rn-animated-star-rating-7.js

const changeOffset = React.useCallback((e: GestureResponderEvent) => {
  const { nativeEvent } = e;

  const distance = (screenWidth - animatedWidth.current) / 2; // view is centered
  const starSize = animatedWidth.current / 5; // 5 stars
  let starVal = Number((nativeEvent.pageX - distance) / starSize);
  const rest = starVal - Math.trunc(starVal);

  if (rest <= 0.5) {
    starVal = Math.trunc(starVal);
  } else {
    starVal = Math.trunc(starVal) + 0.5;
  }

  setOffset(starVal);
}, []);