3b1b-manim/manimlib/animation/creation.py
2019-02-08 16:53:37 -08:00

301 lines
8.1 KiB
Python

import numpy as np
from manimlib.animation.animation import Animation
from manimlib.animation.transform import Transform
from manimlib.animation.composition import Succession
from manimlib.constants import *
from manimlib.mobject.svg.tex_mobject import TextMobject
from manimlib.mobject.types.vectorized_mobject import VMobject
from manimlib.utils.bezier import interpolate
from manimlib.utils.config_ops import digest_config
from manimlib.utils.paths import counterclockwise_path
from manimlib.utils.rate_functions import double_smooth
from manimlib.utils.rate_functions import linear
from manimlib.utils.rate_functions import smooth
# Drawing
class ShowPartial(Animation):
"""
Abstract class for ShowCreation and ShowPassingFlash
"""
def interpolate_submobject(self, submob, start_submob, alpha):
submob.pointwise_become_partial(
start_submob, *self.get_bounds(alpha)
)
def get_bounds(self, alpha):
raise Exception("Not Implemented")
class ShowCreation(ShowPartial):
CONFIG = {
"lag_ratio": 1,
}
def get_bounds(self, alpha):
return (0, alpha)
class Uncreate(ShowCreation):
CONFIG = {
"rate_func": lambda t: smooth(1 - t),
"remover": True
}
class DrawBorderThenFill(Succession):
CONFIG = {
"run_time": 2,
"stroke_width": 2,
"stroke_color": None,
"draw_border_animation_config": {},
"fill_animation_config": {},
}
def __init__(self, vmobject, **kwargs):
self.check_validity_of_input(vmobject)
self.vmobject = vmobject
self.original_vmobject = vmobject.copy()
digest_config(self, kwargs)
Succession.__init__(
self,
self.get_draw_border_animation(vmobject),
self.get_fill_animation(vmobject),
**kwargs,
)
def check_validity_of_input(self, vmobject):
if not isinstance(vmobject, VMobject):
raise Exception("DrawBorderThenFill only works for VMobjects")
def get_draw_border_animation(self, vmobject):
vmobject.set_stroke(
color=self.get_stroke_color(vmobject),
width=self.stroke_width
)
vmobject.set_fill(opacity=0)
return ShowCreation(
vmobject,
**self.draw_border_animation_config
)
def get_stroke_color(self, vmobject):
if self.stroke_color:
return self.stroke_color
elif vmobject.get_stroke_width() > 0:
return vmobject.get_stroke_color()
return vmobject.get_color()
def get_fill_animation(self, vmobject):
return Transform(
vmobject,
self.original_vmobject,
**self.fill_animation_config,
)
def update_mobjects(self, dt):
super().update_mobjects(dt)
self.original_vmobject.update(dt)
class Write(DrawBorderThenFill):
CONFIG = {
"rate_func": linear,
"lag_ratio": 0.5,
}
def __init__(self, mob_or_text, **kwargs):
digest_config(self, kwargs)
if isinstance(mob_or_text, str):
mobject = TextMobject(mob_or_text)
else:
mobject = mob_or_text
if "run_time" not in kwargs:
self.establish_run_time(mobject)
if "lag_factor" not in kwargs:
if len(mobject.family_members_with_points()) < 4:
min_lag_factor = 1
else:
min_lag_factor = 2
self.lag_factor = max(self.run_time - 1, min_lag_factor)
DrawBorderThenFill.__init__(self, mobject, **kwargs)
def establish_run_time(self, mobject):
num_subs = len(mobject.family_members_with_points())
if num_subs < 15:
self.run_time = 1
else:
self.run_time = 2
class ShowIncreasingSubsets(Animation):
def __init__(self, group, **kwargs):
self.all_submobs = group.submobjects
Animation.__init__(self, group, **kwargs)
def interpolate_mobject(self, alpha):
n_submobs = len(self.all_submobs)
index = int(alpha * n_submobs)
self.mobject.submobjects = self.all_submobs[:index]
# Fading
class FadeOut(Transform):
CONFIG = {
"remover": True,
}
def __init__(self, mobject, **kwargs):
target = mobject.copy()
target.fade(1)
Transform.__init__(self, mobject, target, **kwargs)
def clean_up_from_scene(self, scene=None):
Transform.clean_up_from_scene(self, scene)
self.interpolate(0)
class FadeIn(Transform):
def __init__(self, mobject, **kwargs):
target = mobject.copy()
Transform.__init__(self, mobject, target, **kwargs)
self.starting_mobject.fade(1)
if isinstance(self.starting_mobject, VMobject):
self.starting_mobject.set_stroke(width=0)
self.starting_mobject.set_fill(opacity=0)
class FadeInAndShiftFromDirection(Transform):
CONFIG = {
"direction": DOWN,
}
def __init__(self, mobject, direction=None, **kwargs):
digest_config(self, kwargs)
target = mobject.copy()
if direction is None:
direction = self.direction
mobject.shift(direction)
mobject.fade(1)
Transform.__init__(self, mobject, target, **kwargs)
class FadeInFrom(FadeInAndShiftFromDirection):
"""
Alternate name for FadeInAndShiftFromDirection
"""
class FadeInFromDown(FadeInAndShiftFromDirection):
"""
Essential a more convenient form of FadeInAndShiftFromDirection
"""
CONFIG = {
"direction": DOWN,
}
class FadeOutAndShift(FadeOut):
CONFIG = {
"direction": DOWN,
}
def __init__(self, mobject, direction=None, **kwargs):
FadeOut.__init__(self, mobject, **kwargs)
if direction is None:
direction = self.direction
self.target_mobject.shift(direction)
class FadeOutAndShiftDown(FadeOutAndShift):
CONFIG = {
"direction": DOWN,
}
class FadeInFromLarge(Transform):
def __init__(self, mobject, scale_factor=2, **kwargs):
target = mobject.copy()
mobject.scale(scale_factor)
mobject.fade(1)
Transform.__init__(self, mobject, target, **kwargs)
class VFadeIn(Animation):
"""
VFadeIn and VFadeOut only work for VMobjects, but they can be applied
to mobjects while they are being animated in some other way (e.g. shifting
then) in a way that does not work with FadeIn and FadeOut
"""
def interpolate_submobject(self, submobject, starting_submobject, alpha):
submobject.set_stroke(
opacity=interpolate(0, starting_submobject.get_stroke_opacity(), alpha)
)
submobject.set_fill(
opacity=interpolate(0, starting_submobject.get_fill_opacity(), alpha)
)
class VFadeOut(VFadeIn):
CONFIG = {
"remover": True
}
def interpolate_submobject(self, submobject, starting_submobject, alpha):
VFadeIn.interpolate_submobject(
self, submobject, starting_submobject, 1 - alpha
)
# Growing
class GrowFromPoint(Transform):
CONFIG = {
"point_color": None,
}
def __init__(self, mobject, point, **kwargs):
digest_config(self, kwargs)
target = mobject.copy()
mobject.scale(0)
mobject.move_to(point)
if self.point_color:
mobject.set_color(self.point_color)
Transform.__init__(self, mobject, target, **kwargs)
class GrowFromCenter(GrowFromPoint):
def __init__(self, mobject, **kwargs):
GrowFromPoint.__init__(self, mobject, mobject.get_center(), **kwargs)
class GrowFromEdge(GrowFromPoint):
def __init__(self, mobject, edge, **kwargs):
GrowFromPoint.__init__(
self, mobject, mobject.get_critical_point(edge), **kwargs
)
class GrowArrow(GrowFromPoint):
def __init__(self, arrow, **kwargs):
GrowFromPoint.__init__(self, arrow, arrow.get_start(), **kwargs)
class SpinInFromNothing(GrowFromCenter):
CONFIG = {
"path_func": counterclockwise_path()
}
class ShrinkToCenter(Transform):
def __init__(self, mobject, **kwargs):
Transform.__init__(
self, mobject, mobject.get_point_mobject(), **kwargs
)