/*! GetDevicePixelRatio | Author: Tyson Matanich, 2012 | License: MIT */ (function (window) { window.getDevicePixelRatio = function () { var ratio = 1; // To account for zoom, change to use deviceXDPI instead of systemXDPI if (window.screen.systemXDPI !== undefined && window.screen.logicalXDPI !== undefined && window.screen.systemXDPI > window.screen.logicalXDPI) { // Only allow for values > 1 ratio = window.screen.systemXDPI / window.screen.logicalXDPI; } else if (window.devicePixelRatio !== undefined) { ratio = window.devicePixelRatio; } return ratio; }; })(this);