r"""A collection of tip mobjects for use with :class:`~.TipableVMobject`."""
from __future__ import annotations
__all__ = [
"ArrowTip",
"ArrowCircleFilledTip",
"ArrowCircleTip",
"ArrowSquareTip",
"ArrowSquareFilledTip",
"ArrowTriangleTip",
"ArrowTriangleFilledTip",
"StealthTip",
]
import numpy as np
from manim.constants import *
from manim.mobject.geometry.arc import Circle
from manim.mobject.geometry.polygram import Square, Triangle
from manim.mobject.opengl.opengl_compatibility import ConvertToOpenGL
from manim.mobject.types.vectorized_mobject import VMobject
from manim.utils.space_ops import angle_of_vector
[docs]class ArrowTip(VMobject, metaclass=ConvertToOpenGL):
r"""Base class for arrow tips.
.. seealso::
:class:`ArrowTriangleTip`
:class:`ArrowTriangleFilledTip`
:class:`ArrowCircleTip`
:class:`ArrowCircleFilledTip`
:class:`ArrowSquareTip`
:class:`ArrowSquareFilledTip`
:class:`StealthTip`
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
>>> from manim import RegularPolygon, Arrow
>>> 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, Create
>>> class CustomTipExample(Scene):
... def construct(self):
... self.play(Create(arr))
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.tips 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
--------
::
>>> from manim import Arrow
>>> 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
--------
::
>>> from manim import Arrow
>>> 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
--------
::
>>> from manim import Arrow
>>> 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
--------
::
>>> from manim import Arrow
>>> 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
--------
::
>>> from manim import Arrow
>>> 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 StealthTip(ArrowTip):
r"""'Stealth' fighter / kite arrow shape.
Naming is inspired by the corresponding
`TikZ arrow shape <https://tikz.dev/tikz-arrows#sec-16.3>`__.
"""
def __init__(
self,
fill_opacity=1,
stroke_width=3,
length=DEFAULT_ARROW_TIP_LENGTH / 2,
start_angle=PI,
**kwargs,
):
self.start_angle = start_angle
VMobject.__init__(
self, fill_opacity=fill_opacity, stroke_width=stroke_width, **kwargs
)
self.set_points_as_corners(
[
[2, 0, 0], # tip
[-1.2, 1.6, 0],
[0, 0, 0], # base
[-1.2, -1.6, 0],
[2, 0, 0], # close path, back to tip
]
)
self.scale(length / self.length)
@property
def length(self):
"""The length of the arrow tip.
In this case, the length is computed as the height of
the triangle encompassing the stealth tip (otherwise,
the tip is scaled too large).
"""
return np.linalg.norm(self.vector) * 1.6
[docs]class ArrowTriangleTip(ArrowTip, Triangle):
r"""Triangular arrow tip."""
def __init__(
self,
fill_opacity=0,
stroke_width=3,
length=DEFAULT_ARROW_TIP_LENGTH,
width=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 = width
self.stretch_to_fit_width(length)
self.stretch_to_fit_height(width)
[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)