// interface FramePrepareCallback {
//     (frame: number, framesForWarmup: number,
//         framesPerRun: number, cycle: number): void;
// }
// interface RunsFinishedCallback {
//     (cycles: number, framesForWarmup: number,
//         framesPerRun: number, results: Array<number>): void;
// }


// export class Benchmark {

//     protected _running = false;

//     protected _results: Array<number> = new Array<number>();

//     protected _frames: number;

//     protected _runs: number;
//     protected _framesPerCycle: number;
//     protected _framesForWarmup: number;

//     protected _framePrepare: FramePrepareCallback | undefined = undefined;
//     protected _runsFinished: RunsFinishedCallback | undefined = undefined;


//     initialize(cycles: number, framesForWarmup: number, framesPerRun: number,
//         framePrepare: FramePrepareCallback, runsFinished: RunsFinishedCallback): void {

//         if (this._running) {
//             console.log('benchmark already in progress');
//             return;
//         }

//         this._framePrepare = framePrepare;
//         this._runsFinished = runsFinished;


//         this._running = true;

//         this._frames = 0;

//         this._runs = Math.max(0, cycles);
//         this._framesForWarmup = Math.max(0, framesForWarmup);
//         this._framesPerCycle = Math.max(1, framesPerRun);

//         this._results.length = this._runs;
//         this._results.fill(0.0);
//     }

//     frame(): void {

//         if (this._running === false) {
//             return;
//         }
//         ++this._frames;

//         const frames: number = this._frames - this._framesForWarmup;
//         const frame: number = frames < 0 ? frames : frames % this._framesPerCycle;

//         const cycle: number = frames >= 0 ? Math.floor(frames / this._framesPerCycle) : -1;

//         if (frames === 1 - this._framesForWarmup) {
//             console.log('---- benchmark warmup ------');
//         }
//         if (frames === 0) {
//             console.log('---- benchmark started -----');
//         }

//         if ((frames % this._framesPerCycle) === 0 && cycle > 0) {
//             this._results[cycle - 1] = (performance.now() - this._results[cycle - 1]) / this._framesPerCycle;
//             console.log(' --  cycle: ' + cycle.toString().padStart(2, '0') +
//                 ', fps: ' + this._results[cycle - 1].toFixed(4).padStart(9, '0'));
//         }

//         if ((frames % this._framesPerCycle) === 0 && cycle >= 0 && cycle < this._runs) {
//             this._results[cycle] = performance.now();
//         }


//         if (cycle >= this._runs) {

//             this._running = false;
//             console.log('---- benchmark stopped -----');

//             this._framePrepare = undefined;

//             this._runsFinished!(this._runs, this._framesForWarmup, this._framesPerCycle, this._results);
//             this._runsFinished = undefined;

//         } else {

//             this._framePrepare!(frame, this._framesForWarmup, this._framesPerCycle, cycle);

//         }
//     }

//     get running(): boolean {
//         return this._running;
//     }

// }