# Mapbox GL FPS

A frames-per-seconds measurer and GUI control

![Example of GUI FPS counter and report data](mapbox-gl-fps-screenshot.png "Screenshot of Map with FPS Control and report")

## Install 
```
npm install @sttlabs/mapbox-gl-fps@1.0.0
```

## Classes

- class `FPSMeasurer` - An non-dependent class for measuring FPS and calculating stats.
- class `FPSControl` - A MapBox GL GUI Control

## Example with GUI Control

```js
import { FPSControl } from "mapbox-gl-fps/lib/MapboxFPS.min";
var fpsControl = new FPSControl();
myMap.addControl(fpsControl, "top-right");

setTimeout(function () {
  var report = fpsControl.measurer.getMeasurementsReport();
  console.log("Report:", report);
}, 10000);
```

## Example with standalone class

```js
var fpsMeasurer = new MapboxFPS.FPSMeasurer();

fpsMeasurer.startMeasuring();

// Measure 'mock render frames' every 20 ms for 2 seconds
var interval = setInterval(() => {
  measurer.registerRenderFrame();
}, 20);

setTimeout(() => {
  // Stop the mock frame render interval
  clearInterval(interval);

  // Stop measuring
  fpsMeasurer.startMeasuring();

  // Generate report
  var report = measurer.getMeasurementsReport();
  console.log("Report: ", report);
}, 2000);
```

## Generate Report

```js
var fpsMeasurer = new MapboxFPS.FPSMeasurer();
var report = measurer.getMeasurementsReport();
```

returns an object:

```js
// generated report
{
  "measurements": [...], // Array of actual measurements done
  "median": Number,
  "average": Number,
  "variance": Number,
  "stdDev": Number
}
```