import numpy as np


def points_to_waveform(amplitudes: np.ndarray, grad_raster_time: float, times: np.ndarray) -> np.ndarray:
    """
    1D interpolate amplitude values `amplitudes` at time indices `times` as per the gradient raster time
    `grad_raster_time` to generate a gradient waveform.

    Parameters
    ----------
    amplitudes : numpy.ndarray
        Amplitude values at time indices `times`.
    grad_raster_time : float
        Gradient raster time.
    times : numpy.ndarray
        Time indices.

    Returns
    -------
    waveform : numpy.ndarray
        Gradient waveform.
    """
    amplitudes = np.asarray(amplitudes)
    times = np.asarray(times)

    if amplitudes.size == 0:
        return np.array([0])

    grd = (
        np.arange(
            start=round(np.min(times) / grad_raster_time),
            stop=round(np.max(times) / grad_raster_time),
        )
        * grad_raster_time
    )
    waveform = np.interp(x=grd + grad_raster_time / 2, xp=times, fp=amplitudes)

    return waveform
