bipolaroidbipolaroid/editor/utils/interpolate.py

35 lines
1,004 B
Python

import numpy as np
from scipy.interpolate import CubicSpline
from typing import List, Literal
INTERPOLATION_TYPE = Literal["cubic", "linear"]
def interpolate(
control_points: List[float], t: float, type: INTERPOLATION_TYPE
) -> float:
control_points = sorted(control_points)
if type == "cubic":
x = np.linspace(0, 1, len(control_points))
cs = CubicSpline(x, control_points)
return cs(t)
if type == "linear":
n = len(control_points) - 1
segment_indices = np.linspace(0, 1, n + 1)
index = np.searchsorted(segment_indices, t, side="right") - 1
if t == 1:
return control_points[-1]
else:
t_normalized = (t - segment_indices[index]) / (
segment_indices[index + 1] - segment_indices[index]
)
return control_points[index] + t_normalized * (
control_points[index + 1] - control_points[index]
)
raise ValueError("Invalid type")