function WebGLAnimation() { let context = null; let isAnimating = false; let animationLoop = null; let requestId = null; function onAnimationFrame( time, frame ) { animationLoop( time, frame ); requestId = context.requestAnimationFrame( onAnimationFrame ); } return { start: function () { if ( isAnimating === true ) return; if ( animationLoop === null ) return; requestId = context.requestAnimationFrame( onAnimationFrame ); isAnimating = true; }, stop: function () { context.cancelAnimationFrame( requestId ); isAnimating = false; }, setAnimationLoop: function ( callback ) { animationLoop = callback; }, setContext: function ( value ) { context = value; } }; } export { WebGLAnimation };