interaction listeners

/* Scroll Velocity */
document.addEventListener( 'wheel', ( e ) => {
    e.preventDefault()
    this.scrollTarget = e.deltaY / 3
} );

//render()
this.direction = this.scroll > 0 ? -1 : 1

this.scroll -=(this.scroll - this.scrollTarget)*0.1
this.scroll *= 0.9
this.thumbs.forEach( th => {
  th.position.x = this.calcPos(this.scroll, th.position.x)
})

/* Mouse Direction / Velocity (inside mousemove event) */
if ( this.lastMouseX === null || this.lastMouseY === null ) {
  this.lastMouseX = e.clientX;
  this.lastMouseY = e.clientY;
  return;
}

const dx = e.clientX - this.lastMouseX;
const dy = e.clientY - this.lastMouseY;
this.dMouse = new THREE.Vector2( dx, dy );
this.lastMouseX = e.clientX;
this.lastMouseY = e.clientY;