bracketedPixelRatio.js
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bracketedPixelRatio.js
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	/**
	* @module bracketedPixelRatio
	* @private
	*/

	/**
	* Normalizes a user's device pixel ratio to either 1, 1.5, or 2.
	*
	* This is important when the server resizes images on the fly in order to
	* reduce the work it has to do for device pixel ratios that deviate from a
	* set of common ratios.
	*
	* Adapted from mediawiki/core /resources/src/jquery/jquery.hidpi.js
	*
	* @param {number} [dpr=window.devicePixelRatio]
	* @return {number} The bracketed device pixel ratio
	*/
	export default function ( dpr = window.devicePixelRatio ) {
	if ( !dpr ) {
	// Probably legacy browser so assume 1
	return 1;
	}

	if ( dpr > 1.5 ) {
	return 2;
	}

	if ( dpr > 1 ) {
	return 1.5;
	}

	return 1;
	}