also be passed as straight lines such as an arc initialized with ``angle=0``. .. tip:: Two instances of :class:`ArcPolygon` can be transformed properly into one another as well. Be advised that any arc initialized with ``angle=0`` will actually be a straight line, so if a straight section should seamlessly transform into an arced section or vice versa, initialize the straight section with a negligible angle instead (such as ``angle=0.0001``). There is an alternative version (:class:`ArcPolygon`) that can be instantiated with points. See Also -------- :class:`ArcPolygon` Parameters ---------- arcs : Union[:class:`Arc`, :class:`ArcBetweenPoints`] These are the arcs from which the arcpolygon is assembled. kwargs Keyword arguments that are passed to the constructor of :class:`~.VMobject`. Affects how the ArcPolygon itself is drawn, but doesn't affect passed arcs. Attributes ---------- arcs : :class:`list` The arcs used to initialize the ArcPolygonFromArcs:: >>> from manim import ArcPolygonFromArcs, Arc, ArcBetweenPoints >>> ap = ArcPolygonFromArcs(Arc(), ArcBetweenPoints([1,0,0], [0,1,0]), Arc()) >>> ap.arcs [Arc, ArcBetweenPoints, Arc] Examples -------- One example of an arcpolygon is the Reuleaux triangle. Instead of 3 straight lines connecting the outer points, a Reuleaux triangle has 3 arcs connecting those points, making a shape with constant width. Passed arcs are stored as submobjects in the arcpolygon. This means that the arcs are changed along with the arcpolygon, for example when it's shifted, and these arcs can be manipulated after the arcpolygon has been initialized. Also both the arcs contained in an :class:`~.ArcPolygonFromArcs`, as well as the arcpolygon itself are drawn, which affects draw time in :class:`~.Create` for example. In most cases the arcs themselves don't need to be drawn, in which case they can be passed as invisible. .. manim:: ArcPolygonExample class ArcPolygonExample(Scene): def construct(self): arc_conf = {"stroke_width": 0} poly_conf = {"stroke_width": 10, "stroke_color": BLUE, "fill_opacity": 1, "color": PURPLE} a = [-1, 0, 0] b = [1, 0, 0] c = [0, np.sqrt(3), 0] arc0 = ArcBetweenPoints(a, b, radius=2, **arc_conf) arc1 = ArcBetweenPoints(b, c, radius=2, **arc_conf) arc2 = ArcBetweenPoints(c, a, radius=2, **arc_conf) reuleaux_tri = ArcPolygonFromArcs(arc0, arc1, arc2, **poly_conf) self.wait(2) The arcpolygon itself can also be hidden so that instead only the contained arcs are drawn. This can be used to easily debug arcs or to highlight them. .. manim:: ArcPolygonExample2 class ArcPolygonExample2(Scene): def construct(self): arc_conf = {"stroke_width": 3, "stroke_color": BLUE, "fill_opacity": 0.5, "color": GREEN} poly_conf = {"color": None} a = [-1, 0, 0] b = [1, 0, 0] c = [0, np.sqrt(3), 0] arc0 = ArcBetweenPoints(a, b, radius=2, **arc_conf) arc1 = ArcBetweenPoints(b, c, radius=2, **arc_conf) arc2 = ArcBetweenPoints(c, a, radius=2, stroke_color=RED) reuleaux_tri = ArcPolygonFromArcs(arc0, arc1, arc2, **poly_conf) self.wait(2) """ def __init__(self, *arcs, **kwargs): if not all(isinstance(m, (Arc, ArcBetweenPoints)) for m in arcs): raise ValueError( "All ArcPolygon submobjects must be of type Arc/ArcBetweenPoints", ) super().__init__(**kwargs) # Adding the arcs like this makes ArcPolygonFromArcs double as a VGroup. # Also makes changes to the ArcPolygonFromArcs, such as scaling, affect # the arcs, so that their new values are usable. self.add(*arcs) # This enables the use of ArcPolygonFromArcs.arcs as a convenience # because ArcPolygonFromArcs[0] returns itself, not the first Arc. self.arcs = [*arcs] for arc1, arc2 in adjacent_pairs(arcs): self.append_points(arc1.points) line = Line(arc1.get_end(), arc2.get_start()) len_ratio = line.get_length() / arc1.get_arc_length() if math.isnan(len_ratio) or math.isinf(len_ratio): continue line.insert_n_curves(int(arc1.get_num_curves() * len_ratio)) self.append_points(line.points)
[docs]class Triangle(RegularPolygon): """An equilateral triangle. Parameters ---------- kwargs : Any Additional arguments to be passed to :class:`RegularPolygon` Examples -------- .. manim:: TriangleExample :save_last_frame: class TriangleExample(Scene): def construct(self): triangle_1 = Triangle() triangle_2 = Triangle().scale(2).rotate(60*DEGREES) tri_group = Group(triangle_1, triangle_2).arrange(buff=1) self.add(tri_group) """ def __init__(self, **kwargs): super().__init__(n=3, **kwargs)
[docs]class Rectangle(Polygon): """A quadrilateral with two sets of parallel sides. Parameters ---------- color : :class:`~.Colors`, optional The color of the rectangle. height : :class:`float`, optional The vertical height of the rectangle. width : :class:`float`, optional The horizontal width of the rectangle. grid_xstep : :class:`float`, optional Space between vertical grid lines. grid_ystep : :class:`float`, optional Space between horizontal grid lines. mark_paths_closed : :class:`bool`, optional No purpose. close_new_points : :class:`bool`, optional No purpose. kwargs : Any Additional arguments to be passed to :class:`Polygon` Examples ---------- .. manim:: RectangleExample :save_last_frame: class RectangleExample(Scene): def construct(self): rect1 = Rectangle(width=4.0, height=2.0, grid_xstep=1.0, grid_ystep=0.5) rect2 = Rectangle(width=1.0, height=4.0) rects = Group(rect1,rect2).arrange(buff=1) self.add(rects) """ def __init__( self, color: Color = WHITE, height: float = 2.0, width: float = 4.0, grid_xstep: Optional[float] = None, grid_ystep: Optional[float] = None, mark_paths_closed=True, close_new_points=True, **kwargs, ): super().__init__(UR, UL, DL, DR, color=color, **kwargs) self.stretch_to_fit_width(width) self.stretch_to_fit_height(height) v = self.get_vertices() if grid_xstep is not None: grid_xstep = abs(grid_xstep) count = int(width / grid_xstep) grid = VGroup( *( Line( v[1] + i * grid_xstep * RIGHT, v[1] + i * grid_xstep * RIGHT + height * DOWN, color=color, ) for i in range(1, count) ) ) self.add(grid) if grid_ystep is not None: grid_ystep = abs(grid_ystep) count = int(height / grid_ystep) grid = VGroup( *( Line( v[1] + i * grid_ystep * DOWN, v[1] + i * grid_ystep * DOWN + width * RIGHT, color=color, ) for i in range(1, count) ) ) self.add(grid)
[docs]class Square(Rectangle): """A rectangle with equal side lengths. Parameters ---------- side_length : :class:`float`, optional The length of the sides of the square. kwargs : Any Additional arguments to be passed to :class:`Square` Examples -------- .. manim:: SquareExample :save_last_frame: class SquareExample(Scene): def construct(self): square_1 = Square(side_length=2.0).shift(DOWN) square_2 = Square(side_length=1.0).next_to(square_1, direction=UP) square_3 = Square(side_length=0.5).next_to(square_2, direction=UP) self.add(square_1, square_2, square_3) """ def __init__(self, side_length=2.0, **kwargs): self.side_length = side_length super().__init__(height=side_length, width=side_length, **kwargs)
[docs]class RoundedRectangle(Rectangle): """A rectangle with rounded corners. Parameters ---------- corner_radius : :class:`float`, optional The curvature of the corners of the rectangle. kwargs : Any Additional arguments to be passed to :class:`Rectangle` Examples -------- .. manim:: RoundedRectangleExample :save_last_frame: class RoundedRectangleExample(Scene): def construct(self): rect_1 = RoundedRectangle(corner_radius=0.5) rect_2 = RoundedRectangle(corner_radius=1.5, height=4.0, width=4.0) rect_group = Group(rect_1, rect_2).arrange(buff=1) self.add(rect_group) """ def __init__(self, corner_radius=0.5, **kwargs): self.corner_radius = corner_radius super().__init__(**kwargs) self.round_corners(self.corner_radius)
[docs]class ArrowTip(VMobject, metaclass=ConvertToOpenGL): r"""Base class for arrow tips. See Also -------- :class:`ArrowTriangleTip` :class:`ArrowTriangleFilledTip` :class:`ArrowCircleTip` :class:`ArrowCircleFilledTip` :class:`ArrowSquareTip` :class:`ArrowSquareFilledTip` Examples -------- Cannot be used directly, only intended for inheritance:: >>> tip = ArrowTip() Traceback (most recent call last): ... NotImplementedError: Has to be implemented in inheriting subclasses. Instead, use one of the pre-defined ones, or make a custom one like this: .. manim:: CustomTipExample >>> class MyCustomArrowTip(ArrowTip, RegularPolygon): ... def __init__(self, length=0.35, **kwargs): ... RegularPolygon.__init__(self, n=5, **kwargs) ... self.width = length ... self.stretch_to_fit_height(length) >>> arr = Arrow(np.array([-2, -2, 0]), np.array([2, 2, 0]), ... tip_shape=MyCustomArrowTip) >>> isinstance(arr.tip, RegularPolygon) True >>> from manim import Scene >>> class CustomTipExample(Scene): ... def construct(self): ... Using a class inherited from :class:`ArrowTip` to get a non-filled tip is a shorthand to manually specifying the arrow tip style as follows:: >>> arrow = Arrow(np.array([0, 0, 0]), np.array([1, 1, 0]), ... tip_style={'fill_opacity': 0, 'stroke_width': 3}) The following example illustrates the usage of all of the predefined arrow tips. .. manim:: ArrowTipsShowcase :save_last_frame: from manim.mobject.geometry import ArrowTriangleTip, ArrowSquareTip, ArrowSquareFilledTip,\ ArrowCircleTip, ArrowCircleFilledTip class ArrowTipsShowcase(Scene): def construct(self): a00 = Arrow(start=[-2, 3, 0], end=[2, 3, 0], color=YELLOW) a11 = Arrow(start=[-2, 2, 0], end=[2, 2, 0], tip_shape=ArrowTriangleTip) a12 = Arrow(start=[-2, 1, 0], end=[2, 1, 0]) a21 = Arrow(start=[-2, 0, 0], end=[2, 0, 0], tip_shape=ArrowSquareTip) a22 = Arrow([-2, -1, 0], [2, -1, 0], tip_shape=ArrowSquareFilledTip) a31 = Arrow([-2, -2, 0], [2, -2, 0], tip_shape=ArrowCircleTip) a32 = Arrow([-2, -3, 0], [2, -3, 0], tip_shape=ArrowCircleFilledTip) b11 = a11.copy().scale(0.5, scale_tips=True).next_to(a11, RIGHT) b12 = a12.copy().scale(0.5, scale_tips=True).next_to(a12, RIGHT) b21 = a21.copy().scale(0.5, scale_tips=True).next_to(a21, RIGHT) self.add(a00, a11, a12, a21, a22, a31, a32, b11, b12, b21) """ def __init__(self, *args, **kwargs): raise NotImplementedError("Has to be implemented in inheriting subclasses.") @property def base(self): r"""The base point of the arrow tip. This is the point connecting to the arrow line. Examples -------- :: >>> arrow = Arrow(np.array([0, 0, 0]), np.array([2, 0, 0]), buff=0) >>> arrow.tip.base.round(2) + 0. # add 0. to avoid negative 0 in output array([1.65, 0. , 0. ]) """ return self.point_from_proportion(0.5) @property def tip_point(self): r"""The tip point of the arrow tip. Examples -------- :: >>> arrow = Arrow(np.array([0, 0, 0]), np.array([2, 0, 0]), buff=0) >>> arrow.tip.tip_point.round(2) + 0. array([2., 0., 0.]) """ return self.points[0] @property def vector(self): r"""The vector pointing from the base point to the tip point. Examples -------- :: >>> arrow = Arrow(np.array([0, 0, 0]), np.array([2, 2, 0]), buff=0) >>> arrow.tip.vector.round(2) + 0. array([0.25, 0.25, 0. ]) """ return self.tip_point - self.base @property def tip_angle(self): r"""The angle of the arrow tip. Examples -------- :: >>> arrow = Arrow(np.array([0, 0, 0]), np.array([1, 1, 0]), buff=0) >>> round(arrow.tip.tip_angle, 5) == round(PI/4, 5) True """ return angle_of_vector(self.vector) @property def length(self): r"""The length of the arrow tip. Examples -------- :: >>> arrow = Arrow(np.array([0, 0, 0]), np.array([1, 2, 0])) >>> round(arrow.tip.length, 3) 0.35 """ return np.linalg.norm(self.vector)
[docs]class ArrowTriangleTip(ArrowTip, Triangle): r"""Triangular arrow tip.""" def __init__( self, fill_opacity=0, stroke_width=3, length=DEFAULT_ARROW_TIP_LENGTH, start_angle=PI, **kwargs, ): Triangle.__init__( self, fill_opacity=fill_opacity, stroke_width=stroke_width, start_angle=start_angle, **kwargs, ) self.width = length self.stretch_to_fit_height(length)
[docs]class ArrowTriangleFilledTip(ArrowTriangleTip): r"""Triangular arrow tip with filled tip. This is the default arrow tip shape. """ def __init__(self, fill_opacity=1, stroke_width=0, **kwargs): super().__init__(fill_opacity=fill_opacity, stroke_width=stroke_width, **kwargs)
[docs]class ArrowCircleTip(ArrowTip, Circle): r"""Circular arrow tip.""" def __init__( self, fill_opacity=0, stroke_width=3, length=DEFAULT_ARROW_TIP_LENGTH, start_angle=PI, **kwargs, ): self.start_angle = start_angle Circle.__init__( self, fill_opacity=fill_opacity, stroke_width=stroke_width, **kwargs ) self.width = length self.stretch_to_fit_height(length)
[docs]class ArrowCircleFilledTip(ArrowCircleTip): r"""Circular arrow tip with filled tip.""" def __init__(self, fill_opacity=1, stroke_width=0, **kwargs): super().__init__(fill_opacity=fill_opacity, stroke_width=stroke_width, **kwargs)
[docs]class ArrowSquareTip(ArrowTip, Square): r"""Square arrow tip.""" def __init__( self, fill_opacity=0, stroke_width=3, length=DEFAULT_ARROW_TIP_LENGTH, start_angle=PI, **kwargs, ): self.start_angle = start_angle Square.__init__( self, fill_opacity=fill_opacity, stroke_width=stroke_width, side_length=length, **kwargs, ) self.width = length self.stretch_to_fit_height(length)
[docs]class ArrowSquareFilledTip(ArrowSquareTip): r"""Square arrow tip with filled tip.""" def __init__(self, fill_opacity=1, stroke_width=0, **kwargs): super().__init__(fill_opacity=fill_opacity, stroke_width=stroke_width, **kwargs)
[docs]class Cutout(VMobject, metaclass=ConvertToOpenGL): """A shape with smaller cutouts. .. warning:: Technically, this class behaves similar to a symmetric difference: if parts of the ``mobjects`` are not located within the ``main_shape``, these parts will be added to the resulting :class:`~.VMobject`. Parameters ---------- main_shape : :class:`~.VMobject` The primary shape from which cutouts are made. mobjects : :class:`~.VMobject` The smaller shapes which are to be cut out of the ``main_shape``. kwargs Further keyword arguments that are passed to the constructor of :class:`~.VMobject`. Examples -------- .. manim:: CutoutExample class CutoutExample(Scene): def construct(self): s1 = Square().scale(2.5) s2 = Triangle().shift(DOWN + RIGHT).scale(0.5) s3 = Square().shift(UP + RIGHT).scale(0.5) s4 = RegularPolygon(5).shift(DOWN + LEFT).scale(0.5) s5 = RegularPolygon(6).shift(UP + LEFT).scale(0.5) c = Cutout(s1, s2, s3, s4, s5, fill_opacity=1, color=BLUE, stroke_color=RED), run_time=4) self.wait() """ def __init__(self, main_shape, *mobjects, **kwargs): super().__init__(**kwargs) self.append_points(main_shape.points) if main_shape.get_direction() == "CW": sub_direction = "CCW" else: sub_direction = "CW" for mobject in mobjects: self.append_points(mobject.force_direction(sub_direction).points)
[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 : Sequence[:class:`int`] 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 : :class:`bool` 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 : :class:`float` The radius of the :class:`Dot`. If not specified otherwise, this radius will be 1/10 of the arc radius. dot_distance : :class:`float` Relative distance from the center to the arc: 0 puts the dot in the center and 1 on the arc itself. dot_color : :class:`~.Colors` The color of the :class:`Dot`. elbow : :class:`bool` 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=(1, 1), other_angle: bool = False, dot=False, dot_radius=None, dot_distance=0.55, dot_color=WHITE, elbow=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]class RightAngle(Angle): """An elbow-type mobject representing a right angle between two lines. Parameters ---------- line1 : :class:`Line` The first line. line2 : :class:`Line` The second line. length : :class:`float` 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, line2, length=None, **kwargs): super().__init__(line1, line2, radius=length, elbow=True, **kwargs)