evaluate( t ) {

		const pp = this.parameterPositions;
		let i1 = this._cachedIndex,
			t1 = pp[ i1 ],
			t0 = pp[ i1 - 1 ];

		validate_interval: {

			seek: {

				let right;

				linear_scan: {

					//- See http://jsperf.com/comparison-to-undefined/3
					//- slower code:
					//-
					//- 				if ( t >= t1 || t1 === undefined ) {
					forward_scan: if ( ! ( t < t1 ) ) {

						for ( let giveUpAt = i1 + 2; ; ) {

							if ( t1 === undefined ) {

								if ( t < t0 ) break forward_scan;

								// after end

								i1 = pp.length;
								this._cachedIndex = i1;
								return this.copySampleValue_( i1 - 1 );

							}

							if ( i1 === giveUpAt ) break; // this loop

							t0 = t1;
							t1 = pp[ ++ i1 ];

							if ( t < t1 ) {

								// we have arrived at the sought interval
								break seek;

							}

						}

						// prepare binary search on the right side of the index
						right = pp.length;
						break linear_scan;

					}

					//- slower code:
					//-					if ( t < t0 || t0 === undefined ) {
					if ( ! ( t >= t0 ) ) {

						// looping?

						const t1global = pp[ 1 ];

						if ( t < t1global ) {

							i1 = 2; // + 1, using the scan for the details
							t0 = t1global;

						}

						// linear reverse scan

						for ( let giveUpAt = i1 - 2; ; ) {

							if ( t0 === undefined ) {

								// before start

								this._cachedIndex = 0;
								return this.copySampleValue_( 0 );

							}

							if ( i1 === giveUpAt ) break; // this loop

							t1 = t0;
							t0 = pp[ -- i1 - 1 ];

							if ( t >= t0 ) {

								// we have arrived at the sought interval
								break seek;

							}

						}

						// prepare binary search on the left side of the index
						right = i1;
						i1 = 0;
						break linear_scan;

					}

					// the interval is valid

					break validate_interval;

				} // linear scan

				// binary search

				while ( i1 < right ) {

					const mid = ( i1 + right ) >>> 1;

					if ( t < pp[ mid ] ) {

						right = mid;

					} else {

						i1 = mid + 1;

					}

				}

				t1 = pp[ i1 ];
				t0 = pp[ i1 - 1 ];

				// check boundary cases, again

				if ( t0 === undefined ) {

					this._cachedIndex = 0;
					return this.copySampleValue_( 0 );

				}

				if ( t1 === undefined ) {

					i1 = pp.length;
					this._cachedIndex = i1;
					return this.copySampleValue_( i1 - 1 );

				}

			} // seek

			this._cachedIndex = i1;

			this.intervalChanged_( i1, t0, t1 );

		} // validate_interval

		return this.interpolate_( i1, t0, t, t1 );

	}
Evaluate the interpolant at position `t`.

@param {number} t - The interpolation factor.
@return {TypedArray} The result buffer.