Apply filter after transformation

Question

I have a transparent .png image of crossing lines. If the drop-shadow CSS filter is applied, only the lines drop shadow, not the bounding rect (it's not the same as box-shadow).

When I apply both drop-shadow filter and transform: rotate, Chrome and FF draw the shadow first, then rotate the resulting image (merged with the shadow). I want the rotated image to drop shadow instead. (As if there is a static light source, when the image rotates).

Is it possible in pure CSS?

The only solution I see is JS trigonometrical calculation of the shadow parameters every time the image rotates.

Regards,

Answer 1

I am quite sure that this question has been answered before, but couldn't find it, so here it goes:

set the filter on a base element, and apply the transform in the inner one

.base {
  -webkit-filter: drop-shadow(10px 10px 0px red);
  filter: drop-shadow(10px 10px 0px red);
}

.element {
   animation: rotate 6s linear infinite;
  border: solid 3px green;
  border-top-left-radius: 40px;
  width: 200px;
  height: 200px;
  margin: 20px;
 }

@keyframes rotate {
  from {transform: rotate(0deg);}
  to {transform: rotate(360deg);}
}
    

<div class="base">
  <div class="element"></div>
</div>