export default class Time { private static __currentProcessBeginTime = 0 ; private static __lastProcessEndTime = 0 ; private static __lastTickTimeInterval = 0 ; private static __systemStartTime = 0 ; private static _processBegin ( ) { if ( Time . __currentProcessBeginTime === 0 ) { Time . __systemStartTime = performance . now ( ) ; } Time . __currentProcessBeginTime = performance . now ( ) ; } private static _processEnd ( ) { Time . __lastProcessEndTime = performance . now ( ) ; Time . __lastTickTimeInterval = Time . __lastProcessEndTime - Time . __currentProcessBeginTime ; } static get timeFromSystemStart ( ) { return Time . __systemStartTime - performance . now ( ) / 1000 ; } static get lastTickTimeInterval ( ) { return Time . __lastTickTimeInterval / 1000 ; } }