var scaleBy = 2;
            stage.on('wheel', e => {
                e.evt.preventDefault();
                var oldScale = stage.scaleX();

                var mousePointTo = {
                    x: stage.getPointerPosition().x / oldScale - stage.x() / oldScale,
                    y: stage.getPointerPosition().y / oldScale - stage.y() / oldScale
                };

                var newScale =
                    e.evt.deltaY > 0 ? oldScale * scaleBy : oldScale / scaleBy;
                stage.scale({ x: newScale, y: newScale });

                var newPos = {
                    x: -(mousePointTo.x - stage.getPointerPosition().x / newScale) * newScale,
                    y: -(mousePointTo.y - stage.getPointerPosition().y / newScale) * newScale
                };

                stage.position(newPos);
                stage.batchDraw();
            });