author yandeu
 *  description author alteredq / http://alteredqualia.com/
  /**
 * This is the Clock class THREE provides.
 */ class Clock { autoStart : boolean ; startTime : number ; oldTime : number ; elapsedTime : number ; running : boolean ; constructor ( autoStart = true ) { this . autoStart = autoStart !== undefined ? autoStart : true ; this . startTime = 0 ; this . oldTime = 0 ; this . elapsedTime = 0 ; this . running = false ; } start ( ) { this . startTime = ( typeof performance === 'undefined' ? Date : performance ) . now ( ) ; this . oldTime = this . startTime ; this . elapsedTime = 0 ; this . running = true ; } stop ( ) { this . getElapsedTime ( ) ; this . running = false ; this . autoStart = false ; } getElapsedTime ( ) { this . getDelta ( ) ; return this . elapsedTime ; } getDelta ( ) { let diff = 0 ; if ( this . autoStart && ! this . running ) { this . start ( ) ; return 0 ; } if ( this . running ) { const newTime = ( typeof performance === 'undefined' ? Date : performance ) . now ( ) ; diff = ( newTime - this . oldTime ) / 1000 ; this . oldTime = newTime ; this . elapsedTime += diff ; } return diff ; } } export { Clock } ;