需要帮助修复图像 JS 的动态位置

Question

我一直在做一个 JS 项目，在这个项目中，太阳绕着图像转了一圈，根据它的位置，更高的索引 div 会改变不透明度，使它更暗或更亮。我的问题是；有一次太阳绕着圆圈转，但现在不再转了。我已经尝试了很多方法来解决这个问题，但都无济于事。我记录的代码如下：

<style>
  sun{
    position: absolute;
    z-index: 1;
  }
  dark-light{
    z-index: 2;
  }

</style>

CSS:^ JS:v

<script>



  move();

  //calls move


  function move(){
   //set rot
    var rot = 180;

    var pictureToDisplay = prompt('Please insert link to picture to     display','URL Necessary to function properly, but not required. Press enter to continue.');
    //asks user to insert picture link for STATIONARY picture
    var img = document.getElementById('img');

    if (pictureToDisplay == 'URL Necessary to function properly, but not required. Press enter to continue.'){

    }else{
    img.src = pictureToDisplay;
    }
    //Sets stationary picture
    window.setInterval( function() {

      //Repeats every 75 milliseconds forever.

      var obj = document.getElementById('sun');
    // obj. is equal to id sun
      var top = (Math.sin(rot)*500)+500;
      var left = (Math.cos(rot)*500)+500;
      //uses var rot, sine, and cosine to determine moving sun position
      var toppx = top + 'px';
      var leftpx = left + 'px';
      //adds the px after those values
      obj.style.top = toppx;
      obj.style.left = leftpx;
      //attempts to set position of obj (id sun)
      var darkToLight = -0.5+(top/500);
      //determines opacity of div using var top

      //document.write(rot+' = rot : ');

      var lightDiv = document.getElementById('dark-light');
      // same as var obj, but with the div
      lightDiv.style.opacity = darkToLight;
      //sets lightDiv to opacity
      //document.write(toppx,' ,',leftpx,' : ');


    rot = (rot+0.01) % 360;
      //moves rot up by 0.01, modulate 360
    }, 75);
    //back to top of setInterval
  }


</script>

P.S。我不知道 JQuery。编辑：所有的位置都是绝对的，0,0是页面的左上角。我确保不处理底片。太阳应该是绝对的页面，因为它什么都没有。

Answer 1

好吧，我发现我显然不太擅长 css，在添加 style="position:absolute"; 之后它现在可以正常工作了。

需要帮助修复图像 JS 的动态位置

Need help fixing Dynamic Position of Image JS

javascript

trigonometry

position

image

dynamic