interpolate_( i1, t0, t, t1 ) {

		const result = this.resultBuffer,
			values = this.sampleValues,
			stride = this.valueSize,

			alpha = ( t - t0 ) / ( t1 - t0 );

		let offset = i1 * stride;

		for ( let end = offset + stride; offset !== end; offset += 4 ) {

			Quaternion.slerpFlat( result, 0, values, offset - stride, values, offset, alpha );

		}

		return result;

	}
Constructs a new SLERP interpolant.

@param {TypedArray} parameterPositions - The parameter positions hold the interpolation factors.
@param {TypedArray} sampleValues - The sample values.
@param {number} sampleSize - The sample size
@param {TypedArray} [resultBuffer] - The result buffer.