滚动方向

Question

尝试使div用鼠标滚动从右上角到左下角向相反的滚动方向移动。

现在它从左下角到右上角

#block {
position: absolute;
top: 400px;
left: 100px;



<script>
$(function(){
    var lastScrollYPos = 0;
    $(window).on('scroll', function(){
        var $this = $(this),
            $block = $('#block'),
            // retrieves the top and left coordinates
            position = $block.offset(),
            // X and Y factors allows to change the diagonal movement direction and
            // degree. Negative values inverts the direction.
            factorX = 1,
            factorY = 1,
            // retrieves current vertical scrolling position and calculate the
            // relative offset
            scrollYPos = $this.scrollTop(),
            offset = Math.abs(scrollYPos - lastScrollYPos),
            // mouse wheel delta is inverted respect to the direction, so we need to
            // normalize it against the direction
            direction = scrollYPos > lastScrollYPos ? -1 : 1,
            // calculates the new position. NOTE: if integers only are used for factors,
            // then `Math.floor()` isn't required.
            newTop = position.top + Math.floor(direction * offset * factorY),
            newLeft = position.left - Math.floor(direction * offset * factorX);

        // moves the block
        $block.offset({ top: newTop, left: newLeft });
        lastScrollYPos = scrollYPos;
    });
});
  </script>

Answer 1

通过反转方向（如前所述），然后添加最后一个Y位置而不是减去它（我已对此进行评论），我将其翻转了

$(function() {
  var lastScrollYPos = 0;
  $(window).on('scroll', function() {
    var $this = $(this),
      $block = $('#block'),
      // retrieves the top and left coordinates
      position = $block.offset(),
      // X and Y factors allows to change the diagonal movement direction and
      // degree. Negative values inverts the direction.
      factorX = -1,
      factorY = -1,
      // retrieves current vertical scrolling position and calculate the
      // relative offset
      scrollYPos = $this.scrollTop(),
      // ---- Flip around the offset calculation
      offset = Math.abs(scrollYPos + lastScrollYPos),
      // mouse wheel delta is inverted respect to the direction, so we need to
      // normalize it against the direction
      direction = scrollYPos > lastScrollYPos ? -1 : 1,
      // calculates the new position. NOTE: if integers only are used for factors,
      // then `Math.floor()` isn't required.
      newTop = position.top + Math.floor(direction * offset * factorY),
      newLeft = position.left - Math.floor(direction * offset * factorX);

    // moves the block
    $block.offset({
      top: newTop,
      left: newLeft
    });
    lastScrollYPos = scrollYPos;
  });
});

.body {
  height: 1500px;
  width: 1000px;
}

#block {
  height: 750px;
  width: 500px;
  background: blue;
  position: absolute;
  top: -700px;
  left: 400px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="body">
  <div id="block"></div>
</div>