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Factor out partial results from point_from_proportion

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This commit is contained in:
Grant Sanderson
2023-09-04 21:16:18 -07:00
parent 295a0f76cc
commit 39e5d24858
1 changed files with 23 additions and 11 deletions
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34
manimlib/mobject/types/vectorized_mobject.py
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@ -791,12 +791,14 @@ class VMobject(Mobject):
curve_func = self.get_nth_curve_function(n)
return curve_func(residue)
def point_from_proportion(self, alpha: float) -> Vect3:
if alpha <= 0:
return self.get_start()
elif alpha >= 1:
return self.get_end()
def curve_and_prop_of_partial_point(self, alpha) -> Tuple[int, float]:
"""
If you want a point a proportion alpha along the curve, this
gives you the index of the appropriate bezier curve, together
with the proportion along that curve you'd need to travel
"""
if alpha == 0:
return (0, 0.0)
partials: list[float] = [0]
for tup in self.get_bezier_tuples():
if self.consider_points_equal(tup[0], tup[1]):
@ -808,14 +810,24 @@ class VMobject(Mobject):
partials.append(partials[-1] + arclen)
full = partials[-1]
if full == 0:
return self.get_start()
return len(partials), 1.0
# First index where the partial length is more than alpha times the full length
i = next(
index = next(
(i for i, x in enumerate(partials) if x >= full * alpha),
len(partials) # Default
len(partials) - 1 # Default
)
residue = float(inverse_interpolate(partials[i - 1] / full, partials[i] / full, alpha))
return self.get_nth_curve_function(i - 1)(residue)
residue = float(inverse_interpolate(
partials[index - 1] / full, partials[index] / full, alpha
))
return index - 1, residue
def point_from_proportion(self, alpha: float) -> Vect3:
if alpha <= 0:
return self.get_start()
elif alpha >= 1:
return self.get_end()
index, residue = self.curve_and_prop_of_partial_point(alpha)
return self.get_nth_curve_function(index)(residue)
def get_anchors_and_handles(self) -> list[Vect3]:
"""