3b1b-manim/manimlib/mobject/coordinate_systems.py
Grant Sanderson 602809758e
Video work (#1739)
* Enable setting points to a null list, and adding one point at a time.

* Add refresh_locked_data

* Add presenter mode to scenes with -p option

* Allow for an embed by hitting e during interaction

* Add set_min_height, etc.

* Make sure null parametric curve has at least one point

* Account for edge case where \{ is used in Tex

* Allow for logging notes in wait calls, useful for presenter mode

* Simplify choose, and add gen_choose for fractional amounts

* Default to no top on axes

* Allow match_x, match_y, etc. to take in a point

* Allow wait calls to ignore presenter mode

* Just use math.combo, no caching with choose(n, r)

* Use generator instead of list in bezier

* Bubble init_colors should override

* Account for "px" values read in from an svg

* Stop displaying when writing is happening

* Update the way Bubble override SVG colors
2022-02-13 15:16:16 -08:00

548 lines
18 KiB
Python

from abc import abstractmethod
import numpy as np
import numbers
from manimlib.constants import *
from manimlib.mobject.functions import ParametricCurve
from manimlib.mobject.geometry import Arrow
from manimlib.mobject.geometry import Line
from manimlib.mobject.geometry import DashedLine
from manimlib.mobject.geometry import Rectangle
from manimlib.mobject.number_line import NumberLine
from manimlib.mobject.svg.tex_mobject import Tex
from manimlib.mobject.types.vectorized_mobject import VGroup
from manimlib.utils.config_ops import digest_config
from manimlib.utils.config_ops import merge_dicts_recursively
from manimlib.utils.simple_functions import binary_search
from manimlib.utils.space_ops import angle_of_vector
from manimlib.utils.space_ops import get_norm
from manimlib.utils.space_ops import rotate_vector
EPSILON = 1e-8
class CoordinateSystem():
"""
Abstract class for Axes and NumberPlane
"""
CONFIG = {
"dimension": 2,
"default_x_range": [-8.0, 8.0, 1.0],
"default_y_range": [-4.0, 4.0, 1.0],
"width": FRAME_WIDTH,
"height": FRAME_HEIGHT,
"num_sampled_graph_points_per_tick": 20,
}
def __init__(self, **kwargs):
digest_config(self, kwargs)
self.x_range = np.array(self.default_x_range)
self.y_range = np.array(self.default_y_range)
def coords_to_point(self, *coords):
raise Exception("Not implemented")
def point_to_coords(self, point):
raise Exception("Not implemented")
def c2p(self, *coords):
"""Abbreviation for coords_to_point"""
return self.coords_to_point(*coords)
def p2c(self, point):
"""Abbreviation for point_to_coords"""
return self.point_to_coords(point)
def get_origin(self):
return self.c2p(*[0] * self.dimension)
@abstractmethod
def get_axes(self):
raise Exception("Not implemented")
@abstractmethod
def get_all_ranges(self):
raise Exception("Not implemented")
def get_axis(self, index):
return self.get_axes()[index]
def get_x_axis(self):
return self.get_axis(0)
def get_y_axis(self):
return self.get_axis(1)
def get_z_axis(self):
return self.get_axis(2)
def get_x_axis_label(self, label_tex, edge=RIGHT, direction=DL, **kwargs):
return self.get_axis_label(
label_tex, self.get_x_axis(),
edge, direction, **kwargs
)
def get_y_axis_label(self, label_tex, edge=UP, direction=DR, **kwargs):
return self.get_axis_label(
label_tex, self.get_y_axis(),
edge, direction, **kwargs
)
def get_axis_label(self, label_tex, axis, edge, direction, buff=MED_SMALL_BUFF):
label = Tex(label_tex)
label.next_to(
axis.get_edge_center(edge), direction,
buff=buff
)
label.shift_onto_screen(buff=MED_SMALL_BUFF)
return label
def get_axis_labels(self, x_label_tex="x", y_label_tex="y"):
self.axis_labels = VGroup(
self.get_x_axis_label(x_label_tex),
self.get_y_axis_label(y_label_tex),
)
return self.axis_labels
def get_line_from_axis_to_point(self, index, point,
line_func=DashedLine,
color=GREY_A,
stroke_width=2):
axis = self.get_axis(index)
line = line_func(axis.get_projection(point), point)
line.set_stroke(color, stroke_width)
return line
def get_v_line(self, point, **kwargs):
return self.get_line_from_axis_to_point(0, point, **kwargs)
def get_h_line(self, point, **kwargs):
return self.get_line_from_axis_to_point(1, point, **kwargs)
# Useful for graphing
def get_graph(self, function, x_range=None, **kwargs):
t_range = np.array(self.x_range, dtype=float)
if x_range is not None:
t_range[:len(x_range)] = x_range
# For axes, the third coordinate of x_range indicates
# tick frequency. But for functions, it indicates a
# sample frequency
if x_range is None or len(x_range) < 3:
t_range[2] /= self.num_sampled_graph_points_per_tick
graph = ParametricCurve(
lambda t: self.c2p(t, function(t)),
t_range=t_range,
**kwargs
)
graph.underlying_function = function
graph.x_range = x_range
return graph
def get_parametric_curve(self, function, **kwargs):
dim = self.dimension
graph = ParametricCurve(
lambda t: self.coords_to_point(*function(t)[:dim]),
**kwargs
)
graph.underlying_function = function
return graph
def input_to_graph_point(self, x, graph):
if hasattr(graph, "underlying_function"):
return self.coords_to_point(x, graph.underlying_function(x))
else:
alpha = binary_search(
function=lambda a: self.point_to_coords(
graph.quick_point_from_proportion(a)
)[0],
target=x,
lower_bound=self.x_range[0],
upper_bound=self.x_range[1],
)
if alpha is not None:
return graph.quick_point_from_proportion(alpha)
else:
return None
def i2gp(self, x, graph):
"""
Alias for input_to_graph_point
"""
return self.input_to_graph_point(x, graph)
def get_graph_label(self,
graph,
label="f(x)",
x=None,
direction=RIGHT,
buff=MED_SMALL_BUFF,
color=None):
if isinstance(label, str):
label = Tex(label)
if color is None:
label.match_color(graph)
if x is None:
# Searching from the right, find a point
# whose y value is in bounds
max_y = FRAME_Y_RADIUS - label.get_height()
max_x = FRAME_X_RADIUS - label.get_width()
for x0 in np.arange(*self.x_range)[::-1]:
pt = self.i2gp(x0, graph)
if abs(pt[0]) < max_x and abs(pt[1]) < max_y:
x = x0
break
if x is None:
x = self.x_range[1]
point = self.input_to_graph_point(x, graph)
angle = self.angle_of_tangent(x, graph)
normal = rotate_vector(RIGHT, angle + 90 * DEGREES)
if normal[1] < 0:
normal *= -1
label.next_to(point, normal, buff=buff)
label.shift_onto_screen()
return label
def get_v_line_to_graph(self, x, graph, **kwargs):
return self.get_v_line(self.i2gp(x, graph), **kwargs)
def get_h_line_to_graph(self, x, graph, **kwargs):
return self.get_h_line(self.i2gp(x, graph), **kwargs)
# For calculus
def angle_of_tangent(self, x, graph, dx=EPSILON):
p0 = self.input_to_graph_point(x, graph)
p1 = self.input_to_graph_point(x + dx, graph)
return angle_of_vector(p1 - p0)
def slope_of_tangent(self, x, graph, **kwargs):
return np.tan(self.angle_of_tangent(x, graph, **kwargs))
def get_tangent_line(self, x, graph, length=5, line_func=Line):
line = line_func(LEFT, RIGHT)
line.set_width(length)
line.rotate(self.angle_of_tangent(x, graph))
line.move_to(self.input_to_graph_point(x, graph))
return line
def get_riemann_rectangles(self,
graph,
x_range=None,
dx=None,
input_sample_type="left",
stroke_width=1,
stroke_color=BLACK,
fill_opacity=1,
colors=(BLUE, GREEN),
show_signed_area=True):
if x_range is None:
x_range = self.x_range[:2]
if dx is None:
dx = self.x_range[2]
if len(x_range) < 3:
x_range = [*x_range, dx]
rects = []
xs = np.arange(*x_range)
for x0, x1 in zip(xs, xs[1:]):
if input_sample_type == "left":
sample = x0
elif input_sample_type == "right":
sample = x1
elif input_sample_type == "center":
sample = 0.5 * x0 + 0.5 * x1
else:
raise Exception("Invalid input sample type")
height = get_norm(
self.i2gp(sample, graph) - self.c2p(sample, 0)
)
rect = Rectangle(width=x1 - x0, height=height)
rect.move_to(self.c2p(x0, 0), DL)
rects.append(rect)
result = VGroup(*rects)
result.set_submobject_colors_by_gradient(*colors)
result.set_style(
stroke_width=stroke_width,
stroke_color=stroke_color,
fill_opacity=fill_opacity,
)
return result
def get_area_under_graph(self, graph, x_range, fill_color=BLUE, fill_opacity=1):
# TODO
pass
class Axes(VGroup, CoordinateSystem):
CONFIG = {
"axis_config": {
"include_tip": False,
"numbers_to_exclude": [0],
},
"x_axis_config": {},
"y_axis_config": {
"line_to_number_direction": LEFT,
},
"height": FRAME_HEIGHT - 2,
"width": FRAME_WIDTH - 2,
}
def __init__(self,
x_range=None,
y_range=None,
**kwargs):
CoordinateSystem.__init__(self, **kwargs)
VGroup.__init__(self, **kwargs)
if x_range is not None:
self.x_range[:len(x_range)] = x_range
if y_range is not None:
self.y_range[:len(y_range)] = y_range
self.x_axis = self.create_axis(
self.x_range, self.x_axis_config, self.width,
)
self.y_axis = self.create_axis(
self.y_range, self.y_axis_config, self.height
)
self.y_axis.rotate(90 * DEGREES, about_point=ORIGIN)
# Add as a separate group in case various other
# mobjects are added to self, as for example in
# NumberPlane below
self.axes = VGroup(self.x_axis, self.y_axis)
self.add(*self.axes)
self.center()
def create_axis(self, range_terms, axis_config, length):
new_config = merge_dicts_recursively(self.axis_config, axis_config)
new_config["width"] = length
axis = NumberLine(range_terms, **new_config)
axis.shift(-axis.n2p(0))
return axis
def coords_to_point(self, *coords):
origin = self.x_axis.number_to_point(0)
result = origin.copy()
for axis, coord in zip(self.get_axes(), coords):
result += (axis.number_to_point(coord) - origin)
return result
def point_to_coords(self, point):
return tuple([
axis.point_to_number(point)
for axis in self.get_axes()
])
def get_axes(self):
return self.axes
def get_all_ranges(self):
return [self.x_range, self.y_range]
def add_coordinate_labels(self,
x_values=None,
y_values=None,
**kwargs):
axes = self.get_axes()
self.coordinate_labels = VGroup()
for axis, values in zip(axes, [x_values, y_values]):
labels = axis.add_numbers(values, **kwargs)
self.coordinate_labels.add(labels)
return self.coordinate_labels
class ThreeDAxes(Axes):
CONFIG = {
"dimension": 3,
"x_range": np.array([-6.0, 6.0, 1.0]),
"y_range": np.array([-5.0, 5.0, 1.0]),
"z_range": np.array([-4.0, 4.0, 1.0]),
"z_axis_config": {},
"z_normal": DOWN,
"height": None,
"width": None,
"depth": None,
"num_axis_pieces": 20,
"gloss": 0.5,
}
def __init__(self, x_range=None, y_range=None, z_range=None, **kwargs):
Axes.__init__(self, x_range, y_range, **kwargs)
if z_range is not None:
self.z_range[:len(z_range)] = z_range
z_axis = self.create_axis(
self.z_range,
self.z_axis_config,
self.depth,
)
z_axis.rotate(-PI / 2, UP, about_point=ORIGIN)
z_axis.rotate(
angle_of_vector(self.z_normal), OUT,
about_point=ORIGIN
)
z_axis.shift(self.x_axis.n2p(0))
self.axes.add(z_axis)
self.add(z_axis)
self.z_axis = z_axis
for axis in self.axes:
axis.insert_n_curves(self.num_axis_pieces - 1)
def get_all_ranges(self):
return [self.x_range, self.y_range, self.z_range]
class NumberPlane(Axes):
CONFIG = {
"axis_config": {
"stroke_color": WHITE,
"stroke_width": 2,
"include_ticks": False,
"include_tip": False,
"line_to_number_buff": SMALL_BUFF,
"line_to_number_direction": DL,
},
"y_axis_config": {
"line_to_number_direction": DL,
},
"background_line_style": {
"stroke_color": BLUE_D,
"stroke_width": 2,
"stroke_opacity": 1,
},
"height": None,
"width": None,
# Defaults to a faded version of line_config
"faded_line_style": None,
"faded_line_ratio": 4,
"make_smooth_after_applying_functions": True,
}
def __init__(self, x_range=None, y_range=None, **kwargs):
super().__init__(x_range, y_range, **kwargs)
self.init_background_lines()
def init_background_lines(self):
if self.faded_line_style is None:
style = dict(self.background_line_style)
# For anything numerical, like stroke_width
# and stroke_opacity, chop it in half
for key in style:
if isinstance(style[key], numbers.Number):
style[key] *= 0.5
self.faded_line_style = style
self.background_lines, self.faded_lines = self.get_lines()
self.background_lines.set_style(**self.background_line_style)
self.faded_lines.set_style(**self.faded_line_style)
self.add_to_back(
self.faded_lines,
self.background_lines,
)
def get_lines(self):
x_axis = self.get_x_axis()
y_axis = self.get_y_axis()
x_lines1, x_lines2 = self.get_lines_parallel_to_axis(x_axis, y_axis)
y_lines1, y_lines2 = self.get_lines_parallel_to_axis(y_axis, x_axis)
lines1 = VGroup(*x_lines1, *y_lines1)
lines2 = VGroup(*x_lines2, *y_lines2)
return lines1, lines2
def get_lines_parallel_to_axis(self, axis1, axis2):
freq = axis2.x_step
ratio = self.faded_line_ratio
line = Line(axis1.get_start(), axis1.get_end())
dense_freq = (1 + ratio)
step = (1 / dense_freq) * freq
lines1 = VGroup()
lines2 = VGroup()
inputs = np.arange(axis2.x_min, axis2.x_max + step, step)
for i, x in enumerate(inputs):
new_line = line.copy()
new_line.shift(axis2.n2p(x) - axis2.n2p(0))
if i % (1 + ratio) == 0:
lines1.add(new_line)
else:
lines2.add(new_line)
return lines1, lines2
def get_x_unit_size(self):
return self.get_x_axis().get_unit_size()
def get_y_unit_size(self):
return self.get_x_axis().get_unit_size()
def get_axes(self):
return self.axes
def get_vector(self, coords, **kwargs):
kwargs["buff"] = 0
return Arrow(self.c2p(0, 0), self.c2p(*coords), **kwargs)
def prepare_for_nonlinear_transform(self, num_inserted_curves=50):
for mob in self.family_members_with_points():
num_curves = mob.get_num_curves()
if num_inserted_curves > num_curves:
mob.insert_n_curves(num_inserted_curves - num_curves)
mob.make_smooth_after_applying_functions = True
return self
class ComplexPlane(NumberPlane):
CONFIG = {
"color": BLUE,
"line_frequency": 1,
}
def number_to_point(self, number):
number = complex(number)
return self.coords_to_point(number.real, number.imag)
def n2p(self, number):
return self.number_to_point(number)
def point_to_number(self, point):
x, y = self.point_to_coords(point)
return complex(x, y)
def p2n(self, point):
return self.point_to_number(point)
def get_default_coordinate_values(self, skip_first=True):
x_numbers = self.get_x_axis().get_tick_range()[1:]
y_numbers = self.get_y_axis().get_tick_range()[1:]
y_numbers = [complex(0, y) for y in y_numbers if y != 0]
return [*x_numbers, *y_numbers]
def add_coordinate_labels(self, numbers=None, skip_first=True, **kwargs):
if numbers is None:
numbers = self.get_default_coordinate_values(skip_first)
self.coordinate_labels = VGroup()
for number in numbers:
z = complex(number)
if abs(z.imag) > abs(z.real):
axis = self.get_y_axis()
value = z.imag
kwargs["unit"] = "i"
else:
axis = self.get_x_axis()
value = z.real
number_mob = axis.get_number_mobject(value, **kwargs)
# For i and -i, remove the "1"
if z.imag == 1:
number_mob.remove(number_mob[0])
if z.imag == -1:
number_mob.remove(number_mob[1])
number_mob[0].next_to(
number_mob[1], LEFT,
buff=number_mob[0].get_width() / 4
)
self.coordinate_labels.add(number_mob)
self.add(self.coordinate_labels)
return self