"""Mobject representing curly braces."""
from __future__ import annotations
__all__ = ["Brace", "BraceLabel", "ArcBrace", "BraceText", "BraceBetweenPoints"]
from typing import Sequence
import numpy as np
import svgelements as se
from manim._config import config
from manim.mobject.geometry.arc import Arc
from manim.mobject.geometry.line import Line
from manim.mobject.mobject import Mobject
from manim.mobject.opengl.opengl_compatibility import ConvertToOpenGL
from manim.mobject.text.tex_mobject import MathTex, Tex
from ...animation.composition import AnimationGroup
from ...animation.fading import FadeIn
from ...animation.growing import GrowFromCenter
from ...constants import *
from ...mobject.types.vectorized_mobject import VMobject
from ...utils.color import BLACK
from ..svg.svg_mobject import VMobjectFromSVGPath
[docs]class Brace(VMobjectFromSVGPath):
"""Takes a mobject and draws a brace adjacent to it.
Passing a direction vector determines the direction from which the
brace is drawn. By default it is drawn from below.
Parameters
----------
mobject
The mobject adjacent to which the brace is placed.
direction :
The direction from which the brace faces the mobject.
See Also
--------
:class:`BraceBetweenPoints`
Examples
--------
.. manim:: BraceExample
:save_last_frame:
class BraceExample(Scene):
def construct(self):
s = Square()
self.add(s)
for i in np.linspace(0.1,1.0,4):
br = Brace(s, sharpness=i)
t = Text(f"sharpness= {i}").next_to(br, RIGHT)
self.add(t)
self.add(br)
VGroup(*self.mobjects).arrange(DOWN, buff=0.2)
"""
def __init__(
self,
mobject: Mobject,
direction: Sequence[float] | None = DOWN,
buff=0.2,
sharpness=2,
stroke_width=0,
fill_opacity=1.0,
background_stroke_width=0,
background_stroke_color=BLACK,
**kwargs,
):
path_string_template = (
"m0.01216 0c-0.01152 0-0.01216 6.103e-4 -0.01216 0.01311v0.007762c0.06776 "
"0.122 0.1799 0.1455 0.2307 0.1455h{0}c0.03046 3.899e-4 0.07964 0.00449 "
"0.1246 0.02636 0.0537 0.02695 0.07418 0.05816 0.08648 0.07769 0.001562 "
"0.002538 0.004539 0.002563 0.01098 0.002563 0.006444-2e-8 0.009421-2.47e-"
"5 0.01098-0.002563 0.0123-0.01953 0.03278-0.05074 0.08648-0.07769 0.04491"
"-0.02187 0.09409-0.02597 0.1246-0.02636h{0}c0.05077 0 0.1629-0.02346 "
"0.2307-0.1455v-0.007762c-1.78e-6 -0.0125-6.365e-4 -0.01311-0.01216-0.0131"
"1-0.006444-3.919e-8 -0.009348 2.448e-5 -0.01091 0.002563-0.0123 0.01953-"
"0.03278 0.05074-0.08648 0.07769-0.04491 0.02187-0.09416 0.02597-0.1246 "
"0.02636h{1}c-0.04786 0-0.1502 0.02094-0.2185 0.1256-0.06833-0.1046-0.1706"
"-0.1256-0.2185-0.1256h{1}c-0.03046-3.899e-4 -0.07972-0.004491-0.1246-0.02"
"636-0.0537-0.02695-0.07418-0.05816-0.08648-0.07769-0.001562-0.002538-"
"0.004467-0.002563-0.01091-0.002563z"
)
default_min_width = 0.90552
self.buff = buff
angle = -np.arctan2(*direction[:2]) + np.pi
mobject.rotate(-angle, about_point=ORIGIN)
left = mobject.get_corner(DOWN + LEFT)
right = mobject.get_corner(DOWN + RIGHT)
target_width = right[0] - left[0]
linear_section_length = max(
0,
(target_width * sharpness - default_min_width) / 2,
)
path = se.Path(
path_string_template.format(
linear_section_length,
-linear_section_length,
)
)
super().__init__(
path_obj=path,
stroke_width=stroke_width,
fill_opacity=fill_opacity,
background_stroke_width=background_stroke_width,
background_stroke_color=background_stroke_color,
**kwargs,
)
self.flip(RIGHT)
self.stretch_to_fit_width(target_width)
self.shift(left - self.get_corner(UP + LEFT) + self.buff * DOWN)
for mob in mobject, self:
mob.rotate(angle, about_point=ORIGIN)
def put_at_tip(self, mob, use_next_to=True, **kwargs):
if use_next_to:
mob.next_to(self.get_tip(), np.round(self.get_direction()), **kwargs)
else:
mob.move_to(self.get_tip())
buff = kwargs.get("buff", DEFAULT_MOBJECT_TO_MOBJECT_BUFFER)
shift_distance = mob.width / 2.0 + buff
mob.shift(self.get_direction() * shift_distance)
return self
def get_text(self, *text, **kwargs):
text_mob = Tex(*text)
self.put_at_tip(text_mob, **kwargs)
return text_mob
def get_tex(self, *tex, **kwargs):
tex_mob = MathTex(*tex)
self.put_at_tip(tex_mob, **kwargs)
return tex_mob
def get_tip(self):
# Returns the position of the seventh point in the path, which is the tip.
if config["renderer"] == "opengl":
return self.points[34]
return self.points[28] # = 7*4
[docs] def get_direction(self):
vect = self.get_tip() - self.get_center()
return vect / np.linalg.norm(vect)
[docs]class BraceLabel(VMobject, metaclass=ConvertToOpenGL):
"""Create a brace with a label attached.
Parameters
----------
obj
The mobject adjacent to which the brace is placed.
text
The label text.
brace_direction
The direction of the brace. By default ``DOWN``.
label_constructor
A class or function used to construct a mobject representing
the label. By default :class:`~.MathTex`.
font_size
The font size of the label, passed to the ``label_constructor``.
buff
The buffer between the mobject and the brace.
brace_config
Arguments to be passed to :class:`.Brace`.
kwargs
Additional arguments to be passed to :class:`~.VMobject`.
"""
def __init__(
self,
obj: Mobject,
text: str,
brace_direction: np.ndarray = DOWN,
label_constructor: type = MathTex,
font_size: float = DEFAULT_FONT_SIZE,
buff: float = 0.2,
brace_config: dict | None = None,
**kwargs,
):
self.label_constructor = label_constructor
super().__init__(**kwargs)
self.brace_direction = brace_direction
if brace_config is None:
brace_config = {}
self.brace = Brace(obj, brace_direction, buff, **brace_config)
if isinstance(text, (tuple, list)):
self.label = self.label_constructor(font_size=font_size, *text, **kwargs)
else:
self.label = self.label_constructor(str(text), font_size=font_size)
self.brace.put_at_tip(self.label)
self.add(self.brace, self.label)
def creation_anim(self, label_anim=FadeIn, brace_anim=GrowFromCenter):
return AnimationGroup(brace_anim(self.brace), label_anim(self.label))
def shift_brace(self, obj, **kwargs):
if isinstance(obj, list):
obj = self.get_group_class()(*obj)
self.brace = Brace(obj, self.brace_direction, **kwargs)
self.brace.put_at_tip(self.label)
return self
def change_label(self, *text, **kwargs):
self.label = self.label_constructor(*text, **kwargs)
self.brace.put_at_tip(self.label)
return self
def change_brace_label(self, obj, *text, **kwargs):
self.shift_brace(obj)
self.change_label(*text, **kwargs)
return self
[docs]class BraceText(BraceLabel):
def __init__(self, obj, text, label_constructor=Tex, **kwargs):
super().__init__(obj, text, label_constructor=label_constructor, **kwargs)
[docs]class BraceBetweenPoints(Brace):
"""Similar to Brace, but instead of taking a mobject it uses 2
points to place the brace.
A fitting direction for the brace is
computed, but it still can be manually overridden.
If the points go from left to right, the brace is drawn from below.
Swapping the points places the brace on the opposite side.
Parameters
----------
point_1 :
The first point.
point_2 :
The second point.
direction :
The direction from which the brace faces towards the points.
Examples
--------
.. manim:: BraceBPExample
class BraceBPExample(Scene):
def construct(self):
p1 = [0,0,0]
p2 = [1,2,0]
brace = BraceBetweenPoints(p1,p2)
self.play(Create(NumberPlane()))
self.play(Create(brace))
self.wait(2)
"""
def __init__(
self,
point_1: Sequence[float] | None,
point_2: Sequence[float] | None,
direction: Sequence[float] | None = ORIGIN,
**kwargs,
):
if all(direction == ORIGIN):
line_vector = np.array(point_2) - np.array(point_1)
direction = np.array([line_vector[1], -line_vector[0], 0])
super().__init__(Line(point_1, point_2), direction=direction, **kwargs)
[docs]class ArcBrace(Brace):
"""Creates a :class:`~Brace` that wraps around an :class:`~.Arc`.
The direction parameter allows the brace to be applied
from outside or inside the arc.
.. warning::
The :class:`ArcBrace` is smaller for arcs with smaller radii.
.. note::
The :class:`ArcBrace` is initially a vertical :class:`Brace` defined by the
length of the :class:`~.Arc`, but is scaled down to match the start and end
angles. An exponential function is then applied after it is shifted based on
the radius of the arc.
The scaling effect is not applied for arcs with radii smaller than 1 to prevent
over-scaling.
Parameters
----------
arc
The :class:`~.Arc` that wraps around the :class:`Brace` mobject.
direction
The direction from which the brace faces the arc.
``LEFT`` for inside the arc, and ``RIGHT`` for the outside.
Example
-------
.. manim:: ArcBraceExample
:save_last_frame:
:ref_classes: Arc
class ArcBraceExample(Scene):
def construct(self):
arc_1 = Arc(radius=1.5,start_angle=0,angle=2*PI/3).set_color(RED)
brace_1 = ArcBrace(arc_1,LEFT)
group_1 = VGroup(arc_1,brace_1)
arc_2 = Arc(radius=3,start_angle=0,angle=5*PI/6).set_color(YELLOW)
brace_2 = ArcBrace(arc_2)
group_2 = VGroup(arc_2,brace_2)
arc_3 = Arc(radius=0.5,start_angle=-0,angle=PI).set_color(BLUE)
brace_3 = ArcBrace(arc_3)
group_3 = VGroup(arc_3,brace_3)
arc_4 = Arc(radius=0.2,start_angle=0,angle=3*PI/2).set_color(GREEN)
brace_4 = ArcBrace(arc_4)
group_4 = VGroup(arc_4,brace_4)
arc_group = VGroup(group_1, group_2, group_3, group_4).arrange_in_grid(buff=1.5)
self.add(arc_group.center())
"""
def __init__(
self,
arc: Arc | None = None,
direction: Sequence[float] = RIGHT,
**kwargs,
):
if arc is None:
arc = Arc(start_angle=-1, angle=2, radius=1)
arc_end_angle = arc.start_angle + arc.angle
line = Line(UP * arc.start_angle, UP * arc_end_angle)
scale_shift = RIGHT * np.log(arc.radius)
if arc.radius >= 1:
line.scale(arc.radius, about_point=ORIGIN)
super().__init__(line, direction=direction, **kwargs)
self.scale(1 / (arc.radius), about_point=ORIGIN)
else:
super().__init__(line, direction=direction, **kwargs)
if arc.radius >= 0.3:
self.shift(scale_shift)
else:
self.shift(RIGHT * np.log(0.3))
self.apply_complex_function(np.exp)
self.shift(arc.get_arc_center())
![[docs]](../../../../reference/manim.mobject.svg.brace.Brace.html#manim.mobject.svg.brace.Brace){kind=link}
![[docs]](../../../../reference/manim.mobject.svg.brace.Brace.html#manim.mobject.svg.brace.Brace.get_direction){kind=link}
![[docs]](../../../../reference/manim.mobject.svg.brace.BraceLabel.html#manim.mobject.svg.brace.BraceLabel){kind=link}
![[docs]](../../../../reference/manim.mobject.svg.brace.BraceText.html#manim.mobject.svg.brace.BraceText){kind=link}
![[docs]](../../../../reference/manim.mobject.svg.brace.BraceBetweenPoints.html#manim.mobject.svg.brace.BraceBetweenPoints){kind=link}
![[docs]](../../../../reference/manim.mobject.svg.brace.ArcBrace.html#manim.mobject.svg.brace.ArcBrace){kind=link}