interpolate_( /* i1, t0, t, t1 */ ) {

		throw new Error( 'call to abstract method' );
		// implementations shall return this.resultBuffer

	}
Copies a sample value to the result buffer.

@abstract
@param {number} i1 - An index into the sample value buffer.
@param {number} t0 - The previous interpolation factor.
@param {number} t - The current interpolation factor.
@param {number} t1 - The next interpolation factor.
@return {TypedArray} The result buffer.